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Sample records for actions neural evidence

  1. Body-specific motor imagery of hand actions: neural evidence from right- and left-handers

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    Roel M Willems

    2009-11-01

    Full Text Available If motor imagery uses neural structures involved in action execution, then the neural correlates of imagining an action should differ between individuals who tend to execute the action differently. Here we report fMRI data showing that motor imagery is influenced by the way people habitually perform motor actions with their particular bodies; that is, motor imagery is ‘body-specific’ (Casasanto, 2009. During mental imagery for complex hand actions, activation of cortical areas involved in motor planning and execution was left-lateralized in right-handers but right-lateralized in left-handers. We conclude that motor imagery involves the generation of an action plan that is grounded in the participant’s motor habits, not just an abstract representation at the level of the action’s goal. People with different patterns of motor experience form correspondingly different neurocognitive representations of imagined actions.

  2. Neural evidence for the intrinsic value of action as motivation for behavior.

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    Miura, Naoki; Tanabe, Hiroki C; Sasaki, Akihiro; Harada, Tokiko; Sadato, Norihiro

    2017-04-07

    The intrinsic value of an action refers to the inherent sense that experiencing a behavior is enjoyable even if it has no explicit outcome. Previous research has suggested that a common valuation mechanism within the reward network may be responsible for processing the intrinsic value of achieving both the outcome and external reward. However, how the intrinsic value of action is neurally represented remains unknown. We hypothesized that the intrinsic value of action is determined by an action-outcome contingency indicating the behavior is controllable and that the outcome of the action can be evaluated by this feedback. Consequently, the reward network should be activated, reflecting the generation of the intrinsic value of action. To test this hypothesis, we conducted a functional magnetic resonance imaging (fMRI) investigation of a stopwatch game in which the action-outcome contingency was manipulated. This experiment involved 36 healthy volunteers and four versions of a stopwatch game that manipulated controllability (the feeling that participants were controlling the stopwatch themselves) and outcome (a signal allowing participants to see the result of their action). A free-choice experiment was administered after the fMRI to explore preference levels for each game. The results showed that the stopwatch game with the action-outcome contingency evoked a greater degree of enjoyment because the participants chose this condition over those that lacked such a contingency. The ventral striatum and midbrain were activated only when action-outcome contingency was present. Thus, the intrinsic value of action was represented by an increase in ventral striatal and midbrain activation.

  3. Translating working memory into action: behavioral and neural evidence for using motor representations in encoding visuo-spatial sequences.

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    Langner, Robert; Sternkopf, Melanie A; Kellermann, Tanja S; Grefkes, Christian; Kurth, Florian; Schneider, Frank; Zilles, Karl; Eickhoff, Simon B

    2014-07-01

    The neurobiological organization of action-oriented working memory is not well understood. To elucidate the neural correlates of translating visuo-spatial stimulus sequences into delayed (memory-guided) sequential actions, we measured brain activity using functional magnetic resonance imaging while participants encoded sequences of four to seven dots appearing on fingers of a left or right schematic hand. After variable delays, sequences were to be reproduced with the corresponding fingers. Recall became less accurate with longer sequences and was initiated faster after long delays. Across both hands, encoding and recall activated bilateral prefrontal, premotor, superior and inferior parietal regions as well as the basal ganglia, whereas hand-specific activity was found (albeit to a lesser degree during encoding) in contralateral premotor, sensorimotor, and superior parietal cortex. Activation differences after long versus short delays were restricted to motor-related regions, indicating that rehearsal during long delays might have facilitated the conversion of the memorandum into concrete motor programs at recall. Furthermore, basal ganglia activity during encoding selectively predicted correct recall. Taken together, the results suggest that to-be-reproduced visuo-spatial sequences are encoded as prospective action representations (motor intentions), possibly in addition to retrospective sensory codes. Overall, our study supports and extends multi-component models of working memory, highlighting the notion that sensory input can be coded in multiple ways depending on what the memorandum is to be used for.

  4. The neural basis of body form and body action agnosia.

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    Moro, Valentina; Urgesi, Cosimo; Pernigo, Simone; Lanteri, Paola; Pazzaglia, Mariella; Aglioti, Salvatore Maria

    2008-10-23

    Visual analysis of faces and nonfacial body stimuli brings about neural activity in different cortical areas. Moreover, processing body form and body action relies on distinct neural substrates. Although brain lesion studies show specific face processing deficits, neuropsychological evidence for defective recognition of nonfacial body parts is lacking. By combining psychophysics studies with lesion-mapping techniques, we found that lesions of ventromedial, occipitotemporal areas induce face and body recognition deficits while lesions involving extrastriate body area seem causatively associated with impaired recognition of body but not of face and object stimuli. We also found that body form and body action recognition deficits can be double dissociated and are causatively associated with lesions to extrastriate body area and ventral premotor cortex, respectively. Our study reports two category-specific visual deficits, called body form and body action agnosia, and highlights their neural underpinnings.

  5. Sports experience changes the neural processing of action language.

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    Beilock, Sian L; Lyons, Ian M; Mattarella-Micke, Andrew; Nusbaum, Howard C; Small, Steven L

    2008-09-09

    Experience alters behavior by producing enduring changes in the neural processes that support performance. For example, performing a specific action improves the execution of that action via changes in associated sensory and motor neural circuitry, and experience using language improves language comprehension by altering the anatomy and physiology of perisylvian neocortical brain regions. Here we provide evidence that specialized (sports) motor experience enhances action-related language understanding by recruitment of left dorsal lateral premotor cortex, a region normally devoted to higher-level action selection and implementation-even when there is no intention to perform a real action. Experience playing and watching sports has enduring effects on language understanding by changing the neural networks that subserve comprehension to incorporate areas active in performing sports skills. Without such experience, sport novices recruit lower-level sensory-motor regions, thought to support the instantiation of movement, during language processing, and activity in primary motor areas does not help comprehension. Thus, the language system is sufficiently plastic and dynamic to encompass expertise-related neural recruitment outside core language networks.

  6. Marketing actions can modulate neural representations of experienced pleasantness.

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    Plassmann, Hilke; O'Doherty, John; Shiv, Baba; Rangel, Antonio

    2008-01-22

    Despite the importance and pervasiveness of marketing, almost nothing is known about the neural mechanisms through which it affects decisions made by individuals. We propose that marketing actions, such as changes in the price of a product, can affect neural representations of experienced pleasantness. We tested this hypothesis by scanning human subjects using functional MRI while they tasted wines that, contrary to reality, they believed to be different and sold at different prices. Our results show that increasing the price of a wine increases subjective reports of flavor pleasantness as well as blood-oxygen-level-dependent activity in medial orbitofrontal cortex, an area that is widely thought to encode for experienced pleasantness during experiential tasks. The paper provides evidence for the ability of marketing actions to modulate neural correlates of experienced pleasantness and for the mechanisms through which the effect operates.

  7. Brain and language: evidence for neural multifunctionality.

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    Cahana-Amitay, Dalia; Albert, Martin L

    2014-01-01

    This review paper presents converging evidence from studies of brain damage and longitudinal studies of language in aging which supports the following thesis: the neural basis of language can best be understood by the concept of neural multifunctionality. In this paper the term "neural multifunctionality" refers to incorporation of nonlinguistic functions into language models of the intact brain, reflecting a multifunctional perspective whereby a constant and dynamic interaction exists among neural networks subserving cognitive, affective, and praxic functions with neural networks specialized for lexical retrieval, sentence comprehension, and discourse processing, giving rise to language as we know it. By way of example, we consider effects of executive system functions on aspects of semantic processing among persons with and without aphasia, as well as the interaction of executive and language functions among older adults. We conclude by indicating how this multifunctional view of brain-language relations extends to the realm of language recovery from aphasia, where evidence of the influence of nonlinguistic factors on the reshaping of neural circuitry for aphasia rehabilitation is clearly emerging.

  8. Neural basis of understanding communicative actions: Changes associated with knowing the actor's intention and the meanings of the actions.

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    Möttönen, Riikka; Farmer, Harry; Watkins, Kate E

    2016-01-29

    People can communicate by using hand actions, e.g., signs. Understanding communicative actions requires that the observer knows that the actor has an intention to communicate and the meanings of the actions. Here, we investigated how this prior knowledge affects processing of observed actions. We used functional MRI to determine changes in action processing when non-signers were told that the observed actions are communicative (i.e., signs) and learned the meanings of half of the actions. Processing of hand actions activated the left and right inferior frontal gyrus (IFG, BA 44 and 45) when the communicative intention of the actor was known, even when the meanings of the actions remained unknown. These regions were not active when the observers did not know about the communicative nature of the hand actions. These findings suggest that the left and right IFG play a role in understanding the intention of the actor, but do not process visuospatial features of the communicative actions. Knowing the meanings of the hand actions further enhanced activity in the anterior part of the IFG (BA 45), the inferior parietal lobule and posterior inferior and middle temporal gyri in the left hemisphere. These left-hemisphere language regions could provide a link between meanings and observed actions. In sum, the findings provide evidence for the segregation of the networks involved in the neural processing of visuospatial features of communicative hand actions and those involved in understanding the actor's intention and the meanings of the actions.

  9. Neural Behavior Chain Learning of Mobile Robot Actions

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    Lejla Banjanovic-Mehmedovic

    2012-01-01

    Full Text Available This paper presents a visual/motor behavior learning approach, based on neural networks. We propose Behavior Chain Model (BCM in order to create a way of behavior learning. Our behavior-based system evolution task is a mobile robot detecting a target and driving/acting towards it. First, the mapping relations between the image feature domain of the object and the robot action domain are derived. Second, a multilayer neural network for offline learning of the mapping relations is used. This learning structure through neural network training process represents a connection between the visual perceptions and motor sequence of actions in order to grip a target. Last, using behavior learning through a noticed action chain, we can predict mobile robot behavior for a variety of similar tasks in similar environment. Prediction results suggest that the methodology is adequate and could be recognized as an idea for designing different mobile robot behaviour assistance.

  10. Neural mirroring and social interaction: Motor system involvement during action observation relates to early peer cooperation.

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    Endedijk, H M; Meyer, M; Bekkering, H; Cillessen, A H N; Hunnius, S

    2017-01-07

    Whether we hand over objects to someone, play a team sport, or make music together, social interaction often involves interpersonal action coordination, both during instances of cooperation and entrainment. Neural mirroring is thought to play a crucial role in processing other's actions and is therefore considered important for social interaction. Still, to date, it is unknown whether interindividual differences in neural mirroring play a role in interpersonal coordination during different instances of social interaction. A relation between neural mirroring and interpersonal coordination has particularly relevant implications for early childhood, since successful early interaction with peers is predictive of a more favorable social development. We examined the relation between neural mirroring and children's interpersonal coordination during peer interaction using EEG and longitudinal behavioral data. Results showed that 4-year-old children with higher levels of motor system involvement during action observation (as indicated by lower beta-power) were more successful in early peer cooperation. This is the first evidence for a relation between motor system involvement during action observation and interpersonal coordination during other instances of social interaction. The findings suggest that interindividual differences in neural mirroring are related to interpersonal coordination and thus successful social interaction.

  11. A continuous-time neural model for sequential action.

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    Kachergis, George; Wyatte, Dean; O'Reilly, Randall C; de Kleijn, Roy; Hommel, Bernhard

    2014-11-01

    Action selection, planning and execution are continuous processes that evolve over time, responding to perceptual feedback as well as evolving top-down constraints. Existing models of routine sequential action (e.g. coffee- or pancake-making) generally fall into one of two classes: hierarchical models that include hand-built task representations, or heterarchical models that must learn to represent hierarchy via temporal context, but thus far lack goal-orientedness. We present a biologically motivated model of the latter class that, because it is situated in the Leabra neural architecture, affords an opportunity to include both unsupervised and goal-directed learning mechanisms. Moreover, we embed this neurocomputational model in the theoretical framework of the theory of event coding (TEC), which posits that actions and perceptions share a common representation with bidirectional associations between the two. Thus, in this view, not only does perception select actions (along with task context), but actions are also used to generate perceptions (i.e. intended effects). We propose a neural model that implements TEC to carry out sequential action control in hierarchically structured tasks such as coffee-making. Unlike traditional feedforward discrete-time neural network models, which use static percepts to generate static outputs, our biological model accepts continuous-time inputs and likewise generates non-stationary outputs, making short-timescale dynamic predictions.

  12. Neural representation of the sensorimotor speech-action-repository

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    Cornelia eEckers

    2013-04-01

    Full Text Available A speech-action-repository (SAR or mental syllabary has been proposed as a central module for sensorimotor processing of syllables. In this approach, syllables occurring frequently within language are assumed to be stored as holistic sensorimotor patterns, while non-frequent syllables need to be assembled from sub-syllabic units. Thus, frequent syllables are processed efficiently and quickly during production or perception by a direct activation of their sensorimotor patterns. Whereas several behavioral psycholinguistic studies provided evidence in support of the existence of a syllabary, fMRI studies have failed to demonstrate its neural reality. In the present fMRI study a reaction paradigm using homogeneous vs. heterogeneous syllable blocks are used during overt vs. covert speech production and auditory vs. visual presentation modes. Two complementary data analyses were performed: (1 in a logical conjunction, activation for syllable processing independent of input modality and response mode was assessed, in order to support the assumption of existence of a supramodal hub within a SAR. (2 In addition priming effects in the BOLD response in homogeneous vs. heterogeneous blocks were measured in order to identify brain regions, which indicate reduced activity during multiple production/perception repetitions of a specific syllable in order to determine state maps. Auditory-visual conjunction analysis revealed an activation network comprising bilateral precentral gyrus and left inferior frontal gyrus (area 44. These results are compatible with the notion of a supramodal hub within the SAR. The main effect of homogeneity priming revealed an activation pattern of areas within frontal, temporal, and parietal lobe. These findings are taken to represent sensorimotor state maps of the SAR. In conclusion, the present study provided preliminary evidence for a SAR.

  13. The neural basis of predicting the outcomes of planned actions

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    Andrew eJahn

    2011-11-01

    Full Text Available A key feature of human intelligence is the ability to predict the outcomes of one’s own actions prior to executing them. Action values are thought to be represented in part in the dorsal and ventral medial prefrontal cortex, yet current studies have focused on the value of executed actions rather than the anticipated value of a planned action. Thus, little is known about the neural basis of how individuals think (or fail to think about their actions and the potential consequences before they act. We scanned individuals with fMRI while they thought about performing actions that they knew would likely be correct or incorrect. Here we show that merely imagining an error, as opposed to imagining a correct outcome, increases activity in the dorsal anterior cingulate cortex, independently of subsequent actions. This activity overlaps with regions that respond to actual error commission. The findings show a distinct network that signals the prospective outcomes of one’s planned actions. A number of clinical disorders such as schizophrenia and drug abuse involve a failure to take the potential consequences of an action into account prior to acting. Our results thus suggest how dysfunctions of the medial prefrontal cortex may contribute to such failures.

  14. A Neural Dynamic Model Generates Descriptions of Object-Oriented Actions.

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    Richter, Mathis; Lins, Jonas; Schöner, Gregor

    2017-01-01

    Describing actions entails that relations between objects are discovered. A pervasively neural account of this process requires that fundamental problems are solved: the neural pointer problem, the binding problem, and the problem of generating discrete processing steps from time-continuous neural processes. We present a prototypical solution to these problems in a neural dynamic model that comprises dynamic neural fields holding representations close to sensorimotor surfaces as well as dynamic neural nodes holding discrete, language-like representations. Making the connection between these two types of representations enables the model to describe actions as well as to perceptually ground movement phrases-all based on real visual input. We demonstrate how the dynamic neural processes autonomously generate the processing steps required to describe or ground object-oriented actions. By solving the fundamental problems of neural pointing, binding, and emergent discrete processing, the model may be a first but critical step toward a systematic neural processing account of higher cognition.

  15. Neural coding of cooperative vs. affective human interactions: 150 ms to code the action's purpose.

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    Alice Mado Proverbio

    Full Text Available The timing and neural processing of the understanding of social interactions was investigated by presenting scenes in which 2 people performed cooperative or affective actions. While the role of the human mirror neuron system (MNS in understanding actions and intentions is widely accepted, little is known about the time course within which these aspects of visual information are automatically extracted. Event-Related Potentials were recorded in 35 university students perceiving 260 pictures of cooperative (e.g., 2 people dragging a box or affective (e.g., 2 people smiling and holding hands interactions. The action's goal was automatically discriminated at about 150-170 ms, as reflected by occipito/temporal N170 response. The swLORETA inverse solution revealed the strongest sources in the right posterior cingulate cortex (CC for affective actions and in the right pSTS for cooperative actions. It was found a right hemispheric asymmetry that involved the fusiform gyrus (BA37, the posterior CC, and the medial frontal gyrus (BA10/11 for the processing of affective interactions, particularly in the 155-175 ms time window. In a later time window (200-250 ms the processing of cooperative interactions activated the left post-central gyrus (BA3, the left parahippocampal gyrus, the left superior frontal gyrus (BA10, as well as the right premotor cortex (BA6. Women showed a greater response discriminative of the action's goal compared to men at P300 and anterior negativity level (220-500 ms. These findings might be related to a greater responsiveness of the female vs. male MNS. In addition, the discriminative effect was bilateral in women and was smaller and left-sided in men. Evidence was provided that perceptually similar social interactions are discriminated on the basis of the agents' intentions quite early in neural processing, differentially activating regions devoted to face/body/action coding, the limbic system and the MNS.

  16. Applauding with closed hands: neural signature of action-sentence compatibility effects.

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    Pia Aravena

    Full Text Available BACKGROUND: Behavioral studies have provided evidence for an action-sentence compatibility effect (ACE that suggests a coupling of motor mechanisms and action-sentence comprehension. When both processes are concurrent, the action sentence primes the actual movement, and simultaneously, the action affects comprehension. The aim of the present study was to investigate brain markers of bidirectional impact of language comprehension and motor processes. METHODOLOGY/PRINCIPAL FINDINGS: Participants listened to sentences describing an action that involved an open hand, a closed hand, or no manual action. Each participant was asked to press a button to indicate his/her understanding of the sentence. Each participant was assigned a hand-shape, either closed or open, which had to be used to activate the button. There were two groups (depending on the assigned hand-shape and three categories (compatible, incompatible and neutral defined according to the compatibility between the response and the sentence. ACEs were found in both groups. Brain markers of semantic processing exhibited an N400-like component around the Cz electrode position. This component distinguishes between compatible and incompatible, with a greater negative deflection for incompatible. Motor response elicited a motor potential (MP and a re-afferent potential (RAP, which are both enhanced in the compatible condition. CONCLUSIONS/SIGNIFICANCE: The present findings provide the first ACE cortical measurements of semantic processing and the motor response. N400-like effects suggest that incompatibility with motor processes interferes in sentence comprehension in a semantic fashion. Modulation of motor potentials (MP and RAP revealed a multimodal semantic facilitation of the motor response. Both results provide neural evidence of an action-sentence bidirectional relationship. Our results suggest that ACE is not an epiphenomenal post-sentence comprehension process. In contrast, motor

  17. Grasping actions and social interaction: neural bases and anatomical circuitry in the monkey.

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    Stefano eRozzi

    2015-07-01

    Full Text Available The study of the neural mechanisms underlying grasping actions showed that cognitive functions are deeply embedded in motor organization. In the first part of this review, we describe the anatomical structure of the motor cortex in the monkey and the cortical and sub-cortical connections of the different motor areas. In the second part, we review the neurophysiological literature showing that motor neurons are not only involved in movement execution, but also in the transformation of object physical features into motor programs appropriate to grasp them (through visuo-motor transformations. We also discuss evidence indicating that motor neurons can encode the goal of motor acts and the intention behind action execution. Then, we describe one of the mechanisms – the mirror mechanism – considered to be at the basis of action understanding and intention reading, and describe the anatomo-functional pathways through which information about the social context can reach the areas containing mirror neurons. Finally, we briefly show that a clear similarity exists between monkey and human in the organization of the motor and mirror systems. Based on monkey and human literature, we conclude that the mirror mechanism relies on a more extended network than previously thought, and possibly subserves basic social functions. We propose that this mechanism is also involved in preparing appropriate complementary response to observed actions, allowing two individuals to become attuned and cooperate in joint actions.

  18. Neurophysiology of Grasping Actions: Evidence from ERPs

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    Koester, Dirk; Schack, Thomas; Westerholz, Jan

    2016-01-01

    We use our hands very frequently to interact with our environment. Neuropsychology together with lesion models and intracranial recordings and imaging work yielded important insights into the functional neuroanatomical correlates of grasping, one important function of our hands, pointing toward a functional parietofrontal brain network. Event-related potentials (ERPs) register directly electrical brain activity and are endowed with high temporal resolution but have long been assumed to be susceptible to movement artifacts. Recent work has shown that reliable ERPs can be obtained during movement execution. Here, we review the available ERP work on (uni) manual grasping actions. We discuss various ERP components and how they may be related to functional components of grasping according to traditional distinctions of manual actions such as planning and control phases. The ERP results are largely in line with the assumption of a parietofrontal network. But other questions remain, in particular regarding the temporal succession of frontal and parietal ERP effects. With the low number of ERP studies on grasping, not all ERP effects appear to be coherent with one another. Understanding the control of our hands may help to develop further neurocognitive theories of grasping and to make progress in prosthetics, rehabilitation or development of technical systems for support of human actions. PMID:28066310

  19. Neural mechanisms of mindfulness and meditation: Evidence from neuroimaging studies

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    William; R; Marchand

    2014-01-01

    Mindfulness is the dispassionate,moment-by-moment awareness of sensations,emotions and thoughts.Mindfulness-based interventions are being increasingly used for stress,psychological well being,coping with chronic illness as well as adjunctive treatments for psychiatric disorders.However,the neural mechanisms associated with mindfulness have not been well characterized.Recent functional and structural neuroimaging studies are beginning to provide insights into neural processes associated with the practice of mindfulness.A review of this literature revealed compelling evidence that mindfulness impacts the function of the medial cortex and associated default mode network as well as insula and amygdala.Additionally,mindfulness practice appears to effect lateral frontal regions and basal ganglia,at least in some cases.Structural imaging studies are consistent with these findings and also indicate changes in the hippocampus.While many questions remain unanswered,the current literature provides evidence of brain regions and networks relevant for understanding neural processes associated with mindfulness.

  20. Neural associative memories for the integration of language, vision and action in an autonomous agent.

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    Markert, H; Kaufmann, U; Kara Kayikci, Z; Palm, G

    2009-03-01

    Language understanding is a long-standing problem in computer science. However, the human brain is capable of processing complex languages with seemingly no difficulties. This paper shows a model for language understanding using biologically plausible neural networks composed of associative memories. The model is able to deal with ambiguities on the single word and grammatical level. The language system is embedded into a robot in order to demonstrate the correct semantical understanding of the input sentences by letting the robot perform corresponding actions. For that purpose, a simple neural action planning system has been combined with neural networks for visual object recognition and visual attention control mechanisms.

  1. Symmetry Detection in Visual Impairment: Behavioral Evidence and Neural Correlates

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    Zaira Cattaneo

    2014-05-01

    Full Text Available Bilateral symmetry is an extremely salient feature for the human visual system. An interesting issue is whether the perceptual salience of symmetry is rooted in normal visual development. In this review, we discuss empirical work on visual and tactile symmetry detection in normally sighted and visually impaired individuals. On the one hand, available evidence suggests that efficient visual symmetry detection may need normal binocular vision development. On the other hand, converging evidence suggests that symmetry can develop as a principle of haptic perceptual organization in individuals lacking visual experience. Certain features of visual symmetry detection, however, such as the higher salience of the patterns containing a vertical axis of symmetry, do not systematically apply to the haptic modality. The neural correlates (revealed with neuroimaging associated with visual and haptic symmetry detection are also discussed.

  2. Neural Mechanisms Underlying Action Observation in Adults with Down Syndrome

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    Virji-Babul, Naznin; Moiseev, Alexander; Cheung, Teresa; Weeks, Daniel J.; Cheyne, Douglas; Ribary, Urs

    2010-01-01

    Results of a magnetoencephalography (MEG) brain imaging study conducted to examine the cortical responses during action execution and action observation in 10 healthy adults and 8 age-matched adults with Down syndrome are reported. During execution, the motor responses were strongly lateralized on the ipsilateral rather than the contralateral side…

  3. Neural and temporal dynamics underlying visual selection for action

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    Elk, M. van; Schie, H.T. van; Neggers, S.F.W.; Bekkering, H.

    2010-01-01

    The present study investigated the selection for action hypothesis, according to which a subject's action intention to perform a movement influences the way in which visual information is being processed. Subjects were instructed in separate blocks either to grasp or to point to a three-dimensional

  4. Intention, emotion, and action: a neural theory based on semantic pointers.

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    Schröder, Tobias; Stewart, Terrence C; Thagard, Paul

    2014-06-01

    We propose a unified theory of intentions as neural processes that integrate representations of states of affairs, actions, and emotional evaluation. We show how this theory provides answers to philosophical questions about the concept of intention, psychological questions about human behavior, computational questions about the relations between belief and action, and neuroscientific questions about how the brain produces actions. Our theory of intention ties together biologically plausible mechanisms for belief, planning, and motor control. The computational feasibility of these mechanisms is shown by a model that simulates psychologically important cases of intention.

  5. Attribution of intentional causation influences the perception of observed movements: Behavioural evidence and neural correlates

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    James W Moore

    2013-01-01

    Full Text Available Recent research on human agency suggests that intentional causation is associated with a subjective compression in the temporal interval between actions and their effects. That is, intentional movements and their causal effects are perceived as closer together in time than equivalent unintentional movements and their causal effects. This so-called intentional binding effect is consistently found for one’s own self-generated actions. It has also been suggested that intentional binding occurs when observing intentional movements of others. However, this evidence is undermined by limitations of the paradigm used. In the current study we aimed to overcome these limitations using a more rigorous design in combination with functional Magnetic Resonance Imaging (fMRI to explore the neural underpinnings of intentional binding of observed movements. In particular, we aimed to identify brain areas sensitive to the interaction between intentionality and causality attributed to the observed action. Our behavioural results confirmed the occurrence of intentional binding for observed movements using this more rigorous paradigm. Our fMRI results highlighted a collection of brain regions whose activity was sensitive to the interaction between intentionality and causation. Intriguingly, these brain regions have previously been implicated in the sense of agency over one’s own movements. We discuss the implications of these results for intentional binding specifically, and the sense of agency more generally.

  6. Action prediction in younger versus older adults: neural correlates of motor familiarity.

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    Nadine Diersch

    Full Text Available Generating predictions during action observation is essential for efficient navigation through our social environment. With age, the sensitivity in action prediction declines. In younger adults, the action observation network (AON, consisting of premotor, parietal and occipitotemporal cortices, has been implicated in transforming executed and observed actions into a common code. Much less is known about age-related changes in the neural representation of observed actions. Using fMRI, the present study measured brain activity in younger and older adults during the prediction of temporarily occluded actions (figure skating elements and simple movement exercises. All participants were highly familiar with the movement exercises whereas only some participants were experienced figure skaters. With respect to the AON, the results confirm that this network was preferentially engaged for the more familiar movement exercises. Compared to younger adults, older adults recruited visual regions to perform the task and, additionally, the hippocampus and caudate when the observed actions were familiar to them. Thus, instead of effectively exploiting the sensorimotor matching properties of the AON, older adults seemed to rely predominantly on the visual dynamics of the observed actions to perform the task. Our data further suggest that the caudate played an important role during the prediction of the less familiar figure skating elements in better-performing groups. Together, these findings show that action prediction engages a distributed network in the brain, which is modulated by the content of the observed actions and the age and experience of the observer.

  7. Action mechanisms for social cognition: behavioral and neural correlates of developing Theory of Mind.

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    Bowman, Lindsay C; Thorpe, Samuel G; Cannon, Erin N; Fox, Nathan A

    2016-08-29

    Many psychological theories posit foundational links between two fundamental constructs: (1) our ability to produce, perceive, and represent action; and (2) our ability to understand the meaning and motivation behind the action (i.e. Theory of Mind; ToM). This position is contentious, however, and long-standing competing theories of social-cognitive development debate roles for basic action-processing in ToM. Developmental research is key to investigating these hypotheses, but whether individual differences in neural and behavioral measures of motor action relate to social-cognitive development is unknown. We examined 3- to 5-year-old children's (N = 26) EEG mu-desynchronization during production of object-directed action, and explored associations between mu-desynchronization and children's behavioral motor skills, behavioral action-representation abilities, and behavioral ToM. For children with high (but not low) mu-desynchronization, motor skill related to action-representation abilities, and action-representation mediated relations between motor skill and ToM. Results demonstrate novel foundational links between action-processing and ToM, suggesting that basic motor action may be a key mechanism for social-cognitive development, thus shedding light on the origins and emergence of higher social cognition.

  8. Dissociating modality-specific and supramodal neural systems for action understanding.

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    Spunt, Robert P; Lieberman, Matthew D

    2012-03-01

    The neural basis of action understanding in humans remains disputed, with some research implicating the putative mirror neuron system (MNS) and some a mentalizing system (MZS) for inferring mental states. The basis for this dispute may be that action understanding is a heterogeneous construct: actions can be understood from sensory information about body movements or from language about action, and with the goal of understanding the implementation ("how") or motive ("why") of an action. Although extant research implicates the MNS in understanding implementation and the MZS in understanding motive, it remains unknown to what extent these systems subserve modality-specific or supramodal functions in action understanding. While undergoing fMRI, 21 volunteers considered the implementation ("How is she doing it?") and motive ("Why is she doing it?") for actions presented in video or text. Bilateral parietal and right frontal areas of the MNS showed a modality-specific association with perceiving actions in videos, while left-hemisphere MNS showed a supramodal association with understanding implementation. Largely left-hemisphere MZS showed a supramodal association with understanding motive; however, connectivity among the MZS and MNS during the inference of motive was modality specific, being significantly stronger when motive was understood from actions in videos compared to text. These results support a tripartite model of MNS and MZS contributions to action understanding, where distinct areas of the MNS contribute to action perception ("perceiving what") and the representation of action implementation ("knowing how"), while the MZS supports an abstract, modality-independent representation of the mental states that explain action performance ("knowing why").

  9. Acetaminophen reduces social pain: behavioral and neural evidence.

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    Dewall, C Nathan; Macdonald, Geoff; Webster, Gregory D; Masten, Carrie L; Baumeister, Roy F; Powell, Caitlin; Combs, David; Schurtz, David R; Stillman, Tyler F; Tice, Dianne M; Eisenberger, Naomi I

    2010-07-01

    Pain, whether caused by physical injury or social rejection, is an inevitable part of life. These two types of pain-physical and social-may rely on some of the same behavioral and neural mechanisms that register pain-related affect. To the extent that these pain processes overlap, acetaminophen, a physical pain suppressant that acts through central (rather than peripheral) neural mechanisms, may also reduce behavioral and neural responses to social rejection. In two experiments, participants took acetaminophen or placebo daily for 3 weeks. Doses of acetaminophen reduced reports of social pain on a daily basis (Experiment 1). We used functional magnetic resonance imaging to measure participants' brain activity (Experiment 2), and found that acetaminophen reduced neural responses to social rejection in brain regions previously associated with distress caused by social pain and the affective component of physical pain (dorsal anterior cingulate cortex, anterior insula). Thus, acetaminophen reduces behavioral and neural responses associated with the pain of social rejection, demonstrating substantial overlap between social and physical pain.

  10. Self-organizing neural integration of pose-motion features for human action recognition.

    Science.gov (United States)

    Parisi, German I; Weber, Cornelius; Wermter, Stefan

    2015-01-01

    The visual recognition of complex, articulated human movements is fundamental for a wide range of artificial systems oriented toward human-robot communication, action classification, and action-driven perception. These challenging tasks may generally involve the processing of a huge amount of visual information and learning-based mechanisms for generalizing a set of training actions and classifying new samples. To operate in natural environments, a crucial property is the efficient and robust recognition of actions, also under noisy conditions caused by, for instance, systematic sensor errors and temporarily occluded persons. Studies of the mammalian visual system and its outperforming ability to process biological motion information suggest separate neural pathways for the distinct processing of pose and motion features at multiple levels and the subsequent integration of these visual cues for action perception. We present a neurobiologically-motivated approach to achieve noise-tolerant action recognition in real time. Our model consists of self-organizing Growing When Required (GWR) networks that obtain progressively generalized representations of sensory inputs and learn inherent spatio-temporal dependencies. During the training, the GWR networks dynamically change their topological structure to better match the input space. We first extract pose and motion features from video sequences and then cluster actions in terms of prototypical pose-motion trajectories. Multi-cue trajectories from matching action frames are subsequently combined to provide action dynamics in the joint feature space. Reported experiments show that our approach outperforms previous results on a dataset of full-body actions captured with a depth sensor, and ranks among the best results for a public benchmark of domestic daily actions.

  11. Self-Organizing Neural Integration of Pose-Motion Features for Human Action Recognition

    Directory of Open Access Journals (Sweden)

    German Ignacio Parisi

    2015-06-01

    Full Text Available The visual recognition of complex, articulated human movements is fundamental for a wide range of artificial systems oriented towards human-robot communication, action classification, and action-driven perception. These challenging tasks may generally involve the processing of a huge amount of visual information and learning-based mechanisms for generalizing a set of training actions and classifying new samples. To operate in natural environments, a crucial property is the efficient and robust recognition of actions, also under noisy conditions caused by, for instance, systematic sensor errors and temporarily occluded persons. Studies of the mammalian visual system and its outperforming ability to process biological motion information suggest separate neural pathways for the distinct processing of pose and motion features at multiple levels and the subsequent integration of these visual cues for action perception. We present a neurobiologically-motivated approach to achieve noise-tolerant action recognition in real time. Our model consists of self-organizing Growing When Required (GWR networks that obtain progressively generalized representations of sensory inputs and learn inherent spatiotemporal dependencies. During the training, the GWR networks dynamically change their topological structure to better match the input space. We first extract pose and motion features from video sequences and then cluster actions in terms of prototypical pose-motion trajectories. Multi-cue trajectories from matching action frames are subsequently combined to provide action dynamics in the joint feature space. Reported experiments show that our approach outperforms previous results on a dataset of full-body actions captured with a depth sensor, and ranks among the best 21 results for a public benchmark of domestic daily actions.

  12. An integrative neural model of social perception, action observation, and theory of mind.

    Science.gov (United States)

    Yang, Daniel Y-J; Rosenblau, Gabriela; Keifer, Cara; Pelphrey, Kevin A

    2015-04-01

    In the field of social neuroscience, major branches of research have been instrumental in describing independent components of typical and aberrant social information processing, but the field as a whole lacks a comprehensive model that integrates different branches. We review existing research related to the neural basis of three key neural systems underlying social information processing: social perception, action observation, and theory of mind. We propose an integrative model that unites these three processes and highlights the posterior superior temporal sulcus (pSTS), which plays a central role in all three systems. Furthermore, we integrate these neural systems with the dual system account of implicit and explicit social information processing. Large-scale meta-analyses based on Neurosynth confirmed that the pSTS is at the intersection of the three neural systems. Resting-state functional connectivity analysis with 1000 subjects confirmed that the pSTS is connected to all other regions in these systems. The findings presented in this review are specifically relevant for psychiatric research especially disorders characterized by social deficits such as autism spectrum disorder.

  13. Evidence for the Automatic Evaluation of Self-Generated Actions

    Science.gov (United States)

    Aarts, Kristien; De Houwer, Jan; Pourtois, Gilles

    2012-01-01

    The accuracy of simple actions is swiftly determined through specific monitoring brain systems. However, it remains unclear whether this evaluation is accompanied by a rapid and compatible emotional appraisal of the action that allows to mark incorrect actions as negative/bad and conversely correct actions as positive/good. In this study, we used…

  14. Pattern recognition in field crickets: concepts and neural evidence.

    Science.gov (United States)

    Kostarakos, Konstantinos; Hedwig, Berthold

    2015-01-01

    Since decades the acoustic communication behavior of crickets is in the focus of neurobiology aiming to analyze the neural basis of male singing and female phonotactic behavior. For temporal pattern recognition several different concepts have been proposed to elucidate the possible neural mechanisms underlying the tuning of phonotaxis in females. These concepts encompass either some form of a feature detecting mechanism using cross-correlation processing, temporal filter properties of brain neurons or an autocorrelation processing based on a delay-line and coincidence detection mechanism. Current data based on intracellular recordings of auditory brain neurons indicate a sequential processing by excitation and inhibition in a local auditory network within the protocerebrum. The response properties of the brain neurons point towards the concept of an autocorrelation-like mechanism underlying female pattern recognition in which delay-lines by long lasting inhibition may be involved.

  15. Mental training enhances attentional stability: neural and behavioral evidence.

    Science.gov (United States)

    Lutz, Antoine; Slagter, Heleen A; Rawlings, Nancy B; Francis, Andrew D; Greischar, Lawrence L; Davidson, Richard J

    2009-10-21

    The capacity to stabilize the content of attention over time varies among individuals, and its impairment is a hallmark of several mental illnesses. Impairments in sustained attention in patients with attention disorders have been associated with increased trial-to-trial variability in reaction time and event-related potential deficits during attention tasks. At present, it is unclear whether the ability to sustain attention and its underlying brain circuitry are transformable through training. Here, we show, with dichotic listening task performance and electroencephalography, that training attention, as cultivated by meditation, can improve the ability to sustain attention. Three months of intensive meditation training reduced variability in attentional processing of target tones, as indicated by both enhanced theta-band phase consistency of oscillatory neural responses over anterior brain areas and reduced reaction time variability. Furthermore, those individuals who showed the greatest increase in neural response consistency showed the largest decrease in behavioral response variability. Notably, we also observed reduced variability in neural processing, in particular in low-frequency bands, regardless of whether the deviant tone was attended or unattended. Focused attention meditation may thus affect both distracter and target processing, perhaps by enhancing entrainment of neuronal oscillations to sensory input rhythms, a mechanism important for controlling the content of attention. These novel findings highlight the mechanisms underlying focused attention meditation and support the notion that mental training can significantly affect attention and brain function.

  16. Neural network development in late adolescents during observation of risk-taking action.

    Directory of Open Access Journals (Sweden)

    Miyuki Tamura

    Full Text Available Emotional maturity and social awareness are important for adolescents, particularly college students beginning to face the challenges and risks of the adult world. However, there has been relatively little research into personality maturation and psychological development during late adolescence and the neural changes underlying this development. We investigated the correlation between psychological properties (neuroticism, extraversion, anxiety, and depression and age among late adolescents (n = 25, from 18 years and 1 month to 22 years and 8 months. The results revealed that late adolescents became less neurotic, less anxious, less depressive and more extraverted as they aged. Participants then observed video clips depicting hand movements with and without a risk of harm (risk-taking or safe actions during functional magnetic resonance imaging (fMRI. The results revealed that risk-taking actions elicited significantly stronger activation in the bilateral inferior parietal lobule, temporal visual regions (superior/middle temporal areas, and parieto-occipital visual areas (cuneus, middle occipital gyri, precuneus. We found positive correlations of age and extraversion with neural activation in the insula, middle temporal gyrus, lingual gyrus, and precuneus. We also found a negative correlation of age and anxiety with activation in the angular gyrus, precentral gyrus, and red nucleus/substantia nigra. Moreover, we found that insula activation mediated the relationship between age and extraversion. Overall, our results indicate that late adolescents become less anxious and more extraverted with age, a process involving functional neural changes in brain networks related to social cognition and emotional processing. The possible neural mechanisms of psychological and social maturation during late adolescence are discussed.

  17. Using accelerometers for physical actions recognition by a neural fuzzy network.

    Science.gov (United States)

    Liu, Shing-Hong; Chang, Yuan-Jen

    2009-11-01

    Triaxial accelerometers were employed to monitor human actions under various conditions. This study aimed to determine an optimum classification scheme and sensor placement positions for recognizing different types of physical action. Three triaxial accelerometers were placed on the chest, waist, and thigh, and their abilities to recognize the three actions of walking, sitting down, and falling were determined. The features of the resultant triaxial signals from each accelerometer were extracted by an autoregression (AR) model. A self-constructing neural fuzzy inference network (SONFIN) was used to recognize the three actions. The performance of the SONFIN was assessed based on statistical parameters, sensitivity, specificity, and total classification accuracy. The results show that the SONFIN provided a stability total classification accuracy of 96.3% and 88.7% for the training and testing data, when the parameters of the 60-order AR model were used as the input feature vector, and the accelerometer was placed anywhere on the abdomen. Seven elderly individuals performing the three basic actions had 80.4% confirmation for the testing data.

  18. Insulin-like growth factor actions during development of neural stem cells and progenitors in the central nervous system.

    Science.gov (United States)

    Ye, Ping; D'Ercole, A Joseph

    2006-01-01

    Insulin-like growth factor-I (IGF-I) plays a key role in normal development. Recent studies show that IGF-I exerts a wide variety actions in the central nervous system during development as well as in adulthood. This report reviews recent developments on IGF-I actions and its mechanisms in the central nervous system, with a focus on its actions during the development of neural stem cells and progenitors. Available data strongly indicate that IGF-I shortens the length of the cell cycle in neuron progenitors during embryonic life and has an influence on the growth of all neural cell types. The phosphatidylinositol-3 kinase/Akt and mitogen-activated protein kinase pathways seem to be the predominant mediators of IGF-I-stimulated neural cell proliferation and survival. IGF-I actions, however, likely depend on cell type, developmental stage, and microenvironmental milieu.

  19. Experimental evidence for action imitation in killer whales (Orcinus orca).

    Science.gov (United States)

    Abramson, José Z; Hernández-Lloreda, Victoria; Call, Josep; Colmenares, Fernando

    2013-01-01

    Comparative experimental studies of imitative learning have focused mainly on primates and birds. However, cetaceans are promising candidates to display imitative learning as they have evolved in socioecological settings that have selected for large brains, complex sociality, and coordinated predatory tactics. Here we tested imitative learning in killer whales, Orcinus orca. We used a 'do-as-other-does' paradigm in which 3 subjects witnessed a conspecific demonstrator's performance that included 15 familiar and 4 novel behaviours. The three subjects (1) learned the copy command signal 'Do that' very quickly, that is, 20 trials on average; (2) copied 100 % of the demonstrator's familiar and novel actions; (3) achieved full matches in the first attempt for 8-13 familiar behaviours (out of 15) and for the 2 novel behaviours (out of 2) in one subject; and (4) took no longer than 8 trials to accurately copy any familiar behaviour, and no longer than 16 trials to copy any novel behaviour. This study provides experimental evidence for body imitation, including production imitation, in killer whales that is comparable to that observed in dolphins tested under similar conditions. These findings suggest that imitative learning may underpin some of the group-specific traditions reported in killer whales in the field.

  20. Wavelet transform for real-time detection of action potentials in neural signals.

    Science.gov (United States)

    Quotb, Adam; Bornat, Yannick; Renaud, Sylvie

    2011-01-01

    We present a study on wavelet detection methods of neuronal action potentials (APs). Our final goal is to implement the selected algorithms on custom integrated electronics for on-line processing of neural signals; therefore we take real-time computing as a hard specification and silicon area as a price to pay. Using simulated neural signals including APs, we characterize an efficient wavelet method for AP extraction by evaluating its detection rate and its implementation cost. We compare software implementation for three methods: adaptive threshold, discrete wavelet transform (DWT), and stationary wavelet transform (SWT). We evaluate detection rate and implementation cost for detection functions dynamically comparing a signal with an adaptive threshold proportional to its SD, where the signal is the raw neural signal, respectively: (i) non-processed; (ii) processed by a DWT; (iii) processed by a SWT. We also use different mother wavelets and test different data formats to set an optimal compromise between accuracy and silicon cost. Detection accuracy is evaluated together with false negative and false positive detections. Simulation results show that for on-line AP detection implemented on a configurable digital integrated circuit, APs underneath the noise level can be detected using SWT with a well-selected mother wavelet, combined to an adaptive threshold.

  1. Consequences of converting graded to action potentials upon neural information coding and energy efficiency.

    Science.gov (United States)

    Sengupta, Biswa; Laughlin, Simon Barry; Niven, Jeremy Edward

    2014-01-01

    Information is encoded in neural circuits using both graded and action potentials, converting between them within single neurons and successive processing layers. This conversion is accompanied by information loss and a drop in energy efficiency. We investigate the biophysical causes of this loss of information and efficiency by comparing spiking neuron models, containing stochastic voltage-gated Na(+) and K(+) channels, with generator potential and graded potential models lacking voltage-gated Na(+) channels. We identify three causes of information loss in the generator potential that are the by-product of action potential generation: (1) the voltage-gated Na(+) channels necessary for action potential generation increase intrinsic noise and (2) introduce non-linearities, and (3) the finite duration of the action potential creates a 'footprint' in the generator potential that obscures incoming signals. These three processes reduce information rates by ∼50% in generator potentials, to ∼3 times that of spike trains. Both generator potentials and graded potentials consume almost an order of magnitude less energy per second than spike trains. Because of the lower information rates of generator potentials they are substantially less energy efficient than graded potentials. However, both are an order of magnitude more efficient than spike trains due to the higher energy costs and low information content of spikes, emphasizing that there is a two-fold cost of converting analogue to digital; information loss and cost inflation.

  2. Neural recording front-end IC using action potential detection and analog buffer with digital delay for data compression.

    Science.gov (United States)

    Liu, Lei; Yao, Lei; Zou, Xiaodan; Goh, Wang Ling; Je, Minkyu

    2013-01-01

    This paper presents a neural recording analog front-end IC intended for simultaneous neural recording with action potential (AP) detection for data compression in wireless multichannel neural implants. The proposed neural recording front-end IC detects the neural spikes and sends only the preserved AP information for wireless transmission in order to reduce the overall power consumption of the neural implant. The IC consists of a low-noise neural amplifier, an AP detection circuit and an analog buffer with digital delay. The neural amplifier makes use of a current-reuse technique to maximize the transconductance efficiency for attaining a good noise efficiency factor. The AP detection circuit uses an adaptive threshold voltage to generate an enable signal for the subsequent functional blocks. The analog buffer with digital delay is employed using a finite impulse response (FIR) filter which preserves the AP waveform before the enable signal as well as provides low-pass filtering. The neural recording front-end IC has been designed using standard CMOS 0.18-µm technology occupying a core area of 220 µm by 820 µm.

  3. Neural Substrates of Semantic Prospection – Evidence from the Dementias

    Directory of Open Access Journals (Sweden)

    Muireann eIrish

    2016-05-01

    Full Text Available The ability to envisage personally relevant events at a future time point represents an incredibly sophisticated cognitive endeavor and one that appears to be intimately linked to episodic memory integrity. Far less is known regarding the neurocognitive mechanisms underpinning the capacity to envisage non-personal future occurrences, known as semantic future thinking. Moreover the degree of overlap between the neural substrates supporting episodic and semantic forms of prospection remains unclear. To this end, we sought to investigate the capacity for episodic and semantic future thinking in Alzheimer’s disease (n = 15 and disease-matched behavioral-variant frontotemporal dementia (n = 15, neurodegenerative disorders characterized by significant medial temporal lobe and frontal pathology. Participants completed an assessment of past and future thinking across personal (episodic and non-personal (semantic domains, as part of a larger neuropsychological battery investigating episodic and semantic processing, and their performance was contrasted with 20 age- and education-matched healthy older Controls. Participants underwent whole-brain T1 weighted structural imaging and voxel-based morphometry analysis was conducted to determine the relationship between grey matter integrity and episodic and semantic future thinking. Relative to Controls, both patient groups displayed marked future thinking impairments, extending across episodic and semantic domains. Analyses of covariance revealed that while episodic future thinking deficits could be explained solely in terms of episodic memory proficiency, semantic prospection deficits reflected the interplay between episodic and semantic processing. Distinct neural correlates emerged for each form of future simulation with differential involvement of prefrontal, lateral temporal and medial temporal regions. Notably, the hippocampus was implicated irrespective of future thinking domain, with the suggestion of

  4. Neural Mechanisms of Illusory Motion: Evidence from ERP Study

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    Xu Y. A. N. Yun

    2011-05-01

    Full Text Available ERPs were used to examine the neural correlates of illusory motion, by presenting the Rice Wave illusion (CI, its two variants (WI and NI and a real motion video (RM. Results showed that: Firstly, RM elicited a more negative deflection than CI, NI and WI between 200–350ms. Secondly, between 500–600ms, CI elicited a more positive deflection than NI and WI, and RM elicited a more positive deflection than CI, what's more interesting was the sequential enhancement of brain activity with the corresponding motion strength. We inferred that the former component might reflect the successful encoding of the local motion signals in detectors at the lower stage; while the latter one might be involved in the intensive representations of visual input in real/illusory motion perception, this was the whole motion-signal organization in the later stage of motion perception. Finally, between 1185–1450 ms, a significant positive component was found between illusory/real motion tasks than NI (no motion. Overall, we demonstrated that there was a stronger deflection under the corresponding lager motion strength. These results reflected not only the different temporal patterns between illusory and real motion but also extending to their distinguishing working memory representation and storage.

  5. Evidence for single top quark production using Bayesian neural networks

    Energy Technology Data Exchange (ETDEWEB)

    Kau, Daekwang [Florida State Univ., Tallahassee, FL (United States)

    2007-01-01

    We present results of a search for single top quark production in p$\\bar{p}$ collisions using a dataset of approximately 1 fb-1 collected with the D0 detector. This analysis considers the muon+jets and electron+jets final states and makes use of Bayesian neural networks to separate the expected signals from backgrounds. The observed excess is associated with a p-value of 0.081%, assuming the background-only hypothesis, which corresponds to an excess over background of 3.2 standard deviations for a Gaussian density. The p-value computed using the SM signal cross section of 2.9 pb is 1.6%, corresponding to an expected significance of 2.2 standard deviations. Assuming the observed excess is due to single top production, we measure a single top quark production cross section of σ(p$\\bar{p}$ → tb + X, tqb + X) = 4.4 ± 1.5 pb.

  6. From evidence to action. Understanding clinical practice guidelines.

    NARCIS (Netherlands)

    Poolman, R.W.; Verheyen, C.C.P.M.; Kerkhoffs, G.M.; Bhandari, M.; Schünemann, H.J.

    2009-01-01

    Good guidelines will help us to take evidence into practice. In a survey among Dutch orthopedic surgeons, development and use of evidence-based guidelines was perceived as one of the best ways of moving from opinion-based to evidence-based orthopedic practice. The increasing number of guidelines mea

  7. Serotonin transporter polymorphism modulates neural correlates of real-life joint action. An investigation with functional near-infrared spectroscopy (fNIRS).

    Science.gov (United States)

    Herrmann, M J; Bogon, J; Quester, S; Cordes, A; Stenneken, P; Reif, A; Ehlis, A-C

    2015-04-30

    A functional polymorphism (5-HTTLPR) within the serotonin transporter gene (SERT) has been associated with personality dimensions such as neuroticism, with emotional reactivity to negative events, and with an increased risk of affective disorders. More specifically, the short (S) allele of 5-HTTLPR has been linked to increased amygdala activity and has been identified as a risk allele for depressive disorders. Recently, Homberg and Lesch (2011) urged for a conceptual change in the current deficit-oriented connotation of the 5-HTTLPR S-allele and argued that the S-allele could be considered adaptive in certain contexts. They postulated that S-allele carriers show hypervigilant behavior in social situations and should thus show increased social conformity. Therefore, we tested whether 5-HTTLPR modulates the neural correlates of real-life social joint action through functional near-infrared spectroscopy (fNIRS). Thirty participants, homozygote for 5-HTTLPR, were measured and analyzed while they were involved in a previously published joint-action paradigm, which reliably leads to an activation of the left parietal cortex. We found that homozygote S-allele carriers showed increased inferior parietal lobe activation, compared to the LL-allele carriers for the contrast "joint action greater solo action". Therefore, our results provide evidence for beneficial effects of the S-allele on the neural correlates of social interactions.

  8. Neural Stem Cell Differentiation Is Dictated by Distinct Actions of Nuclear Receptor Corepressors and Histone Deacetylases

    Directory of Open Access Journals (Sweden)

    Gonçalo Castelo-Branco

    2014-09-01

    Full Text Available Signaling factors including retinoic acid (RA and thyroid hormone (T3 promote neuronal, oligodendrocyte, and astrocyte differentiation of cortical neural stem cells (NSCs. However, the functional specificity of transcriptional repressor checkpoints controlling these differentiation programs remains unclear. Here, we show by genome-wide analysis that histone deacetylase (HDAC2 and HDAC3 show overlapping and distinct promoter occupancy at neuronal and oligodendrocyte-related genes in NSCs. The absence of HDAC3, but not HDAC2, initiated a neuronal differentiation pathway in NSCs. The ablation of the corepressor NCOR or HDAC2, in conjunction with T3 treatment, resulted in increased expression of oligodendrocyte genes, revealing a direct HDAC2-mediated repression of Sox8 and Sox10 expression. Interestingly, Sox10 was required also for maintaining the more differentiated state by repression of stem cell programming factors such as Sox2 and Sox9. Distinct and nonredundant actions of NCORs and HDACs are thus critical for control of lineage progression and differentiation programs in neural progenitors.

  9. A Prospective Longitudinal Study of Perceived Infant Outcomes at 18-24 months: Neural and Psychological Correlates of Parental Thoughts and Actions Assessed during the First Month Postpartum

    Directory of Open Access Journals (Sweden)

    Pilyoung eKim

    2015-11-01

    Full Text Available The first postpartum months constitute a critical period for parents to establish an emotional bond with their infants. Neural responses to infant-related stimuli have been associated with parental sensitivity. However, the associations among these neural responses, parenting, and later infant outcomes for mothers and fathers are unknown. In the current longitudinal study, we investigated the relationships between parental thoughts/actions and neural activation in mothers and fathers in the neonatal period with infant outcomes at the toddler stage. At the first month postpartum, mothers (n=21 and fathers (n=19 underwent a neuroimaging session during which they listened to their own and unfamiliar baby’s cry. Parenting-related thoughts/behaviors were assessed by interview twice at the first month and 3-4 months postpartum and infants’ socioemotional outcomes were reported by mothers and fathers at 18-24 months postpartum. In mothers, higher levels of anxious thoughts/actions about parenting at the first month postpartum, but not at 3-4 months postpartum, were associated with infant’s low socioemotional competencies at 18-24 months. Anxious thoughts/actions were also associated with heightened responses in the motor cortex and reduced responses in the substantia nigra to own infant cry sounds. On the other hand, in fathers, higher levels of positive perception of being a parent at the first month postpartum, but not at 3-4 months postpartum, were associated with higher infant socioemotional competencies at 18-24 months. Positive thoughts were associated with heightened responses in the auditory cortex and caudate to own infant cry sounds. The current study provides evidence that parental thoughts are related to concurrent neural responses to their infants at the first month postpartum as well as their infant’s future socioemotional outcome at 18-24 months. Parent differences suggest that anxious thoughts in mothers and positive thoughts in

  10. On the inference of agency in operant action : an examination of the cognitive and neural underpinnings in health and schizophrenia

    NARCIS (Netherlands)

    Renes, R.A.

    2016-01-01

    This dissertation elucidates cognitive and neural underpinnings of the sense of agency, which is the feeling that we are in control of our actions and the subsequent consequences. This consciously accessible sensation of control is pervasive, sometimes subtle, and can even be illusory in nature. Fur

  11. Neural representation of reward probability: evidence from the illusion of control.

    Science.gov (United States)

    Kool, Wouter; Getz, Sarah J; Botvinick, Matthew M

    2013-06-01

    To support reward-based decision-making, the brain must encode potential outcomes both in terms of their incentive value and their probability of occurrence. Recent research has made it clear that the brain bears multiple representations of reward magnitude, meaning that a single choice option may be represented differently-and even inconsistently-in different brain areas. There are some hints that the same may be true for reward probability. Preliminary evidence hints that, even as systematic distortions of probability are expressed in behavior, these may not always be uniformly reflected at the neural level: Some neural representations of probability may be immune from such distortions. This study provides new evidence consistent with this possibility. Participants in a behavioral experiment displayed a classic "illusion of control," providing higher estimates of reward probability for gambles they had chosen than for identical gambles that were imposed on them. However, an fMRI study of the same task revealed that neural prediction error signals, arising when gamble outcomes were revealed, were unaffected by the illusion of control. The resulting behavioral-neural dissociation reinforces the case for multiple, inconsistent internal representations of reward probability, while also prompting a reinterpretation of the illusion of control effect itself.

  12. Neural strategies for selective attention distinguish fast-action video game players.

    Science.gov (United States)

    Krishnan, Lavanya; Kang, Albert; Sperling, George; Srinivasan, Ramesh

    2013-01-01

    We investigated the psychophysical and neurophysiological differences between fast-action video game players (specifically first person shooter players, FPS) and non-action players (role-playing game players, RPG) in a visual search task. We measured both successful detections (hit rates) and steady-state visually evoked EEG potentials (SSVEPs). Search difficulty was varied along two dimensions: number of adjacent attended and ignored regions (1, 2 and 4), and presentation rate of novel search arrays (3, 8.6 and 20 Hz). Hit rates decreased with increasing presentation rates and number of regions, with the FPS players performing on average better than the RPG players. The largest differences in hit rate, between groups, occurred when four regions were simultaneously attended. We computed signal-to-noise ratio (SNR) of SSVEPs and used partial least squares regression to model hit rates, SNRs and their relationship at 3 Hz and 8.6 Hz. The following are the most significant results: RPG players' parietal responses to the attended 8.6 Hz flicker were predictive of hit rate and were positively correlated with it, indicating attentional signal enhancement. FPS players' parietal responses to the ignored 3 Hz flicker were predictive of hit rate and were positively correlated with it, indicating distractor suppression. Consistent with these parietal responses, RPG players' frontal responses to the attended 8.6 Hz flicker, increased as task difficulty increased with number of regions; FPS players' frontal responses to the ignored 3 Hz flicker increased with number of regions. Thus the FPS players appear to employ an active suppression mechanism to deploy selective attention simultaneously to multiple interleaved regions, while RPG primarily use signal enhancement. These results suggest that fast-action gaming can affect neural strategies and the corresponding networks underlying attention, presumably by training mechanisms of distractor suppression.

  13. Distinctive laterality of neural networks supporting action understanding in left- and right-handed individuals: An EEG coherence study.

    Science.gov (United States)

    Kelly, Rachel; Mizelle, J C; Wheaton, Lewis A

    2015-08-01

    Prior work has demonstrated that perspective and handedness of observed actions can affect action understanding differently in right and left-handed persons, suggesting potential differences in the neural networks underlying action understanding between right and left-handed individuals. We sought to evaluate potential differences in these neural networks using electroencephalography (EEG). Right- and left-handed participants observed images of tool-use actions from egocentric and allocentric perspectives, with right- and left-handed actors performing the actions. Participants judged the outcome of the observed actions, and response accuracy and latency were recorded. Behaviorally, the highest accuracy and shortest latency was found in the egocentric perspective for right- and left-handed observers. Handedness of subject showed an effect on accuracy and latency also, where right-handed observers were faster to respond than left-handed observers, but on average were less accurate. Mu band (8-10 Hz) cortico-cortical coherence analysis indicated that right-handed observers have coherence in the motor dominant left parietal-premotor networks when looking at an egocentric right or allocentric left hands. When looking in an egocentric perspective at a left hand or allocentric right hand, coherence was lateralized to right parietal-premotor areas. In left-handed observers, bilateral parietal-premotor coherence patterns were observed regardless of actor handedness. These findings suggest that the cortical networks involved in understanding action outcomes are dependent on hand dominance, and notably right handed participants seem to utilize motor systems based on the limb seen performing the action. The decreased accuracy for right-handed participants on allocentric images could be due to asymmetrical lateralization of encoding action and motoric dominance, which may interfere with translating allocentric limb action outcomes. Further neurophysiological studies will

  14. Do Bans on Affirmative Action Hurt Minority Students? Evidence from the Texas Top 10% Plan

    Science.gov (United States)

    Cortes, Kalena E.

    2010-01-01

    In light of the recent bans on affirmative action in higher education, this paper provides new evidence on the effects of alternative admissions policies on the persistence and college completion of minority students. I find that the change from affirmative action to the Top 10% Plan in Texas decreased both retention and graduation rates of…

  15. Cervical cancer control in India: taking evidence to action.

    Science.gov (United States)

    Farooqui, Habib Hasan; Zodpey, Sanjay

    2012-05-01

    The most prevalent types of human papillomavirus in cervical cancer in India are HPV 16 and HPV 18, found in 60.7 per cent and 16 per cent of cases respectively. A comprehensive strategy with a judicious mix of interventions on health promotion, specific protection (vaccination), early diagnosis (screening), and treatment should be instituted to prevent and control cervical cancer in India. Proponents of vaccination and screening argue for enhanced investments on these interventions based on their relative cost-effectiveness. For policymakers, the major concerns about these interventions remain affordability and cost to government. Herein we try to review comprehensively the evidence on prevention and control interventions and to recommend appropriate policies to guide public health decision-making.

  16. The grammar of visual narrative: Neural evidence for constituent structure in sequential image comprehension.

    Science.gov (United States)

    Cohn, Neil; Jackendoff, Ray; Holcomb, Phillip J; Kuperberg, Gina R

    2014-11-01

    Constituent structure has long been established as a central feature of human language. Analogous to how syntax organizes words in sentences, a narrative grammar organizes sequential images into hierarchic constituents. Here we show that the brain draws upon this constituent structure to comprehend wordless visual narratives. We recorded neural responses as participants viewed sequences of visual images (comics strips) in which blank images either disrupted individual narrative constituents or fell at natural constituent boundaries. A disruption of either the first or the second narrative constituent produced a left-lateralized anterior negativity effect between 500 and 700ms. Disruption of the second constituent also elicited a posteriorly-distributed positivity (P600) effect. These neural responses are similar to those associated with structural violations in language and music. These findings provide evidence that comprehenders use a narrative structure to comprehend visual sequences and that the brain engages similar neurocognitive mechanisms to build structure across multiple domains.

  17. Enhanced Neural Processing of Goal-directed Actions After Active Training in 4-Month-Old Infants.

    Science.gov (United States)

    Bakker, Marta; Sommerville, Jessica A; Gredebäck, Gustaf

    2016-03-01

    The current study explores the neural correlates of action perception and its relation to infants' active experience performing goal-directed actions. Study 1 provided active training with sticky mittens that enables grasping and object manipulation in prereaching 4-month-olds. After training, EEG was recorded while infants observed images of hands grasping toward (congruent) or away from (incongruent) objects. We demonstrate that brief active training facilitates social perception as indexed by larger amplitude of the P400 ERP component to congruent compared with incongruent trials. Study 2 presented 4-month-old infants with passive training in which they observed an experimenter perform goal-directed reaching actions, followed by an identical ERP session to that used in Study 1. The second study did not demonstrate any differentiation between congruent and incongruent trials. These results suggest that (1) active experience alters the brains' response to goal-directed actions performed by others and (2) visual exposure alone is not sufficient in developing the neural networks subserving goal processing during action observation in infancy.

  18. Self-reported empathy and neural activity during action imitation and observation in schizophrenia

    Directory of Open Access Journals (Sweden)

    William P. Horan

    2014-01-01

    Conclusions: Although patients with schizophrenia demonstrated largely normal patterns of neural activation across the finger movement and facial expression tasks, they reported decreased self perceived empathy and failed to show the typical relationship between neural activity and self-reported empathy seen in controls. These findings suggest that patients show a disjunction between automatic neural responses to low level social cues and higher level, integrative social cognitive processes involved in self-perceived empathy.

  19. Evidence for sex-specific shifting of neural processes underlying learning and memory following stress.

    Science.gov (United States)

    Beck, Kevin D; Luine, Victoria N

    2010-02-09

    Recent human research has been focused upon determining whether there is evidence that stress responses cause qualitative changes in neural activity such that people change their learning strategies from a spatial/contextual memory process through the hippocampus to a procedural stimulus-response process through the caudate nucleus. Moreover, interest has shifted to determining whether males and females exhibit the same type of stress-induced change in neural processing of associations. Presented is a select review of 2 different animal models that have examined how acute or chronic stressors change learning in a sex-specific manner. This is followed by a brief review of recent human studies documenting how learning and memory functions change following stressor exposure. In both cases, it is clear that ovarian hormones have a significant influence on how stress affects learning processes in females. We then examine the evidence for a role of acetylcholine, dopamine, norepinephrine, or serotonin in modulating this shifting of processing and how that may differ across sex. Conclusions drawn suggest that there may be evidence for sex-specific changes in amygdala and hippocampus neuromodulation; however, the behavioral data are still not conclusive as to whether this represents a common or sex-specific shift in how males and females process associations after stressor exposure.

  20. Recognition of the physiological actions of the triphasic EMG pattern by a dynamic recurrent neural network.

    Science.gov (United States)

    Cheron, Guy; Cebolla, Ana Maria; Bengoetxea, Ana; Leurs, Françoise; Dan, Bernard

    2007-03-06

    Triphasic electromyographic (EMG) patterns with a sequence of activity in agonist (AG1), antagonist (ANT) and again in agonist (AG2) muscles are characteristic of ballistic movements. They have been studied in terms of rectangular pulse-width or pulse-height modulation. In order to take into account the complexity of the EMG signal within the bursts, we used a dynamic recurrent neural network (DRNN) for the identification of this pattern in subjects performing fast elbow flexion movements. Biceps and triceps EMGs were fed to all 35 fully-connected hidden units of the DRNN for mapping onto elbow angular acceleration signals. DRNN training was supervised, involving learning rule adaptations of synaptic weights and time constants of each unit. We demonstrated that the DRNN is able to perfectly reproduce the acceleration profile of the ballistic movements. Then we tested the physiological plausibility of all the networks that reached an error level below 0.001 by selectively increasing the amplitude of each burst of the triphasic pattern and evaluating the effects on the simulated accelerating profile. Nineteen percent of these simulations reproduced the physiological action classically attributed to the 3 EMG bursts: AG1 increase showed an increase of the first accelerating pulse, ANT an increase of the braking pulse and AG2 an increase of the clamping pulse. These networks also recognized the physiological function of the time interval between AG1 and ANT, reproducing the linear relationship between time interval and movement amplitude. This task-dynamics recognition has implications for the development of DRNN as diagnostic tools and prosthetic controllers.

  1. Variations in retrieval monitoring during action memory judgments: evidence from event-related potentials (ERPs).

    Science.gov (United States)

    Leynes, P Andrew; Kakadia, Bhavika

    2013-02-01

    The present study investigated the neuroscience of memory for actions using event-related potentials (ERPs). Actions were performed, initiated but not completed (i.e., interrupted), or watched while the experimenter performed the action during encoding. Memory was assessed in a reality monitoring (RM) test (performed vs. watched actions), as well as in an internal source monitoring (ISM) test (performed vs. interrupted) while ERPs were recorded. Behavioral measures provided evidence of robust old/new recognition for all actions, but the analysis of source errors revealed that interrupted actions were often confused with performed actions. The ERP correlate of recollection, the parietal "old/new" effect (700-900ms), was observed for all actions. The right frontal "old/new" effect (1500-1800ms) that correlates with general memory monitoring was observed in RM but not in ISM. Instead, ISM was associated with the late posterior negativity (LPN) that has been connected to more specific memory monitoring. This pattern of ERP findings suggest that, in this context, general monitoring was used to discriminate self- versus other-performed actions, whereas more specific monitoring was required to support the discrimination of completed and interrupted actions. We argue that the mix of general/specific monitoring processes is shaped by the global retrieval context, which includes the number of memory features that overlap and the combination of sources being considered among other factors.

  2. Do bans on affirmative action hurt minority students? Evidence from the Texas Top 10% Plan

    OpenAIRE

    2010-01-01

    In light of the recent bans on affirmative action in higher education, this paper provides new evidence on the effects of alternative admissions policies on the persistence and college completion of minority students. I find that the change from affirmative action to the Top 10% Plan in Texas decreased both retention and graduation rates of lower-ranked minority students. Results show that both fall-to-fall freshmen retention and six-year college graduation of seconddecile minority students d...

  3. The porous boundaries between explicit and implicit memory: behavioral and neural evidence.

    Science.gov (United States)

    Dew, Ilana T Z; Cabeza, Roberto

    2011-04-01

    Explicit memory refers to the conscious retrieval of past information or experiences, whereas implicit memory refers to an unintentional or nonconscious form of retrieval. Much of the literature in cognitive psychology and cognitive neuroscience has focused on differences between explicit and implicit memory, and the traditional view is that they rely on distinct brain systems. However, the potential interplay between implicit and explicit memory is not always clear. This review draws from behavioral and functional neuroimaging evidence to evaluate three areas in which implicit and explicit memory may be interrelated. First, we discuss views of familiarity-based recognition in terms of its relationship with implicit memory. Second, we review the challenges of distinguishing between implicit memory and involuntary aware memory, at both behavioral and neural levels. Finally, we examine evidence indicating that implicit and explicit retrieval of relational information may rely on a common neural mechanism. Taken together, these areas indicate that, under certain circumstances, there may be an important and influential relationship between conscious and nonconscious expressions of memory.

  4. Knowing when not to swing: EEG evidence that enhanced perception-action coupling underlies baseball batter expertise.

    Science.gov (United States)

    Muraskin, Jordan; Sherwin, Jason; Sajda, Paul

    2015-12-01

    Given a decision that requires less than half a second for evaluating the characteristics of the incoming pitch and generating a motor response, hitting a baseball potentially requires unique perception-action coupling to achieve high performance. We designed a rapid perceptual decision-making experiment modeled as a Go/No-Go task yet tailored to reflect a real scenario confronted by a baseball hitter. For groups of experts (Division I baseball players) and novices (non-players), we recorded electroencephalography (EEG) while they performed the task. We analyzed evoked EEG single-trial variability, contingent negative variation (CNV), and pre-stimulus alpha power with respect to the expert vs. novice groups. We found strong evidence for differences in inhibitory processes between the two groups, specifically differential activity in supplementary motor areas (SMA), indicative of enhanced inhibitory control in the expert (baseball player) group. We also found selective activity in the fusiform gyrus (FG) and orbital gyrus in the expert group, suggesting an enhanced perception-action coupling in baseball players that differentiates them from matched controls. In sum, our results show that EEG correlates of decision formation can be used to identify neural markers of high-performance athletes.

  5. Evidence-Based Practice and School Libraries: Interconnections of Evidence, Advocacy, and Actions

    Science.gov (United States)

    Todd, Ross J.

    2015-01-01

    This author states that a professional focus on evidence based practice (EBP) for school libraries emerged from the International Association of School Librarianship conference when he presented the concept. He challenged the school library profession to actively engage in professional and reflective practices that chart, measure, document, and…

  6. Evaluation of the legal consequences of action affects neural activity and emotional experience during the resolution of moral dilemmas.

    Science.gov (United States)

    Pletti, Carolina; Sarlo, Michela; Palomba, Daniela; Rumiati, Rino; Lotto, Lorella

    2015-03-01

    In any modern society killing is regarded as a severe violation of the legal codes that is subjected to penal judgment. Therefore, it is likely that people take legal consequences into account when deciding about the hypothetical killing of one person in classic moral dilemmas, with legal concerns contributing to decision-making. In particular, by differing for the degree of intentionality and emotional salience, Footbridge- and Trolley-type dilemmas might promote differential assignment of blame and punishment while implicating the same severity of harm. The present study was aimed at comparing the neural activity, subjective emotional reactions, and behavioral choices in two groups of participants who either took (Legal group) or did not take (No Legal group) legal consequences into account when deciding on Footbridge-type and Trolley-type moral dilemmas. Stimulus- and response-locked ERPs were measured to investigate the neural activity underlying two separate phases of the decision process. No difference in behavioral choices was found between groups. However, the No Legal group reported greater overall emotional impact, associated with lower preparation for action, suggesting greater conflict between alternative motor responses representing the different decision choices. In contrast, the Legal group showed an overall dampened affective experience during decision-making associated with greater overall action readiness and intention to act, reflecting lower conflict in responding. On these bases, we suggest that in moral dilemmas legal consequences of actions provide a sort of reference point on which people can rely to support a decision, independent of dilemma type.

  7. Recognizing Combinations of Facial Action Units with Different Intensity Using a Mixture of Hidden Markov Models and Neural Network

    CERN Document Server

    Khademi, Mahmoud; Kiapour, Mohammad H; Kiaei, Ali A

    2010-01-01

    Facial Action Coding System consists of 44 action units (AUs) and more than 7000 combinations. Hidden Markov models (HMMs) classifier has been used successfully to recognize facial action units (AUs) and expressions due to its ability to deal with AU dynamics. However, a separate HMM is necessary for each single AU and each AU combination. Since combinations of AU numbering in thousands, a more efficient method will be needed. In this paper an accurate real-time sequence-based system for representation and recognition of facial AUs is presented. Our system has the following characteristics: 1) employing a mixture of HMMs and neural network, we develop a novel accurate classifier, which can deal with AU dynamics, recognize subtle changes, and it is also robust to intensity variations, 2) although we use an HMM for each single AU only, by employing a neural network we can recognize each single and combination AU, and 3) using both geometric and appearance-based features, and applying efficient dimension reducti...

  8. Promoting Student Engagement through Evidence-Based Action Research with Teachers

    Science.gov (United States)

    Strambler, Michael J.; McKown, Clark

    2013-01-01

    We present findings from a group-randomized teacher action research intervention to promote academic engagement and achievement among elementary school students. Eighteen teachers from 3 elementary schools were randomly assigned to 1 of 2 groups. Intervention teachers studied evidence-based instructional practices that cultivate academic…

  9. Neural evidence for description dependent reward processing in the framing effect.

    Science.gov (United States)

    Yu, Rongjun; Zhang, Ping

    2014-01-01

    Human decision making can be influenced by emotionally valenced contexts, known as the framing effect. We used event-related brain potentials to investigate how framing influences the encoding of reward. We found that the feedback related negativity (FRN), which indexes the "worse than expected" negative prediction error in the anterior cingulate cortex (ACC), was more negative for the negative frame than for the positive frame in the win domain. Consistent with previous findings that the FRN is not sensitive to "better than expected" positive prediction error, the FRN did not differentiate the positive and negative frame in the loss domain. Our results provide neural evidence that the description invariance principle which states that reward representation and decision making are not influenced by how options are presented is violated in the framing effect.

  10. Neural mechanisms of time-based prospective memory: evidence for transient monitoring.

    Directory of Open Access Journals (Sweden)

    Kevin M Oksanen

    Full Text Available In daily life, we often need to remember to perform an action after, or at, a specific period of time (e.g., take pizza out of oven in 15 minutes. Surprisingly, little is known about the neural mechanisms that support this form of memory, termed time-based prospective memory (PM. Here we pioneer an fMRI paradigm that enables examination of both sustained and transient processes engaged during time-based PM. Participants were scanned while performing a demanding on-going task (n-back working memory, with and without an additional time-based PM demand. During the PM condition participants could access a hidden clock with a specific button-press response, while in the control condition, pseudo-clocks randomly appeared and were removed via the same response. Analyses tested for sustained activation associated with the PM condition, and also transient activation associated with clock-checks and the PM target response. Contrary to prior findings with event-based PM (i.e., remembering to perform a future action when a specific event occurs, no sustained PM-related activity was observed in anterior prefrontal cortex (aPFC or elsewhere in the brain; instead, transient clock-related activity was observed in this region. Critically, the activation was anticipatory, increasing before clock-check responses. Anticipatory activity prior to the PM target response was weaker in aPFC, but strong in pre-Supplementary Motor Area (pre-SMA; relative to clock-check responses, suggesting a functional double dissociation related to volitional decision-making. Together, the results suggest that aPFC-activity dynamics during time-based PM reflect a distinct transient monitoring process, enabling integration of the PM intention with current temporal information to facilitate scheduling of upcoming PM-related actions.

  11. Cognitive Enhancement Through Action Video Game Training: Great Expectations Require Greater Evidence

    Directory of Open Access Journals (Sweden)

    Joseph eBisoglio

    2014-02-01

    Full Text Available Action video game training may hold promise as a cognitive intervention with the potential to enhance daily functioning and remediate impairments, but this must be more thoroughly evaluated through evidence-based practices. We review current research on the effect of action video game training on visual attention and visuospatial processing, executive functions, and learning and memory. Focusing on studies that utilize strict experimental controls and synthesize behavioral and neurophysiological data, we examine whether there is sufficient evidence to support a causal relationship between action video game training and beneficial changes in cognition. Convergent lines of behavioral and neurophysiological evidence tentatively support the efficacy of training, but the magnitude and specificity of these effects remain obscure. Causal inference is thus far limited by a lack of standardized and well-controlled methodology. Considering future directions, we suggest stringent adherence to evidence based practices and collaboration modeled after clinical trial networks. Finally, we recommend the exploration of more complex causal models, such as indirect causal relationships and interactions that may be masking true effects.

  12. Cognitive enhancement through action video game training: great expectations require greater evidence.

    Science.gov (United States)

    Bisoglio, Joseph; Michaels, Timothy I; Mervis, Joshua E; Ashinoff, Brandon K

    2014-01-01

    Action video game training may hold promise as a cognitive intervention with the potential to enhance daily functioning and remediate impairments, but this must be more thoroughly evaluated through evidence-based practices. We review current research on the effect of action video game training on visual attention and visuospatial processing, executive functions, and learning and memory. Focusing on studies that utilize strict experimental controls and synthesize behavioral and neurophysiological data, we examine whether there is sufficient evidence to support a causal relationship between action video game training and beneficial changes in cognition. Convergent lines of behavioral and neurophysiological evidence tentatively support the efficacy of training, but the magnitude and specificity of these effects remain obscure. Causal inference is thus far limited by a lack of standardized and well-controlled methodology. Considering future directions, we suggest stringent adherence to evidence-based practices and collaboration modeled after clinical trial networks. Finally, we recommend the exploration of more complex causal models, such as indirect causal relationships and interactions that may be masking true effects.

  13. Will Increasing Folic Acid in Fortified Grain Products Further Reduce Neural Tube Defects without Causing Harm?: Consideration of the Evidence

    Science.gov (United States)

    Will Increasing Folic Acid in Fortified Grain Products Further Reduce Neural Tube Defects without Causing Harm?: Consideration of the Evidence. In the January issue of this journal, Johnston (1) includes our group’s recent analysis of data from the 1999-2002 National Health and Nutrition Examination...

  14. The 'fractionable autism triad': a review of evidence from behavioural, genetic, cognitive and neural research.

    Science.gov (United States)

    Happé, Francesca; Ronald, Angelica

    2008-12-01

    Autism is diagnosed on the basis of a triad of impairments in social interaction, communication, and flexible imaginative functions (with restricted and repetitive behaviors and interests; RRBIs). There has been a strong presumption that these different features of the syndrome are strongly intertwined and proceed from a common cause at the genetic, cognitive and neural levels. In this review we examine evidence for an alternative approach, considering the triad as largely 'fractionable'. We present evidence from our own twin studies, and review relevant literature on autism and autistic-like traits in other groups. We suggest that largely independent genes may operate on social skills/impairments, communication abilities, and RRBIs, requiring a change in molecular-genetic research approaches. At the cognitive level, we suggest that satisfactory accounts exist for each of the triad domains, but no single unitary account can explain both social and nonsocial features of autism. We discuss the implications of the fractionable-triad approach for both diagnosis and future research directions.

  15. Enhancement of cognitive and neural functions through complex reasoning training: evidence from normal and clinical populations.

    Science.gov (United States)

    Chapman, Sandra B; Mudar, Raksha A

    2014-01-01

    Public awareness of cognitive health is fairly recent compared to physical health. Growing evidence suggests that cognitive training offers promise in augmenting cognitive brain performance in normal and clinical populations. Targeting higher-order cognitive functions, such as reasoning in particular, may promote generalized cognitive changes necessary for supporting the complexities of daily life. This data-driven perspective highlights cognitive and brain changes measured in randomized clinical trials that trained gist reasoning strategies in populations ranging from teenagers to healthy older adults, individuals with brain injury to those at-risk for Alzheimer's disease. The evidence presented across studies support the potential for Gist reasoning training to strengthen cognitive performance in trained and untrained domains and to engage more efficient communication across widespread neural networks that support higher-order cognition. The meaningful benefits of Gist training provide compelling motivation to examine optimal dose for sustained benefits as well as to explore additive benefits of meditation, physical exercise, and/or improved sleep in future studies.

  16. Enhancement of Cognitive and Neural Functions through Complex Reasoning Training: Evidence from Normal and Clinical Populations

    Directory of Open Access Journals (Sweden)

    Sandra Bond Chapman

    2014-04-01

    Full Text Available Public awareness of cognitive health is fairly recent compared to physical health. Growing evidence suggests that cognitive training offers promise in augmenting cognitive brain performance in normal and clinical populations. Targeting higher-order cognitive functions, such as reasoning in particular, may promote generalized cognitive changes necessary for supporting the complexities of daily life. This data-driven perspective highlights cognitive and brain changes measured in randomized clinical trials that trained gist reasoning strategies in populations ranging from teenagers to healthy older adults, individuals with brain injury to those at-risk for Alzheimer’s disease. The evidence presented across studies support the potential for Gist reasoning training to strengthen cognitive performance in trained and untrained domains and to engage more efficient communication across widespread neural networks that support higher-order cognition. The meaningful benefits of Gist training provide compelling motivation to examine optimal dose for sustained benefits as well as to explore additive benefits of meditation, physical exercise, and/or improved sleep in future studies.

  17. Evidence for dual mechanisms of action prediction dependent on acquired visual-motor experiences.

    Science.gov (United States)

    Mulligan, Desmond; Lohse, Keith R; Hodges, Nicola J

    2016-10-01

    To test mechanisms underpinning action prediction, we directly controlled experience in a dart-throwing training study. A motor-visual group physically practiced throwing darts and a perceptual training group learned to associate dart throw actions (occluded video clips) with landing outcomes. A final control group did not practice. Accuracy was assessed on related prediction tests before and after practice (involving temporally occluded video clips). These tests were performed while additionally performing simple, action-incongruent secondary motor tasks with either the right (observed throwing arm) or left effector, in addition to an attention control task. Motor proficiency tests were also performed. Although both trained groups improved their prediction accuracy after training, only the motor-visual group showed interference associated with the right-arm secondary motor task after practice. No interference was shown for the left-arm motor task. These effects were evidenced regardless of whether predictions were made in response to video stimuli or static clips. Moreover, improvements on the motor proficiency test were only shown for the motor-visual group. These results show evidence in support of motor simulation processes during action prediction among observers with motor experience. Prediction accuracy can be achieved via nonmotor processes (for the perceptual group), but there was no evidence that physically experienced performers could effectively switch processes to maintain prediction accuracy. (PsycINFO Database Record

  18. Predicting others' actions via grasp and gaze: evidence for distinct brain networks.

    Science.gov (United States)

    Ramsey, Richard; Cross, Emily S; Hamilton, Antonia F de C

    2012-07-01

    During social interactions, how do we predict what other people are going to do next? One view is that we use our own motor experience to simulate and predict other people's actions. For example, when we see Sally look at a coffee cup or grasp a hammer, our own motor system provides a signal that anticipates her next action. Previous research has typically examined such gaze and grasp-based simulation processes separately, and it is not known whether similar cognitive and brain systems underpin the perception of object-directed gaze and grasp. Here we use functional magnetic resonance imaging to examine to what extent gaze- and grasp-perception rely on common or distinct brain networks. Using a 'peeping window' protocol, we controlled what an observed actor could see and grasp. The actor could peep through one window to see if an object was present and reach through a different window to grasp the object. However, the actor could not peep and grasp at the same time. We compared gaze and grasp conditions where an object was present with matched conditions where the object was absent. When participants observed another person gaze at an object, left anterior inferior parietal lobule (aIPL) and parietal operculum showed a greater response than when the object was absent. In contrast, when participants observed the actor grasp an object, premotor, posterior parietal, fusiform and middle occipital brain regions showed a greater response than when the object was absent. These results point towards a division in the neural substrates for different types of motor simulation. We suggest that left aIPL and parietal operculum are involved in a predictive process that signals a future hand interaction with an object based on another person's eye gaze, whereas a broader set of brain areas, including parts of the action observation network, are engaged during observation of an ongoing object-directed hand action.

  19. Evidence-based modeling of mode-of-action for functional ingredients influencing Alzheimer’s disease through neurotrophin pathway

    Directory of Open Access Journals (Sweden)

    Erfan Younesi

    2014-08-01

    Full Text Available Background: Brain-derived neurotrophic factor (BDNF is the most widely expressed member of the neurotrophin family in the human brain and is crucially involved in the development of neural circuits, modulation of synaptic plasticity, and regulation of cognitive functions, including learning and memory. Many studies have shown the association of altered BDNF levels with neurodegenerative and neuropsychiatric disorders. However, BDNF is not able to cross the blood-brain barrier and, thus, its delivery to the nervous system is a challenge. Therefore, functional diets with the ability to induce production of BDNF in the brain may offer an alternative route. The objective of this study was three-fold: first, to find out diets that are causally linked to the agonistic activity of BDNF in the neurotrophin signaling pathway; second and mainly, to investigate mode-of-action of these functional diets through systems-based mechanistic modeling in the context of Alzheimer’s disease; and third, to demonstrate the proof-of-concept application of systems biology methods, that are well established in the pharmaceutical sector, to the emerging field of functional food. Methods: In the first step, two cause-and-effect models of BDNF signaling in two states, i.e. normal state and Alzheimer’s disease state, were constructed using published knowledge in scientific literature and pathway databases. A “differential model analysis” between the two states was performed by which mechanistic mode-of-action of BDNF in neurotrophin signaling pathway could be explained with a high molecular resolution in both normal and disease states. The BDNF mode-of-action model was further validated using the “biomarkerguided validation” approach. In the second step, scientific evidence on the effect of various functional diets on BDNF levels and BDNF-related biological processes or outcomes was harvested from biomedical literature using a disease-specific semantic search

  20. Central perception of position sense involves a distributed neural network - Evidence from lesion-behavior analyses.

    Science.gov (United States)

    Findlater, Sonja E; Desai, Jamsheed A; Semrau, Jennifer A; Kenzie, Jeffrey M; Rorden, Chris; Herter, Troy M; Scott, Stephen H; Dukelow, Sean P

    2016-06-01

    It is well established that proprioceptive inputs from the periphery are important for the constant update of arm position for perception and guiding motor action. The degree to which we are consciously aware of the position of our limb depends on the task. Our understanding of the central processing of position sense is rather limited, largely based on findings in animals and individual human case studies. The present study used statistical lesion-behavior analysis and an arm position matching task to investigate position sense in a large sample of subjects after acute stroke. We excluded subjects who performed abnormally on clinical testing or a robotic visually guided reaching task with their matching arm in order to minimize the potential confound of ipsilesional impairment. Our findings revealed that a number of regions are important for processing position sense and include the posterior parietal cortex, the transverse temporal gyrus, and the arcuate fasciculus. Further, our results revealed that position sense has dissociable components - spatial variability, perceived workspace area, and perceived workspace location. Each component is associated with unique neuroanatomical correlates. These findings extend the current understanding of the neural processing of position sense and identify some brain areas that are not classically associated with proprioception.

  1. Youth Excel: towards a pan-Canadian platform linking evidence and action for prevention.

    Science.gov (United States)

    Riley, Barbara L; Manske, Steve; Cameron, Roy

    2011-05-15

    Population-level intervention is required to prevent cancer and other chronic diseases. It also promotes health for those living with established risk factors and illness. In this article, the authors describe a vision and approach for continuously improving population-level programs and policies within and beyond the health sector. The vision and approach are anchored in contemporary thinking about what is required to link evidence and action in the field of population and public health. The authors believe that, as a cancer prevention and control community, organizations and practitioners must be able to use the best available evidence to inform action and continually generate evidence that improves prevention policies and programs on an ongoing basis. These imperatives require leaders in policy, practice, and research fields to work together to jointly plan, conduct, and act on relevant evidence. The Propel Center and colleagues are implementing this approach in Youth Excel-a pan-Canadian initiative that brings together national and provincial organizations from health and education sectors and capitalizes on a history of collaboration. The objective of Youth Excel is to build sustainable capacity for knowledge development and exchange that can guide and redirect prevention efforts in a rapidly evolving social environment. This goal is to contribute to creating health-promoting environments and to accelerate progress in preventing cancer and other diseases among youth and young adults and in the wider population. Although prevention is the aim, health-promoting environments also can support health gains for individuals of all ages and with established illness. In addition, the approach Youth Excel is taking to link evidence and action may be applicable to early intervention and treatment components of cancer control.

  2. Neural alpha oscillations index the balance between self-other integration and segregation in real-time joint action.

    Science.gov (United States)

    Novembre, Giacomo; Sammler, Daniela; Keller, Peter E

    2016-08-01

    Shared knowledge and interpersonal coordination are prerequisites for most forms of social behavior. Influential approaches to joint action have conceptualized these capacities in relation to the separate constructs of co-representation (knowledge) and self-other entrainment (coordination). Here we investigated how brain mechanisms involved in co-representation and entrainment interact to support joint action. To do so, we used a musical joint action paradigm to show that the neural mechanisms underlying co-representation and self-other entrainment are linked via a process - indexed by EEG alpha oscillations - regulating the balance between self-other integration and segregation in real time. Pairs of pianists performed short musical items while action familiarity and interpersonal (behavioral) synchronization accuracy were manipulated in a factorial design. Action familiarity referred to whether or not pianists had rehearsed the musical material performed by the other beforehand. Interpersonal synchronization was manipulated via congruent or incongruent tempo change instructions that biased performance timing towards the impending, new tempo. It was observed that, when pianists were familiar with each other's parts, millisecond variations in interpersonal synchronized behavior were associated with a modulation of alpha power over right centro-parietal scalp regions. Specifically, high behavioral entrainment was associated with self-other integration, as indexed by alpha suppression. Conversely, low behavioral entrainment encouraged reliance on internal knowledge and thus led to self-other segregation, indexed by alpha enhancement. These findings suggest that alpha oscillations index the processing of information about self and other depending on the compatibility of internal knowledge and external (environmental) events at finely resolved timescales.

  3. A critical view of the use of genetic tools to unveil neural circuits: the case of leptin action in reproduction.

    Science.gov (United States)

    Elias, Carol F

    2014-01-01

    The remarkable development and refinement of the Cre-loxP system coupled with the nonstop production of new mouse models and virus vectors have impelled the growth of various fields of investigation. In this article, I will discuss the data collected using these genetic tools in our area of interest, giving specific emphasis to the identification of the neuronal populations that relay leptin action in reproductive physiology. A series of mouse models that allow manipulation of the leptin receptor gene have been generated. Of those, I will discuss the use of two models of leptin receptor gene reexpression (LepR(neo/neo) and LepR(loxTB/loxTB)) and one model of leptin signaling blockade (LepR(flox/flox)). I will also highlight the differences of using stereotaxic delivery of virus vectors expressing DNA-recombinases (Flp and Cre) and mouse models expressing Cre-recombinase. Our findings indicate that leptin action in the ventral premammillary nucleus is sufficient, but not required, for leptin action in reproduction and that leptin action in Kiss1 neurons arises after pubertal maturation; therefore, direct leptin signaling in Kiss1 neurons is neither required nor sufficient for the permissive action of leptin in pubertal development. It also became evident that the full action of leptin in the reproductive neuroendocrine axis requires the engagement of an integrated circuitry, yet to be fully unveiled.

  4. Neural Correlates of Indicators of Sound Change in Cantonese: Evidence from Cortical and Subcortical Processes

    Science.gov (United States)

    Maggu, Akshay R.; Liu, Fang; Antoniou, Mark; Wong, Patrick C. M.

    2016-01-01

    Across time, languages undergo changes in phonetic, syntactic, and semantic dimensions. Social, cognitive, and cultural factors contribute to sound change, a phenomenon in which the phonetics of a language undergo changes over time. Individuals who misperceive and produce speech in a slightly divergent manner (called innovators) contribute to variability in the society, eventually leading to sound change. However, the cause of variability in these individuals is still unknown. In this study, we examined whether such misperceptions are represented in neural processes of the auditory system. We investigated behavioral, subcortical (via FFR), and cortical (via P300) manifestations of sound change processing in Cantonese, a Chinese language in which several lexical tones are merging. Across the merging categories, we observed a similar gradation of speech perception abilities in both behavior and the brain (subcortical and cortical processes). Further, we also found that behavioral evidence of tone merging correlated with subjects' encoding at the subcortical and cortical levels. These findings indicate that tone-merger categories, that are indicators of sound change in Cantonese, are represented neurophysiologically with high fidelity. Using our results, we speculate that innovators encode speech in a slightly deviant neurophysiological manner, and thus produce speech divergently that eventually spreads across the community and contributes to sound change. PMID:28066218

  5. Neural mechanisms underlying pain's ability to reorient attention: evidence for sensitization of somatic threat detectors.

    Science.gov (United States)

    Dowman, Robert

    2014-06-01

    Pain typically signals damage to the body, and as such can be perceived as threatening and can elicit a strong emotional response. This ecological significance undoubtedly underlies pain's well-known ability to demand attention. However, the neural mechanisms underlying this ability are poorly understood. Previous work from the author's laboratory has reported behavioral evidence suggesting that participants disengage their attention from an incorrectly cued visual target stimulus and reorient it toward a somatic target more rapidly when the somatic target is painful than when it is nonpainful. Furthermore, electrophysiological data suggest that this effect is mediated by a stimulus-driven process, in which somatic threat detectors located in the dorsal posterior insula activate the medial and lateral prefrontal cortex areas involved in reorienting attention toward the painful target. In these previous studies, the painful and nonpainful somatic targets were given in separate experiments involving different participants. Here, the nonpainful and painful somatic targets were presented in random order within the same block of trials. Unlike in the previous studies, both the nonpainful and painful somatic targets activated the somatic threat detectors, and the times taken to disengage and reorient attention were the same for both. These electrophysiological and behavioral data suggest that somatic threat detectors can become sensitized to nonpainful somatic stimuli that are presented in a context that includes painful stimuli.

  6. Linking perception, cognition, and action: psychophysical observations and neural network modelling.

    Directory of Open Access Journals (Sweden)

    Juan Carlos Méndez

    Full Text Available It has been argued that perception, decision making, and movement planning are in reality tightly interwoven brain processes. However, how they are implemented in neural circuits is still a matter of debate. We tested human subjects in a temporal categorization task in which intervals had to be categorized as short or long. Subjects communicated their decision by moving a cursor into one of two possible targets, which appeared separated by different angles from trial to trial. Even though there was a 1 second-long delay between interval presentation and decision communication, categorization difficulty affected subjects' performance, reaction (RT and movement time (MT. In addition, reaction and movement times were also influenced by the distance between the targets. This implies that not only perceptual, but also movement-related considerations were incorporated into the decision process. Therefore, we searched for a model that could use categorization difficulty and target separation to describe subjects' performance, RT, and MT. We developed a network consisting of two mutually inhibiting neural populations, each tuned to one of the possible categories and composed of an accumulation and a memory node. This network sequentially acquired interval information, maintained it in working memory and was then attracted to one of two possible states, corresponding to a categorical decision. It faithfully replicated subjects' RT and MT as a function of categorization difficulty and target distance; it also replicated performance as a function of categorization difficulty. Furthermore, this model was used to make new predictions about the effect of untested durations, target distances and delay durations. To our knowledge, this is the first biologically plausible model that has been proposed to account for decision making and communication by integrating both sensory and motor planning information.

  7. Normative findings of electrically evoked compound action potential measurements using the neural response telemetry of the Nucleus CI24M cochlear implant system.

    NARCIS (Netherlands)

    Cafarelli-Dees, D.; Dillier, N.; Lai, W.K.; Wallenberg, E. von; Dijk, B. van; Akdas, F.; Aksit, M.; Batman, C.; Beynon, A.J.; Burdo, S.; Chanal, J.M.; Collet, L.; Conway, M.; Coudert, C.; Craddock, L.; Cullington, H.; Deggouj, N.; Fraysse, B.; Grabel, S.; Kiefer, J.; Kiss, J.G.; Lenarz, T.; Mair, A.; Maune, S.; Muller-Deile, J.; Piron, J.P.; Razza, S.; Tasche, C.; Thai-Van, H.; Toth, F.; Truy, E.; Uziel, A.; Smoorenburg, G.F.

    2005-01-01

    One hundred and forty-seven adult recipients of the Nucleus 24 cochlear implant system, from 13 different European countries, were tested using neural response telemetry to measure the electrically evoked compound action potential (ECAP), according to a standardised postoperative measurement procedu

  8. Complex Dynamic Thresholds and Generation of the Action Potentials in the Neural-Activity Model

    Science.gov (United States)

    Kirillov, S. Yu.; Nekorkin, V. I.

    2016-05-01

    This work is devoted to studying the processes of activation of the neurons whose excitation thresholds are not constant and vary in time (the so-called dynamic thresholds). The neuron dynamics is described by the FitzHugh-Nagumo model with nonlinear behavior of the recovery variable. The neuron response to the external pulsed activating action in the presence of a slowly varying synaptic current is studied within the framework of this model. The structure of the dynamic threshold is studied and its properties depending on the external-action parameters are established. It is found that the formation of the "folds" in the separatrix threshold manifold in the model phase space is a typical feature of the complex dynamic threshold. High neuron sensitivity to the action of the comparatively weak slow control signals is established. This explains the capability of the neurons to perform flexible tuning of their selective properties for detecting various external signals in sufficiently short times (of the order of duration of several spikes).

  9. Work at night and breast cancer - report on evidence-based options for preventive actions

    DEFF Research Database (Denmark)

    Bonde, Jens Peter; Hansen, Johnni; Kolstad, Henrik A.

    2012-01-01

    actions, 16 researchers in basic, epidemiological and applied sciences convened at a workshop in Copenhagen 26-27 October 2011. This paper summarizes the evidence from epidemiological and experimental studies and presents possible recommendations for prevention of the effects of night work on breast...... cancer. Among those studies that quantified duration of shift work, there were statistically significant elevations in risk only after about 20 years working night shift. It is unclear from these studies whether or not there is a modest but real elevated risk for shorter durations. Hence, restriction...... by suppression of melatonin secretion. Work during the night is widespread worldwide. To provide additional evidence-based recommendations on prevention of diseases related to night shift work, large studies on the impact of various shift schedules and type of light on circadian rhythms need to be conducted...

  10. Interprofessional collaborative practice within cancer teams: Translating evidence into action. A mixed methods study protocol

    Directory of Open Access Journals (Sweden)

    Roberge Danièle

    2010-07-01

    Full Text Available Abstract Background A regional integrated cancer network has implemented a program (educational workshops, reflective and mentoring activities designed to support the uptake of evidence-informed interprofessional collaborative practices (referred to in this text as EIPCP within cancer teams. This research project, which relates to the Registered Nurses' Association of Ontario (RNAO Best Practice Guidelines and other sources of research evidence, represents a unique opportunity to learn more about the factors and processes involved in the translation of evidence-based recommendations into professional practices. The planned study seeks to address context-specific challenges and the concerns of nurses and other stakeholders regarding the uptake of evidence-based recommendations to effectively promote and support interprofessional collaborative practices. Aim This study aims to examine the uptake of evidence-based recommendations from best practice guidelines intended to enhance interprofessional collaborative practices within cancer teams. Design The planned study constitutes a practical trial, defined as a trial designed to provide comprehensive information that is grounded in real-world healthcare dynamics. An exploratory mixed methods study design will be used. It will involve collecting quantitative data to assess professionals' knowledge and attitudes, as well as practice environment factors associated with effective uptake of evidence-based recommendations. Semi-structured interviews will be conducted concurrently with care providers to gather qualitative data for describing the processes involved in the translation of evidence into action from both the users' (n = 12 and providers' (n = 24 perspectives. The Graham et al. Ottawa Model of Research Use will serve to construct operational definitions of concepts, and to establish the initial coding labels to be used in the thematic analysis of the qualitative data. Quantitative and qualitative

  11. Interactive actions of Bdnf methylation and cell metabolism for building neural resilience under the influence of diet.

    Science.gov (United States)

    Tyagi, Ethika; Zhuang, Yumei; Agrawal, Rahul; Ying, Zhe; Gomez-Pinilla, Fernando

    2015-01-01

    Quality nutrition during the period of brain formation is a predictor of brain functional capacity and plasticity during adulthood; however it is not clear how this conferred plasticity imparts long-term neural resilience. Here we report that early exposure to dietary omega-3 fatty acids orchestrates key interactions between metabolic signals and Bdnf methylation creating a reservoir of neuroplasticity that can protect the brain against the deleterious effects of switching to a Western diet (WD). We observed that the switch to a WD increased Bdnf methylation specific to exon IV, in proportion to anxiety-like behavior, in Sprague Dawley rats reared in low omega-3 fatty acid diet, and these effects were abolished by the DNA methyltransferase inhibitor 5-aza-2'-deoxycytidine. Blocking methylation also counteracted the reducing action of WD on the transcription regulator CTCF binding to Bdnf promoter IV. In vitro studies confirmed that CTCF binding to Bdnf promoter IV is essential for the action of DHA on BDNF regulation. Diet is also intrinsically associated to cell metabolism, and here we show that the switch to WD downregulated cell metabolism (NAD/NADH ratio and SIRT1). The fact that DNA methyltransferase inhibitor did not alter these parameters suggests they occur upstream to methylation. In turn, the methylation inhibitor counteracted the action of WD on PGC-1α, a mitochondrial transcription co-activator and BDNF regulator, suggesting that PGC-1α is an effector of Bdnf methylation. Results support a model in which diet can build an "epigenetic memory" during brain formation that confers resilience to metabolic perturbations occurring in adulthood.

  12. Connectivity patterns during music listening: Evidence for action-based processing in musicians.

    Science.gov (United States)

    Alluri, Vinoo; Toiviainen, Petri; Burunat, Iballa; Kliuchko, Marina; Vuust, Peter; Brattico, Elvira

    2017-03-28

    Musical expertise is visible both in the morphology and functionality of the brain. Recent research indicates that functional integration between multi-sensory, somato-motor, default-mode (DMN), and salience (SN) networks of the brain differentiates musicians from non-musicians during resting state. Here, we aimed at determining whether brain networks differentially exchange information in musicians as opposed to non-musicians during naturalistic music listening. Whole-brain graph-theory analyses were performed on participants' fMRI responses. Group-level differences revealed that musicians' primary hubs comprised cerebral and cerebellar sensorimotor regions whereas non-musicians' dominant hubs encompassed DMN-related regions. Community structure analyses of the key hubs revealed greater integration of motor and somatosensory homunculi representing the upper limbs and torso in musicians. Furthermore, musicians who started training at an earlier age exhibited greater centrality in the auditory cortex, and areas related to top-down processes, attention, emotion, somatosensory processing, and non-verbal processing of speech. We here reveal how brain networks organize themselves in a naturalistic music listening situation wherein musicians automatically engage neural networks that are action-based while non-musicians use those that are perception-based to process an incoming auditory stream. Hum Brain Mapp, 2017. © 2017 Wiley Periodicals, Inc.

  13. Evidence for a neural source of the precedence effect in sound localization.

    Science.gov (United States)

    Brown, Andrew D; Jones, Heath G; Kan, Alan; Thakkar, Tanvi; Stecker, G Christopher; Goupell, Matthew J; Litovsky, Ruth Y

    2015-11-01

    Normal-hearing human listeners and a variety of studied animal species localize sound sources accurately in reverberant environments by responding to the directional cues carried by the first-arriving sound rather than spurious cues carried by later-arriving reflections, which are not perceived discretely. This phenomenon is known as the precedence effect (PE) in sound localization. Despite decades of study, the biological basis of the PE remains unclear. Though the PE was once widely attributed to central processes such as synaptic inhibition in the auditory midbrain, a more recent hypothesis holds that the PE may arise essentially as a by-product of normal cochlear function. Here we evaluated the PE in a unique human patient population with demonstrated sensitivity to binaural information but without functional cochleae. Users of bilateral cochlear implants (CIs) were tested in a psychophysical task that assessed the number and location(s) of auditory images perceived for simulated source-echo (lead-lag) stimuli. A parallel experiment was conducted in a group of normal-hearing (NH) listeners. Key findings were as follows: 1) Subjects in both groups exhibited lead-lag fusion. 2) Fusion was marginally weaker in CI users than in NH listeners but could be augmented by systematically attenuating the amplitude of the lag stimulus to coarsely simulate adaptation observed in acoustically stimulated auditory nerve fibers. 3) Dominance of the lead in localization varied substantially among both NH and CI subjects but was evident in both groups. Taken together, data suggest that aspects of the PE can be elicited in CI users, who lack functional cochleae, thus suggesting that neural mechanisms are sufficient to produce the PE.

  14. Neural correlates of uncertain decision making: ERP evidence from the Iowa Gambling Task

    Directory of Open Access Journals (Sweden)

    Ji-fang eCui

    2013-11-01

    Full Text Available In our daily life, it is very common to make decisions in uncertain situations. The Iowa Gambling Task (IGT has been widely used in laboratory studies because of its good simulation of uncertainty in real life activities. The present study aimed to examine the neural correlates of uncertain decision making with the IGT. Twenty-six university students completed this study. An adapted IGT was administered to them, and the EEG data were recorded. The adapted IGT we used allowed us to analyze the choice evaluation, response selection, and feedback evaluation stages of uncertain decision making within the same paradigm. In the choice evaluation stage, the advantageous decks evoked larger P3 amplitude in the left hemisphere, while the disadvantageous decks evoked larger P3 in the right hemisphere. In the response selection stage, the response of pass (the card was not turned over; the participants neither won nor lost money evoked larger negativity preceding the response compared to that of play (the card was turned over; the participant either won or lost money. In the feedback evaluation stage, feedback-related negativity was only sensitive to the valence (win/loss but not the magnitude (large/small of the outcome, and P3 was sensitive to both the valence and the magnitude of the outcome. These results were consistent with the notion that a positive somatic state was represented in the left hemisphere and a negative somatic state was represented in the right hemisphere. There were also anticipatory ERP effects that guided the participants’ responses and provided evidence for the somatic marker hypothesis with more precise timing.

  15. Deciding not to decide: computational and neural evidence for hidden behavior in sequential choice.

    Science.gov (United States)

    Gluth, Sebastian; Rieskamp, Jörg; Büchel, Christian

    2013-10-01

    Understanding the cognitive and neural processes that underlie human decision making requires the successful prediction of how, but also of when, people choose. Sequential sampling models (SSMs) have greatly advanced the decision sciences by assuming decisions to emerge from a bounded evidence accumulation process so that response times (RTs) become predictable. Here, we demonstrate a difficulty of SSMs that occurs when people are not forced to respond at once but are allowed to sample information sequentially: The decision maker might decide to delay the choice and terminate the accumulation process temporarily, a scenario not accounted for by the standard SSM approach. We developed several SSMs for predicting RTs from two independent samples of an electroencephalography (EEG) and a functional magnetic resonance imaging (fMRI) study. In these studies, participants bought or rejected fictitious stocks based on sequentially presented cues and were free to respond at any time. Standard SSM implementations did not describe RT distributions adequately. However, by adding a mechanism for postponing decisions to the model we obtained an accurate fit to the data. Time-frequency analysis of EEG data revealed alternating states of de- and increasing oscillatory power in beta-band frequencies (14-30 Hz), indicating that responses were repeatedly prepared and inhibited and thus lending further support for the existence of a decision not to decide. Finally, the extended model accounted for the results of an adapted version of our paradigm in which participants had to press a button for sampling more information. Our results show how computational modeling of decisions and RTs support a deeper understanding of the hidden dynamics in cognition.

  16. Evidence for a Sex-Dependent MAOA× Childhood Stress Interaction in the Neural Circuitry of Aggression.

    Science.gov (United States)

    Holz, Nathalie; Boecker, Regina; Buchmann, Arlette F; Blomeyer, Dorothea; Baumeister, Sarah; Hohmann, Sarah; Jennen-Steinmetz, Christine; Wolf, Isabella; Rietschel, Marcella; Witt, Stephanie H; Plichta, Michael M; Meyer-Lindenberg, Andreas; Schmidt, Martin H; Esser, Günter; Banaschewski, Tobias; Brandeis, Daniel; Laucht, Manfred

    2016-03-01

    Converging evidence emphasizes the role of an interaction between monoamine oxidase A (MAOA) genotype, environmental adversity, and sex in the pathophysiology of aggression. The present study aimed to clarify the impact of this interaction on neural activity in aggression-related brain systems. Functional magnetic resonance imaging was performed in 125 healthy adults from a high-risk community sample followed since birth. DNA was genotyped for the MAOA-VNTR (variable number of tandem repeats). Exposure to childhood life stress (CLS) between the ages of 4 and 11 years was assessed using a standardized parent interview, aggression by the Youth/Young Adult Self-Report between the ages of 15 and 25 years, and the VIRA-R (Vragenlijst Instrumentele En Reactieve Agressie) at the age of 15 years. Significant interactions were obtained between MAOA genotype, CLS, and sex relating to amygdala, hippocampus, and anterior cingulate cortex (ACC) response, respectively. Activity in the amygdala and hippocampus during emotional face-matching increased with the level of CLS in male MAOA-L, while decreasing in male MAOA-H, with the reverse pattern present in females. Findings in the opposite direction in the ACC during a flanker NoGo task suggested that increased emotional activity coincided with decreased inhibitory control. Moreover, increasing amygdala activity was associated with higher Y(A)SR aggression in male MAOA-L and female MAOA-H carriers. Likewise, a significant association between amygdala activity and reactive aggression was detected in female MAOA-H carriers. The results point to a moderating role of sex in the MAOA× CLS interaction for intermediate phenotypes of emotional and inhibitory processing, suggesting a possible mechanism in conferring susceptibility to violence-related disorders.

  17. Deciding not to decide: computational and neural evidence for hidden behavior in sequential choice.

    Directory of Open Access Journals (Sweden)

    Sebastian Gluth

    2013-10-01

    Full Text Available Understanding the cognitive and neural processes that underlie human decision making requires the successful prediction of how, but also of when, people choose. Sequential sampling models (SSMs have greatly advanced the decision sciences by assuming decisions to emerge from a bounded evidence accumulation process so that response times (RTs become predictable. Here, we demonstrate a difficulty of SSMs that occurs when people are not forced to respond at once but are allowed to sample information sequentially: The decision maker might decide to delay the choice and terminate the accumulation process temporarily, a scenario not accounted for by the standard SSM approach. We developed several SSMs for predicting RTs from two independent samples of an electroencephalography (EEG and a functional magnetic resonance imaging (fMRI study. In these studies, participants bought or rejected fictitious stocks based on sequentially presented cues and were free to respond at any time. Standard SSM implementations did not describe RT distributions adequately. However, by adding a mechanism for postponing decisions to the model we obtained an accurate fit to the data. Time-frequency analysis of EEG data revealed alternating states of de- and increasing oscillatory power in beta-band frequencies (14-30 Hz, indicating that responses were repeatedly prepared and inhibited and thus lending further support for the existence of a decision not to decide. Finally, the extended model accounted for the results of an adapted version of our paradigm in which participants had to press a button for sampling more information. Our results show how computational modeling of decisions and RTs support a deeper understanding of the hidden dynamics in cognition.

  18. The neural basis of semantic cognition: converging evidence from neuropsychology, neuroimaging and TMS.

    Science.gov (United States)

    Jefferies, Elizabeth

    2013-03-01

    Recent studies suggest that a complex, distributed neural network underpins semantic cognition. This article reviews our contribution to this emerging picture and traces the putative roles of each region within this network. Neuropsychological studies indicate that semantic cognition draws on at least two interacting components: semantic representations [degraded in semantic dementia (SD)] and control processes [deficient in patients with multimodal semantic impairment following stroke aphasia (SA)]. To explore the first component, we employed distortion-corrected functional magnetic resonance imaging (fMRI) and transcranial magnetic stimulation (TMS) in healthy volunteers: these studies convergently indicated that the anterior temporal lobes (ATLs; atrophied in SD) combine information from different modalities within an amodal semantic "hub". Regions of cortex that code specific semantic features ("spokes") also make a critical contribution to knowledge within particular categories. This network of brain regions interacts with semantic control processes reliant on left inferior frontal gyrus (LIFG), posterior middle temporal gyrus (pMTG) and inferior parietal cortices. SA patients with damage to these regions have difficulty focussing on aspects of knowledge that are relevant to the current goal or context, in both verbal and non-verbal tasks. SA patients with LIFG and temporoparietal lesions show similar deficits of semantic control, suggesting that a large-scale distributed cortical network underpins semantic control. Convergent evidence is again provided by fMRI and TMS. We separately manipulated the representational and control demands of a semantic task in fMRI, and found a dissociation within the temporal lobe: ATL was sensitive to the number of meanings retrieved, while pMTG and LIFG showed effects of semantic selection. Moreover, TMS to LIFG and pMTG produced equal disruption of tasks tapping semantic control. The next challenges are to delineate the

  19. Facial Action and Emotional Language: ERP Evidence that Blocking Facial Feedback Selectively Impairs Sentence Comprehension.

    Science.gov (United States)

    Davis, Joshua D; Winkielman, Piotr; Coulson, Seana

    2015-11-01

    There is a lively and theoretically important debate about whether, how, and when embodiment contributes to language comprehension. This study addressed these questions by testing how interference with facial action impacts the brain's real-time response to emotional language. Participants read sentences about positive and negative events (e.g., "She reached inside the pocket of her coat from last winter and found some (cash/bugs) inside it.") while ERPs were recorded. Facial action was manipulated within participants by asking participants to hold chopsticks in their mouths using a position that allowed or blocked smiling, as confirmed by EMG. Blocking smiling did not influence ERPs to the valenced words (e.g., cash, bugs) but did influence ERPs to final words of sentences describing positive events. Results show that affectively positive sentences can evoke smiles and that such facial action can facilitate the semantic processing indexed by the N400 component. Overall, this study offers causal evidence that embodiment impacts some aspects of high-level comprehension, presumably involving the construction of the situation model.

  20. Motor imagery during action observation: A brief review of evidence, theory and future research opportunities

    Directory of Open Access Journals (Sweden)

    Daniel Lloyd Eaves

    2016-11-01

    Full Text Available Motor imagery (MI and action observation (AO have traditionally been viewed as two separate techniques, which can both be used alongside physical practice to enhance motor learning and rehabilitation. Their independent use has been shown to be effective, and there is clear evidence that the two processes can elicit similar activity in the motor system. Building on these well-established findings, research has now turned to investigate the effects of their combined use. In this article, we first review the available neurophysiological and behavioral evidence for the effects of combined action observation and motor imagery (‘AO+MI’ on motor processes. We next describe a conceptual framework for their combined use, and then discuss several areas for future research into AO+MI processes. In this review, we advocate a more integrated approach to AO+MI techniques than has previously been adopted by movement scientists and practitioners alike. We hope this early review of an emergent body of research, along with a related set of research questions, can inspire new work in this area. We are optimistic that future research will further confirm if, how, and when this combined approach to AO+MI can be more effective in motor learning and rehabilitation settings, relative to the more traditional application of AO or MI independently.

  1. Intelligence moderates reinforcement learning: a mini-review of the neural evidence.

    Science.gov (United States)

    Chen, Chong

    2015-06-01

    Our understanding of the neural basis of reinforcement learning and intelligence, two key factors contributing to human strivings, has progressed significantly recently. However, the overlap of these two lines of research, namely, how intelligence affects neural responses during reinforcement learning, remains uninvestigated. A mini-review of three existing studies suggests that higher IQ (especially fluid IQ) may enhance the neural signal of positive prediction error in dorsolateral prefrontal cortex, dorsal anterior cingulate cortex, and striatum, several brain substrates of reinforcement learning or intelligence.

  2. Granger causality mapping during joint actions reveals evidence for forward models that could overcome sensory-motor delays.

    Directory of Open Access Journals (Sweden)

    Idil Kokal

    Full Text Available Studies investigating joint actions have suggested a central role for the putative mirror neuron system (pMNS because of the close link between perception and action provided by these brain regions [1], [2], [3]. In contrast, our previous functional magnetic resonance imaging (fMRI experiment demonstrated that the BOLD response of the pMNS does not suggest that it directly integrates observed and executed actions during joint actions [4]. To test whether the pMNS might contribute indirectly to the integration process by sending information to brain areas responsible for this integration (integration network, here we used Granger causality mapping (GCM [5]. We explored the directional information flow between the anterior sites of the pMNS and previously identified integrative brain regions. We found that the left BA44 sent more information than it received to both the integration network (left thalamus, right middle occipital gyrus and cerebellum and more posterior nodes of the pMNS (BA2. Thus, during joint actions, two anatomically separate networks therefore seem effectively connected and the information flow is predominantly from anterior to posterior areas of the brain. These findings suggest that the pMNS is involved indirectly in joint actions by transforming observed and executed actions into a common code and is part of a generative model that could predict the future somatosensory and visual consequences of observed and executed actions in order to overcome otherwise inevitable neural delays.

  3. Exploring the neural correlates of goal-directed action and intention understanding.

    Science.gov (United States)

    Carter, Elizabeth J; Hodgins, Jessica K; Rakison, David H

    2011-01-15

    Because we are a cooperative species, understanding the goals and intentions of others is critical for human survival. In this fMRI study, participants viewed reaching behaviors in which one of four animated characters moved a hand towards one of two objects and either (a) picked up the object, (b) missed the object, or (c) changed his path halfway to lift the other object. The characters included a human, a humanoid robot, stacked boxes with an arm, and a mechanical claw. The first three moved in an identical, human-like biological pattern. Right posterior superior temporal sulcus (pSTS) activity increased when the human or humanoid robot shifted goals or missed the target relative to obtaining the original goal. This suggests that the pSTS was engaged differentially for figures that appeared more human-like rather than for all human-like motion. Medial frontal areas that are part of a protagonist-monitoring network with the right pSTS (e.g., Mason and Just, 2006) were most engaged for the human character, followed by the robot character. The current data suggest that goal-directed action and intention understanding require this network and it is used similarly for the two processes. Moreover, it is modulated by character identity rather than only the presence of biological motion. We discuss the implications for behavioral theories of goal-directed action and intention understanding.

  4. 涡虫神经再生的分子机制%Molecular actions guiding neural regeneration in planarian

    Institute of Scientific and Technical Information of China (English)

    张燕芬; 叶波平; 王大勇

    2008-01-01

    Planarian is among the simplest animals that possess a centralized nervous system (CNS),and its neural regeneration involves the replacement of cells lost to normal 'wear and tear' (cell turnover),and/or injury.In this review,we state and discuss the recent studies on molecular control of neural regeneration in planarians.The spatial and temporal expression patterns of genes in intact and regenerating planarian CNS have already been described relatively clearly.The bone morphogenetic protein (BMP) and Writ signaling pathways are identified to regulate neural regeneration.During neural regeneration,conserved axon guidance mechanisms are necessary for proper wiring of the nervous system.In addition,apoptosis may play an important role in controlling cell numbers,eliminating unnecessary tissues or cells and remodeling the old tissues for regenerating CNS.The bilateral symmetry is established by determination of anterior-posterior (A-P) and dorsal-ventral (D-V) patterns.Moreover,neurons positive to dopamine,serotonin (5-HT),and gamma-aminobutyric acid (GABA) have been detected in planarians.Therefore,planarians present us with new,experimentally accessible contexts to study the molecular actions guiding neural regeneration.%涡虫是具有简单中枢神经系统的模式动物之一,其神经再生过程包括受损细胞的替换以及细胞的再生过程.本文阐述并讨论了近年来利用涡虫进行神经再生研究取得的研究进展.目前,参与涡虫神经再生相关基因的时空间表达图谱己被相对清晰地勾勒出来.骨形成蛋白和Wnt信号通路已被鉴定参与神经再生的调控.在神经再生过程中,保守的轴突导向机制为神经系统网络的正确形成所必需.此外,细胞凋亡在控制细胞数量、消除多余组织和细胞以及重新塑造再生的神经系统中发挥着重要作用.而且,在涡虫中多巴胺能神经元、五羟色胺能神经元和γ-氨基丁酸能神经元可以被有效地予以标

  5. Physiological modules for generating discrete and rhythmic movements: action identification by a dynamic recurrent neural network.

    Science.gov (United States)

    Bengoetxea, Ana; Leurs, Françoise; Hoellinger, Thomas; Cebolla, Ana M; Dan, Bernard; McIntyre, Joseph; Cheron, Guy

    2014-01-01

    In this study we employed a dynamic recurrent neural network (DRNN) in a novel fashion to reveal characteristics of control modules underlying the generation of muscle activations when drawing figures with the outstretched arm. We asked healthy human subjects to perform four different figure-eight movements in each of two workspaces (frontal plane and sagittal plane). We then trained a DRNN to predict the movement of the wrist from information in the EMG signals from seven different muscles. We trained different instances of the same network on a single movement direction, on all four movement directions in a single movement plane, or on all eight possible movement patterns and looked at the ability of the DRNN to generalize and predict movements for trials that were not included in the training set. Within a single movement plane, a DRNN trained on one movement direction was not able to predict movements of the hand for trials in the other three directions, but a DRNN trained simultaneously on all four movement directions could generalize across movement directions within the same plane. Similarly, the DRNN was able to reproduce the kinematics of the hand for both movement planes, but only if it was trained on examples performed in each one. As we will discuss, these results indicate that there are important dynamical constraints on the mapping of EMG to hand movement that depend on both the time sequence of the movement and on the anatomical constraints of the musculoskeletal system. In a second step, we injected EMG signals constructed from different synergies derived by the PCA in order to identify the mechanical significance of each of these components. From these results, one can surmise that discrete-rhythmic movements may be constructed from three different fundamental modules, one regulating the co-activation of all muscles over the time span of the movement and two others elliciting patterns of reciprocal activation operating in orthogonal directions.

  6. Physiological modules for generating discrete and rhythmic movements: action identification by a dynamic recurrent neural network.

    Directory of Open Access Journals (Sweden)

    Ana eBengoetxea

    2014-09-01

    Full Text Available In this study we employed a dynamic recurrent neural network (DRNN in a novel fashion to reveal characteristics of control modules underlying the generation of muscle activations when drawing figures with the outstretched arm. We asked healthy human subjects to perform four different figure-eight movements in each of two workspaces (frontal plane and sagittal plane. We then trained a DRNN to predict the movement of the wrist from information in the EMG signals from seven different muscles. We trained different instances of the same network on a single movement direction, on all four movement directions in a single movement plane, or on all eight possible movement patterns and looked at the ability of the DRNN to generalize and predict movements for trials that were not included in the training set. Within a single movement plane, a DRNN trained on one movement direction was not able to predict movements of the hand for trials in the other three directions, but a DRNN trained simultaneously on all four movement directions could generalize across movement directions within the same plane. Similarly, the DRNN was able to reproduce the kinematics of the hand for both movement planes, but only if it was trained on examples performed in each one. As we will discuss, these results indicate that there are important dynamical constraints on the mapping of EMG to hand movement that depend on both the time sequence of the movement and on the anatomical constraints of the musculoskeletal system. In a second step, we injected EMG signals constructed from different synergies derived by the PCA in order to identify the mechanical significance of each of these components. From these results, one can surmise that discrete-rhythmic movements may be constructed from three different fundamental modules, one regulating the co-activation of all muscles over the time span of the movement and two others patterns of reciprocal activation operating in orthogonal

  7. AKT signaling mediates IGF-I survival actions on otic neural progenitors.

    Directory of Open Access Journals (Sweden)

    Maria R Aburto

    Full Text Available BACKGROUND: Otic neurons and sensory cells derive from common progenitors whose transition into mature cells requires the coordination of cell survival, proliferation and differentiation programmes. Neurotrophic support and survival of post-mitotic otic neurons have been intensively studied, but the bases underlying the regulation of programmed cell death in immature proliferative otic neuroblasts remains poorly understood. The protein kinase AKT acts as a node, playing a critical role in controlling cell survival and cell cycle progression. AKT is activated by trophic factors, including insulin-like growth factor I (IGF-I, through the generation of the lipidic second messenger phosphatidylinositol 3-phosphate by phosphatidylinositol 3-kinase (PI3K. Here we have investigated the role of IGF-dependent activation of the PI3K-AKT pathway in maintenance of otic neuroblasts. METHODOLOGY/PRINCIPAL FINDINGS: By using a combination of organotypic cultures of chicken (Gallus gallus otic vesicles and acoustic-vestibular ganglia, Western blotting, immunohistochemistry and in situ hybridization, we show that IGF-I-activation of AKT protects neural progenitors from programmed cell death. IGF-I maintains otic neuroblasts in an undifferentiated and proliferative state, which is characterised by the upregulation of the forkhead box M1 (FoxM1 transcription factor. By contrast, our results indicate that post-mitotic p27(Kip-positive neurons become IGF-I independent as they extend their neuronal processes. Neurons gradually reduce their expression of the Igf1r, while they increase that of the neurotrophin receptor, TrkC. CONCLUSIONS/SIGNIFICANCE: Proliferative otic neuroblasts are dependent on the activation of the PI3K-AKT pathway by IGF-I for survival during the otic neuronal progenitor phase of early inner ear development.

  8. Signed language and human action processing: evidence for functional constraints on the human mirror-neuron system.

    Science.gov (United States)

    Corina, David P; Knapp, Heather Patterson

    2008-12-01

    In the quest to further understand the neural underpinning of human communication, researchers have turned to studies of naturally occurring signed languages used in Deaf communities. The comparison of the commonalities and differences between spoken and signed languages provides an opportunity to determine core neural systems responsible for linguistic communication independent of the modality in which a language is expressed. The present article examines such studies, and in addition asks what we can learn about human languages by contrasting formal visual-gestural linguistic systems (signed languages) with more general human action perception. To understand visual language perception, it is important to distinguish the demands of general human motion processing from the highly task-dependent demands associated with extracting linguistic meaning from arbitrary, conventionalized gestures. This endeavor is particularly important because theorists have suggested close homologies between perception and production of actions and functions of human language and social communication. We review recent behavioral, functional imaging, and neuropsychological studies that explore dissociations between the processing of human actions and signed languages. These data suggest incomplete overlap between the mirror-neuron systems proposed to mediate human action and language.

  9. "Cuts in Action": A High-Density EEG Study Investigating the Neural Correlates of Different Editing Techniques in Film.

    Science.gov (United States)

    Heimann, Katrin S; Uithol, Sebo; Calbi, Marta; Umiltà, Maria A; Guerra, Michele; Gallese, Vittorio

    2016-11-24

    In spite of their striking differences with real-life perception, films are perceived and understood without effort. Cognitive film theory attributes this to the system of continuity editing, a system of editing guidelines outlining the effect of different cuts and edits on spectators. A major principle in this framework is the 180° rule, a rule recommendation that, to avoid spectators' attention to the editing, two edited shots of the same event or action should not be filmed from angles differing in a way that expectations of spatial continuity are strongly violated. In the present study, we used high-density EEG to explore the neural underpinnings of this rule. In particular, our analysis shows that cuts and edits in general elicit early ERP component indicating the registration of syntactic violations as known from language, music, and action processing. However, continuity edits and cuts-across the line differ from each other regarding later components likely to be indicating the differences in spatial remapping as well as in the degree of conscious awareness of one's own perception. Interestingly, a time-frequency analysis of the occipital alpha rhythm did not support the hypothesis that such differences in processing routes are mainly linked to visual attention. On the contrary, our study found specific modulations of the central mu rhythm ERD as an indicator of sensorimotor activity, suggesting that sensorimotor networks might play an important role. We think that these findings shed new light on current discussions about the role of attention and embodied perception in film perception and should be considered when explaining spectators' different experience of different kinds of cuts.

  10. The music of your emotions: neural substrates involved in detection of emotional correspondence between auditory and visual music actions.

    Science.gov (United States)

    Petrini, Karin; Crabbe, Frances; Sheridan, Carol; Pollick, Frank E

    2011-04-29

    In humans, emotions from music serve important communicative roles. Despite a growing interest in the neural basis of music perception, action and emotion, the majority of previous studies in this area have focused on the auditory aspects of music performances. Here we investigate how the brain processes the emotions elicited by audiovisual music performances. We used event-related functional magnetic resonance imaging, and in Experiment 1 we defined the areas responding to audiovisual (musician's movements with music), visual (musician's movements only), and auditory emotional (music only) displays. Subsequently a region of interest analysis was performed to examine if any of the areas detected in Experiment 1 showed greater activation for emotionally mismatching performances (combining the musician's movements with mismatching emotional sound) than for emotionally matching music performances (combining the musician's movements with matching emotional sound) as presented in Experiment 2 to the same participants. The insula and the left thalamus were found to respond consistently to visual, auditory and audiovisual emotional information and to have increased activation for emotionally mismatching displays in comparison with emotionally matching displays. In contrast, the right thalamus was found to respond to audiovisual emotional displays and to have similar activation for emotionally matching and mismatching displays. These results suggest that the insula and left thalamus have an active role in detecting emotional correspondence between auditory and visual information during music performances, whereas the right thalamus has a different role.

  11. The music of your emotions: neural substrates involved in detection of emotional correspondence between auditory and visual music actions.

    Directory of Open Access Journals (Sweden)

    Karin Petrini

    Full Text Available In humans, emotions from music serve important communicative roles. Despite a growing interest in the neural basis of music perception, action and emotion, the majority of previous studies in this area have focused on the auditory aspects of music performances. Here we investigate how the brain processes the emotions elicited by audiovisual music performances. We used event-related functional magnetic resonance imaging, and in Experiment 1 we defined the areas responding to audiovisual (musician's movements with music, visual (musician's movements only, and auditory emotional (music only displays. Subsequently a region of interest analysis was performed to examine if any of the areas detected in Experiment 1 showed greater activation for emotionally mismatching performances (combining the musician's movements with mismatching emotional sound than for emotionally matching music performances (combining the musician's movements with matching emotional sound as presented in Experiment 2 to the same participants. The insula and the left thalamus were found to respond consistently to visual, auditory and audiovisual emotional information and to have increased activation for emotionally mismatching displays in comparison with emotionally matching displays. In contrast, the right thalamus was found to respond to audiovisual emotional displays and to have similar activation for emotionally matching and mismatching displays. These results suggest that the insula and left thalamus have an active role in detecting emotional correspondence between auditory and visual information during music performances, whereas the right thalamus has a different role.

  12. Poverty and child health in the UK: using evidence for action

    Science.gov (United States)

    Wickham, Sophie; Anwar, Elspeth; Barr, Ben; Law, Catherine; Taylor-Robinson, David

    2016-01-01

    There are currently high levels of child poverty in the UK, and for the first time in almost two decades child poverty has started to rise in absolute terms. Child poverty is associated with a wide range of health-damaging impacts, negative educational outcomes and adverse long-term social and psychological outcomes. The poor health associated with child poverty limits children's potential and development, leading to poor health and life chances in adulthood. This article outlines some key definitions with regard to child poverty, reviews the links between child poverty and a range of health, developmental, behavioural and social outcomes for children, describes gaps in the evidence base and provides an overview of current policies relevant to child poverty in the UK. Finally, the article outlines how child health professionals can take action by (1) supporting policies to reduce child poverty, (2) providing services that reduce the health consequences of child poverty and (3) measuring and understanding the problem and assessing the impact of action. PMID:26857824

  13. An action-incongruent secondary task modulates prediction accuracy in experienced performers: evidence for motor simulation.

    Science.gov (United States)

    Mulligan, Desmond; Lohse, Keith R; Hodges, Nicola J

    2016-07-01

    We provide behavioral evidence that the human motor system is involved in the perceptual decision processes of skilled performers, directly linking prediction accuracy to the (in)ability of the motor system to activate in a response-specific way. Experienced and non-experienced dart players were asked to predict, from temporally occluded video sequences, the landing position of a dart thrown previously by themselves (self) or another (other). This prediction task was performed while additionally performing (a) an action-incongruent secondary motor task (right arm force production), (b) a congruent secondary motor task (mimicking) or (c) an attention-matched task (tone-monitoring). Non-experienced dart players were not affected by any of the secondary task manipulations, relative to control conditions, yet prediction accuracy decreased for the experienced players when additionally performing the force-production, motor task. This interference effect was present for 'self' as well as 'other' decisions, reducing the accuracy of experienced participants to a novice level. The mimicking (congruent) secondary task condition did not interfere with (or facilitate) prediction accuracy for either group. We conclude that visual-motor experience moderates the process of decision making, such that a seemingly visual-cognitive prediction task relies on activation of the motor system for experienced performers. This fits with a motor simulation account of action prediction in sports and other tasks, and alerts to the specificity of these simulative processes.

  14. Poverty and child health in the UK: using evidence for action.

    Science.gov (United States)

    Wickham, Sophie; Anwar, Elspeth; Barr, Ben; Law, Catherine; Taylor-Robinson, David

    2016-08-01

    There are currently high levels of child poverty in the UK, and for the first time in almost two decades child poverty has started to rise in absolute terms. Child poverty is associated with a wide range of health-damaging impacts, negative educational outcomes and adverse long-term social and psychological outcomes. The poor health associated with child poverty limits children's potential and development, leading to poor health and life chances in adulthood. This article outlines some key definitions with regard to child poverty, reviews the links between child poverty and a range of health, developmental, behavioural and social outcomes for children, describes gaps in the evidence base and provides an overview of current policies relevant to child poverty in the UK. Finally, the article outlines how child health professionals can take action by (1) supporting policies to reduce child poverty, (2) providing services that reduce the health consequences of child poverty and (3) measuring and understanding the problem and assessing the impact of action.

  15. The Neural Correlates Underlying Belief Reasoning for Self and for Others: Evidence from ERPs

    Science.gov (United States)

    Jiang, Qin; Wang, Qi; Li, Peng; Li, Hong

    2016-01-01

    Belief reasoning is typical mental state reasoning in theory of mind (ToM). Although previous studies have explored the neural bases of belief reasoning, the neural correlates of belief reasoning for self and for others are rarely addressed. The decoupling mechanism of distinguishing the mental state of others from one’s own is essential for ToM processing. To address the electrophysiological bases underlying the decoupling mechanism, the present event-related potential study compared the time course of neural activities associated with belief reasoning for self and for others when the belief belonging to self was consistent or inconsistent with others. Results showed that during a 450–600 ms period, belief reasoning for self elicited a larger late positive component (LPC) than for others when beliefs were inconsistent with each other. The LPC divergence is assumed to reflect the categorization of agencies in ToM processes. PMID:27757093

  16. Neural Basis of Intrinsic Motivation: Evidence from Event-Related Potentials.

    Science.gov (United States)

    Jin, Jia; Yu, Liping; Ma, Qingguo

    2015-01-01

    Human intrinsic motivation is of great importance in human behavior. However, although researchers have focused on this topic for decades, its neural basis was still unclear. The current study employed event-related potentials to investigate the neural disparity between an interesting stop-watch (SW) task and a boring watch-stop task (WS) to understand the neural mechanisms of intrinsic motivation. Our data showed that, in the cue priming stage, the cue of the SW task elicited smaller N2 amplitude than that of the WS task. Furthermore, in the outcome feedback stage, the outcome of the SW task induced smaller FRN amplitude and larger P300 amplitude than that of the WS task. These results suggested that human intrinsic motivation did exist and that it can be detected at the neural level. Furthermore, intrinsic motivation could be quantitatively indexed by the amplitude of ERP components, such as N2, FRN, and P300, in the cue priming stage or feedback stage. Quantitative measurements would also be convenient for intrinsic motivation to be added as a candidate social factor in the construction of a machine learning model.

  17. Neural systems for social cognition in Klinefelter syndrome (47.XXY) : evidence from fMRI

    NARCIS (Netherlands)

    van Rijn, S.; Swaab, H; Baas, D; de Haan, E; Kahn, R.S.; Aleman, A.

    2012-01-01

    Klinefelter syndrome (KS) is a chromosomal condition (47, XXY) that may help us to unravel gene-brain behavior pathways to psychopathology. The phenotype includes social cognitive impairments and increased risk for autism traits. We used functional MRI to study neural mechanisms underlying social in

  18. Neural Basis of Intrinsic Motivation: Evidence from Event-Related Potentials

    Directory of Open Access Journals (Sweden)

    Jia Jin

    2015-01-01

    Full Text Available Human intrinsic motivation is of great importance in human behavior. However, although researchers have focused on this topic for decades, its neural basis was still unclear. The current study employed event-related potentials to investigate the neural disparity between an interesting stop-watch (SW task and a boring watch-stop task (WS to understand the neural mechanisms of intrinsic motivation. Our data showed that, in the cue priming stage, the cue of the SW task elicited smaller N2 amplitude than that of the WS task. Furthermore, in the outcome feedback stage, the outcome of the SW task induced smaller FRN amplitude and larger P300 amplitude than that of the WS task. These results suggested that human intrinsic motivation did exist and that it can be detected at the neural level. Furthermore, intrinsic motivation could be quantitatively indexed by the amplitude of ERP components, such as N2, FRN, and P300, in the cue priming stage or feedback stage. Quantitative measurements would also be convenient for intrinsic motivation to be added as a candidate social factor in the construction of a machine learning model.

  19. Neural Signatures of Number Processing in Human Infants: Evidence for Two Core Systems Underlying Numerical Cognition

    Science.gov (United States)

    Hyde, Daniel C.; Spelke, Elizabeth S.

    2011-01-01

    Behavioral research suggests that two cognitive systems are at the foundations of numerical thinking: one for representing 1-3 objects in parallel and one for representing and comparing large, approximate numerical magnitudes. We tested for dissociable neural signatures of these systems in preverbal infants by recording event-related potentials…

  20. On the Nature of the Intrinsic Connectivity of the Cat Motor Cortex: Evidence for a Recurrent Neural Network Topology

    DEFF Research Database (Denmark)

    Capaday, Charles; Ethier, C; Brizzi, L

    2009-01-01

    Capaday C, Ethier C, Brizzi L, Sik A, van Vreeswijk C, Gingras D. On the nature of the intrinsic connectivity of the cat motor cortex: evidence for a recurrent neural network topology. J Neurophysiol 102: 2131-2141, 2009. First published July 22, 2009; doi: 10.1152/jn.91319.2008. The details...... and functional significance of the intrinsic horizontal connections between neurons in the motor cortex (MCx) remain to be clarified. To further elucidate the nature of this intracortical connectivity pattern, experiments were done on the MCx of three cats. The anterograde tracer biocytin was ejected...

  1. cables1 is required for embryonic neural development: molecular, cellular, and behavioral evidence from the zebrafish.

    Science.gov (United States)

    Groeneweg, Jolijn W; White, Yvonne A R; Kokel, David; Peterson, Randall T; Zukerberg, Lawrence R; Berin, Inna; Rueda, Bo R; Wood, Antony W

    2011-01-01

    In vitro studies have suggested that the Cables1 gene regulates epithelial cell proliferation, whereas other studies suggest a role in promoting neural differentiation. In efforts to clarify the functions of Cables1 in vivo, we conducted gain- and loss-of-function studies targeting its ortholog (cables1) in the zebrafish embryo. Similar to rodents, zebrafish cables1 mRNA expression is detected most robustly in embryonic neural tissues. Antisense knockdown of cables1 leads to increased numbers of apoptotic cells, particularly in brain tissue, in addition to a distinct behavioral phenotype, characterized by hyperactivity in response to stimulation. Apoptosis and the behavioral abnormality could be rescued by co-expression of a morpholino-resistant cables1 construct. Suppression of p53 expression in cables1 morphants partially rescued both apoptosis and the behavioral phenotype, suggesting that the phenotype of cables1 morphants is due in part to p53-dependent apoptosis. Alterations in the expression patterns of several neural transcription factors were observed in cables1 morphants during early neurulation, suggesting that cables1 is required for early neural differentiation. Ectopic overexpression of cables1 strongly disrupted embryonic morphogenesis, while overexpression of a cables1 mutant lacking the C-terminal cyclin box had little effect, suggesting functional importance of the cyclin box. Lastly, marked reductions in p35, but not Cdk5, were observed in cables1 morphants. Collectively, these data suggest that cables1 is important for neural differentiation during embryogenesis, in a mechanism that likely involves interactions with the Cdk5/p35 kinase pathway.

  2. Evidence for Neural Computations of Temporal Coherence in an Auditory Scene and Their Enhancement during Active Listening.

    Science.gov (United States)

    O'Sullivan, James A; Shamma, Shihab A; Lalor, Edmund C

    2015-05-06

    The human brain has evolved to operate effectively in highly complex acoustic environments, segregating multiple sound sources into perceptually distinct auditory objects. A recent theory seeks to explain this ability by arguing that stream segregation occurs primarily due to the temporal coherence of the neural populations that encode the various features of an individual acoustic source. This theory has received support from both psychoacoustic and functional magnetic resonance imaging (fMRI) studies that use stimuli which model complex acoustic environments. Termed stochastic figure-ground (SFG) stimuli, they are composed of a "figure" and background that overlap in spectrotemporal space, such that the only way to segregate the figure is by computing the coherence of its frequency components over time. Here, we extend these psychoacoustic and fMRI findings by using the greater temporal resolution of electroencephalography to investigate the neural computation of temporal coherence. We present subjects with modified SFG stimuli wherein the temporal coherence of the figure is modulated stochastically over time, which allows us to use linear regression methods to extract a signature of the neural processing of this temporal coherence. We do this under both active and passive listening conditions. Our findings show an early effect of coherence during passive listening, lasting from ∼115 to 185 ms post-stimulus. When subjects are actively listening to the stimuli, these responses are larger and last longer, up to ∼265 ms. These findings provide evidence for early and preattentive neural computations of temporal coherence that are enhanced by active analysis of an auditory scene.

  3. What are they up to? The role of sensory evidence and prior knowledge in action understanding.

    Directory of Open Access Journals (Sweden)

    Valerian Chambon

    Full Text Available Explaining or predicting the behaviour of our conspecifics requires the ability to infer the intentions that motivate it. Such inferences are assumed to rely on two types of information: (1 the sensory information conveyed by movement kinematics and (2 the observer's prior expectations--acquired from past experience or derived from prior knowledge. However, the respective contribution of these two sources of information is still controversial. This controversy stems in part from the fact that "intention" is an umbrella term that may embrace various sub-types each being assigned different scopes and targets. We hypothesized that variations in the scope and target of intentions may account for variations in the contribution of visual kinematics and prior knowledge to the intention inference process. To test this hypothesis, we conducted four behavioural experiments in which participants were instructed to identify different types of intention: basic intentions (i.e. simple goal of a motor act, superordinate intentions (i.e. general goal of a sequence of motor acts, or social intentions (i.e. intentions accomplished in a context of reciprocal interaction. For each of the above-mentioned intentions, we varied (1 the amount of visual information available from the action scene and (2 participant's prior expectations concerning the intention that was more likely to be accomplished. First, we showed that intentional judgments depend on a consistent interaction between visual information and participant's prior expectations. Moreover, we demonstrated that this interaction varied according to the type of intention to be inferred, with participant's priors rather than perceptual evidence exerting a greater effect on the inference of social and superordinate intentions. The results are discussed by appealing to the specific properties of each type of intention considered and further interpreted in the light of a hierarchical model of action representation.

  4. Neural networks and forecasting stock price movements-accounting approach: Empirical evidence from Iran

    Directory of Open Access Journals (Sweden)

    Hossein Naderi

    2012-08-01

    Full Text Available Stock market prediction is one of the most important interesting areas of research in business. Stock markets prediction is normally assumed as tedious task since there are many factors influencing the market. The primary objective of this paper is to forecast trend closing price movement of Tehran Stock Exchange (TSE using financial accounting ratios from year 2003 to year 2008. The proposed study of this paper uses two approaches namely Artificial Neural Networks and multi-layer perceptron. Independent variables are accounting ratios and dependent variable of stock price , so the latter was gathered for the industry of Motor Vehicles and Auto Parts. The results of this study show that neural networks models are useful tools in forecasting stock price movements in emerging markets but multi-layer perception provides better results in term of lowering error terms.

  5. Neural evidence that three dimensions organize mental state representation: Rationality, social impact, and valence.

    Science.gov (United States)

    Tamir, Diana I; Thornton, Mark A; Contreras, Juan Manuel; Mitchell, Jason P

    2016-01-05

    How do people understand the minds of others? Existing psychological theories have suggested a number of dimensions that perceivers could use to make sense of others' internal mental states. However, it remains unclear which of these dimensions, if any, the brain spontaneously uses when we think about others. The present study used multivoxel pattern analysis (MVPA) of neuroimaging data to identify the primary organizing principles of social cognition. We derived four unique dimensions of mental state representation from existing psychological theories and used functional magnetic resonance imaging to test whether these dimensions organize the neural encoding of others' mental states. MVPA revealed that three such dimensions could predict neural patterns within the medial prefrontal and parietal cortices, temporoparietal junction, and anterior temporal lobes during social thought: rationality, social impact, and valence. These results suggest that these dimensions serve as organizing principles for our understanding of other people.

  6. The moon illusion and size-distance scaling--evidence for shared neural patterns.

    Science.gov (United States)

    Weidner, Ralph; Plewan, Thorsten; Chen, Qi; Buchner, Axel; Weiss, Peter H; Fink, Gereon R

    2014-08-01

    A moon near to the horizon is perceived larger than a moon at the zenith, although--obviously--the moon does not change its size. In this study, the neural mechanisms underlying the "moon illusion" were investigated using a virtual 3-D environment and fMRI. Illusory perception of an increased moon size was associated with increased neural activity in ventral visual pathway areas including the lingual and fusiform gyri. The functional role of these areas was further explored in a second experiment. Left V3v was found to be involved in integrating retinal size and distance information, thus indicating that the brain regions that dynamically integrate retinal size and distance play a key role in generating the moon illusion.

  7. Bilingualism increases neural response consistency and attentional control: evidence for sensory and cognitive coupling.

    Science.gov (United States)

    Krizman, Jennifer; Skoe, Erika; Marian, Viorica; Kraus, Nina

    2014-01-01

    Auditory processing is presumed to be influenced by cognitive processes - including attentional control - in a top-down manner. In bilinguals, activation of both languages during daily communication hones inhibitory skills, which subsequently bolster attentional control. We hypothesize that the heightened attentional demands of bilingual communication strengthens connections between cognitive (i.e., attentional control) and auditory processing, leading to greater across-trial consistency in the auditory evoked response (i.e., neural consistency) in bilinguals. To assess this, we collected passively-elicited auditory evoked responses to the syllable [da] in adolescent Spanish-English bilinguals and English monolinguals and separately obtained measures of attentional control and language ability. Bilinguals demonstrated enhanced attentional control and more consistent brainstem and cortical responses. In bilinguals, but not monolinguals, brainstem consistency tracked with language proficiency and attentional control. We interpret these enhancements in neural consistency as the outcome of strengthened attentional control that emerged from experience communicating in two languages.

  8. Neural Correlates of Developmental Speech and Language Disorders: Evidence from Neuroimaging.

    Science.gov (United States)

    Liégeois, Frédérique; Mayes, Angela; Morgan, Angela

    2014-01-01

    Disorders of speech and language arise out of a complex interaction of genetic, environmental, and neural factors. Little is understood about the neural bases of these disorders. Here we systematically reviewed neuroimaging findings in Speech disorders (SD) and Language disorders (LD) over the last five years (2008-2013; 10 articles). In participants with SD, structural and functional anomalies in the left supramarginal gyrus suggest a possible deficit in sensory feedback or integration. In LD, cortical and subcortical anomalies were reported in a widespread language network, with little consistency across studies except in the superior temporal gyri. In summary, both functional and structural anomalies are associated with LD and SD, including greater activity and volumes relative to controls. The variability in neuroimaging approach and heterogeneity within and across participant samples restricts our full understanding of the neurobiology of these conditions- reducing the potential for devising novel interventions targeted at the underlying pathology.

  9. Erythropoietin modulates neural and cognitive processing of emotional information in biomarker models of antidepressant drug action in depressed patients

    DEFF Research Database (Denmark)

    Miskowiak, Kamilla W; Favaron, Elisa; Hafizi, Sepehr

    2010-01-01

    Erythropoietin (Epo) has neuroprotective and neurotrophic effects, and may be a novel therapeutic agent in the treatment of psychiatric disorders. We have demonstrated antidepressant-like effects of Epo on the neural and cognitive processing of facial expressions in healthy volunteers. The curren...... study investigates the effects of Epo on the neural and cognitive response to emotional facial expressions in depressed patients....

  10. Erythropoietin modulates neural and cognitive processing of emotional information in biomarker models of antidepressant drug action in depressed patients

    DEFF Research Database (Denmark)

    Miskowiak, Kamilla W; Favaron, Elisa; Hafizi, Sepehr;

    2010-01-01

    Erythropoietin (Epo) has neuroprotective and neurotrophic effects, and may be a novel therapeutic agent in the treatment of psychiatric disorders. We have demonstrated antidepressant-like effects of Epo on the neural and cognitive processing of facial expressions in healthy volunteers. The current...... study investigates the effects of Epo on the neural and cognitive response to emotional facial expressions in depressed patients....

  11. The Athlete's Brain: Cross-Sectional Evidence for Neural Efficiency during Cycling Exercise.

    Science.gov (United States)

    Ludyga, Sebastian; Gronwald, Thomas; Hottenrott, Kuno

    2016-01-01

    The "neural efficiency" hypothesis suggests that experts are characterized by a more efficient cortical function in cognitive tests. Although this hypothesis has been extended to a variety of movement-related tasks within the last years, it is unclear whether or not neural efficiency is present in cyclists performing endurance exercise. Therefore, this study examined brain cortical activity at rest and during exercise between cyclists of higher (HIGH; n = 14; 55.6 ± 2.8 mL/min/kg) and lower (LOW; n = 15; 46.4 ± 4.1 mL/min/kg) maximal oxygen consumption (VO2MAX). Male and female participants performed a graded exercise test with spirometry to assess VO2MAX. After 3 to 5 days, EEG was recorded at rest with eyes closed and during cycling at the individual anaerobic threshold over a 30 min period. Possible differences in alpha/beta ratio as well as alpha and beta power were investigated at frontal, central, and parietal sites. The statistical analysis revealed significant differences between groups (F = 12.04; p = 0.002), as the alpha/beta ratio was increased in HIGH compared to LOW in both the resting state (p ≤ 0.018) and the exercise condition (p ≤ 0.025). The present results indicate enhanced neural efficiency in subjects with high VO2MAX, possibly due to the inhibition of task-irrelevant cognitive processes.

  12. The Athlete’s Brain: Cross-Sectional Evidence for Neural Efficiency during Cycling Exercise

    Directory of Open Access Journals (Sweden)

    Sebastian Ludyga

    2016-01-01

    Full Text Available The “neural efficiency” hypothesis suggests that experts are characterized by a more efficient cortical function in cognitive tests. Although this hypothesis has been extended to a variety of movement-related tasks within the last years, it is unclear whether or not neural efficiency is present in cyclists performing endurance exercise. Therefore, this study examined brain cortical activity at rest and during exercise between cyclists of higher (HIGH; n=14; 55.6 ± 2.8 mL/min/kg and lower (LOW; n=15; 46.4 ± 4.1 mL/min/kg maximal oxygen consumption (VO2MAX. Male and female participants performed a graded exercise test with spirometry to assess VO2MAX. After 3 to 5 days, EEG was recorded at rest with eyes closed and during cycling at the individual anaerobic threshold over a 30 min period. Possible differences in alpha/beta ratio as well as alpha and beta power were investigated at frontal, central, and parietal sites. The statistical analysis revealed significant differences between groups (F=12.04; p=0.002, as the alpha/beta ratio was increased in HIGH compared to LOW in both the resting state (p≤0.018 and the exercise condition (p≤0.025. The present results indicate enhanced neural efficiency in subjects with high VO2MAX, possibly due to the inhibition of task-irrelevant cognitive processes.

  13. Neural and Behavioral Evidence for an Online Resetting Process in Visual Working Memory.

    Science.gov (United States)

    Balaban, Halely; Luria, Roy

    2017-02-01

    Visual working memory (VWM) guides behavior by holding a set of active representations and modifying them according to changes in the environment. This updating process relies on a unique mapping between each VWM representation and an actual object in the environment. Here, we destroyed this mapping by either presenting a coherent object but then breaking it into independent parts or presenting an object but then abruptly replacing it with a different object. This allowed us to introduce the neural marker and behavioral consequence of an online resetting process in humans' VWM. Across seven experiments, we demonstrate that this resetting process involves abandoning the old VWM contents because they no longer correspond to the objects in the environment. Then, VWM encodes the novel information and reestablishes the correspondence between the new representations and the objects. The resetting process was marked by a unique neural signature: a sharp drop in the amplitude of the electrophysiological index of VWM contents (the contralateral delay activity), presumably indicating the loss of the existent object-to-representation mappings. This marker was missing when an updating process occurred. Moreover, when tracking moving items, VWM failed to detect salient changes in the object's shape when these changes occurred during the resetting process. This happened despite the object being fully visible, presumably because the mapping between the object and a VWM representation was lost. Importantly, we show that resetting, its neural marker, and the behavioral cost it entails, are specific to situations that involve a destruction of the objects-to-representations correspondence.

  14. Cross-linguistic differences in the neural representation of human language: evidence from users of signed languages.

    Science.gov (United States)

    Corina, David P; Lawyer, Laurel A; Cates, Deborah

    2012-01-01

    Studies of deaf individuals who are users of signed languages have provided profound insight into the neural representation of human language. Case studies of deaf signers who have incurred left- and right-hemisphere damage have shown that left-hemisphere resources are a necessary component of sign language processing. These data suggest that, despite frank differences in the input and output modality of language, core left perisylvian regions universally serve linguistic function. Neuroimaging studies of deaf signers have generally provided support for this claim. However, more fine-tuned studies of linguistic processing in deaf signers are beginning to show evidence of important differences in the representation of signed and spoken languages. In this paper, we provide a critical review of this literature and present compelling evidence for language-specific cortical representations in deaf signers. These data lend support to the claim that the neural representation of language may show substantive cross-linguistic differences. We discuss the theoretical implications of these findings with respect to an emerging understanding of the neurobiology of language.

  15. Cross-linguistic differences in the neural representation of human language: evidence from users of signed languages.

    Directory of Open Access Journals (Sweden)

    David eCorina

    2013-01-01

    Full Text Available Studies of deaf individuals who are users of signed languages have provided profound insight into the neural representation of human language. Case studies of deaf signers who have incurred left- and right-hemisphere damage have shown that left-hemisphere resources are a necessary component of sign language processing. These data suggest that, despite frank differences in the input and output modality of language,; core left perisylvian regions universally serve linguistic function. Neuroimaging studies of deaf signers have generally provided support for this claim. However, more fine-tuned studies of linguistic processing in deaf signers are beginning to show evidence of important differences in the representation of signed and spoken languages. In this paper, we provide a critical review of this literature and present compelling evidence for language-specific cortical representations in deaf signers. These data lend support to the claim that the neural representation of language may show substantive cross-linguistic differences. We discuss the theoretical implications of these findings with respect to an emerging understanding of the neurobiology of language.

  16. Is recursion language-specific? Evidence of recursive mechanisms in the structure of intentional action.

    Science.gov (United States)

    Vicari, Giuseppe; Adenzato, Mauro

    2014-05-01

    In their 2002 seminal paper Hauser, Chomsky and Fitch hypothesize that recursion is the only human-specific and language-specific mechanism of the faculty of language. While debate focused primarily on the meaning of recursion in the hypothesis and on the human-specific and syntax-specific character of recursion, the present work focuses on the claim that recursion is language-specific. We argue that there are recursive structures in the domain of motor intentionality by way of extending John R. Searle's analysis of intentional action. We then discuss evidence from cognitive science and neuroscience supporting the claim that motor-intentional recursion is language-independent and suggest some explanatory hypotheses: (1) linguistic recursion is embodied in sensory-motor processing; (2) linguistic and motor-intentional recursions are distinct and mutually independent mechanisms. Finally, we propose some reflections about the epistemic status of HCF as presenting an empirically falsifiable hypothesis, and on the possibility of testing recursion in different cognitive domains.

  17. Evidence-Based Practice and Teacher Action-Research: A Reflection on the Nature and Direction of "Change"

    Science.gov (United States)

    Colucci-Gray, Laura; Das, Sharmistha; Gray, Donald; Robson, Dean; Spratt, Jennifer

    2013-01-01

    This study was conceived as an opportunity to reflect on the place of action-research in the contested landscape of educational change in the UK where increasing emphasis has been put on the use of evidence to drive reform. In the context of a government-sponsored project in Scotland, this study looked at the impact of a scholarship initiative…

  18. Systematic implementation of evidence-based practice in a clinical nursing setting : a participatory action research project

    NARCIS (Netherlands)

    Friesen-Storms, Jolanda; Moser, Albine; Loo, Sandra van der; Beurskens, Anna; Bours, Gerrie

    2015-01-01

    Aims and objectives: To describe the process of implementing evidence-based practice (EBP) in a clinical nursing setting. Background: EBP has become a major issue in nursing, it is insufficiently integrated in daily practice and its implementation is complex. Design: Participatory action researc

  19. Analytics4Action Evaluation Framework: A Review of Evidence-Based Learning Analytics Interventions at the Open University UK

    Science.gov (United States)

    Rienties, Bart; Boroowa, Avinash; Cross, Simon; Kubiak, Chris; Mayles, Kevin; Murphy, Sam

    2016-01-01

    There is an urgent need to develop an evidence-based framework for learning analytics whereby stakeholders can manage, evaluate, and make decisions about which types of interventions work well and under which conditions. In this article, we will work towards developing a foundation of an Analytics4Action Evaluation Framework (A4AEF) that is…

  20. Neural mechanisms of human perceptual learning: electrophysiological evidence for a two-stage process.

    Directory of Open Access Journals (Sweden)

    Carlos M Hamamé

    Full Text Available BACKGROUND: Humans and other animals change the way they perceive the world due to experience. This process has been labeled as perceptual learning, and implies that adult nervous systems can adaptively modify the way in which they process sensory stimulation. However, the mechanisms by which the brain modifies this capacity have not been sufficiently analyzed. METHODOLOGY/PRINCIPAL FINDINGS: We studied the neural mechanisms of human perceptual learning by combining electroencephalographic (EEG recordings of brain activity and the assessment of psychophysical performance during training in a visual search task. All participants improved their perceptual performance as reflected by an increase in sensitivity (d' and a decrease in reaction time. The EEG signal was acquired throughout the entire experiment revealing amplitude increments, specific and unspecific to the trained stimulus, in event-related potential (ERP components N2pc and P3 respectively. P3 unspecific modification can be related to context or task-based learning, while N2pc may be reflecting a more specific attentional-related boosting of target detection. Moreover, bell and U-shaped profiles of oscillatory brain activity in gamma (30-60 Hz and alpha (8-14 Hz frequency bands may suggest the existence of two phases for learning acquisition, which can be understood as distinctive optimization mechanisms in stimulus processing. CONCLUSIONS/SIGNIFICANCE: We conclude that there are reorganizations in several neural processes that contribute differently to perceptual learning in a visual search task. We propose an integrative model of neural activity reorganization, whereby perceptual learning takes place as a two-stage phenomenon including perceptual, attentional and contextual processes.

  1. From evidence to action to deliver a healthy start for the next generation.

    Science.gov (United States)

    Mason, Elizabeth; McDougall, Lori; Lawn, Joy E; Gupta, Anuradha; Claeson, Mariam; Pillay, Yogan; Presern, Carole; Lukong, Martina Baye; Mann, Gillian; Wijnroks, Marijke; Azad, Kishwar; Taylor, Katherine; Beattie, Allison; Bhutta, Zulfiqar A; Chopra, Mickey

    2014-08-01

    attention to increasing of health worker numbers and skills with attention to high-quality childbirth care for newborn babies as well as mothers and children; and (5) evaluation, tracking coverage of priority interventions and packages of care with clear accountability to accelerate progress and reach the poorest groups. The Every Newborn Action Plan provides an evidence-based roadmap towards care for every woman, and a healthy start for every newborn baby, with a right to be counted, survive, and thrive wherever they are born.

  2. Electroencephalogram evidence for the activation of human mirror neuron system during the observation of intransitive shadow and line drawing actions

    Institute of Scientific and Technical Information of China (English)

    Huaping Zhu; Yaoru Sun; Fang Wang

    2013-01-01

    Previous studies have demonstrated that hand shadows may activate the motor cortex associated with the mirror neuron system in human brain. However, there is no evidence of activity of the human mirror neuron system during the observation of intransitive movements by shadows and line drawings of hands. This study examined the suppression of electroencephalography mu waves hand actions, hand shadow actions and actions made by line drawings of hands. The results showed significant desynchronization of the mu rhythm ("mu suppression") across the sensorimotor cortex (recorded at C3, Cz and C4), the frontal cortex (recorded at F3, Fz and F4) and the central and right posterior parietal cortex (recorded at Pz and P4) under all three conditions. Our experimental findings suggest that the observation of "impoverished hand actions", such as intransitive movements of shadows and line drawings of hands, is able to activate widespread cortical areas related to the putative human mirror neuron system.

  3. Neural evidence for compromised motor imagery in right hemiparetic cerebral palsy

    Directory of Open Access Journals (Sweden)

    Michiel Van Elk

    2010-11-01

    Full Text Available In the present EEG study we investigated the neural and temporal dynamics of motor imagery in participants with right-sided HCP (n = 10 and in left-handed control participants (n = 10. A mental rotation task was used in which participants were required to judge the laterality of hand pictures. At a behavioral level participants with HCP were slower in making hand laterality judgments compared to control subjects, especially when presented with pictures representing the affected hand. At a neural level, individuals with HCP were characterized by a reduced rotation-related negativity (RRN over parietal areas, that was delayed in onset with respect to control participants. Interestingly, participants that were relatively mildly impaired showed a stronger RRN for the rotation of right hand stimuli than participants that were more strongly impaired in their motor function, suggesting a direct relation between the motor imagery process and the biomechanical constraints of the participant. Together, the results provide new insights in the relation between motor imagery and motor capabilities and indicate that participants with HCP may be characterized by a compromised ability to use motor imagery.

  4. Neural evidence for a 3-state model of visual short-term memory.

    Science.gov (United States)

    Nee, Derek Evan; Jonides, John

    2013-07-01

    Recent research has suggested that short-term memory (STM) can be partitioned into three distinct states. By this model, a single item is held in the focus of attention making it available for immediate processing (focus of attention), a capacity-limited set of additional items is actively maintained for future processing (direct access region), and other recently presented information is passively active, but can nevertheless influence ongoing cognition (activated portion of long-term memory). While there is both behavioral and neural support for this 3-state model in verbal STM, it is unclear whether the model generalizes to non-verbal STM. Here, we tested a 3-state model of visual STM using fMRI. We found a triple dissociation of regions involved in the access of each hypothesized state. The inferior parietal cortex mediated access to the focus of attention, the medial temporal lobe (MTL) including the hippocampus mediated access to the direct access region, and the left ventrolateral prefrontal cortex (VLPFC) mediated access to the activated portion of long-term memory. Direct comparison with previously collected verbal STM data revealed overlapping neural activations involved in the access of each state across different forms of content suggesting that mechanisms of access are domain general. These data support a 3-state model of STM.

  5. Development of social skills in children: neural and behavioral evidence for the elaboration of cognitive models

    Science.gov (United States)

    Soto-Icaza, Patricia; Aboitiz, Francisco; Billeke, Pablo

    2015-01-01

    Social skills refer to a wide group of abilities that allow us to interact and communicate with others. Children learn how to solve social situations by predicting and understanding other's behaviors. The way in which humans learn to interact successfully with others encompasses a complex interaction between neural, behavioral, and environmental elements. These have a role in the accomplishment of positive developmental outcomes, including peer acceptance, academic achievement, and mental health. All these social abilities depend on widespread brain networks that are recently being studied by neuroscience. In this paper, we will first review the studies on this topic, aiming to clarify the behavioral and neural mechanisms related to the acquisition of social skills during infancy and their appearance in time. Second, we will briefly describe how developmental diseases like Autism Spectrum Disorders (ASD) can inform about the neurobiological mechanisms of social skills. We finally sketch a general framework for the elaboration of cognitive models in order to facilitate the comprehension of human social development. PMID:26483621

  6. Development of social skills in children: neural and behavioral evidence for the elaboration of cognitive models.

    Science.gov (United States)

    Soto-Icaza, Patricia; Aboitiz, Francisco; Billeke, Pablo

    2015-01-01

    Social skills refer to a wide group of abilities that allow us to interact and communicate with others. Children learn how to solve social situations by predicting and understanding other's behaviors. The way in which humans learn to interact successfully with others encompasses a complex interaction between neural, behavioral, and environmental elements. These have a role in the accomplishment of positive developmental outcomes, including peer acceptance, academic achievement, and mental health. All these social abilities depend on widespread brain networks that are recently being studied by neuroscience. In this paper, we will first review the studies on this topic, aiming to clarify the behavioral and neural mechanisms related to the acquisition of social skills during infancy and their appearance in time. Second, we will briefly describe how developmental diseases like Autism Spectrum Disorders (ASD) can inform about the neurobiological mechanisms of social skills. We finally sketch a general framework for the elaboration of cognitive models in order to facilitate the comprehension of human social development.

  7. Mechanisms of action of spa therapies in rheumatic diseases: what scientific evidence is there?

    Science.gov (United States)

    Fioravanti, Antonella; Cantarini, Luca; Guidelli, Giacomo Maria; Galeazzi, Mauro

    2011-01-01

    Spa therapy represents a popular treatment for many rheumatic diseases. The mechanisms by which immersion in mineral or thermal water or the application of mud alleviates suffering in rheumatic diseases are not fully understood. The net benefit is probably the result of a combination of factors, with mechanical, thermal and chemical effects among the most prominent ones. Buoyancy, immersion, resistance and temperature all play important roles. According to the gate theory, pain relief may be due to the pressure and temperature of the water on skin; hot stimuli may influence muscle tone and pain intensity, helping to reduce muscle spasm and to increase the pain threshold. Mud-bath therapy increases plasma β-endorphin levels and secretion of corticotrophin, cortisol, growth hormone and prolactin. It has recently been demonstrated that thermal mud-pack therapy induces a reduction in the circulating levels of prostaglandin E2 (PGE2), leukotriene B4 (LTB4), interleukin-1β (IL-1β) and tumour necrosis factor-α (TNF-α), important mediators of inflammation and pain. Spa therapy has been found to cause an increase in insulin-like growth factor-1 (IGF1), which stimulates cartilage metabolism, and transforming growth factor-β (TGF-β). There is also evidence of the positive action of mud-packs and thermal baths on the oxidant/antioxidant system, with a reduction in the release of reactive oxygen (ROS) and nitrogen (RNS) species. Overall, thermal stress has an immunosuppressive effect. Many other non-specific factors may also contribute to the beneficial effects observed after spa therapy in some rheumatic diseases, including effects on cardiovascular risk factors, and changes in the environment, pleasant surroundings and the absence of work duties.

  8. How treatment affects the brain: meta-analysis evidence of neural substrates underpinning drug therapy and psychotherapy in major depression.

    Science.gov (United States)

    Boccia, Maddalena; Piccardi, Laura; Guariglia, Paola

    2016-06-01

    The idea that modifications of affect, behavior and cognition produced by psychotherapy are mediated by biological underpinnings predates the advent of the modern neurosciences. Recently, several studies demonstrated that psychotherapy outcomes are linked to modifications in specific brain regions. This opened the debate over the similarities and dissimilarities between psychotherapy and pharmacotherapy. In this study, we used activation likelihood estimation meta-analysis to investigate the effects of psychotherapy (PsyTh) and pharmacotherapy (DrugTh) on brain functioning in Major Depression (MD). Our results demonstrate that the two therapies modify different neural circuits. Specifically, PsyTh induces selective modifications in the left inferior and superior frontal gyri, middle temporal gyrus, lingual gyrus and middle cingulate cortex, as well as in the right middle frontal gyrus and precentral gyrus. Otherwise, DrugTh selectively affected brain activation in the right insula in MD patients. These results are in line with previous evidence of the synergy between psychotherapy and pharmacotherapy but they also demonstrate that the two therapies have different neural underpinnings.

  9. Active vision during action execution, observation and imagery: evidence for shared motor representations.

    Directory of Open Access Journals (Sweden)

    Sheree A McCormick

    Full Text Available The concept of shared motor representations between action execution and various covert conditions has been demonstrated through a number of psychophysiological modalities over the past two decades. Rarely, however, have researchers considered the congruence of physical, imaginary and observed movement markers in a single paradigm and never in a design where eye movement metrics are the markers. In this study, participants were required to perform a forward reach and point Fitts' Task on a digitizing tablet whilst wearing an eye movement system. Gaze metrics were used to compare behaviour congruence between action execution, action observation, and guided and unguided movement imagery conditions. The data showed that participants attended the same task-related visual cues between conditions but the strategy was different. Specifically, the number of fixations was significantly different between action execution and all covert conditions. In addition, fixation duration was congruent between action execution and action observation only, and both conditions displayed an indirect Fitts' Law effect. We therefore extend the understanding of the common motor representation by demonstrating, for the first time, common spatial eye movement metrics across simulation conditions and some specific temporal congruence for action execution and action observation. Our findings suggest that action observation may be an effective technique in supporting motor processes. The use of video as an adjunct to physical techniques may be beneficial in supporting motor planning in both performance and clinical rehabilitation environments.

  10. Neural evidence reveals the rapid effects of reward history on selective attention.

    Science.gov (United States)

    MacLean, Mary H; Giesbrecht, Barry

    2015-05-05

    Selective attention is often framed as being primarily driven by two factors: task-relevance and physical salience. However, factors like selection and reward history, which are neither currently task-relevant nor physically salient, can reliably and persistently influence visual selective attention. The current study investigated the nature of the persistent effects of irrelevant, physically non-salient, reward-associated features. These features affected one of the earliest reliable neural indicators of visual selective attention in humans, the P1 event-related potential, measured one week after the reward associations were learned. However, the effects of reward history were moderated by current task demands. The modulation of visually evoked activity supports the hypothesis that reward history influences the innate salience of reward associated features, such that even when no longer relevant, nor physically salient, these features have a rapid, persistent, and robust effect on early visual selective attention.

  11. Neural correlates of "feeling-of-not-knowing":Evidence from functional MRI

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The neural correlates of "feeling-of-not- knowing" ("FOnK", i.e. the feeling-of-knowing judgments that accurately predicted "not knowing" or "misses" in the criterion test) were investigated by the event-related fMRI method through an RJR (recall-judgment-recognition) procedure that adopted unrelated word pairs as materials. Results revealed that, relative to the inaccurate "FOnK" predictions, the accurate ones were associated with activities in right ventral prefrontal cortex (PFC) and insula, the areas that were known to subserve "cue specification" in which the retrieval cues were converted into "descriptors" that could be used for direct memory search. This result implied that the accurate "FOnK" predictions relayed more on "cue specification" process than the inaccurate ones and was in consistent with the cue familiarity heuristic hypothesis of feeling-of-knowing.

  12. COGNITIVE LEARNING OF INTELLIGENCE SYSTEMS USING NEURAL NETWORKS: EVIDENCE FROM THE AUSTRALIAN CAPITAL MARKETS

    Directory of Open Access Journals (Sweden)

    Joachim Tan

    2002-01-01

    Full Text Available Artificial neural networks (ANNs allow users to improve forecasts through pattern recognition. The purpose of this paper is to validate ANNs as a detection tool in four financial markets. This study investigates whether market inefficiencies exist using ANN as a model. It also investigates whether additional publicly available information can provide investors with a trading advantage. In finance, any forecasting advantage obtained through the use of publicly available information albeit internal or/and external market factors suggest inefficiencies in the financial markets. In this paper, we explore the efficiency of the United States, Japan, Hong Kong and Australia. In Australia, using the ASX 200 index, we demonstrate how the inclusion of external information to our ANN improves our forecasting. Our results show accounting for external market signals significantly improves forecasts of the ASX200 index by an additional 10 percent. This suggests the inclusion of publicly available information from other markets, can improve predictions and returns for investors.

  13. Affirmative Action in Education: Evidence From Engineering College Admissions in India. NBER Working Paper No. 13926

    Science.gov (United States)

    Bertrand, Marianne; Hanna, Rema; Mullainathan, Sendhil

    2008-01-01

    Many countries mandate affirmative action in university admissions for traditionally disadvantaged groups. Little is known about either the efficacy or costs of these programs. This paper examines affirmative action in engineering colleges in India for "lower-caste" groups. We find that it successfully targets the financially…

  14. Pupillometric evidence for the locus coeruleus-noradrenaline system facilitating attentional processing of action-triggered visual stimuli

    Directory of Open Access Journals (Sweden)

    Ken eKihara

    2015-06-01

    Full Text Available It has been argued that attentional processing of visual stimuli is facilitated by a voluntary action that triggers the stimulus onset. However, the relationship between action-induced facilitation of attention and the neural substrates has not been well established. The present study investigated whether the locus coeruleus-noradrenaline (LC-NA system is involved in this facilitation effect. A rapid serial visual presentation paradigm was used to assess the dynamics of transient attention in humans. Participants were instructed to change a digit stream to a letter stream by pressing a button and specifying successive targets of four letters. Pupil dilation was measured as an index of LC-NA function. Accuracy of target identification was better when the temporal delay between participants' key press and target onset was 800 ms than when targets appeared just after the key press or when targets appeared without key press. Accuracy of target identification was positively correlated with both the peak amplitude of pupil dilation and the pupil size at the time of the key press. These results indicate that target identification in the visual task is closely linked to pupil dilation. We conclude that the LC-NA system plays an important role in the facilitation of transient attention driven by voluntary action.

  15. Pupillometric evidence for the locus coeruleus-noradrenaline system facilitating attentional processing of action-triggered visual stimuli.

    Science.gov (United States)

    Kihara, Ken; Takeuchi, Tatsuto; Yoshimoto, Sanae; Kondo, Hirohito M; Kawahara, Jun I

    2015-01-01

    It has been argued that attentional processing of visual stimuli is facilitated by a voluntary action that triggers the stimulus onset. However, the relationship between action-induced facilitation of attention and the neural substrates has not been well established. The present study investigated whether the locus coeruleus-noradrenaline (LC-NA) system is involved in this facilitation effect. A rapid serial visual presentation paradigm was used to assess the dynamics of transient attention in humans. Participants were instructed to change a digit stream to a letter stream by pressing a button and specifying successive targets of four letters. Pupil dilation was measured as an index of LC-NA function. Accuracy of target identification was better when the temporal delay between participants' key press and target onset was 800 ms than when targets appeared just after the key press or when targets appeared without key press. Accuracy of target identification was positively correlated with both the peak amplitude of pupil dilation and the pupil size at the time of the key press. These results indicate that target identification in the visual task is closely linked to pupil dilation. We conclude that the LC-NA system plays an important role in the facilitation of transient attention driven by voluntary action.

  16. Transfer of training from one working memory task to another: Behavioural and neural evidence

    Directory of Open Access Journals (Sweden)

    Erin L. Beatty

    2015-06-01

    Full Text Available N-back working memory (WM tasks necessitate the maintenance and updating of dynamic rehearsal sets during performance. The delayed matching-to-sample (dMTS task is another WM task, which in turn involves the encoding, maintenance, and retrieval of stimulus representations in sequential order. Because both n-back and dMTS engage WM function, we hypothesized that compared to a control task not taxing WM, training on the n-back task would be associated with better performance on dMTS by virtue of training a shared mental capacity. We tested this hypothesis by randomly assigning subjects (N = 43 to train on either the n-back (including 2-back and 3-back levels or an active control task. Following training, dMTS was administered in the fMRI scanner. The n-back group performed marginally better than the active control group on dMTS. In addition, although the n-back group improved more on the less difficult 2-back level than the more difficult 3-back level across training sessions, it was improvement on the 3-back level that accounted for 21% of the variance in dMTS performance. For the control group, improvement in training across sessions was unrelated to dMTS performance. At the neural level, greater activation in the left inferior frontal gyrus, right posterior parietal cortex and the cerebellum distinguished the n-back group from the control group in the maintenance phase of dMTS. Degree of improvement on the 3-back level across training sessions was correlated with activation in right lateral prefrontal and motor cortices in the maintenance phase of dMTS. Our results suggest that although n-back training is more likely to improve performance in easier blocks, it is improvement in more difficult blocks that is predictive of performance on a target task drawing on WM. In addition, the extent to which training on a task can transfer to another task is likely due to the engagement of shared cognitive capacities and underlying neural substrates

  17. Dopaminergic modulation of positive expectations for goal-directed action: evidence from Parkinson’s disease

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    Noham eWolpe

    2015-10-01

    Full Text Available Parkinson’s disease (PD impairs the control of movement and cognition, including the planning of action and its consequences. This provides the opportunity to study the dopaminergic influences on the perception and awareness of action. Here we examined the perception of the outcome of a goal-directed action made by medicated patients with PD. A visuomotor task probed the integration of sensorimotor signals with the positive expectations of outcomes (Self priors, which in healthy adults bias perception towards success in proportion to trait optimism. We tested the hypotheses that (i the priors on the perception of the consequences of one’s own actions differ between patients and age- and sex-matched controls, and (ii that these priors are modulated by the levodopa dose equivalent in patients. There was no overall difference between patients and controls in the perceptual priors used. However, the precision of patient priors was inversely related to their levodopa dose equivalent. Patients with high levodopa dose equivalent showed more accurate priors, representing predictions that were closer to the true distribution of performance. Such accuracy has previously been demonstrated when observing the actions of others, suggesting abnormal awareness of action in these patients. These results confirm a link between dopamine and the positive expectation of the outcome of one’s own actions, and may have implications for the management of PD.

  18. Prevention and control of noncommunicable diseases through evidence-based public health: implementing the NCD 2020 action plan.

    Science.gov (United States)

    Diem, Günter; Brownson, Ross C; Grabauskas, Vilius; Shatchkute, Aushra; Stachenko, Sylvie

    2016-09-01

    The control of noncommunicable diseases (NCDs) was addressed by the declaration of the 66th United Nations (UN) General Assembly followed by the World Health Organization's (WHO) NCD 2020 action plan. There is a clear need to better apply evidence in public health settings to tackle both behaviour-related factors and the underlying social and economic conditions. This article describes concepts of evidence-based public health (EBPH) and outlines a set of actions that are essential for successful global NCD prevention. The authors describe the importance of knowledge translation with the goal of increasing the effectiveness of public health services, relying on both quantitative and qualitative evidence. In particular, the role of capacity building is highlighted because it is fundamental to progress in controlling NCDs. Important challenges for capacity building include the need to bridge diverse disciplines, build the evidence base across countries and the lack of formal training in public health sciences. As brief case examples, several successful capacity-building efforts are highlighted to address challenges and further evidence-based decision making. The need for a more comprehensive public health approach, addressing social, environmental and cultural conditions, has led to government-wide and society-wide strategies that are now on the agenda due to efforts such as the WHO's NCD 2020 action plan and Health 2020: the European Policy for Health and Wellbeing. These efforts need research to generate evidence in new areas (e.g. equity and sustainability), training to build public health capacity and a continuous process of improvement and knowledge generation and translation.

  19. Neural evidence of allophonic perception in children at risk for dyslexia.

    Science.gov (United States)

    Noordenbos, M W; Segers, E; Serniclaes, W; Mitterer, H; Verhoeven, L

    2012-07-01

    Learning to read is a complex process that develops normally in the majority of children and requires the mapping of graphemes to their corresponding phonemes. Problems with the mapping process nevertheless occur in about 5% of the population and are typically attributed to poor phonological representations, which are--in turn--attributed to underlying speech processing difficulties. We examined auditory discrimination of speech sounds in 6-year-old beginning readers with a familial risk of dyslexia (n=31) and no such risk (n=30) using the mismatch negativity (MMN). MMNs were recorded for stimuli belonging to either the same phoneme category (acoustic variants of /bə/) or different phoneme categories (/bə/ vs. /də/). Stimuli from different phoneme categories elicited MMNs in both the control and at-risk children, but the MMN amplitude was clearly lower in the at-risk children. In contrast, the stimuli from the same phoneme category elicited an MMN in only the children at risk for dyslexia. These results show children at risk for dyslexia to be sensitive to acoustic properties that are irrelevant in their language. Our findings thus suggest a possible cause of dyslexia in that they show 6-year-old beginning readers with at least one parent diagnosed with dyslexia to have a neural sensitivity to speech contrasts that are irrelevant in the ambient language. This sensitivity clearly hampers the development of stable phonological representations and thus leads to significant reading impairment later in life.

  20. Neural signatures of third-party punishment: evidence from penetrating traumatic brain injury.

    Science.gov (United States)

    Glass, Leila; Moody, Lara; Grafman, Jordan; Krueger, Frank

    2016-02-01

    The ability to survive within a cooperative society depends on impartial third-party punishment (TPP) of social norm violations. Two cognitive mechanisms have been postulated as necessary for the successful completion of TPP: evaluation of legal responsibility and selection of a suitable punishment given the magnitude of the crime. Converging neuroimaging research suggests two supporting domain-general networks; a mentalizing network for evaluation of legal responsibility and a central-executive network for determination of punishment. A whole-brain voxel-based lesion-symptom mapping approach was used in conjunction with a rank-order TPP task to identify brain regions necessary for TPP in a large sample of patients with penetrating traumatic brain injury. Patients who demonstrated atypical TPP had specific lesions in core regions of the mentalizing (dorsomedial prefrontal cortex [PFC], ventromedial PFC) and central-executive (bilateral dorsolateral PFC, right intraparietal sulcus) networks. Altruism and executive functioning (concept formation skills) were significant predictors of TPP: altruism was uniquely associated with TPP in patients with lesions in right dorsolateral PFC and executive functioning was uniquely associated with TPP in individuals with lesions in left PFC. Our findings contribute to the extant literature to support underlying neural networks associated with TPP, with specific brain-behavior causal relationships confirming recent functional neuroimaging research.

  1. Neural Bases of Unconscious Error Detection in a Chinese Anagram Solution Task: Evidence from ERP Study.

    Directory of Open Access Journals (Sweden)

    Hua-Zhan Yin

    Full Text Available In everyday life, error monitoring and processing are important for improving ongoing performance in response to a changing environment. However, detecting an error is not always a conscious process. The temporal activation patterns of brain areas related to cognitive control in the absence of conscious awareness of an error remain unknown. In the present study, event-related potentials (ERPs in the brain were used to explore the neural bases of unconscious error detection when subjects solved a Chinese anagram task. Our ERP data showed that the unconscious error detection (UED response elicited a more negative ERP component (N2 than did no error (NE and detect error (DE responses in the 300-400-ms time window, and the DE elicited a greater late positive component (LPC than did the UED and NE in the 900-1200-ms time window after the onset of the anagram stimuli. Taken together with the results of dipole source analysis, the N2 (anterior cingulate cortex might reflect unconscious/automatic conflict monitoring, and the LPC (superior/medial frontal gyrus might reflect conscious error recognition.

  2. The price of your soul: neural evidence for the non-utilitarian representation of sacred values.

    Science.gov (United States)

    Berns, Gregory S; Bell, Emily; Capra, C Monica; Prietula, Michael J; Moore, Sara; Anderson, Brittany; Ginges, Jeremy; Atran, Scott

    2012-03-05

    Sacred values, such as those associated with religious or ethnic identity, underlie many important individual and group decisions in life, and individuals typically resist attempts to trade off their sacred values in exchange for material benefits. Deontological theory suggests that sacred values are processed based on rights and wrongs irrespective of outcomes, while utilitarian theory suggests that they are processed based on costs and benefits of potential outcomes, but which mode of processing an individual naturally uses is unknown. The study of decisions over sacred values is difficult because outcomes cannot typically be realized in a laboratory, and hence little is known about the neural representation and processing of sacred values. We used an experimental paradigm that used integrity as a proxy for sacredness and which paid real money to induce individuals to sell their personal values. Using functional magnetic resonance imaging (fMRI), we found that values that people refused to sell (sacred values) were associated with increased activity in the left temporoparietal junction and ventrolateral prefrontal cortex, regions previously associated with semantic rule retrieval. This suggests that sacred values affect behaviour through the retrieval and processing of deontic rules and not through a utilitarian evaluation of costs and benefits.

  3. Motor-related brain activity during action observation: a neural substrate for electrocorticographic brain-computer interfaces after spinal cord injury

    Directory of Open Access Journals (Sweden)

    Jennifer L Collinger

    2014-02-01

    Full Text Available After spinal cord injury (SCI, motor commands from the brain are unable to reach peripheral nerves and muscles below the level of the lesion. Action observation, in which a person observes someone else performing an action, has been used to augment traditional rehabilitation paradigms. Similarly, action observation can be used to derive the relationship between brain activity and movement kinematics for a motor-based brain-computer interface (BCI even when the user cannot generate overt movements. BCIs use brain signals to control external devices to replace functions that have been lost due to SCI or other motor impairment. Previous studies have reported congruent motor cortical activity during observed and overt movements using magnetoencephalography (MEG and functional magnetic resonance imaging (fMRI. Recent single-unit studies using intracortical microelectrodes also demonstrated that a large number of motor cortical neurons had similar firing rate patterns between overt and observed movements. Given the increasing interest in electrocorticography (ECoG-based BCIs, our goal was to identify whether action observation-related cortical activity could be recorded using ECoG during grasping tasks. Specifically, we aimed to identify congruent neural activity during observed and executed movements in both the sensorimotor rhythm (10-40 Hz and the high-gamma band (65-115 Hz which contains significant movement-related information. We observed significant motor-related high-gamma band activity during action observation in both able-bodied individuals and one participant with a complete C4 SCI. Furthermore, in able-bodied participants, both the low and high frequency bands demonstrated congruent activity between action execution and observation. Our results suggest that action observation could be an effective and critical procedure for deriving the mapping from ECoG signals to intended movement for an ECoG-based BCI system for individuals with

  4. The functional neuroanatomy of actions.

    Science.gov (United States)

    Watson, Christine E; Chatterjee, Anjan

    2011-04-19

    Our current understanding of the neural basis of semantic memory is informed primarily by studies of concrete objects. However, conceptual knowledge encompasses many other, albeit less concrete, domains. This article reviews evidence from neuroimaging and patient studies that speaks to the neural basis of action concepts and the words that refer to them. These data highlight 2 important principles governing the neural instantiation of semantic knowledge. First, the organization of conceptual representations in the brain parallels perception and action. Action concepts are at least partially represented within modality-specific areas responsible for the perception and execution of dynamic actions. Second, unimodal sensory and motor cortices act as "points of entry" for more abstract action knowledge. Increasingly abstract conceptual knowledge derived from these modalities is represented in brain areas located anterior and centripetal to modality-specific regions. Extending research on the neural basis of semantics to include dynamic and relational aspects of the world gives us a more complete appreciation of the range of cognitive and communication impairments that may be experienced by patients with neurologic disease.

  5. Health inequity in people with intellectual disabilities: from evidence to action applying an appreciative inquiry approach

    NARCIS (Netherlands)

    Naaldenberg, J.; Banks, R.; Lennox, N.; Ouellette-Kunz, H.; Meijer, M.; Schrojenstein Lantman, H.M. van

    2015-01-01

    BACKGROUND: The current understanding of health inequities in people with intellectual disabilities does not readily translate into improvements in health status or health care. To identify opportunities for action, the 2013 IASSIDD health SIRG conference organized ten intensive workshops. MATERIALS

  6. Three speech sounds, one motor action: Evidence for speech-motor disparity from English flap production

    OpenAIRE

    Derrick, Donald; Stavness, Ian; Gick, Bryan

    2015-01-01

    The assumption that units of speech production bear a one-to-one relationship to speech motor actions pervades otherwise widely varying theories of speech motor behavior. This speech production and simulation study demonstrates that commonly occurring flap sequences may violate this assumption. In the word “Saturday,” a sequence of three sounds may be produced using a single, cyclic motor action. Under this view, the initial upward tongue tip motion, starting with the first vowel and moving t...

  7. Neural and muscular control functions of the gut in odontocetes: morphologic evidence in beaked whales and beluga whales.

    Science.gov (United States)

    Pfeiffer, C J

    1993-01-01

    The present data provide some new and unique, gastrointestinal morphologic findings in two species of toothed whales, the Cuvier's beaked whale (Ziphius cavirostris) and the beluga or white whale (Delphinapterus leucas), which are discussed relative to their atypical feeding behavior and alimentary tract functions. Specifically, the findings show myenteric neural modifications and muscularis externa structural specializations which may support voluntary and involuntary fore- and hindgut behavior. Histologic evidence of intercalation-like striations in the gastric and colonic musculature was discovered, as well as an unusual massive size of the colonic myenteric plexuses. These observations, which are not evident in terrestrial mammalian gastrointestinal tracts, may help explain the unusual upper gastrointestinal tract motility such as ingestion-by-sucking in the absence of prehensile teeth and processing of ingesta in a multi-compartmentalized pyloric stomach. Further, the hindgut modifications may help explain the animal's acute, rectal discharge escape mechanism, likened to squid inking, which seems to be an evolved function of some cetaceans.

  8. Neural bases of falsification in conditional proposition testing: evidence from an fMRI study.

    Science.gov (United States)

    Liu, Jimei; Zhang, Meng; Jou, Jerwen; Wu, Xin; Li, Wei; Qiu, Jiang

    2012-08-01

    The ability of testing the validity of a conditional statement is important in our everyday life. However, the brain mechanisms underlying this process, especially falsification process which is important in daily life, but especially crucial to scientific reasoning and research is not as yet completely clear. Therefore, in the present study, we used event-related functional magnetic resonance imaging (fMRI) to examine the neural bases of the falsification process in testing the validity of a conditional statement as used in Wason's (1966) selection task. Our fMRI results showed that: (1) compared with the baseline condition, both Falsification (by using Modus Ponens, and Modus Tollens) and Non-Falsification conditions (affirming the consequent, and denying the antecedent) activated the left frontal areas (BA44/45, or BA6), and basal ganglia, the areas previously found in the rule-guided conditional reasoning operations; the parietal area (BA40, BA7) for recruiting cognitive resources to represent and maintain the different evidential information in working memory. (2) The left middle frontal gyrus (BA9) and cerebellum were shown to be activated in the contrast of Falsification condition versus Non-Falsification condition and in the contrast of MT versus Non-Falsification condition. These results indicated that the left middle frontal gyrus (BA9) might be the key brain region involved in the falsification process of conditional statement for which abstracting and integrating logical relationships, and inhibiting the distraction of the irrelevant information were the essential processes. Moreover, the cerebellum was found to be responsible for constructing an internal working model. In addition, our brain imaging results might support the dual-process theory of reasoning.

  9. The modulating effect of personality traits on neural error monitoring: evidence from event-related FMRI.

    Science.gov (United States)

    Sosic-Vasic, Zrinka; Ulrich, Martin; Ruchsow, Martin; Vasic, Nenad; Grön, Georg

    2012-01-01

    The present study investigated the association between traits of the Five Factor Model of Personality (Neuroticism, Extraversion, Openness for Experiences, Agreeableness, and Conscientiousness) and neural correlates of error monitoring obtained from a combined Eriksen-Flanker-Go/NoGo task during event-related functional magnetic resonance imaging in 27 healthy subjects. Individual expressions of personality traits were measured using the NEO-PI-R questionnaire. Conscientiousness correlated positively with error signaling in the left inferior frontal gyrus and adjacent anterior insula (IFG/aI). A second strong positive correlation was observed in the anterior cingulate gyrus (ACC). Neuroticism was negatively correlated with error signaling in the inferior frontal cortex possibly reflecting the negative inter-correlation between both scales observed on the behavioral level. Under present statistical thresholds no significant results were obtained for remaining scales. Aligning the personality trait of Conscientiousness with task accomplishment striving behavior the correlation in the left IFG/aI possibly reflects an inter-individually different involvement whenever task-set related memory representations are violated by the occurrence of errors. The strong correlations in the ACC may indicate that more conscientious subjects were stronger affected by these violations of a given task-set expressed by individually different, negatively valenced signals conveyed by the ACC upon occurrence of an error. Present results illustrate that for predicting individual responses to errors underlying personality traits should be taken into account and also lend external validity to the personality trait approach suggesting that personality constructs do reflect more than mere descriptive taxonomies.

  10. The modulating effect of personality traits on neural error monitoring: evidence from event-related FMRI.

    Directory of Open Access Journals (Sweden)

    Zrinka Sosic-Vasic

    Full Text Available The present study investigated the association between traits of the Five Factor Model of Personality (Neuroticism, Extraversion, Openness for Experiences, Agreeableness, and Conscientiousness and neural correlates of error monitoring obtained from a combined Eriksen-Flanker-Go/NoGo task during event-related functional magnetic resonance imaging in 27 healthy subjects. Individual expressions of personality traits were measured using the NEO-PI-R questionnaire. Conscientiousness correlated positively with error signaling in the left inferior frontal gyrus and adjacent anterior insula (IFG/aI. A second strong positive correlation was observed in the anterior cingulate gyrus (ACC. Neuroticism was negatively correlated with error signaling in the inferior frontal cortex possibly reflecting the negative inter-correlation between both scales observed on the behavioral level. Under present statistical thresholds no significant results were obtained for remaining scales. Aligning the personality trait of Conscientiousness with task accomplishment striving behavior the correlation in the left IFG/aI possibly reflects an inter-individually different involvement whenever task-set related memory representations are violated by the occurrence of errors. The strong correlations in the ACC may indicate that more conscientious subjects were stronger affected by these violations of a given task-set expressed by individually different, negatively valenced signals conveyed by the ACC upon occurrence of an error. Present results illustrate that for predicting individual responses to errors underlying personality traits should be taken into account and also lend external validity to the personality trait approach suggesting that personality constructs do reflect more than mere descriptive taxonomies.

  11. Dissociation between Semantic Representations for Motion and Action Verbs: Evidence from Patients with Left Hemisphere Lesions

    Science.gov (United States)

    Taylor, Lawrence J.; Evans, Carys; Greer, Joanna; Senior, Carl; Coventry, Kenny R.; Ietswaart, Magdalena

    2017-01-01

    This multiple single case study contrasted left hemisphere stroke patients (N = 6) to healthy age-matched control participants (N = 15) on their understanding of action (e.g., holding, clenching) and motion verbs (e.g., crumbling, flowing). The tasks required participants to correctly identify the matching verb or associated picture. Dissociations on action and motion verb content depending on lesion site were expected. As predicted for verbs containing an action and/or motion content, modified t-tests confirmed selective deficits in processing motion verbs in patients with lesions involving posterior parietal and lateral occipitotemporal cortex. In contrast, deficits in verbs describing motionless actions were found in patients with more anterior lesions sparing posterior parietal and lateral occipitotemporal cortex. These findings support the hypotheses that semantic representations for action and motion are behaviorally and neuro-anatomically dissociable. The findings clarify the differential and critical role of perceptual and motor regions in processing modality-specific semantic knowledge as opposed to a supportive but not necessary role. We contextualize these results within theories from both cognitive psychology and cognitive neuroscience that make claims over the role of sensory and motor information in semantic representation. PMID:28261070

  12. Dissociation between Semantic Representations for Motion and Action Verbs: Evidence from Patients with Left Hemisphere Lesions.

    Science.gov (United States)

    Taylor, Lawrence J; Evans, Carys; Greer, Joanna; Senior, Carl; Coventry, Kenny R; Ietswaart, Magdalena

    2017-01-01

    This multiple single case study contrasted left hemisphere stroke patients (N = 6) to healthy age-matched control participants (N = 15) on their understanding of action (e.g., holding, clenching) and motion verbs (e.g., crumbling, flowing). The tasks required participants to correctly identify the matching verb or associated picture. Dissociations on action and motion verb content depending on lesion site were expected. As predicted for verbs containing an action and/or motion content, modified t-tests confirmed selective deficits in processing motion verbs in patients with lesions involving posterior parietal and lateral occipitotemporal cortex. In contrast, deficits in verbs describing motionless actions were found in patients with more anterior lesions sparing posterior parietal and lateral occipitotemporal cortex. These findings support the hypotheses that semantic representations for action and motion are behaviorally and neuro-anatomically dissociable. The findings clarify the differential and critical role of perceptual and motor regions in processing modality-specific semantic knowledge as opposed to a supportive but not necessary role. We contextualize these results within theories from both cognitive psychology and cognitive neuroscience that make claims over the role of sensory and motor information in semantic representation.

  13. Nucleus accumbens is involved in human action monitoring: evidence from invasive electrophysiological recordings

    Directory of Open Access Journals (Sweden)

    Thomas F Münte

    2008-03-01

    Full Text Available The Nucleus accumbens (Nacc has been proposed to act as a limbic-motor interface. Here, using invasive intraoperative recordings in an awake patient suffering from obsessive-compulsive disease (OCD, we demonstrate that its activity is modulated by the quality of performance of the subject in a choice reaction time task designed to tap action monitoring processes. Action monitoring, that is, error detection and correction, is thought to be supported by a system involving the dopaminergic midbrain, the basal ganglia, and the medial prefrontal cortex. In surface electrophysiological recordings, action monitoring is indexed by an error-related negativity (ERN appearing time-locked to the erroneous responses and emanating from the medial frontal cortex. In preoperative scalp recordings the patient's ERN was found to be signifi cantly increased compared to a large (n= 83 normal sample, suggesting enhanced action monitoring processes. Intraoperatively, error-related modulations were obtained from the Nacc but not from a site 5 mm above. Importantly, crosscorrelation analysis showed that error-related activity in the Nacc preceded surface activity by 40 ms. We propose that the Nacc is involved in action monitoring, possibly by using error signals from the dopaminergic midbrain to adjust the relative impact of limbic and prefrontal inputs on frontal control systems in order to optimize goal-directed behavior.

  14. Neural Correlates of Action Observation and Execution in 14-Month-Old Infants: An Event-Related EEG Desynchronization Study

    Science.gov (United States)

    Marshall, Peter J.; Young, Thomas; Meltzoff, Andrew N.

    2011-01-01

    There is increasing interest in neurobiological methods for investigating the shared representation of action perception and production in early development. We explored the extent and regional specificity of EEG desynchronization in the infant alpha frequency range (6-9 Hz) during action observation and execution in 14-month-old infants.…

  15. "Comments on Slavin": Synthesizing Evidence from Impact Evaluations in Education to Inform Action

    Science.gov (United States)

    Chatterji, Madhabi

    2008-01-01

    Traditional methods for preparing systematic reviews and syntheses of effectiveness studies rely on a limited set of methodological criteria to include studies that measure and report effects too narrowly to forward the mission of evidence-based practice. This article discusses why and how the criteria for study selection, evidence screening, and…

  16. Anticipatory affect during action preparation: evidence from backward compatibility in dual-task performance.

    Science.gov (United States)

    Eder, Andreas B; Pfister, Roland; Dignath, David; Hommel, Bernhard

    2016-07-14

    Upcoming responses in the second of two subsequently performed tasks can speed up compatible responses in the temporally preceding first task. Two experiments extend previous demonstration of such backward compatibility to affective features: responses to affective stimuli were faster in Task 1 when an affectively compatible response effect was anticipated for Task 2. This emotional backward-compatibility effect demonstrates that representations of the affective consequences of the Task 2 response were activated before the selection of a response in Task 1 was completed. This finding is problematic for the assumption of a serial stimulus-response translation stage. It also shows that the affective consequence of a response is anticipated during, and has an impact on stimulus-response translation, which implies that action planning considers codes representing and predicting the emotional consequences of actions. Implications for the control of emotional actions are discussed.

  17. Evidence of involvement of central neural mechanisms in generating fibromyalgia pain.

    Science.gov (United States)

    Staud, Roland

    2002-08-01

    Fibromyalgia syndrome (FMS) is characterized by widespread pain, fatigue, sleep abnormalities, and distress. Because FMS lacks consistent evidence of tissue abnormalities, recent investigations have focused on central nervous system mechanisms of pain. Abnormal temporal summation of second pain (wind-up) and central sensitization have been described recently in patients with FMS. Wind-up and central sensitization, which rely on central pain mechanisms, occur after prolonged C-nociceptor input and depend on activation of nociceptor-specific neurons and wide dynamic range neurons in the dorsal horn of the spinal cord. Other abnormal central pain mechanisms recently detected in patients with FMS include diffuse noxious inhibitory controls. These pain inhibitory mechanisms rely on spinal cord and supraspinal systems involving pain facilitatory and pain inhibitory pathways. Brain-imaging techniques that can detect neuronal activation after nociceptive stimuli have provided additional evidence for abnormal central pain mechanisms in FMS. Brain images have corroborated the augmented reported pain experience of patients with fibromyalgia during experimental pain stimuli. In addition, thalamic activity, which contributes significantly to pain processing, was decreased in fibromyalgia. However, central pain mechanisms of fibromyalgia may not depend exclusively on neuronal activation. Neuroglial activation has been found to play an important role in the induction and maintenance of chronic pain. These findings may have important implications for future research and the treatment of fibromyalgia pain.

  18. Interactive actions of Bdnf methylation and cell metabolism for building neural resilience under the influence of diet

    OpenAIRE

    Tyagi, Ethika; Zhuang, Yumei; Agrawal, Rahul; Ying, Zhe; Gomez-Pinilla, Fernando

    2014-01-01

    Quality nutrition during the period of brain formation is a predictor of brain functional capacity and plasticity during adulthood; however it is not clear how this conferred plasticity imparts long-term neural resilience. Here we report that early exposure to dietary omega-3 fatty acids orchestrates key interactions between metabolic signals and Bdnf methylation creating a reservoir of neuroplasticity that can protect the brain against the deleterious effects of switching to a western diet (...

  19. The Theory of Reasoned Action and Self-Construal: Evidence from Three Cultures.

    Science.gov (United States)

    Park, Hee Sun; Levine, Timothy R.

    1999-01-01

    Investigates the effects of self-construals on the attitudinal and normative components of the Theory of Reasoned Action in the cultures of Korea, Hawaii, and the mainland United States. Finds that undergraduate students in all three locations scored higher on independence than interdependence, and culture appears to affect the extent to which…

  20. Do Affirmative Action Bans Lower Minority College Enrollment and Attainment?: Evidence from Statewide Bans

    Science.gov (United States)

    Backes, Ben

    2012-01-01

    Using institutional data on race-specific college enrollment and completion, I examine whether minority students were less likely to enroll in a four-year public college or receive a degree following a statewide affirmative action ban. As in previous studies, I find that black and Hispanic enrollment dropped at the top institutions; however, there…

  1. Object manipulation and motion perception: Evidence of an influence of action planning on visual processing

    NARCIS (Netherlands)

    Lindemann, O.; Bekkering, H.

    2009-01-01

    In 3 experiments, the authors investigated the bidirectional coupling of perception and action in the context of object manipulations and motion perception. Participants prepared to grasp an X-shaped object along one of its 2 diagonals and to rotate it in a clockwise or a counterclockwise direction.

  2. UN Global Action Programme and Education for Sustainable Development: A Critical Appraisal of the Evidence Base

    Science.gov (United States)

    Fischer, Daniel; Aubrecht, Elisabeth Lena; Brück, Maria; Ditges, Laura; Gathen, Lea; Jahns, Maximilian; Petersmann, Moritz; Rau, Jörn; Wellmann, Christiane

    2015-01-01

    The United Nations (UN) proclaimed the years 2005 to 2014 the World Decade on Education for Sustainable Development (ESD). As a follow up on the World Decade, the UN launched a Global Action Programme (GAP) that is designed to set the framework for international activities on ESD. The GAP focuses on five priority areas that are of high relevance…

  3. Discovering the dementia evidence base: Tools to support knowledge to action in dementia care (innovative practice).

    Science.gov (United States)

    Hayman, Sarah L; Tieman, Jennifer J

    2016-09-01

    Dementia requires expert care and decision making, based on sound evidence. Reliable evidence is difficult for busy dementia care professionals to find quickly. This study developed an experimentally tested search filter as an innovative tool to retrieve literature on dementia. It has a known retrieval performance and can be provided as an open access web link directly to current literature. The Dementia Search Filter was developed using validated methodology. An Expert Advisory Group of dementia care practitioners and researchers ratified a representative set of relevant studies and undertook post hoc relevance assessment, to ensure the usefulness of the search filter. The Dementia Search Filter is published on two websites and combined with expert searches to link to evidence on dementia, at end of life in aged care settings and more generally. Evidence accessed by the Dementia Search Filter will help overcome barriers to finding current relevant research in the field, for practitioners, researchers and decision makers.

  4. Simulating the 'other-race' effect with autoassociative neural networks: further evidence in favor of the face-space model.

    Science.gov (United States)

    Caldara, Roberto; Hervé, Abdi

    2006-01-01

    Other-race (OR) faces are less accurately recognized than same-race (SR) faces, but faster classified by race. This phenomenon has often been reported as the 'other-race' effect (ORE). Valentine (1991 Quarterly Journal of Experimental Psychology A: Human Experimental Psychology 43 161-204) proposed a theoretical multidimensional face-space model that explained both of these results, in terms of variations in exemplar density between races. According to this model, SR faces are more widely distributed across the dimensions of the space than OR faces. However, this model does not quantify nor state the dimensions coded within this face space. The aim of the present study was to test the face-space explanation of the ORE with neural network simulations by quantifying its dimensions. We found the predicted density properties of Valentine's framework in the face-projection spaces of the autoassociative memories. This was supported by an interaction for exemplar density between the race of the learned face set and the race of the faces. In addition, the elaborated face representations showed optimal responses for SR but not for OR faces within SR face spaces when explored at the individual level, as gender errors occurred significantly more often in OR than in SR face-space representations. Altogether, our results add further evidence in favor of a statistical exemplar density explanation of the ORE as suggested by Valentine, and question the plausibility of such coding for faces in the framework of recent neuroimaging studies.

  5. The Physics of Decision Making:. Stochastic Differential Equations as Models for Neural Dynamics and Evidence Accumulation in Cortical Circuits

    Science.gov (United States)

    Holmes, Philip; Eckhoff, Philip; Wong-Lin, K. F.; Bogacz, Rafal; Zacksenhouse, Miriam; Cohen, Jonathan D.

    2010-03-01

    We describe how drift-diffusion (DD) processes - systems familiar in physics - can be used to model evidence accumulation and decision-making in two-alternative, forced choice tasks. We sketch the derivation of these stochastic differential equations from biophysically-detailed models of spiking neurons. DD processes are also continuum limits of the sequential probability ratio test and are therefore optimal in the sense that they deliver decisions of specified accuracy in the shortest possible time. This leaves open the critical balance of accuracy and speed. Using the DD model, we derive a speed-accuracy tradeoff that optimizes reward rate for a simple perceptual decision task, compare human performance with this benchmark, and discuss possible reasons for prevalent sub-optimality, focussing on the question of uncertain estimates of key parameters. We present an alternative theory of robust decisions that allows for uncertainty, and show that its predictions provide better fits to experimental data than a more prevalent account that emphasises a commitment to accuracy. The article illustrates how mathematical models can illuminate the neural basis of cognitive processes.

  6. Economic evidence on identifying clinically actionable findings with whole-genome sequencing: a scoping review.

    OpenAIRE

    2016-01-01

    The American College of Medical Genetics and Genomics (ACMG) recommends that mutations in 56 genes for 24 conditions are clinically actionable and should be reported as secondary findings after whole-genome sequencing (WGS). Our aim was to identify published economic evaluations of detecting mutations in these genes among the general population or among targeted/high-risk populations and conditions and identify gaps in knowledge. A targeted PubMed search from 1994 through November 2014 was pe...

  7. The real-time link between person perception and action: brain potential evidence for dynamic continuity.

    Science.gov (United States)

    Freeman, Jonathan B; Ambady, Nalini; Midgley, Katherine J; Holcomb, Phillip J

    2011-01-01

    Using event-related potentials, we investigated how the brain extracts information from another's face and translates it into relevant action in real time. In Study 1, participants made between-hand sex categorizations of sex-typical and sex-atypical faces. Sex-atypical faces evoked negativity between 250 and 550 ms (N300/N400 effects), reflecting the integration of accumulating sex-category knowledge into a coherent sex-category interpretation. Additionally, the lateralized readiness potential revealed that the motor cortex began preparing for a correct hand response while social category knowledge was still gradually evolving in parallel. In Study 2, participants made between-hand eye-color categorizations as part of go/no-go trials that were contingent on a target's sex. On no-go trials, although the hand did not actually move, information about eye color partially prepared the motor cortex to move the hand before perception of sex had finalized. Together, these findings demonstrate the dynamic continuity between person perception and action, such that ongoing results from face processing are immediately and continuously cascaded into the motor system over time. The preparation of action begins based on tentative perceptions of another's face before perceivers have finished interpreting what they just saw.

  8. Neural evidence for competition-mediated suppression in the perception of a single object.

    Science.gov (United States)

    Cacciamani, Laura; Scalf, Paige E; Peterson, Mary A

    2015-11-01

    Multiple objects compete for representation in visual cortex. Competition may also underlie the perception of a single object. Computational models implement object perception as competition between units on opposite sides of a border. The border is assigned to the winning side, which is perceived as an object (or "figure"), whereas the other side is perceived as a shapeless ground. Behavioral experiments suggest that the ground is inhibited to a degree that depends on the extent to which it competed for object status, and that this inhibition is relayed to low-level brain areas. Here, we used fMRI to assess activation for ground regions of task-irrelevant novel silhouettes presented in the left or right visual field (LVF or RVF) while participants performed a difficult task at fixation. Silhouettes were designed so that the insides would win the competition for object status. The outsides (grounds) suggested portions of familiar objects in half of the silhouettes and novel objects in the other half. Because matches to object memories affect the competition, these two types of silhouettes operationalized, respectively, high competition and low competition from the grounds. The results showed that activation corresponding to ground regions was reduced for high- versus low-competition silhouettes in V4, where receptive fields (RFs) are large enough to encompass the familiar objects in the grounds, and in V1/V2, where RFs are much smaller. These results support a theory of object perception involving competition-mediated ground suppression and feedback from higher to lower levels. This pattern of results was observed in the left hemisphere (RVF), but not in the right hemisphere (LVF). One explanation of the lateralized findings is that task-irrelevant silhouettes in the RVF captured attention, allowing us to observe these effects, whereas those in the LVF did not. Experiment 2 provided preliminary behavioral evidence consistent with this possibility.

  9. Working memory encoding and maintenance deficits in schizophrenia: neural evidence for activation and deactivation abnormalities.

    Science.gov (United States)

    Anticevic, Alan; Repovs, Grega; Barch, Deanna M

    2013-01-01

    Substantial evidence implicates working memory (WM) as a core deficit in schizophrenia (SCZ), purportedly due to primary deficits in dorsolateral prefrontal cortex functioning. Recent findings suggest that SCZ is also associated with abnormalities in suppression of certain regions during cognitive engagement--namely the default mode system--that may further contribute to WM pathology. However, no study has systematically examined activation and suppression abnormalities across both encoding and maintenance phases of WM in SCZ. Twenty-eight patients and 24 demographically matched healthy subjects underwent functional magnetic resonance imaging at 3T while performing a delayed match-to-sample WM task. Groups were accuracy matched to rule out performance effects. Encoding load was identical across subjects to facilitate comparisons across WM phases. We examined activation differences using an assumed model approach at the whole-brain level and within meta-analytically defined WM areas. Despite matched performance, we found regions showing less recruitment during encoding and maintenance for SCZ subjects. Furthermore, we identified 2 areas closely matching the default system, which SCZ subjects failed to deactivate across WM phases. Lastly, activation in prefrontal regions predicted the degree of deactivation for healthy but not SCZ subjects. Current results replicate and extend prefrontal recruitment abnormalities across WM phases in SCZ. Results also indicate deactivation abnormalities across WM phases, possibly due to inefficient prefrontal recruitment. Such regional deactivation may be critical for suppressing sources of interference during WM trace formation. Thus, deactivation deficits may constitute an additional source of impairments, which needs to be further characterized for a complete understanding of WM pathology in SCZ.

  10. Preliminary evidence for a postsynaptic action of beta-bungarotoxin in mammalian skeletal muscle

    Science.gov (United States)

    Storella, R. J.; Schouchoff, A. L.; Fujii, M.; Hill, J.; Fletcher, J. E.; Jiang, M. S.; Smith, L. A.

    1992-01-01

    Two hours after treatment with beta-bungarotoxin (0.34-0.4 microM), when there was complete neuromuscular block, the peak contracture response to 50 microM succinylcholine was significantly reduced by about 35% in the mouse phrenic nerve-diaphragm preparation. Additionally, significant phospholipase A2 activity was detected on primary cell cultures from skeletal muscle which were incubated for 2 hr with concentrations of beta-bungarotoxin greater than or equal to 0.1 microM. Thus, beta-bungarotoxin appears to have pharmacologically and biochemically detectable postsynaptic actions in mammalian muscle systems.

  11. Computational Framework Explains How Animals Select Actions With Rewarding Outcomes

    OpenAIRE

    Gurney, K.N.; Humphries, M.D.; Redgrave, P.

    2015-01-01

    Operant learning requires that reinforcement signals interact with action representations at a suitable neural interface. Much evidence suggests that this occurs when phasic dopamine, acting as a reinforcement prediction error, gates plasticity at cortico-striatal synapses, and thereby changes the future likelihood of selecting the action(s) coded by striatal neurons. But this hypothesis faces serious challenges. First, cortico-striatal plasticity is inexplicably complex, depending on spike t...

  12. Enforcement actions and their effectiveness in securities regulation: Empirical evidence from management earnings forecasts

    Directory of Open Access Journals (Sweden)

    Yunling Song

    2012-03-01

    Full Text Available Due to resource constraints, securities regulators cannot find or punish all firms that have conducted irregular or even illegal activities (hereafter referred to as fraud. Those who study securities regulations can only find the instances of fraud that have been punished, not those that have not been punished, and it is these unknown cases that would make the best control sample for studies of enforcement action criteria. China’s mandatory management earnings forecasts solve this sampling problem. In the A-share market, firms that have not forecasted as mandated are likely in a position to be punished by securities regulators or are attempting to escape punishment, and their identification allows researchers to build suitable study and control samples when examining securities regulations. Our results indicate that enforcement actions taken by securities regulators are selective. The probability that a firm will be punished for irregular management forecasting is significantly related to proxies for survival rates. Specifically, fraudulent firms with lower return on assets (ROAs or higher cash flow risk are more likely to be punished. Further analysis shows that selective enforcement of regulations has had little positive effect on the quality of listed firms’ management forecasts.

  13. Enforcement actions and their effectiveness in securities regulation:Empirical evidence from management earnings forecasts

    Institute of Scientific and Technical Information of China (English)

    Yunling Song; Xinwei Ji

    2012-01-01

    Due to resource constraints,securities regulators cannot find or punish all firms that have conducted irregular or even illegal activities(hereafter referred to as fraud).Those who study securities regulations can only find the instances of fraud that have been punished,not those that have not been punished,and it is these unknown cases that would make the best control sample for studies of enforcement action criteria.China’s mandatory management earnings forecasts solve this sampling problem.In the A-share market,firms that have not forecasted as mandated are likely in a position to be punished by securities regulators or are attempting to escape punishment,and their identification allows researchers to build suitable study and control samples when examining securities regulations.Our results indicate that enforcement actions taken by securities regulators are selective.The probability that a firm will be punished for irregular management forecasting is significantly related to proxies for survival rates.Specifically,fraudulent firms with lower return on assets(ROAs) or higher cash flow risk are more likely to be punished.Further analysis shows that selective enforcement of regulations has had little positive effect on the quality of listed firms’ management forecasts.

  14. Compliance costs caused by agency action? Empirical evidence and implications for tax compliance

    OpenAIRE

    Eichfelder, Sebastian; Kegels, Chantal

    2012-01-01

    The compliance costs of private taxpayers are not only affected by the tax law itself but also by its implementation through the tax authorities. In this paper we analyze the effect of the tax authorities on the burden of complying with tax regulations. Using survey data of Belgian businesses and controlling for potential endogeneity, we find empirical evidence that tax authority behavior is an important cost driver. According to our estimate, a customer-unfriendly tax administration increase...

  15. Neural circuitry underlying the central hypertensive action of nesfatin-1: melanocortins, corticotropin-releasing hormone, and oxytocin.

    Science.gov (United States)

    Yosten, Gina L C; Samson, Willis K

    2014-05-15

    Nesfatin-1 is produced in the periphery and in the brain where it has been demonstrated to regulate appetite, stress hormone secretion, and cardiovascular function. The anorexigenic action of central nesfatin-1 requires recruitment of neurons producing the melanocortins and centrally projecting oxytocin (OT) and corticotropin-releasing hormone (CRH) neurons. We previously have shown that two components of this pathway, the central melanocortin and oxytocin systems, contribute to the hypertensive action of nesfatin-1 as well. We hypothesized that the cardiovascular effect of nesfatin-1 also was dependent on activation of neurons expressing CRH receptors, and that the order of activation of the melanocortin-CRH-oxytocin circuit was preserved for both the anorexigenic and hypertensive actions of the peptide. Pretreatment of male rats with the CRH-2 receptor antagonist astressin2B abrogated nesfatin-1-induced increases in mean arterial pressure (MAP). Furthermore, the hypertensive action of CRH was blocked by pretreatment with an oxytocin receptor antagonist ornithine vasotocin (OVT), indicating that the hypertensive effect of nesfatin-1 may require activation of oxytocinergic (OTergic) neurons in addition to recruitment of CRH neurons. Interestingly, we found that the hypertensive effect of α-melanocyte stimulating hormone (α-MSH) itself was not blocked by either astressin2B or OVT. These data suggest that while α-MSH-producing neurons are part of a core melanocortin-CRH-oxytocin circuit regulating food intake, and a subpopulation of melanocortin neurons activated by nesfatin-1 do mediate the hypertensive action of the peptide, α-MSH can signal independently from this circuit to increase MAP.

  16. Neural networks for action representation underlying automatic mimicry: A functional magnetic-resonance imaging and dynamic causal modeling study

    Directory of Open Access Journals (Sweden)

    Akihiro T Sasaki

    2012-08-01

    Full Text Available Automatic mimicry is based on the tight linkage between motor and perception action representations in which internal models play a key role. Based on the anatomical connection, we hypothesized that the direct effective connectivity from the posterior superior temporal sulcus (pSTS to the ventral premotor area (PMv formed an inverse internal model, converting visual representation into a motor plan, and that reverse connectivity formed a forward internal model, converting the motor plan into a sensory outcome of action. To test this hypothesis, we employed dynamic causal-modeling analysis with functional magnetic-resonance imaging. Twenty-four normal participants underwent a change-detection task involving two visually-presented balls that were either manually rotated by the investigator’s right hand (‘Hand’ or automatically rotated. The effective connectivity from the pSTS to the PMv was enhanced by hand observation and suppressed by execution, corresponding to the inverse model. Opposite effects were observed from the PMv to the pSTS, suggesting the forward model. Additionally, both execution and hand observation commonly enhanced the effective connectivity from the pSTS to the inferior parietal lobule (IPL, the IPL to the primary sensorimotor cortex (S/M1, the PMv to the IPL, and the PMv to the S/M1. Representation of the hand action therefore was implemented in the motor system including the S/M1. During hand observation, effective connectivity toward the pSTS was suppressed whereas that toward the PMv and S/M1 was enhanced. Thus the action-representation network acted as a dynamic feedback-control system during action observation.

  17. Do Bans on Affirmative Action Hurt Minority Students? Evidence from the Texas Top 10% Plan. Upjohn Institute Working Paper No. 10-168

    Science.gov (United States)

    Cortes, Kalena E.

    2010-01-01

    In light of the recent bans on affirmative action in higher education, this paper provides new evidence on the effects of alternative admissions policies on the persistence and college completion of minority students. I find that the change from affirmative action to the Top 10% Plan in Texas decreased both retention and graduation rates of…

  18. Evidence for Action on HIV Treatment and Care Systems in low and middle-income countries: background and introduction.

    Science.gov (United States)

    Ross, David A; South, Annabelle; Weller, Ian; Hakim, James

    2012-12-01

    Despite the unprecedented scale-up of treatment for HIV in low and middle-income countries over the past decade, 49% of adults and 77% of children in need of HIV treatment still do not have access to it. ART programmes that were initially set up as an emergency response now need to be adapted to ensure that they include all the essential components and are well integrated with other health services; meet the needs of special groups, including children, adolescents, pregnant women and older people; address the mental health needs of HIV-positive people; and monitor as well as report their impact in valid and comparable ways.This supplement is an output from the Evidence for Action on HIV Treatment and Care Systems research programme consortium. Evidence for Action was a 5-year, multidisciplinary research programme, which ran from 2006 to 2011, with partners in India, Malawi, Uganda, Zambia and the United Kingdom.The primary aim of this supplement is to stimulate reflection and provide guidance on what should be in the package of HIV treatment and care systems, as national programmes look to maintain the major advances of the past decade and scale-up treatment to the other 50% of people in need of it.

  19. Modulation of ethanol-intake by morphine: Evidence for a central site of action

    Energy Technology Data Exchange (ETDEWEB)

    Wild, K.D.; Reid, L.D. (Rensselaer Polytechnic Institute, Troy, NY (USA))

    1990-01-01

    Previous studies have shown that subcutaneous administration of low doses of morphine increase, while subcutaneous naloxone decreases, ethanol-intake in rats. However, the site of action of morphine modulation of ethanol-intake remains unclear. In an attempt to elucidate this issue, seven graded doses of morphine were given intracerebroventricularly to rats 15 min prior to an opportunity to consume water and sweetened alcoholic beverage for 2 hr. Two lower doses of intracerebroventricular morphine reliably increased ethanol-intake, while higher doses decreased intake of water. Preference ratios were reliably increased by morphine doses of 1 {mu}g and higher. The present data provide support for a central site of morphine modulation of ethanol-intake.

  20. The effect of action video game playing on sensorimotor learning: Evidence from a movement tracking task.

    Science.gov (United States)

    Gozli, Davood G; Bavelier, Daphne; Pratt, Jay

    2014-10-12

    Research on the impact of action video game playing has revealed performance advantages on a wide range of perceptual and cognitive tasks. It is not known, however, if playing such games confers similar advantages in sensorimotor learning. To address this issue, the present study used a manual motion-tracking task that allowed for a sensitive measure of both accuracy and improvement over time. When the target motion pattern was consistent over trials, gamers improved with a faster rate and eventually outperformed non-gamers. Performance between the two groups, however, did not differ initially. When the target motion was inconsistent, changing on every trial, results revealed no difference between gamers and non-gamers. Together, our findings suggest that video game playing confers no reliable benefit in sensorimotor control, but it does enhance sensorimotor learning, enabling superior performance in tasks with consistent and predictable structure.

  1. Ecosystem health of the Great Barrier Reef: Time for effective management action based on evidence

    Science.gov (United States)

    Brodie, Jon; Pearson, Richard G.

    2016-12-01

    The Great Barrier Reef (GBR) is a World Heritage site off the north-eastern coast of Australia. The GBR is worth A 15-20 billion/year to the Australian economy and provides approximately 64,000 full time jobs. Many of the species and ecosystems of the GBR are in poor condition and continue to decline. The principal causes of the decline are catchment pollutant runoff associated with agricultural and urban land uses, climate change impacts and the effects of fishing. Many important ecosystems of the GBR region are not included inside the boundaries of the World Heritage Area. The current management regime for catchment pollutant runoff and climate change is clearly inadequate to prevent further decline. We propose a refocus of management on a "Greater GBR" (containing not only the major ecosystems and species of the GBR, but also its catchment) and on a set of management actions to halt the decline of the GBR. Proposed actions include: (1) Strengthen management in the areas of the Greater GBR where ecosystems are in good condition, with Torres Strait, northern Cape York and Hervey Bay being the systems with highest current integrity; (2) Investigate methods of cross-boundary management to achieve simultaneous cost-effective terrestrial, freshwater and marine ecosystem protection in the Greater GBR; (3) Develop a detailed, comprehensive, costed water quality management plan for the Greater GBR; (4) Use the Great Barrier Reef Marine Park Act and the Environment Protection and Biodiversity Conservation Act to regulate catchment activities that lead to damage to the Greater GBR, in conjunction with the relevant Queensland legislation; (5) Fund catchment and coastal management to the required level to solve pollution issues for the Greater GBR by 2025, before climate change impacts on Greater GBR ecosystems become overwhelming; (6) Continue enforcement of the zoning plan; (7) Australia to show commitment to protecting the Greater GBR through greenhouse gas emissions

  2. Dopamine depletion affects communicative intentionality in Parkinson's disease patients: Evidence from action kinematics.

    Science.gov (United States)

    Straulino, Elisa; Scaravilli, Tomaso; Castiello, Umberto

    2016-04-01

    Appropriate communication is at the heart of successful, healthy social interactions in humans. Deficits in social communication are a hallmark of several neurological and psychiatric disorders. Yet, very little research has been devoted to understanding the mechanisms underlying these issues. It has been suggested that dopamine is a candidate neurotransmitter system involved in stimulating communication in individuals that are not highly motivated to communicate. A typical model to study dopaminergic dysfunctions in humans is represented by Parkinson's disease (PD) patients, who show motor, cognitive and motivational symptoms. Our study aimed to investigate the effects of social communication on actions in non-demented PD patients receiving dopamine replacement therapy (Levodopa = l-Dopa) and in neurologically healthy control participants. Patients' ability to modulate motor patterning depending on the communicative intention motivating the action to be performed was evaluated both in "on" (with l-Dopa) and "off" (without l-Dopa) states. In two main conditions, participants were requested to reach towards, grasp an object, and either simply lift it (individual condition) or lift it with the intent to communicate a meaning to a partner (communicative condition). Movements' kinematics was recorded using a three-dimensional motion analysis system. The results indicate that kinematics is sensitive to communicative intention and that l-Dopa treatment has positive effects on translating communicative intentions into specific motor patterns in PD patients. Although the to-be-grasped object remained the same both the controls and the PD patients in an 'on' state adopted different kinematic patterning for the 'individual' and the 'communication' conditions. The PD patients in the 'off' state, instead, were unable to kinematically differentiate between the two conditions. We contend that social and communicative impairments are associated with abnormalities in

  3. Self-other disturbance in borderline personality disorder: Neural, self-report, and performance-based evidence.

    Science.gov (United States)

    Beeney, Joseph E; Hallquist, Michael N; Ellison, William D; Levy, Kenneth N

    2016-01-01

    Individuals with borderline personality disorder (BPD) display an impoverished sense of self and representations of self and others that shift between positive and negative poles. However, little research has investigated the nature of representational disturbance in BPD. The present study takes a multimodal approach. A card sort task was used to investigate complexity, integration, and valence of self-representation in BPD. Impairment in maintenance of self and other representations was assessed using a personality representational maintenance task. Finally, functional MRI (fMRI) was used to assess whether individuals with BPD show neural abnormalities related specifically to the self and what brain areas may be related to poor representational maintenance. Individuals with BPD sorted self-aspects suggesting more complexity of self-representation, but also less integration and more negative valence overall. On the representational maintenance task, individuals with BPD showed less consistency in their representations of self and others over the 3-hr period, but only for abstract, personality-based representations. Performance on this measure mediated between-groups brain activation in several areas supporting social cognition. We found no evidence for social-cognitive disturbance specific to the self. Additionally, the BPD group showed main effects, insensitive to condition, of hyperactivation in the medial prefrontal cortex, temporal parietal junction, several regions of the frontal pole, the precuneus and middle temporal gyrus, all areas crucial social cognition. In contrast, controls evidenced greater activation in visual, sensory, motor, and mirror neuron regions. These findings are discussed in relation to research regarding hypermentalization and the overlap between self- and other-disturbance.

  4. Runway self-administration of intracerebroventricular cocaine: evidence of mixed positive and negative drug actions.

    Science.gov (United States)

    Guzman, Daniel; Ettenberg, Aaron

    2007-02-01

    In previous work from our laboratory, animals running for intravenous cocaine developed a unique approach-avoidance 'retreat behavior' that was hypothesized to result from cocaine's well documented reinforcing (positive) and anxiogenic (negative) properties. To assess the role of central mechanisms in producing cocaine's positive and negative effects, we assessed whether or not animals running a straight alley for intracerebroventricular applications of cocaine would produce a similar behavioral profile to that previously observed with intravenous applications. Retreat frequency and location were measured in male Sprague-Dawley rats trained to run an alley for one of four doses of intracerebroventricular-administered cocaine (0, 25, 50 or 100 microg cocaine/infusion). Testing involved a single trial per day over 14 consecutive days with a single infusion of cocaine delivered upon goal box entry. The 100 and 50 microg intracerebroventricular cocaine groups exhibited significantly higher retreat frequencies than the 25 and 0 microg groups and the nature and magnitude of the behavior was comparable to that previously observed with intravenous cocaine. These results suggest that the intracerebroventricular self-administration of cocaine results in mixed positive and negative consequences and therefore likely stem from the drug's actions within the central nervous system.

  5. Differential neural activation for camouflage detection task in Field-independent and Field-Dependent individuals: Evidence from fMRI

    Indian Academy of Sciences (India)

    Janani Rajagopalan; Shilpi Modi; Pawan Kumar; Subash Khushu; Manas K Mandal

    2015-12-01

    It is not clearly known as to why some people identify camouflaged objects with ease compared with others. The literature suggests that Field-Independent individuals detect camouflaged object better than their Field-Dependent counterparts, without having evidence at the neural activation level. A paradigm was designed to obtain neural correlates of camouflage detection, with real-life photographs, using functional magnetic resonance imaging. Twenty-three healthy human subjects were stratified as Field-Independent (Fl) and Field-Dependent (FD), with Witkins Embedded Figure Test. FIs performed better than FDs (marginal significance; =0.054) during camouflage detection task. fMRI revealed differential activation pattern between Fl and FD subjects for this task. One sample T-test showed greater activation in terms of cluster size in FDs, whereas FIs showed additional areas for the same task. On direct comparison of the two groups, Fl subjects showed additional activation in parts of primary visual cortex, thalamus, cerebellum, inferior and middle frontal gyrus. Conversely, FDs showed greater activation in inferior frontal gyms, precentral gyms, putamen, caudate nucleus and superior parietal lobule as compared to FIs. The results give preliminary evidence to the differential neural activation underlying the variances in cognitive styles of the two groups.

  6. Yoga for the Treatment of Insomnia among Cancer Patients: Evidence, Mechanisms of Action, and Clinical Recommendations.

    Science.gov (United States)

    Mustian, Karen M; Janelsins, Michelle; Peppone, Luke J; Kamen, Charles

    Up to 90% of cancer patients report symptoms of insomnia during and after treatment. Symptoms of insomnia include excessive daytime sleepiness, difficulty falling asleep, difficulty staying asleep, and waking up too early. Insomnia symptoms are among the most prevalent, distressing and persistent cancer- and cancer treatment-related toxicities reported by patients, and can be severe enough to increase cancer morbidity and mortality. Despite the ubiquity of insomnia symptoms, they are under-screened, under-diagnosed, and under-treated in cancer patients. When insomnia symptoms are identified, providers are hesitant to prescribe, and patients are hesitant to take pharmaceuticals due to polypharmacy concerns. In addition, sleep medications do not cure insomnia. Yoga is a well-tolerated mode of exercise with promising evidence for its efficacy in improving insomnia symptoms among cancer patients. This article reviews existing clinical research on the effectiveness of yoga for treating insomnia among cancer patients. The article also provides clinical recommendations for prescribing yoga for the treatment of insomnia in this population.

  7. Evidence from the UK Zoonoses Action Plan in favour of localised anomalies of Salmonella infection on United Kingdom pig farms.

    Science.gov (United States)

    Clough, Helen E; Fenton, Sarah E; French, Nigel P; Miller, Alexander J; Cook, Alasdair J C

    2009-05-01

    Salmonella spp. are important food-borne pathogens. Abattoir studies demonstrated that almost a quarter of British finisher pigs might carry Salmonella, which led to the introduction by the British Pig Executive of their Zoonoses Action Plan (ZAP) to monitor the Salmonella status of United Kingdom pig farms by testing meat juice samples using an ELISA system. We used the K-function and approaches from the field of geostatistics to study routine data from ZAP. We demonstrated that there is statistical evidence that geographically localized anomalies of Salmonella infection were present in one of three regions studied. The physical mechanisms underlying this structure remain unclear: spatial structure might be present as a result of shared spatially structured (second-order) or non-spatially structured (first-order) risk factors, transmission processes, or a combination of both. We have demonstrated a way to use routinely collected surveillance data to enhance the knowledge of spatial disease epidemiology.

  8. Real world evidence: a form of big data, transforming healthcare data into actionable real time insights and informed business decisions

    Directory of Open Access Journals (Sweden)

    Uttam Kumar Barick

    2015-09-01

    Full Text Available Data has always played an important role in assisting business decisions and overall improvement of a company’s strategies. The introduction of what has come to be named ‘BIG data’ has changed the industry paradigm altogether for a few domains like media, mobility, retail and social. Data from the real world is also considered as BIG data based on its magnitude, sources and the industry’s capacity to handle the same. Although, the healthcare industry has been using real world data for decades, digitization of health records has demonstrated its value to all the stakeholders with a reaffirmation of interest in it. Over time, companies are looking to adopt new technologies in linking these fragmented data for meaningful and actionable insights to demonstrate their value over competition. It has also been noticed that the consequences of not demonstrating the value of data are sometimes leads regulators and payers to be severe. The real challenge though is not in identifying data sets but transforming these data sets into actionable real time insights and business decisions. Evidence and value development frameworks need to work side by side, harnessing meaningful insights in parallel to product development from early phase to life-cycle management. This should in-turn create evidence and value-based insights for multiple stakeholders across the industry; ultimately supporting the patient as the end user to take informed decisions that impact access to care. This article attempts to review the current state of affairs in the area of BIG data in pharma OR BIG DIP as it is increasingly being referred to.

  9. Molecular and biochemical evidence for the involvement of calcium/calmodulin in auxin action

    Science.gov (United States)

    Yang, T.; Poovaiah, B. W.

    2000-01-01

    -dependent manner suggests that calcium/CaM regulate ZmSAUR1 at the post-translational level. Our data provide the first direct evidence for the involvement of calcium/CaM-mediated signaling in auxin-mediated signal transduction.

  10. The neural correlates of agrammatism: Evidence from aphasic and healthy speakers performing an overt picture description task

    Directory of Open Access Journals (Sweden)

    Eva eSchoenberger

    2014-03-01

    Full Text Available Functional brain imaging studies have improved our knowledge of the neural localization of language functions and the functional recovery after a lesion. However, the neural correlates of agrammatic symptoms in aphasia remain largely unknown. The present fMRI study examined the neural correlates of morpho-syntactic encoding and agrammatic errors in continuous language production by combining three approaches. First, the neural mechanisms underlying natural morpho-syntactic processing in a picture description task were analyzed in 15 healthy speakers. Second, agrammatic-like speech behavior was induced in the same group of healthy speakers to study the underlying functional processes by limiting the utterance length. In a third approach, five agrammatic participants performed the picture description task to gain insights in the neural correlates of agrammatism and the functional reorganization of language processing after stroke. In all approaches, utterances were analyzed for syntactic completeness, complexity and morphology. Event-related data analysis was conducted by defining every clause-like unit (CLU as an event with its onset-time and duration. Agrammatic and correct CLUs were contrasted. Due to the small sample size as well as heterogeneous lesion sizes and sites with lesion foci in the insula lobe, inferior frontal, superior temporal and inferior parietal areas the activation patterns in the agrammatic speakers were analyzed on a single subject level. In the group of healthy speakers, posterior temporal and inferior parietal areas were associated with greater morpho-syntactic demands in complete and complex CLUs. The intentional manipulation of morpho-syntactic structures and the omission of function words were associated with additional inferior frontal activation. Overall, the results revealed that the investigation of the neural correlates of agrammatic language production can be reasonably conducted with an overt language production

  11. Scaling up of physical activity interventions in Brazil: how partnerships and research evidence contributed to policy action.

    Science.gov (United States)

    Parra, Diana C; Hoehner, Christine M; Hallal, Pedro C; Reis, Rodrigo S; Simoes, Eduardo J; Malta, Deborah C; Pratt, Michael; Brownson, Ross C

    2013-12-01

    The global health burden due to physical inactivity is enormous and growing. There is a need to consider new ways of generating evidence and to identify the role of government in promoting physical activity at the population level. In this paper, we summarize key findings from a large-scale cross-national collaboration to understand physical activity promotion in Brazil. We describe the main aspects of the partnership of Project GUIA (Guide for Useful Interventions for Activity in Brazil and Latin America) that sustained the collaborative effort for eight years and describe how the evidence gathered from the collaboration triggered political action in Brazil to scale up a physical activity intervention at the national level. Project GUIA is a cross-national multidisciplinary research partnership designed to understand and evaluate current efforts for physical activity promotion at the community level in Latin America. This example of scaling up is unprecedented for promoting health in the region and is an example that must be followed and evaluated.

  12. Is there a domain-general cognitive structuring system? Evidence from structural priming across music, math, action descriptions, and language.

    Science.gov (United States)

    Van de Cavey, Joris; Hartsuiker, Robert J

    2016-01-01

    Cognitive processing in many domains (e.g., sentence comprehension, music listening, and math solving) requires sequential information to be organized into an integrational structure. There appears to be some overlap in integrational processing across domains, as shown by cross-domain interference effects when for example linguistic and musical stimuli are jointly presented (Koelsch, Gunter, Wittfoth, & Sammler, 2005; Slevc, Rosenberg, & Patel, 2009). These findings support theories of overlapping resources for integrational processing across domains (cfr. SSIRH Patel, 2003; SWM, Kljajevic, 2010). However, there are some limitations to the studies mentioned above, such as the frequent use of unnaturalistic integrational difficulties. In recent years, the idea has risen that evidence for domain-generality in structural processing might also be yielded though priming paradigms (cfr. Scheepers, 2003). The rationale behind this is that integrational processing across domains regularly requires the processing of dependencies across short or long distances in the sequence, involving respectively less or more syntactic working memory resources (cfr. SWM, Kljajevic, 2010), and such processing decisions might persist over time. However, whereas recent studies have shown suggestive priming of integrational structure between language and arithmetics (though often dependent on arithmetic performance, cfr. Scheepers et al., 2011; Scheepers & Sturt, 2014), it remains to be investigated to what extent we can also find evidence for priming in other domains, such as music and action (cfr. SWM, Kljajevic, 2010). Experiment 1a showed structural priming from the processing of musical sequences onto the position in the sentence structure (early or late) to which a relative clause was attached in subsequent sentence completion. Importantly, Experiment 1b showed that a similar structural manipulation based on non-hierarchically ordered color sequences did not yield any priming effect

  13. Neural response to modulating the probability that actions of self or other result in auditory tones: A parametric fMRI study into causal ambiguity.

    Science.gov (United States)

    de Bézenac, Christophe E; Sluming, Vanessa; Gouws, André; Corcoran, Rhiannon

    2016-09-01

    In normal circumstances we can easily distinguish between changes to the external world brought about by our own actions from those with external causes. However, in certain contexts our sense of ownership and agency over acts is not so clear. Neuroimaging studies have implicated a number of regions in the sense of agency, some of which have been shown to vary continuously with action-outcome discordance. However, little is known about dynamic, ambiguous contexts characterised by a lack of information for self-other differentiation, yet such ambiguous states are important in relation to symptoms and levels of consciousness that characterise certain mental health conditions. With a block-design fMRI paradigm, we investigated neural responses to changes in the probability that a participant's irregular finger taps over 12s would result in auditory tones as opposed to tones generated by 'another's finger taps'. The main findings were that misattribution increased in ambiguous conditions where the probability of a tone belonging to self and other was equal. Task-sensitive brain regions, previously identified in self-agency, motor cognition, and ambiguity processing, showed a quadratic response to our self-to-other manipulation, with particular sensitivity to self-control. Task performance (low error and bias) was related to attenuated response in ambiguous conditions while increased response in regions associated with the default mode network was associated with greater overall error and bias towards other. These findings suggest that causal ambiguity as it occurs over time is a prominent feature in sense of agency, one that may eventually contribute to a more comprehensive understanding of positive symptoms of psychosis.

  14. Using Complement Coercion to Understand the Neural Basis of Semantic Composition: Evidence from an fMRI Study

    Science.gov (United States)

    Husband, E. Matthew; Kelly, Lisa A.; Zhu, David C.

    2011-01-01

    Previous research regarding the neural basis of semantic composition has relied heavily on violation paradigms, which often compare implausible sentences that violate world knowledge to plausible sentences that do not violate world knowledge. This comparison is problematic as it may involve extralinguistic operations such as contextual repair and…

  15. Experiencing Past and Future Personal Events: Functional Neuroimaging Evidence on the Neural Bases of Mental Time Travel

    Science.gov (United States)

    Botzung, Anne; Denkova, Ekaterina; Manning, Lilianne

    2008-01-01

    Functional MRI was used in healthy subjects to investigate the existence of common neural structures supporting re-experiencing the past and pre-experiencing the future. Past and future events evocation appears to involve highly similar patterns of brain activation including, in particular, the medial prefrontal cortex, posterior regions and the…

  16. The Neural Basis of Reversible Sentence Comprehension: Evidence from Voxel-Based Lesion Symptom Mapping in Aphasia

    Science.gov (United States)

    Thothathiri, Malathi; Kimberg, Daniel Y.; Schwartz, Myrna F.

    2012-01-01

    We explored the neural basis of reversible sentence comprehension in a large group of aphasic patients (n = 79). Voxel-based lesion symptom mapping revealed a significant association between damage in temporo-parietal cortex and impaired sentence comprehension. This association remained after we controlled for phonological working memory. We…

  17. The Neural Basis of Risk Ratings: Evidence from a Functional Magnetic Resonance Imaging (fMRI) Study

    Science.gov (United States)

    Vorhold, V.; Giessing, C.; Wiedemann, P. M.; Schutz, H.; Gauggel, S.; Fink, G. R.

    2007-01-01

    Research investigating risk perception suggests that not only the quantitative parameters used in technical risk assessment (i.e., frequency and severity of harm) but also "qualitative" aspects such as the dread a hazard provokes or its controllability influence risk judgments. It remains to be elucidated, however, which neural mechanism underlie…

  18. The causes of neural tube defect:evidence-based research%神经管缺陷发生原因的循证医学研究

    Institute of Scientific and Technical Information of China (English)

    谷茜; 刘佳琦; 何达; 葛智馨; 陈英耀; 厉传琳

    2011-01-01

    目的:通过系统性综述的方法,分析神经管缺陷(NTDs)的病因.方法:检索国内外文献数据库,检索时间从建库~2009年12月,纳入神经管缺陷病因学的系统性综述/Meta分析和随机对照试验,中文文献研究设计等级为病例-对照研究.结果:共纳入系统性综述/Meta分析9篇,随机对照试验2篇,病例-对照研究7篇.现有证据显示,遗传方面,MTHFR基因677位点TT基因型是非拉丁裔欧洲人群子代NTDs发生的危险因素;与HCY(同型半胱氨酸)代谢途径有关的酶或基因突变可引起NTDs发生概率增加,具有家族史及NTDs生产史其子代NTDs发病率较高.环境暴露方面,孕妇高热、父亲接触有机溶剂和使用抗癫痫药物(卡马西平和丙戊酸)是NTDs发生的危险因素,现有证据不支持紫外线照射和使用克罗米酚柠檬酸盐影响子代NTDs的发病风险的假设.生活行为方面,孕妇超重或肥胖、多次孕产史是NTDs发生的危险因素,使用IVF辅助生殖技术对NTDs发病的影响仍存在争议.结论:NTDs病因复杂,具有较高证据等级的病因学研究不多,病因仍有待探索.目前在孕早期补充叶酸是被广泛推荐使用的有效干预措施.%Objective: To analyze the causes of neural tube defect by systematic review. Methods: The international and national databases (from establishment to December 2009) were searched, all systematic reviews/Meta analysis and randomized controlled trials researches about the etiology of neural tube defect were included, case - control studies were also supplemented in Chinese literatures. Results: 9 systematic reviews/ Meta analysis researches, 2 randomized controlled trials and 7 case -control studies in Chinese were included. The current evidence suggested that TT genotype in 677 locus of MTHFR gene was a risk factor of neural tube defect of non - Latin European descents from the genetic point of view; the enzymatic mutation and gene mutation related to

  19. Hypertonic saline does not reverse the sodium channel blocking actions of lidocaine: evidence from electrophysiologic and defibrillation studies.

    Science.gov (United States)

    Ujhelyi, M R; Schur, M; Frede, T; Bottorff, M B; Gabel, M; Markel, M L

    1997-01-01

    Studies have shown that increasing extracellular sodium concentration can partially reverse sodium channel blockade. However, there is conflicting in vitro evidence in this regard for lidocaine. The effects of lidocaine on cardiac electrophysiology and defibrillation were studied in a basal and hypernatremic state to determine reversibility of sodium channel blockade. Electrophysiologic studies measured right ventricular effective refractory period at 350 ms pacing cycle length and QRS interval, JT interval, and monophasic action potential duration during sinus rhythm and right ventricular pacing (350 ms cycle length) in 14 pentobarbital-anesthetized swine (25-30 kg). Defibrillation threshold (DFT) was measured by quantitating successful conversion of sustained ventricular fibrillation to normal sinus rhythm. Each pig was randomly assigned to a treatment group with three study phases; group 1 = baseline, lidocaine (20 mg/kg/h), and lidocaine plus placebo (D5W; n = 7); and group 2 = baseline, lidocaine, and lidocaine plus hypertonic saline (2-3 mM/kg/h; n = 7). In groups 1 and 2, lidocaine infused alone significantly (p Lidocaine alone reduced right ventricular action potential duration (APD) in groups 1 and 2 (214 +/- 18 to 206 +/- 20 ms; p lidocaine, DFT and QRS duration values were unaffected (14.7 +/- 5.4 to 16.1 +/- 3.7 J and 103 +/- 12 to 100 +/- 11 ms, respectively). However, APD and JT intervals returned to basal values when hypertonic saline was added to lidocaine (212 +/- 8 to 225 +/- 13; p Lidocaine slowed ventricular conduction velocity and reduced APD. The administration of hypertonic saline to increase extracellular sodium concentrations failed to reverse the effect of lidocaine on conduction-velocity slowing or elevated DFT values. Hypertonic saline did reverse the effects of lidocaine on repolarization parameters. These data suggest that shortening of repolarization is not a mechanism by which lidocaine makes it more difficult to defibrillate the

  20. Where does brain neural activation in aesthetic responses to visual art occur? Meta-analytic evidence from neuroimaging studies.

    Science.gov (United States)

    Boccia, M; Barbetti, S; Piccardi, L; Guariglia, C; Ferlazzo, F; Giannini, A M; Zaidel, D W

    2016-01-01

    Here we aimed at finding the neural correlates of the general aspect of visual aesthetic experience (VAE) and those more strictly correlated with the content of the artworks. We applied a general activation likelihood estimation (ALE) meta-analysis to 47 fMRI experiments described in 14 published studies. We also performed four separate ALE analyses in order to identify the neural substrates of reactions to specific categories of artworks, namely portraits, representation of real-world-visual-scenes, abstract paintings, and body sculptures. The general ALE revealed that VAE relies on a bilateral network of areas, and the individual ALE analyses revealed different maximal activation for the artworks' categories as function of their content. Specifically, different content-dependent areas of the ventral visual stream are involved in VAE, but a few additional brain areas are involved as well. Thus, aesthetic-related neural responses to art recruit widely distributed networks in both hemispheres including content-dependent brain areas of the ventral visual stream. Together, the results suggest that aesthetic responses are not independent of sensory, perceptual, and cognitive processes.

  1. How the Mastery Rubric for Statistical Literacy Can Generate Actionable Evidence about Statistical and Quantitative Learning Outcomes

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    Rochelle E. Tractenberg

    2016-12-01

    Full Text Available Statistical literacy is essential to an informed citizenry; and two emerging trends highlight a growing need for training that achieves this literacy. The first trend is towards “big” data: while automated analyses can exploit massive amounts of data, the interpretation—and possibly more importantly, the replication—of results are challenging without adequate statistical literacy. The second trend is that science and scientific publishing are struggling with insufficient/inappropriate statistical reasoning in writing, reviewing, and editing. This paper describes a model for statistical literacy (SL and its development that can support modern scientific practice. An established curriculum development and evaluation tool—the Mastery Rubric—is integrated with a new, developmental, model of statistical literacy that reflects the complexity of reasoning and habits of mind that scientists need to cultivate in order to recognize, choose, and interpret statistical methods. This developmental model provides actionable evidence, and explicit opportunities for consequential assessment that serves students, instructors, developers/reviewers/accreditors of a curriculum, and institutions. By supporting the enrichment, rather than increasing the amount, of statistical training in the basic and life sciences, this approach supports curriculum development, evaluation, and delivery to promote statistical literacy for students and a collective quantitative proficiency more broadly.

  2. How and to what end may consciousness contribute to action? Attributing properties of consciousness to an embodied, minimally cognitive artificial neural network

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    Holk eCruse

    2013-06-01

    Full Text Available An artificial neural network called reaCog is described which is based on a decentralized, reactive and embodied architecture to control non-trivial hexapod walking in unpredictable environment (Walknet as well as insect-like navigation (Navinet. In reaCog, these basic networks are extended in such a way that the complete system, reaCog, adopts the capability of inventing new behaviors and - via internal simulation - of planning ahead. This cognitive expansion enables the reactive system to be enriched with additional procedures. Here, we focus on the question to what extent properties of phenomena to be characterized on a different level of description as for example consciousness can be found in this minimally cognitive system. Adopting a monist view, we argue that the phenomenal aspect of mental phenomena can be neglected when discussing the function of such a system. Under this condition, reaCog is discussed to be equipped with properties as are bottom-up and top-down attention, intentions, volition and some aspects of Access Consciousness. These properties have not been explicitly implemented but emerge from the cooperation between the elements of the network. The aspects of access consciousness found in reaCog concern the above mentioned ability to plan ahead and to invent and guide (new actions. Furthermore, global accessibility of memory elements, another aspect characterizing Access Consciousness is realized by this network. reaCog allows for both reactive/automatic control and (access- conscious control of behavior. We discuss examples for interactions between both the reactive domain and the conscious domain. Metacognition or Reflexive Consciousness is not a property of reaCog. Possible expansions are discussed to allow for further properties of Access Consciousness, verbal report on internal states, and for Metacognition. In summary, we argue that already simple networks allow for properties of consciousness if leaving the phenomenal

  3. The Smoke around Mirror Neurons: Goals as Sociocultural and Emotional Organizers of Perception and Action in Learning

    Science.gov (United States)

    Immordino-Yang, Mary Helen

    2008-01-01

    From the pragmatists to the neo-Piagetians, development has been understood to involve cycles of perception and action--the internalization of interactions with the world and the construction of skills for acting in the world. From a neurobiological standpoint, new evidence suggests that neural activities related to action and perception converge…

  4. Evidence for the embodiment of space perception: Concurrent hand but not arm action moderates reachability and egocentric distance perception.

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    Stephane eGrade

    2015-06-01

    Full Text Available The perception of reachability (i.e., whether an object is within reach relies on body representations and action simulation. Similarly, egocentric distance estimation (i.e., the perception of the distance an object is from the self is thought to be partly derived from embodied action simulation. Although motor simulation is important for both, it is unclear whether the cognitive processes underlying these behaviors rely on the same motor processes. To investigate this, we measured the impact of a motor interference dual-task paradigm on reachability judgment, egocentric distance estimation, and allocentric length estimation (i.e., how distant two stimuli are from each other independent from the self used as a control task. Participants were required to make concurrent actions with either hand actions of foam ball grip squeezing or arm actions of weight lifting, or no concurrent actions. Results showed that concurrent squeeze actions significantly slowed response speed in the reachability judgment and egocentric distance estimation tasks, but that there was no impact of the concurrent actions on allocentric length estimation. Together, these results suggest that reachability and distance perception, both egocentric perspective tasks, and in contrast to the allocentric perspective task, involve action simulation cognitive processes. The results are discussed in terms of the implication of action simulation when evaluating the position of a target relative to the observer’s body, supporting an embodied view of spatial cognition.

  5. The impact of social action funds on child health in a conflict affected country: evidence from Angola.

    Science.gov (United States)

    Djimeu, Eric W

    2014-04-01

    Although recent evidence shows significant and long-lasting detrimental effects of armed conflict on child health, there is lack of studies rigorously assessing the effectiveness of different social and economic development interventions aiming to mitigate the impact of armed conflict on child health. In order to fill this knowledge gap, this study assesses the impact of health projects and water, sanitation, and waste management interventions financed by the Angola Social Action Fund (ASAF) from 1994 to 2001 on child health. I use data from Inquérito aos Agregados Familiares sobre Despesas e Receitas 2000/2001(IDR 2001), a household survey on expenditures and incomes conducted between February 2000 and February 2001 in Angola. IDR 2001 uses a stratified sampling design in which 12 households were surveyed in a random fashion in each aldeia (village) in rural areas and bairro (neighborhood) in urban areas. Using propensity score matching, a fixed effects model, and propensity-based weighted regression, I find that ASAF leads to a statistically significant increase of the height-for-age Z-scores (HAZ) by 0.335 standard deviations of children less than 5 years. This finding is robust to different implementations of the propensity score model specification and when conducting the sensitivity analysis of hidden bias. The main result that emerges from an analysis of heterogeneous effects shows that ASAF has no impact on children living in war displaced households. Despite many challenges faced by conflict affected countries, social funds which are one the key instruments of the World Bank used to promote development at the local level can be used to mitigate the impact of armed conflict on child health. For children living in war displaced households, specific interventions should be designed to mitigate the impact of armed conflict.

  6. Preliminary Evidence for Impaired Brain Activity of Neural Reward Processing in Children and Adolescents with Reactive Attachment Disorder.

    Science.gov (United States)

    Tomoda, Akemi

    2016-01-01

    Childhood maltreatment, which markedly increases risks for psychopathology, is associated with structural and functional brain differences. Especially, exposure to parental verbal abuse (PVA) or interparental violence during childhood is associated with negative outcomes such as depression, posttraumatic stress disorder (PTSD), and reduced cognitive abilities. Other forms of childhood maltreatment have been associated with brain structure or developmental alteration. Our earlier studies elucidated potential discernible effects of PVA and witnessing domestic violence during childhood on brain morphology, including gray matter volume or cortical thickness. Brain regions that process and convey the adverse sensory input of the abuse might be modified specifically by such experiences, particularly in subjects exposed to a single type of maltreatment. Exposure to multiple types of maltreatment is more commonly associated with morphological alterations in the corticolimbic regions. These findings fit with preclinical studies showing that sensory cortices are highly plastic structures. Using tasks with high and low monetary rewards while subjects underwent functional MRI, we also examined whether neural activity during reward processing was altered, or not, in children and adolescents with reactive attachment disorder (RAD). Significantly reduced activity in the caudate and nucleus accumbens was observed during a high monetary reward condition in the RAD group compared to the typically developed group. The striatal neural reward activity in the RAD group was also markedly decreased. The present results suggest that dopaminergic dysfunction occurred in the striatum in children and adolescents with RAD, potentially leading to a future risk of psychiatric disorders such as dependence.

  7. THEORY OF MIND AND THE WHOLE BRAIN FUNCTIONAL CONNECTIVITY: BEHAVIORAL AND NEURAL EVIDENCES WITH THE AMSTERDAM RESTING STATE QUESTIONNAIRE

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    ANTONELLA eMARCHETTI

    2015-12-01

    Full Text Available A topic of common interest to psychologists and philosophers is the spontaneous flow of thoughts when the individual is awake but not involved in cognitive demands. This argument, classically referred to as the stream of consciousness of James, is now known in the psychological literature as Mind-Wandering. Although of great interest, this construct has been scarcely investigated so far. Diaz and colleagues (2013 created the Amsterdam Resting State Questionnaire (ARSQ, composed of 27 items, distributed in seven factors: discontinuity of mind, theory of mind (ToM, self, planning, sleepiness, comfort and somatic awareness. The present study aims at: testing psychometric properties of the ARSQ in a sample of 670 Italian subjects; exploring the neural correlates of a subsample of participants (N=28 divided into two groups on the basis of the scores obtained in the ToM factor. Results show a satisfactory reliability of the original factional structure in the Italian sample. In the subjects with a high mean in the ToM factor compared to low mean subjects, functional MRI revealed: a network (48 nodes with higher functional connectivity (FC with a dominance of the left hemisphere; an increased within-lobe FC in frontal and insular lobes. In both neural and behavioral terms, our results support the idea that the mind, which does not rest even when explicitly asked to do so, has various and interesting mentalistic-like contents.

  8. Mind your errors: evidence for a neural mechanism linking growth mind-set to adaptive posterror adjustments.

    Science.gov (United States)

    Moser, Jason S; Schroder, Hans S; Heeter, Carrie; Moran, Tim P; Lee, Yu-Hao

    2011-12-01

    How well people bounce back from mistakes depends on their beliefs about learning and intelligence. For individuals with a growth mind-set, who believe intelligence develops through effort, mistakes are seen as opportunities to learn and improve. For individuals with a fixed mind-set, who believe intelligence is a stable characteristic, mistakes indicate lack of ability. We examined performance-monitoring event-related potentials (ERPs) to probe the neural mechanisms underlying these different reactions to mistakes. Findings revealed that a growth mind-set was associated with enhancement of the error positivity component (Pe), which reflects awareness of and allocation of attention to mistakes. More growth-minded individuals also showed superior accuracy after mistakes compared with individuals endorsing a more fixed mind-set. It is critical to note that Pe amplitude mediated the relationship between mind-set and posterror accuracy. These results suggest that neural mechanisms indexing on-line awareness of and attention to mistakes are intimately involved in growth-minded individuals' ability to rebound from mistakes.

  9. Evidence for increased SOX3 dosage as a risk factor for X-linked hypopituitarism and neural tube defects.

    Science.gov (United States)

    Bauters, Marijke; Frints, Suzanna G; Van Esch, Hilde; Spruijt, Liesbeth; Baldewijns, Marcella M; de Die-Smulders, Christine E M; Fryns, Jean-Pierre; Marynen, Peter; Froyen, Guy

    2014-08-01

    Genomic duplications of varying lengths at Xq26-q27 involving SOX3 have been described in families with X-linked hypopituitarism. Using array-CGH we detected a 1.1 Mb microduplication at Xq27 in a large family with three males suffering from X-linked hypopituitarism. The duplication was mapped from 138.7 to 139.8 Mb, harboring only two annotated genes, SOX3 and ATP11C, and was shown to be a direct tandem copy number gain. Unexpectedly, the microduplication did not fully segregate with the disease in this family suggesting that SOX3 duplications have variable penetrance for X-linked hypopituitarism. In the same family, a female fetus presenting with a neural tube defect was also shown to carry the SOX3 copy number gain. Since we also demonstrated increased SOX3 mRNA levels in amnion cells derived from an unrelated t(X;22)(q27;q11) female fetus with spina bifida, we propose that increased levels of SOX3 could be a risk factor for neural tube defects.

  10. Stronger Discounting of External Cause by Action in Human Adults: Evidence for an Action-Based Hypothesis of Visual Collision Perception

    Science.gov (United States)

    Mitsumatsu, Hidemichi

    2013-01-01

    When an actor performs an action on an external object, the actor feels that he or she is exerting a force on that object. By extension, when an observer views a collision between 2 objects, he or she is able to perceive the force that is exerted on the objects during the collision. The latter case is puzzling, as force is not a visual feature per…

  11. Aging and decision making under uncertainty: behavioral and neural evidence for the preservation of decision making in the absence of learning in old age.

    Science.gov (United States)

    Hosseini, S M Hadi; Rostami, Maryam; Yomogida, Yukihito; Takahashi, Makoto; Tsukiura, Takashi; Kawashima, Ryuta

    2010-10-01

    Decision making under uncertainty is an essential component of everyday life. Recent psychological studies suggest that older adults, despite age-related neurological decline, can make advantageous decisions when information about the contingencies of the outcomes is available. In this study, a two-choice prediction paradigm has been used, in conjunction with functional magnetic resonance imaging (fMRI), to investigate the effects of normal aging on neural substrates underlying uncertain decision making in the absence of learning that have not been addressed in previous neuroimaging studies. Neuroimaging results showed that both the healthy older and young adults recruited a network of brain regions comprising the right dorsolateral prefrontal cortex, bilateral inferior parietal lobule, medial frontal cortex, and right lateral orbitofrontal cortex during the prediction task. As was hypothesized, the performance of older adults in the prediction task was not impaired compared to young adults. Although no significant age-related increases in brain activity have been found, we observed an age-related decrease in activity in the right inferior parietal lobule. We speculate that the observed age-related decrease in parietal activity could be explained by age-related differences in decision making behavior revealed by questionnaire results and maximizing scores. Together, this study demonstrates behavioral and neural evidence for the preservation of decision making in older adults when information about the contingencies of the outcome is available.

  12. Binding Action and Emotion in Social Understanding

    Science.gov (United States)

    Ferri, Francesca; Ebisch, Sjoerd J. H.; Costantini, Marcello; Salone, Anatolia; Arciero, Giampiero; Mazzola, Viridiana; Ferro, Filippo Maria; Romani, Gian Luca; Gallese, Vittorio

    2013-01-01

    In social life actions are tightly linked with emotions. The integration of affective- and action-related information has to be considered as a fundamental component of appropriate social understanding. The present functional magnetic resonance imaging study aimed at investigating whether an emotion (Happiness, Anger or Neutral) dynamically expressed by an observed agent modulates brain activity underlying the perception of his grasping action. As control stimuli, participants observed the same agent either only expressing an emotion or only performing a grasping action. Our results showed that the observation of an action embedded in an emotional context (agent’s facial expression), compared with the observation of the same action embedded in a neutral context, elicits higher neural response at the level of motor frontal cortices, temporal and occipital cortices, bilaterally. Particularly, the dynamic facial expression of anger modulates the re-enactment of a motor representation of the observed action. This is supported by the evidence that observing actions embedded in the context of anger, but not happiness, compared with a neutral context, elicits stronger activity in the bilateral pre-central gyrus and inferior frontal gyrus, besides the pre-supplementary motor area, a region playing a central role in motor control. Angry faces not only seem to modulate the simulation of actions, but may also trigger motor reaction. These findings suggest that emotions exert a modulatory role on action observation in different cortical areas involved in action processing. PMID:23349792

  13. Evidence of mirror neurons in human inferior frontal gyrus.

    Science.gov (United States)

    Kilner, James M; Neal, Alice; Weiskopf, Nikolaus; Friston, Karl J; Frith, Chris D

    2009-08-12

    There is much current debate about the existence of mirror neurons in humans. To identify mirror neurons in the inferior frontal gyrus (IFG) of humans, we used a repetition suppression paradigm while measuring neural activity with functional magnetic resonance imaging. Subjects either executed or observed a series of actions. Here we show that in the IFG, responses were suppressed both when an executed action was followed by the same rather than a different observed action and when an observed action was followed by the same rather than a different executed action. This pattern of responses is consistent with that predicted by mirror neurons and is evidence of mirror neurons in the human IFG.

  14. Left occipitotemporal cortex contributes to the discrimination of tool-associated hand actions: fMRI and TMS evidence

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    Francesca ePerini

    2014-08-01

    Full Text Available Functional neuroimaging studies have implicated the left lateral occipitotemporal cortex (LOTC in both tool and hand perception but the functional role of this region is not fully known. Here, by using a task manipulation, we tested whether tool-/hand-selective LOTC contributes to the discrimination of tool-associated hand actions. Participants viewed briefly presented pictures of kitchen and garage tools while they performed one of two tasks: in the action task, they judged whether the tool is associated with a hand rotation action (e.g., screwdriver or a hand squeeze action (e.g., garlic press, while in the location task they judged whether the tool is typically found in the kitchen (e.g., garlic press or in the garage (e.g., screwdriver. Both tasks were performed on the same stimulus set and were matched for difficulty. Contrasting fMRI responses between these tasks showed stronger activity during the action task than the location task in both tool- and hand-selective LOTC regions, which closely overlapped. No differences were found in nearby object- and motion-selective control regions. Importantly, these findings were confirmed by a TMS study, which showed that effective TMS over the tool-/hand-selective LOTC region significantly slowed responses for tool action discriminations relative to tool location discriminations, with no such difference during sham TMS. We conclude that left LOTC contributes to the discrimination of tool-associated hand actions.

  15. Precision Medicine Intelligence - evidence scoring evaluating the clinical actionability of BRAF V600E in multiple non-melanoma solid tumors.

    Science.gov (United States)

    Crescenzo, A

    2016-07-01

    With the ever-increasing growth of next-generation sequencing literature, how can researchers and clinicians assess clinical actionability and utility and objectively assign confidence to gene variant-phenotype associations? This article presents an informatics solution for clinical interpretation of patient-derived genomic and molecular data containing manually curated scientific evidence supporting gene variant-disease and -drug response phenotypes in somatic cancers. An algorithm for direct evidence scoring will be used to demonstrate the diverse utility of BRAF V600E in treating many common cancers.

  16. Evolvable Neural Software System

    Science.gov (United States)

    Curtis, Steven A.

    2009-01-01

    The Evolvable Neural Software System (ENSS) is composed of sets of Neural Basis Functions (NBFs), which can be totally autonomously created and removed according to the changing needs and requirements of the software system. The resulting structure is both hierarchical and self-similar in that a given set of NBFs may have a ruler NBF, which in turn communicates with other sets of NBFs. These sets of NBFs may function as nodes to a ruler node, which are also NBF constructs. In this manner, the synthetic neural system can exhibit the complexity, three-dimensional connectivity, and adaptability of biological neural systems. An added advantage of ENSS over a natural neural system is its ability to modify its core genetic code in response to environmental changes as reflected in needs and requirements. The neural system is fully adaptive and evolvable and is trainable before release. It continues to rewire itself while on the job. The NBF is a unique, bilevel intelligence neural system composed of a higher-level heuristic neural system (HNS) and a lower-level, autonomic neural system (ANS). Taken together, the HNS and the ANS give each NBF the complete capabilities of a biological neural system to match sensory inputs to actions. Another feature of the NBF is the Evolvable Neural Interface (ENI), which links the HNS and ANS. The ENI solves the interface problem between these two systems by actively adapting and evolving from a primitive initial state (a Neural Thread) to a complicated, operational ENI and successfully adapting to a training sequence of sensory input. This simulates the adaptation of a biological neural system in a developmental phase. Within the greater multi-NBF and multi-node ENSS, self-similar ENI s provide the basis for inter-NBF and inter-node connectivity.

  17. Neural processing of recollection, familiarity and priming at encoding: evidence from a forced-choice recognition paradigm.

    Science.gov (United States)

    Meng, Yingfang; Ye, Xiaohong; Gonsalves, Brian D

    2014-10-17

    The distinction between neural mechanisms of explicit and implicit expressions of memory has been well studied at the retrieval stage, but less at encoding. In addition, dissociations obtained in many studies are complicated by methodological difficulties in obtaining process-pure measures of different types of memory. In this experiment, we applied a subsequent memory paradigm and a two-stage forced-choice recognition test to classify study ERP data into four categories: subsequent remembered (later retrieved accompanied by detailed information), subsequent known (later retrieved accompanied by a feeling of familiarity), subsequent primed (later retrieved without conscious awareness) and subsequent forgotten (not retrieved). Differences in subsequent memory effects (DM effects) were measured by comparing ERP waveform associated with later memory based on recollection, familiarity or priming with ERP waveform for later forgotten items. The recollection DM effect involved a robust sustained (onset at 300 ms) prefrontal positive-going DM effect which was right-lateralized, and a later (onset at 800 ms) occipital negative-going DM effect. Familiarity involved an earlier (300-400 ms) prefrontal positive-going DM effect and a later (500-600 ms) parietal positive-going DM effect. Priming involved a negative-going DM effect which onset at 600 ms, mainly distributed over anterior brain sites. These results revealed a sequence of components that represented cognitive processes underlying the encoding of verbal information into episodic memory, and separately supported later remembering, knowing and priming.

  18. Normal perception of Mooney faces in developmental prosopagnosia: Evidence from the N170 component and rapid neural adaptation.

    Science.gov (United States)

    Towler, John; Gosling, Angela; Duchaine, Bradley; Eimer, Martin

    2016-03-01

    Individuals with developmental prosopagnosia (DP) have a severe difficulty recognizing the faces of known individuals in the absence of any history of neurological damage. These recognition problems may be linked to selective deficits in the holistic/configural processing of faces. We used two-tone Mooney images to study the processing of faces versus non-face objects in DP when it is based on holistic information (or the facial gestalt) in the absence of obvious local cues about facial features. A rapid adaptation procedure was employed for a group of 16 DPs. Naturalistic photographs of upright faces were preceded by upright or inverted Mooney faces or by Mooney houses. DPs showed face-sensitive N170 components in response to Mooney faces versus houses, and N170 amplitude reductions for inverted as compared to upright Mooney faces. They also showed the typical pattern of N170 adaptation effects, with reduced N170 components when upright naturalistic test faces were preceded by upright Mooney faces, demonstrating that the perception of Mooney and naturalistic faces recruits shared neural populations. Our findings demonstrate that individuals with DP can utilize global information about face configurations for categorical discriminations between faces and non-face objects, and suggest that face processing deficits emerge primarily at more fine-grained higher level stages of face perception.

  19. Perception-Action in children with ASD

    Directory of Open Access Journals (Sweden)

    Claes eVon Hofsten

    2012-12-01

    Full Text Available How do disturbances to perception and action relate to the deficiencies expressed by children with autism? The ability to predict what is going to happen next is crucial for the construction of all actions and children develop these predictive abilities early in development. Children with autism, however, are deficient in the ability to foresee future events and to plan movements and movement sequences. They are also deficient in the understanding of other people’s actions. This includes communicative actions as they are ultimately based on movements. Today there are two promising neurobiological interpretation of ASD. First, there is strong evidence that the Mirror Neuron System (MNS is impaired. As stated by this hypothesis, action production and action understanding are intimately related. Both these functions rely on predictive models of the sensory consequences of actions and depend on connectivity between the parietal and pre-motor areas. Secondly, action prediction is accomplished through a system that includes a loop from the posterior parietal cortex through the cerebellum and back to the premotor and motor areas of the brain. Impairment of this loop is probably also part of the explanation of the prediction problems in children with ASD. Both the cortico-cerebellar loop and the MNS rely on distant neural connections. There are multiple evidence that such connections are weak in children with autism.

  20. Neural evidence for the use of digit-image mnemonic in a superior memorist: An fMRI study

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    Li-Jun eYin

    2015-03-01

    Full Text Available Some superior memorists demonstrated exceptional memory for reciting a large body of information. The underlying neural correlates, however, are seldom addressed. C.L., the current holder of Guinness World Record for reciting 67,890 digits in π, participated in this functional magnetic resonance imaging (fMRI study. Thirteen participants without any mnemonics training were included as controls. Our previous studies suggested that C.L. used a digit-image mnemonic in studying and recalling lists of digits, namely associating 2-digit groups of ‘00’ to ‘99’ with images and generating vivid stories out of them (Hu, Ericsson, Yang & Lu, 2009. Thus, 2-digit condition was included, with 1-digit numbers and letters as control conditions. We hypothesized that 2-digit condition in C.L. should elicit the strongest activity in the brain regions which are associated with his mnemonic. Functional MRI results revealed that bilateral frontal poles (FPs, BA10, left superior parietal lobule (SPL, left premotor cortex (PMC, and left dorsolateral prefrontal cortex (DLPFC, were more engaged in both the study and recall phase of 2-digit condition for C.L. relative to controls. Moreover, the left middle/inferior frontal gyri (M/IFG and intraparietal sulci (IPS were less engaged in the study phase of 2-digit condition for C.L. (vs. controls. These results suggested that C.L. relied more on brain regions that are associated with episodic memory other than verbal rehearsal while he used his mnemonic strategies. This study supported theoretical accounts of restructured cognitive mechanisms for the acquisition of superior memory performance.

  1. Neural Consequences of Increasing Body Weight: Evidence from Somatosensory Evoked Potentials and the Frequency-Specificity of Brain Oscillations

    Science.gov (United States)

    Lhomond, Olivia; Teasdale, Normand; Simoneau, Martin; Mouchnino, Laurence

    2016-01-01

    Previous studies on the control of human balance suggested that increased pressure under the feet, leading to reduced plantar sole mechanoreceptors sensitivity, increases body sway. Although this suggestion is attracting, it is unclear whether increased plantar sole pressure simply reduces the transmission of plantar sole afferent to the cortex or also alters the sensorimotor integrative mechanisms. Here we used electrical stimulation applied under the sole of the foot to probe the sensorimotor mechanisms processing foot mechanoreceptors. Balance control of healthy individuals was assessed either when wearing a loaded vest or in normal-weight condition. In the Loaded condition, we observed decreased cortical activity over the primary somatosensory cortex (SI) for both an early P50-N90 somatosensory evoked potential (SEP) and for oscillatory brain activity within the gamma band (30–80 Hz). These reductions were interpreted as a disrupted early sensory transmission (i.e., decreased early SEP) leading to a decreased perception of plantar sole sensory information (i.e., decreased gamma band power). These early sensory mechanisms for the Loaded condition were associated with an increase in the late P170-N210 SEP and oscillatory brain activity within the beta band (19–24 Hz). These neural signatures involved areas which are engaged in sensorimotor integrative processes (secondary somatosensory cortex (SII) and right temporoparietal junction). Altered early and late sensory processes may result from the increase pressure on the mechanoreceptors of the foot sole and not from postural instability per se. Indeed, postural instability with normal weight condition did not lead to SEP changes. PMID:27445758

  2. Meditation experience predicts less negative appraisal of pain: electrophysiological evidence for the involvement of anticipatory neural responses.

    Science.gov (United States)

    Brown, Christopher A; Jones, Anthony K P

    2010-09-01

    The aim of mindfulness meditation is to develop present-focused, non-judgmental, attention. Therefore, experience in meditation should be associated with less anticipation and negative appraisal of pain. In this study we compared a group of individuals with meditation experience to a control group to test whether any differences in the affective appraisal of pain could be explained by lower anticipatory neural processing. Anticipatory and pain-evoked ERPs and reported pain unpleasantness were recorded in response to laser stimuli of matched subjective intensity between the two groups. ERP data were analysed after source estimation with LORETA. No group effects were found on the laser energies used to induce pain. More experienced meditators perceived the pain as less unpleasant relative to controls, with meditation experience correlating inversely with unpleasantness ratings. ERP source data for anticipation showed that in meditators, lower activity in midcingulate cortex relative to controls was related to the lower unpleasantness ratings, and was predicted by lifetime meditation experience. Meditators also reversed the normal positive correlation between medial prefrontal cortical activity and pain unpleasantness during anticipation. Meditation was also associated with lower activity in S2 and insula during the pain-evoked response, although the experiment could not disambiguate this activity from the preceding anticipation response. Our data is consistent with the hypothesis that meditation reduces the anticipation and negative appraisal of pain, but effects on pain-evoked activity are less clear and may originate from preceding anticipatory activity. Further work is required to directly test the causal relationship between meditation, pain anticipation, and pain experience.

  3. Expressive timing facilitates the neural processing of phrase boundaries in music: evidence from event-related potentials.

    Directory of Open Access Journals (Sweden)

    Eva Istók

    Full Text Available The organization of sound into meaningful units is fundamental to the processing of auditory information such as speech and music. In expressive music performance, structural units or phrases may become particularly distinguishable through subtle timing variations highlighting musical phrase boundaries. As such, expressive timing may support the successful parsing of otherwise continuous musical material. By means of the event-related potential technique (ERP, we investigated whether expressive timing modulates the neural processing of musical phrases. Musicians and laymen listened to short atonal scale-like melodies that were presented either isochronously (deadpan or with expressive timing cues emphasizing the melodies' two-phrase structure. Melodies were presented in an active and a passive condition. Expressive timing facilitated the processing of phrase boundaries as indicated by decreased N2b amplitude and enhanced P3a amplitude for target phrase boundaries and larger P2 amplitude for non-target boundaries. When timing cues were lacking, task demands increased especially for laymen as reflected by reduced P3a amplitude. In line, the N2b occurred earlier for musicians in both conditions indicating general faster target detection compared to laymen. Importantly, the elicitation of a P3a-like response to phrase boundaries marked by a pitch leap during passive exposure suggests that expressive timing information is automatically encoded and may lead to an involuntary allocation of attention towards significant events within a melody. We conclude that subtle timing variations in music performance prepare the listener for musical key events by directing and guiding attention towards their occurrences. That is, expressive timing facilitates the structuring and parsing of continuous musical material even when the auditory input is unattended.

  4. Short historical survey of pattern formation in the endo-mesoderm and the neural anlage in the vertebrates: the role of vertical and planar inductive actions.

    Science.gov (United States)

    Nieuwkoop, P D

    1997-04-01

    After some introductory remarks about vertical versus horizontal inductive interactions and about planar versus homoiogenetic induction, the author discusses: a) the historical development of the more recently studied endo-mesoderm induction in the Urodeles and in the anuran Xenopus laevis, b) the possible causal relationship between endo-mesoderm induction and the initiation of the gastrulation process, and c) the older history of the regional neural induction as initially studied in the Urodeles and only recently analysed in the anuran Xenopus laevis. The essential vertical interaction in the neural induction process both in urodelian and in anuran amphibians is emphasized.

  5. The decision to engage cognitive control is driven by expected reward-value: neural and behavioral evidence.

    Directory of Open Access Journals (Sweden)

    Matthew L Dixon

    Full Text Available Cognitive control is a fundamental skill reflecting the active use of task-rules to guide behavior and suppress inappropriate automatic responses. Prior work has traditionally used paradigms in which subjects are told when to engage cognitive control. Thus, surprisingly little is known about the factors that influence individuals' initial decision of whether or not to act in a reflective, rule-based manner. To examine this, we took three classic cognitive control tasks (Stroop, Wisconsin Card Sorting Task, Go/No-Go task and created novel 'free-choice' versions in which human subjects were free to select an automatic, pre-potent action, or an action requiring rule-based cognitive control, and earned varying amounts of money based on their choices. Our findings demonstrated that subjects' decision to engage cognitive control was driven by an explicit representation of monetary rewards expected to be obtained from rule-use. Subjects rarely engaged cognitive control when the expected outcome was of equal or lesser value as compared to the value of the automatic response, but frequently engaged cognitive control when it was expected to yield a larger monetary outcome. Additionally, we exploited fMRI-adaptation to show that the lateral prefrontal cortex (LPFC represents associations between rules and expected reward outcomes. Together, these findings suggest that individuals are more likely to act in a reflective, rule-based manner when they expect that it will result in a desired outcome. Thus, choosing to exert cognitive control is not simply a matter of reason and willpower, but rather, conforms to standard mechanisms of value-based decision making. Finally, in contrast to current models of LPFC function, our results suggest that the LPFC plays a direct role in representing motivational incentives.

  6. A new framework for cortico-striatal plasticity: behavioural theory meets in vitro data at the reinforcement-action interface

    OpenAIRE

    Gurney, Kevin; Humphries, Mark D.; Redgrave, Peter

    2015-01-01

    Operant learning requires that reinforcement signals interact with action representations at a suitable neural interface. Much evidence suggests that this occurs when phasic dopamine, acting as a reinforcement prediction error, gates plasticity at cortico-striatal synapses, and thereby changes the future likelihood of selecting the action(s) coded by striatal neurons. But this hypothesis faces serious challenges. First, cortico-striatal plasticity is inexplicably complex, depending on spike t...

  7. Comparing the processing of music and language meaning using EEG and FMRI provides evidence for similar and distinct neural representations.

    Directory of Open Access Journals (Sweden)

    Nikolaus Steinbeis

    Full Text Available Recent demonstrations that music is capable of conveying semantically meaningful information has raised several questions as to what the underlying mechanisms of establishing meaning in music are, and if the meaning of music is represented in comparable fashion to language meaning. This paper presents evidence showing that expressed affect is a primary pathway to music meaning and that meaning in music is represented in a very similar fashion to language meaning. In two experiments using EEG and fMRI, it was shown that single chords varying in harmonic roughness (consonance/dissonance and thus perceived affect could prime the processing of subsequently presented affective target words, as indicated by an increased N400 and activation of the right middle temporal gyrus (MTG. Most importantly, however, when primed by affective words, single chords incongruous to the preceding affect also elicited an N400 and activated the right posterior STS, an area implicated in processing meaning of a variety of signals (e.g. prosody, voices, motion. This provides an important piece of evidence in support of music meaning being represented in a very similar but also distinct fashion to language meaning: Both elicit an N400, but activate different portions of the right temporal lobe.

  8. Comparing the processing of music and language meaning using EEG and FMRI provides evidence for similar and distinct neural representations.

    Science.gov (United States)

    Steinbeis, Nikolaus; Koelsch, Stefan

    2008-05-21

    Recent demonstrations that music is capable of conveying semantically meaningful information has raised several questions as to what the underlying mechanisms of establishing meaning in music are, and if the meaning of music is represented in comparable fashion to language meaning. This paper presents evidence showing that expressed affect is a primary pathway to music meaning and that meaning in music is represented in a very similar fashion to language meaning. In two experiments using EEG and fMRI, it was shown that single chords varying in harmonic roughness (consonance/dissonance) and thus perceived affect could prime the processing of subsequently presented affective target words, as indicated by an increased N400 and activation of the right middle temporal gyrus (MTG). Most importantly, however, when primed by affective words, single chords incongruous to the preceding affect also elicited an N400 and activated the right posterior STS, an area implicated in processing meaning of a variety of signals (e.g. prosody, voices, motion). This provides an important piece of evidence in support of music meaning being represented in a very similar but also distinct fashion to language meaning: Both elicit an N400, but activate different portions of the right temporal lobe.

  9. Neural control of lengthening contractions.

    Science.gov (United States)

    Duchateau, Jacques; Enoka, Roger M

    2016-01-01

    A number of studies over the last few decades have established that the control strategy employed by the nervous system during lengthening (eccentric) differs from those used during shortening (concentric) and isometric contractions. The purpose of this review is to summarize current knowledge on the neural control of lengthening contractions. After a brief discussion of methodological issues that can confound the comparison between lengthening and shortening actions, the review provides evidence that untrained individuals are usually unable to fully activate their muscles during a maximal lengthening contraction and that motor unit activity during submaximal lengthening actions differs from that during shortening actions. Contrary to common knowledge, however, more recent studies have found that the recruitment order of motor units is similar during submaximal shortening and lengthening contractions, but that discharge rate is systematically lower during lengthening actions. Subsequently, the review examines the mechanisms responsible for the specific control of maximal and submaximal lengthening contractions as reported by recent studies on the modulation of cortical and spinal excitability. As similar modulation has been observed regardless of contraction intensity, it appears that spinal and corticospinal excitability are reduced during lengthening compared with shortening and isometric contractions. Nonetheless, the modulation observed during lengthening contractions is mainly attributable to inhibition at the spinal level.

  10. Proprioception contributes to the sense of agency during visual observation of hand movements: evidence from temporal judgments of action

    DEFF Research Database (Denmark)

    Balslev, Daniela; Cole, Jonathan; Miall, R Chris

    2007-01-01

    The ability to recognize visually one's own movement is important for motor control and, through attribution of agency, for social interactions. Agency of actions may be decided by comparisons of visual feedback, efferent signals, and proprioceptive inputs. Because the ability to identify one's own...... visual feedback from passive movements is decreased relative to active movements, or in some cases is even absent, the role of proprioception in self-recognition has been questioned. Proprioception during passive and active movements may, however, differ, and so to address any role for proprioception...... in the sense of agency, the active movement condition must be examined. Here we tested a chronically deafferented man (I.W.) and an age-matched group of six healthy controls in a task requiring judgement of the timing of action. Subjects performed finger movements and watched a visual cursor that moved either...

  11. Predicate structures, gesture, and simultaneity in the representation of action in British Sign Language: evidence from deaf children and adults.

    Science.gov (United States)

    Cormier, Kearsy; Smith, Sandra; Sevcikova, Zed

    2013-01-01

    British Sign Language (BSL) signers use a variety of structures, such as constructed action (CA), depicting constructions (DCs), or lexical verbs, to represent action and other verbal meanings. This study examines the use of these verbal predicate structures and their gestural counterparts, both separately and simultaneously, in narratives by deaf children with various levels of exposure to BSL (ages 5;1 to 7;5) and deaf adult native BSL signers. Results reveal that all groups used the same types of predicative structures, including children with minimal BSL exposure. However, adults used CA, DCs, and/or lexical signs simultaneously more frequently than children. These results suggest that simultaneous use of CA with lexical and depicting predicates is more complex than the use of these predicate structures alone and thus may take deaf children more time to master.

  12. Chlordiazepoxide enhances the anxiogenic action of CGS 8216 in the social interaction test: evidence for benzodiazepine withdrawal?

    Science.gov (United States)

    File, S E; Pellow, S

    1985-07-01

    The benzodiazepine receptor 'inverse agonist' CGS 8216 has a specific anxiogenic action in the social interaction test that cannot be reversed by other compounds acting at the benzodiazepine site: Ro 15-1788, FG 7142 or beta-CCE. We tried to reverse the anxiogenic effect with chlordiazepoxide, which is able to antagonise the anxiogenic effects of several other compounds acting at benzodiazepine or related sites. Chlordiazepoxide given acutely (10-20 mg/kg) was unable to antagonise the anxiogenic action of CGS 8216 (5-10 mg/kg); instead there was a tendency to enhance its effects. The effects of chlordiazepoxide after 5 days pretreatment were then assessed, since chronic treatment is necessary to reverse the anxiogenic actions of Ro 15-1788 and Ro 5-4864. At 5 mg/kg chronically, chlordiazepoxide was unable to antagonise the anxiogenic effect of CGS 8216, and at 20 mg/kg there was a significant enhancement of the effects of CGS 8216 on social interaction without an effect on locomotor activity. These results are discussed in terms of withdrawal from benzodiazepine treatment.

  13. Establishing New Mappings between Familiar Phones: Neural and Behavioral Evidence for Early Automatic Processing of Nonnative Contrasts.

    Science.gov (United States)

    Barrios, Shannon L; Namyst, Anna M; Lau, Ellen F; Feldman, Naomi H; Idsardi, William J

    2016-01-01

    To attain native-like competence, second language (L2) learners must establish mappings between familiar speech sounds and new phoneme categories. For example, Spanish learners of English must learn that [d] and [ð], which are allophones of the same phoneme in Spanish, can distinguish meaning in English (i.e., /deɪ/ "day" and /ðeɪ/ "they"). Because adult listeners are less sensitive to allophonic than phonemic contrasts in their native language (L1), novel target language contrasts between L1 allophones may pose special difficulty for L2 learners. We investigate whether advanced Spanish late-learners of English overcome native language mappings to establish new phonological relations between familiar phones. We report behavioral and magnetoencepholographic (MEG) evidence from two experiments that measured the sensitivity and pre-attentive processing of three listener groups (L1 English, L1 Spanish, and advanced Spanish late-learners of English) to differences between three nonword stimulus pairs ([idi]-[iði], [idi]-[iɾi], and [iði]-[iɾi]) which differ in phones that play a different functional role in Spanish and English. Spanish and English listeners demonstrated greater sensitivity (larger d' scores) for nonword pairs distinguished by phonemic than by allophonic contrasts, mirroring previous findings. Spanish late-learners demonstrated sensitivity (large d' scores and MMN responses) to all three contrasts, suggesting that these L2 learners may have established a novel [d]-[ð] contrast despite the phonological relatedness of these sounds in the L1. Our results suggest that phonological relatedness influences perceived similarity, as evidenced by the results of the native speaker groups, but may not cause persistent difficulty for advanced L2 learners. Instead, L2 learners are able to use cues that are present in their input to establish new mappings between familiar phones.

  14. Evidence for the role of DNA strand passage in the mechanism of action of microcin B17 on DNA gyrase.

    Science.gov (United States)

    Pierrat, Olivier A; Maxwell, Anthony

    2005-03-22

    Microcin B17 (MccB17) is a DNA gyrase poison; in previous work, this bacterial toxin was found to slowly and incompletely inhibit the reactions of supercoiling and relaxation of DNA by gyrase and to stabilize the cleavage complex, depending on the presence of ATP and the DNA topology. We now show that the action of MccB17 on the gyrase ATPase reaction and cleavage complex formation requires a linear DNA fragment of more than 150 base pairs. MccB17 is unable to stimulate the ATPase reaction by stabilizing the weak interactions between short linear DNA fragments (70 base pairs or less) and gyrase, in contrast with the quinolone ciprofloxacin. However, MccB17 can affect the ATP-dependent relaxation of DNA by gyrase lacking its DNA-wrapping or ATPase domains. From these findings, we propose a mode of action of MccB17 requiring a DNA molecule long enough to allow the transport of a segment through the DNA gate of the enzyme. Furthermore, we suggest that MccB17 may trap a transient intermediate state of the gyrase reaction present only during DNA strand passage and enzyme turnover. The proteolytic signature of MccB17 from trypsin treatment of the full enzyme requires DNA and ATP and shows a protection of the C-terminal 47-kDa domain of gyrase, indicating the involvement of this domain in the toxin mode of action and consistent with its proposed role in the mechanism of DNA strand passage. We suggest that the binding site of MccB17 is in the C-terminal domain of GyrB.

  15. Comparison of Monetary Policy Actions and Central Bank Communication on Tackling Asset Price Bubbles-Evidence from China's Stock Market.

    Science.gov (United States)

    Sun, Ou; Liu, Zhixin

    2016-01-01

    We examine the different effects of monetary policy actions and central bank communication on China's stock market bubbles with a Time-varying Parameter SVAR model. We find that with negative responses of fundamental component and positive responses of bubble component of asset prices, contractionary monetary policy induces the observed stock prices to rise during periods of large bubbles. By contrast, central bank communication acts on the market through expectation guidance and has more significant effects on stock prices in the long run, which implies that central bank communication be used as an effective long-term instrument for the central bank's policymaking.

  16. The African Network for Evidence-to-Action on Disability: A role player in the realisation of the UNCRPD in Africa

    Directory of Open Access Journals (Sweden)

    Rachel Kachaje

    2014-06-01

    Full Text Available This African Journal of Disability supplement focuses on papers presented at the third AfriNEAD Symposium in 2011. In this closing editorial, we want to give an overview of the rationale and major modes of operation of the African Network for Evidence-to-Action on Disability (AfriNEAD with special focus on recommendations made at the 2011 AfriNEAD Symposium. AfriNEAD is guided and informed by the United Nations Convention on the Rights of Persons with Disabilities (UNCRPD for its research themes. The issues that emerged from AfriNEAD 2011 ranged from children and youth with disabilities; education across the lifespan; economic empowerment; the development process in Africa; health, HIV and AIDS and community-based rehabilitation; holistic wellness; to research evidence and utilisation. Disability-related stigma, the value of emancipatory research and the need to recognise a broader scope of valid methodologies were also highlighted.

  17. Evidence that 17alpha-estradiol is biologically active in the uterine tissue: Antiuterotonic and antiuterotrophic action

    Directory of Open Access Journals (Sweden)

    Navarrete Erika

    2005-07-01

    Full Text Available Abstract Background 17alpha-Estradiol has been considered as the hormonally inactive isomer of 17beta-estradiol. Recently, nongenomic (smooth muscle relaxation and genomic (light estrogenic activity effects of 17alpha-estradiol have been reported, but no reports have yet determined its possible antiestrogenic activity. Therefore, this study investigated: the nongenomic action of 17alpha-estradiol on uterine contractile activity and its potential agonist-antagonist activity on uterine growth. Methods Uterine rings from rats were isometrically recorded. Different concentrations (0.2–200 microM of 17alpha-estradiol were tested on spontaneous contraction and equimolarly compared with 17beta-estradiol. To examine the mechanism of 17alpha-estradiol action, its effect was studied in presence of beta2-antagonist (propranolol, antiestrogens (tamoxifen and ICI 182,780 or inhibitors of protein synthesis (cycloheximide and transcription (actinomycin D. Moreover, contractions induced by high potassium (KCl solution or calcium in depolarized tissues by KCl-calcium free solution were exposed to 17alpha-estradiol. Collaterally, we performed an uterotrophic assay in adult ovariectomized rats measuring the uterine wet weight. The administration for three days of 0.3 microM/day/Kg 17beta-estradiol was equimolarly compared with the response produced by 17alpha-estradiol. Antiuterotrophic activity was assayed by administration of 0.3 microM/day/Kg 17beta-estradiol and various doses ratios (1:1, 1:3, 1:5, and 1:100 of 17alpha-estradiol. Results The estradiol isomers elicited an immediate relaxation, concentration-dependent and reversible on spontaneous contraction. 17alpha-Estradiol presented lower potency than 17beta-estradiol although it did not antagonize 17beta-estradiol-induced relaxation. Relaxation to 17alpha-estradiol was not inhibited by propranolol, tamoxifen, ICI 182,780, cycloheximide or actinomycin D. The KCl contractions were also sensitive to 17alpha

  18. The human premotor cortex is 'mirror' only for biological actions.

    Science.gov (United States)

    Tai, Yen F; Scherfler, Christoph; Brooks, David J; Sawamoto, Nobukatsu; Castiello, Umberto

    2004-01-20

    Previous work has shown that both human adults and children attend to grasping actions performed by another person but not necessarily to those made by a mechanical device. According to recent neurophysiological data, the monkey premotor cortex contains "mirror" neurons that discharge both when the monkey performs specific manual grasping actions and when it observes another individual performing the same or similar actions. However, when a human model uses tools to perform grasping actions, the mirror neurons are not activated. A similar "mirror" system has been described in humans, but whether or not it is also tuned specifically to biological actions has never been tested. Here we show that when subjects observed manual grasping actions performed by a human model a significant neural response was elicited in the left premotor cortex. This activation was not evident for the observation of grasping actions performed by a robot model commanded by an experimenter. This result indicates for the first time that in humans the mirror system is biologically tuned. This system appears to be the neural substrate for biological preference during action coding.

  19. Structures and dynamics of transnational cooperation networks: evidence based on Local Action Groups in the Veneto Region, Italy

    Directory of Open Access Journals (Sweden)

    Elena Pisani

    2014-12-01

    Full Text Available The paper assesses the structures and dynamics of transnational cooperation projects promoted by Local Action Groups (LAGs in different periods (from LEADER II to LEADER Axis using Social Network Analysis (SNA in a specific case study: the Veneto Region in Italy. The classical indexes of SNA have been critically examined, and the paper also presents innovative indexes that can capture the peculiarity of transnational cooperation: disaggregated densities of the network and transnational centrality of the node. These indexes are useful in order to quantify how transnational a network actually is, and to measure the power-information that each actor (LAG can acquire through its transnational contacts. The methodology can become a tool for Managing Authorities to implement new forms of evaluation of transnational cooperation of LAGs.

  20. Creation of a Research Community in a K-12 School System Using Action Research and Evidence Based Practice

    Directory of Open Access Journals (Sweden)

    Jean K. Sand

    2009-06-01

    Full Text Available Objective - The purpose of this study was to apply skills developed from an Action Research Training Model (Gordon in the design of two action research projects to ensure that students are ethical users of ideas and information. It was deemed necessary to assess prior knowledge and attitudes of students and teachers in order to identify issues to be addressed. Methods - Both projects employed the use of survey instruments, which presented students with scenarios involving aspects of information use, and asked whether or not the actions in the scenarios were examples of ethical use. The high school survey was administered to 381 students in tenth grade English classes. The elementary survey was administered to 87 students in fifth grade. A more comprehensive survey was administered at the high school level. For each student behavior addressed by the survey, there were two questions: one eliciting the teacher’s perception of how often students engaged in that behavior, and the second how often the teacher had to confront a student about the same behavior. Participation was voluntary, and 36 teachers took the survey. Results - Surveys administered at the high school level showed that most students have a good understanding of the ethical use of information regarding clear instances of plagiarism. Students’ understanding was less clear in two major areas: creating a bibliography that accurately reflects the sources used to create the work, and the level of collaboration or assistance that is appropriate in completing a research assignment. The teacher surveys showed some discrepancy between perception of the frequency of certain types of unethical student behavior and how often teachers challenged students on that behavior. The surveys showed that teachers found plagiarism to be the most prevalent behavior, while obtaining copies of exams and buying papers were the least frequently occurring behaviors. At the elementary level, results indicated

  1. The role of the epidermis in the control of scarring: evidence for mechanism of action for silicone gel.

    Science.gov (United States)

    Tandara, Andrea A; Mustoe, Thomas A

    2008-10-01

    Hypertrophic scars can be reduced by the application of silicone dressing; however, the detailed mechanism of silicone action is still unknown. It is known that silicone gel sheets cause a hydration of the epidermal layer of the skin. An in vitro co-culture experiment has shown that hydration of keratinocytes has a suppressive effect on the metabolism of the underlying fibroblasts resulting in reduced collagen deposition. We tested the hypothesis that silicone sheeting in vivo has a beneficial effect on scarring by reducing keratinocyte stimulation, with a resulting decrease in dermal thickness, hence scar hypertrophy. Silicone adhesive gel sheets were applied to scars in our rabbit ear model of hypertrophic scarring 14 days postwounding for a total of 16 days. Scarring was measured in this model by the scar elevation index (SEI), a ratio of the area of newly formed dermis to the area of the dermis of unwounded skin, and the epidermal thickness index (ETI), a ratio of the averaged epidermal height of the scar to the epidermal thickness of normal epidermis. Specific staining [anti-PCNA (proliferating cell nuclear antigen) and Masson trichrome] was performed to reveal differences in scar morphology. SEIs were significantly reduced after silicone gel sheet application versus untreated scars corresponding to a 70% reduction in scar hypertrophy. Total occlusion reduced scar hypertrophy by 80% compared to semi-occlusion. ETIs of untreated scars were increased by more than 100% compared to uninjured skin. Silicone gel treatment significantly reduced epidermal thickness by more than 30%. Our findings demonstrate that 2 weeks of silicone gel application at a very early onset of scarring reduces dermal and epidermal thickness which appears to be due to a reduction in keratinocyte stimulation. Oxygen can be ruled out as a mechanism of action of silicone occlusive treatment. Hydration of the keratinocytes seems to be the key stimulus.

  2. Electrophysiological evidence for the action of a center-surround mechanism on semantic processing in the left hemisphere

    Directory of Open Access Journals (Sweden)

    Diana eDeacon

    2013-12-01

    Full Text Available Physiological evidence was sought for a center-surround attentional mechanism (CSM, which has been proposed to assist in the retrieval of weakly activated items from semantic memory. The CSM operates by facilitating strongly related items in the center of the weakly activated area of semantic memory, and inhibiting less strongly related items in its surround. In this study weak activation was created by having subjects acquire the meanings of new words to a recall criterion of only 50%. Subjects who attained this approximate criterion level of performance were subsequently included in a semantic priming task, during which ERPs were recorded. Primes were newly learned rare words, and targets were either synonyms, nonsynonymously related words, or unrelated words. All stimuli were presented to the RVF/LH (right visual field/left hemisphere or the LVF/RH (left visual field/right hemisphere. Under RVF/LH stimulation the newly learned word primes produced facilitation on N400 for synonym targets, and inhibition for related targets. No differences were observed under LVF/RH stimulation. The LH thus, supports a CSM, whereby a synonym in the center of attention focused on the newly learned word is facilitated, whereas a related word in the surround is inhibited. The data are consistent with the view of this laboratory that semantic memory is subserved by a spreading activation system in the LH. Also consistent with our view, there was no evidence of spreading activation in the RH. The findings are discussed in the context of additional recent theories of semantic memory. Finally, the adult right hemisphere may require more learning than the LH in order to demonstrate evidence of meaning acquisition.

  3. Functional magnetic resonance imaging reveals the neural substrates of arm transport and grip formation in reach-to-grasp actions in humans.

    Science.gov (United States)

    Cavina-Pratesi, Cristiana; Monaco, Simona; Fattori, Patrizia; Galletti, Claudio; McAdam, Teresa D; Quinlan, Derek J; Goodale, Melvyn A; Culham, Jody C

    2010-08-01

    Picking up a cup requires transporting the arm to the cup (transport component) and preshaping the hand appropriately to grasp the handle (grip component). Here, we used functional magnetic resonance imaging to examine the human neural substrates of the transport component and its relationship with the grip component. Participants were shown three-dimensional objects placed either at a near location, adjacent to the hand, or at a far location, within reach but not adjacent to the hand. Participants performed three tasks at each location as follows: (1) touching the object with the knuckles of the right hand; (2) grasping the object with the right hand; or (3) passively viewing the object. The transport component was manipulated by positioning the object in the far versus the near location. The grip component was manipulated by asking participants to grasp the object versus touching it. For the first time, we have identified the neural substrates of the transport component, which include the superior parieto-occipital cortex and the rostral superior parietal lobule. Consistent with past studies, we found specialization for the grip component in bilateral anterior intraparietal sulcus and left ventral premotor cortex; now, however, we also find activity for the grasp even when no transport is involved. In addition to finding areas specialized for the transport and grip components in parietal cortex, we found an integration of the two components in dorsal premotor cortex and supplementary motor areas, two regions that may be important for the coordination of reach and grasp.

  4. Evidence for Helical Magnetic fields in Kiloparsec-Scale AGN Jets and the Action of a Cosmic Battery

    Science.gov (United States)

    Gabuzda, D. C.; Christodoulou, D. M.; Contopulos, I.; Kazanas, D.

    2012-01-01

    A search for transverse kiloparsec-scale gradients in Faraday rotation-measure (RM) maps of extragalactic radio sources in the literature has yielded 6 AGNs displaying continuous, monotonic RM gradients across their jets, oriented roughly orthogonal to the local jet direction. The most natural interpretation of such transverse RM gradients is that they are caused by the systematic change in the line-of-sight components of helical magnetic fields associated with these jets. All the identified transverse RM gradients increase in the counterclockwise (CCW) direction on the sky relative to the centers of these AGNs. Taken together with the results of Contopoulos et al. who found evidence for a predominance of clockwise (CW) transverse RM gradients across parsec-scale (VLBI) jets, this provides new evidence for preferred orientations of RM gradients due to helical jet magnetic fields, with a reversal from CW in the inner jets to CCW farther from the centers of activity. This can be explained by the "Poynting-Robertson cosmic-battery" mechanism, which can generate helical magnetic fields with a. characteristic "twist," which are expelled with the jet outflows. If the Poynting-Robertson battery mechanism is not operating, an alternative mechanism must be identified, which is able to explain the 'predominance of CW /CCW RM gradients on parsec/kiloparsec scales.

  5. Fault diagnosis of DCT electronic control system based on neural network and evidence theory%基于神经网络和证据理论的DCT电控系统故障诊断

    Institute of Scientific and Technical Information of China (English)

    孔慧芳; 段锐; 鲍伟

    2015-01-01

    为了提高双离合器自动变速器(dual‐clutch transmission ,DCT )电控系统故障诊断精度,文章提出了一种基于神经网络和证据理论的DCT电控系统故障诊断方法。该方法首先分别用BP神经网络和RBF神经网络对DC T电控系统进行故障诊断,然后利用D‐S证据理论将两者的诊断结果进行决策融合,得出最终的诊断结果。仿真结果表明,该方法能够有效提高DC T电控系统故障诊断的精度。%In order to improve the fault diagnosis accuracy of dual‐clutch transmission(DCT ) electronic control system ,a fault diagnosis scheme based on neural network and D‐S evidence theory is devel‐oped .Both the fault diagnosis based on BP neural network and based on RBF neural network of DCT electronic control system are studied .Then the D‐S evidence theory is applied to fusing the diagnosis results of BP neural network and RBF neural network .The simulation results are presented to demon‐strate the validity and effectiveness of the fault diagnosis scheme .

  6. mGluR2/3 mechanisms in primate dorsolateral prefrontal cortex: Evidence for both presynaptic and postsynaptic actions

    Science.gov (United States)

    Jin, Lu E.; Wang, Min; Yang, Sheng-Tao; Yang, Yang; Galvin, Veronica C.; Lightbourne, Taber C.; Ottenheimer, David; Zhong, Qiaonan; Stein, Josh; Raja, Anusha; Paspalas, Constantinos D.; Arnsten, Amy F.T.

    2016-01-01

    Cognitive deficits in psychiatric and age-related disorders generally involve dysfunction of the dorsolateral prefrontal cortex (dlPFC), but there are few treatments for these debilitating symptoms. Group II metabotropic glutamate receptors (mGluR2/3), which couple to Gi/Go, have been a focus of therapeutics based on rodent research, where mGluR2/3 have been shown to reduce axonal glutamate release and increase glial glutamate uptake. However, this strategy has had mixed results in patients, and understanding mGluR2/3 mechanisms in primates will help guide therapeutic interventions. The current study examined mGluR2/3 localization and actions in the primate dlPFC layer III circuits underlying working memory, where the persistent firing of “Delay cells” is mediated by NMDA receptors and weakened by cAMP-PKA-potassium channel signaling in dendritic spines. Immunoelectron microscopy identified postsynaptic mGluR2/3 in the spines, in addition to the traditional presynaptic and astrocytic locations. In vivo iontophoretic application of the mGluR2/3 agonists (2R, 4R)-APDC or LY379268 onto dlPFC Delay cells produced an inverted-U effect on working memory representation, with enhanced neuronal firing following low doses of mGluR2/3 agonists. The enhancing effects were reversed by an mGluR2/3 antagonist or by activating cAMP signaling, consistent with mGluR2/3 inhibiting postsynaptic cAMP signaling in spines. Systemic administration of these agonists to monkeys performing a working memory task also produced an inverted-U dose-response, where low doses improved performance but higher doses, similar to clinical trials, had mixed effects. Our data suggest that low dose mGluR2/3 stimulation may have therapeutic effects through unexpected postsynaptic actions in dlPFC, strengthening synaptic connections and improving cognitive function. PMID:27502475

  7. Evidence for simvastatin anti-inflammatory actions based on quantitative analyses of NETosis and other inflammation/oxidation markers

    Directory of Open Access Journals (Sweden)

    Walid M. Al-Ghoul

    2014-01-01

    Full Text Available Simvastatin (SMV has been shown to exhibit promising anti-inflammatory properties alongside its classic cholesterol lowering action. We tested these emerging effects in a major thermal injury mouse model (3rd degree scald, ~20% TBSA with previously documented, inflammation-mediated intestinal defects. Neutrophil extracellular traps (NETs inflammation measurement methods were used alongside classic gut mucosa inflammation and leakiness measurements with exogenous melatonin treatment as a positive control. Our hypothesis is that simvastatin has protective therapeutic effects against early postburn gut mucosa inflammation and leakiness. To test this hypothesis, we compared untreated thermal injury (TI adult male mice with TI littermates treated with simvastatin (0.2 mg/kg i.p., TI+SMV immediately following burn injury and two hours before being sacrificed the day after; melatonin-treated (Mel (1.86 mg/kg i.p., TI+Mel mice were compared as a positive control. Mice were assessed for the following: (1 tissue oxidation and neutrophil infiltration in terminal ileum mucosa using classic carbonyl, Gr-1, and myeloperoxidase immunohistochemical or biochemical assays, (2 NETosis in terminal ileum and colon mucosa homogenates and peritoneal and fluid blood samples utilizing flow cytometric analyses of the surrogate NETosis biomarkers, picogreen and Gr-1, and (3 transepithelial gut leakiness as measured in terminal ileum and colon with FITC-dextran and transepithelial electrical resistance (TEER. Our results reveal that simvastatin and melatonin exhibit consistently comparable therapeutic protective effects against the following: (1 gut mucosa oxidative stress as revealed in the terminal ileum by markers of protein carbonylation as well as myeloperoxidase (MPO and Gr-1 infiltration, (2 NETosis as revealed in the gut milieu, peritoneal lavage and plasma utilizing picogreen and Gr-1 flow cytometry and microscopy, and (3 transepithelial gut leakiness as assessed

  8. A role for the precuneus in thought–action fusion: Evidence from participants with significant obsessive–compulsive symptoms

    Directory of Open Access Journals (Sweden)

    Rhiannon Jones

    2014-01-01

    Full Text Available Likelihood thought–action fusion (TAF-L refers to a cognitive bias in which individuals believe that the mere thought of a negative event increases its likelihood of occurring in reality. TAF-L is most commonly associated with obsessive–compulsive disorder (OCD but is also present in depression, generalized anxiety disorder and psychosis. We induced TAF-L in individuals with high (High-OC, N = 23 and low (Low-OC, N = 24 levels of OC traits, and used low resolution electromagnetic tomography (LORETA to localise the accompanying electrical brain activity patterns. The results showed greater TAF-L in the High-OC than in the Low-OC group (p < .005, which was accompanied by significantly greater upper beta frequency (19–30 Hz activity in the precuneus (p < .05. Further, the precuneus activity was positively correlated with self-reported magnitude of TAF-L (p < .01, suggesting a specific role of this region in this cognitive bias. Results are discussed with reference to self-referential processing and the default-mode network.

  9. Managing and Mitigating the Health Risks of Climate Change: Calling for Evidence-Informed Policy and Action

    Science.gov (United States)

    Tong, Shilu; Confalonieri, Ulisses; Ebi, Kristie; Olsen, Jorn

    2016-01-01

    Summary: Climate change affects many natural and social systems and processes that are essential for life. It disrupts the Earth’s life-support systems that underpin the world’s capacity to supply adequate food and fresh water, and it disturbs the eco-physical buffering against natural disasters. Epidemiologists need to develop and improve research and monitoring programs to better understand the scale and immediacy of the threat of climate change to human health and to act within a much larger and more comprehensive framework. To address one of the greatest environmental issues of our lifetime, the scientific and policy-making communities should work together to formulate evidence-informed public policy to mitigate greenhouse gas emissions and adapt to its inevitable impacts in this generation and, more importantly, in future generations to come. PMID:27689449

  10. From science to action: Principles for undertaking environmental research that enables knowledge exchange and evidence-based decision-making.

    Science.gov (United States)

    Cvitanovic, C; McDonald, J; Hobday, A J

    2016-12-01

    Effective conservation requires knowledge exchange among scientists and decision-makers to enable learning and support evidence-based decision-making. Efforts to improve knowledge exchange have been hindered by a paucity of empirically-grounded guidance to help scientists and practitioners design and implement research programs that actively facilitate knowledge exchange. To address this, we evaluated the Ningaloo Research Program (NRP), which was designed to generate new scientific knowledge to support evidence-based decisions about the management of the Ningaloo Marine Park in north-western Australia. Specifically, we evaluated (1) outcomes of the NRP, including the extent to which new knowledge informed management decisions; (2) the barriers that prevented knowledge exchange among scientists and managers; (3) the key requirements for improving knowledge exchange processes in the future; and (4) the core capacities that are required to support knowledge exchange processes. While the NRP generated expansive and multidisciplinary science outputs directly relevant to the management of the Ningaloo Marine Park, decision-makers are largely unaware of this knowledge and little has been integrated into decision-making processes. A range of barriers prevented efficient and effective knowledge exchange among scientists and decision-makers including cultural differences among the groups, institutional barriers within decision-making agencies, scientific outputs that were not translated for decision-makers and poor alignment between research design and actual knowledge needs. We identify a set of principles to be implemented routinely as part of any applied research program, including; (i) stakeholder mapping prior to the commencement of research programs to identify all stakeholders, (ii) research questions to be co-developed with stakeholders, (iii) implementation of participatory research approaches, (iv) use of a knowledge broker, and (v) tailored knowledge management

  11. Neural overlap in processing music and speech.

    Science.gov (United States)

    Peretz, Isabelle; Vuvan, Dominique; Lagrois, Marie-Élaine; Armony, Jorge L

    2015-03-19

    Neural overlap in processing music and speech, as measured by the co-activation of brain regions in neuroimaging studies, may suggest that parts of the neural circuitries established for language may have been recycled during evolution for musicality, or vice versa that musicality served as a springboard for language emergence. Such a perspective has important implications for several topics of general interest besides evolutionary origins. For instance, neural overlap is an important premise for the possibility of music training to influence language acquisition and literacy. However, neural overlap in processing music and speech does not entail sharing neural circuitries. Neural separability between music and speech may occur in overlapping brain regions. In this paper, we review the evidence and outline the issues faced in interpreting such neural data, and argue that converging evidence from several methodologies is needed before neural overlap is taken as evidence of sharing.

  12. The integration of size and weight cues for perception and action: evidence for a weight-size illusion.

    Science.gov (United States)

    Hirsiger, Sarah; Pickett, Kristen; Konczak, Jürgen

    2012-11-01

    Humans routinely estimate the size and weight of objects. Yet, when lifting two objects of equal weight but different size, they often perceive the smaller object as being heavier. This size-weight illusion (SWI) is known to have a lesser effect on motor control of object lifting. How the nervous system combines "weight" and "size" cues with prior experience and whether these cues are differentially integrated for perception and sensorimotor action is still not fully understood. Therefore, we assessed not only whether the experience of size biases weight perception, but also if experience of weight biases the size perception of objects. Further, to investigate differences between perceptual and motor systems for cue-experience integration, participants haptically explored the weight of an object with one hand and then shaped the aperture of their other hand to indicate its perceived size. Results-First, next to a SWI, healthy adults (N = 21) perceived lighter objects as being smaller and heavier objects as being larger, demonstrating a weight-size illusion (WSI). Second, participants were more susceptible to either the SWI or WSI. Third, aperture of the non-exploring hand was scaled to perceived weight and not to physical size. Hand openings were consistently smaller than physical size, with SWI-sensitive participants being significantly more affected than WSI-sensitive subjects. We conclude: first, both size and weight perceptions are biased by prior experience. Weight perception is biased by expectations of size, while size perception is influenced by the expectancy of weight. Second, humans have the tendency to use one cue predominantly for both types of perception. Third, combining perceived weight with expected size influenced hand motor control, while online haptic feedback was largely ignored. Finally, we present a processing model underlying the size-weight cue integration for the perceptual and motor system.

  13. Evidence for a central mode of action for etoricoxib (COX-2 inhibitor) in patients with painful knee osteoarthritis.

    Science.gov (United States)

    Arendt-Nielsen, Lars; Egsgaard, Line Lindhardt; Petersen, Kristian Kjær

    2016-08-01

    The COX-2 inhibitor etoricoxib modulates the peripheral and central nociceptive mechanisms in animals. This interaction has not been studied in patients with pain. This randomized, double-blind, placebo-controlled, 2-way crossover, 4-week treatment study investigated the pain mechanisms modulated by etoricoxib in patients with painful knee osteoarthritis. Patients were randomized to group A (60 mg/d etoricoxib followed by placebo) or B (placebo followed by 60 mg/d etoricoxib). The quantitative, mechanistic pain biomarkers were pressure pain thresholds, temporal summation (TS), and conditioning pain modulation. Clinical readouts were Brief Pain Inventory, WOMAC, painDETECT questionnaire (PD-Q), and time and pain intensity during walking and stair climbing. Etoricoxib as compared with placebo significantly modulated the pressure pain thresholds (P = 0.012, localized sensitization) at the knee and leg (control site) (P = 0.025, spreading sensitization) and TS assessed from the knee (P = 0.038) and leg (P = 0.045). Conditioning pain modulation was not modulated. The Brief Pain Inventory (pain scores), PD-Q, WOMAC, and walking and stair climbing tests were all significantly improved by etoricoxib. Based on a minimum of 30% or 50% pain alleviation (day 0-day 28), responders and nonresponders were defined. The nonresponders showed a significant association between increased facilitation of TS and increased pain alleviation. None of the other parameters predicted the degree of pain alleviation. Generally, a responder to etoricoxib has the most facilitated TS. In conclusion, etoricoxib (1) modulated central pain modulatory mechanisms and (2) improved pain and function in painful osteoarthritis. Stronger facilitation of TS may indicate a better response to etoricoxib, supporting the central mode-of-action of the drug.

  14. Addressing the social and environmental determinants of urban health equity: evidence for action and a research agenda.

    Science.gov (United States)

    Friel, Sharon; Akerman, Marco; Hancock, Trevor; Kumaresan, Jacob; Marmot, Michael; Melin, Thomas; Vlahov, David

    2011-10-01

    Urban living is the new reality for the majority of the world's population. Urban change is taking place in a context of other global challenges--economic globalization, climate change, financial crises, energy and food insecurity, old and emerging armed conflicts, as well as the changing patterns of communicable and noncommunicable diseases. These health and social problems, in countries with different levels of infrastructure and health system preparedness, pose significant development challenges in the 21st century. In all countries, rich and poor, the move to urban living has been both good and bad for population health, and has contributed to the unequal distribution of health both within countries (the urban-rural divide) and within cities (the rich-poor divide). In this series of papers, we demonstrate that urban planning and design and urban social conditions can be good or bad for human health and health equity depending on how they are set up. We argue that climate change mitigation and adaptation need to go hand-in-hand with efforts to achieve health equity through action in the social determinants. And we highlight how different forms of governance can shape agendas, policies, and programs in ways that are inclusive and health-promoting or perpetuate social exclusion, inequitable distribution of resources, and the inequities in health associated with that. While today we can describe many of the features of a healthy and sustainable city, and the governance and planning processes needed to achieve these ends, there is still much to learn, especially with respect to tailoring these concepts and applying them in the cities of lower- and middle-income countries. By outlining an integrated research agenda, we aim to assist researchers, policy makers, service providers, and funding bodies/donors to better support, coordinate, and undertake research that is organized around a conceptual framework that positions health, equity, and sustainability as central

  15. Somatosensory-motor adaptation of orofacial actions in posterior parietal and ventral premotor cortices.

    Directory of Open Access Journals (Sweden)

    Krystyna Grabski

    Full Text Available Recent studies have provided evidence for sensory-motor adaptive changes and action goal coding of visually guided manual action in premotor and posterior parietal cortices. To extend these results to orofacial actions, devoid of auditory and visual feedback, we used a repetition suppression paradigm while measuring neural activity with functional magnetic resonance imaging during repeated intransitive and silent lip, jaw and tongue movements. In the motor domain, this paradigm refers to decreased activity in specific neural populations due to repeated motor acts and has been proposed to reflect sensory-motor adaptation. Orofacial movements activated a set of largely overlapping, common brain areas forming a core neural network classically involved in orofacial motor control. Crucially, suppressed neural responses during repeated orofacial actions were specifically observed in the left ventral premotor cortex, the intraparietal sulcus, the inferior parietal lobule and the superior parietal lobule. Since no visual and auditory feedback were provided during orofacial actions, these results suggest somatosensory-motor adaptive control of intransitive and silent orofacial actions in these premotor and parietal regions.

  16. How early is infants’ attention to objects and actions shaped by culture? New evidence from 24-month-olds raised in the US and China

    Directory of Open Access Journals (Sweden)

    Sandra R Waxman

    2016-02-01

    Full Text Available Researchers have proposed that the culture in which we are raised shapes the way that we attend to the objects and events that surround us. What remains unclear, however, is how early any such culturally-inflected differences emerge in development. Here, we address this issue directly, asking how 24-month-old infants from the US and China deploy their attention to objects and actions in dynamic scenes. By analyzing infants’ eye movements while they observed dynamic scenes, the current experiment revealed striking convergences, overall, in infants’ patterns of visual attention in the two communities, but also pinpointed a brief period during which their attention reliably diverged. This divergence, though modest, suggested that infants from the US devoted relatively more attention to the objects and those from China devoted relatively more attention to the actions in which they were engaged. This provides the earliest evidence for strong overlap in infants’ attention to objects and events in dynamic scenes, but also raises the possibility that by 24 months, infants’ attention may also be shaped subtly by the culturally-inflected attentional proclivities characteristic of adults in their cultural communities.

  17. Analyses of fugu hoxa2 genes provide evidence for subfunctionalization of neural crest cell and rhombomere cis-regulatory modules during vertebrate evolution.

    Science.gov (United States)

    McEllin, Jennifer A; Alexander, Tara B; Tümpel, Stefan; Wiedemann, Leanne M; Krumlauf, Robb

    2016-01-15

    Hoxa2 gene is a primary player in regulation of craniofacial programs of head development in vertebrates. Here we investigate the evolution of a Hoxa2 neural crest enhancer identified originally in mouse by comparing and contrasting the fugu hoxa2a and hoxa2b genes with their orthologous teleost and mammalian sequences. Using sequence analyses in combination with transgenic regulatory assays in zebrafish and mouse embryos we demonstrate subfunctionalization of regulatory activity for expression in hindbrain segments and neural crest cells between these two fugu co-orthologs. hoxa2a regulatory sequences have retained the ability to mediate expression in neural crest cells while those of hoxa2b include cis-elements that direct expression in rhombomeres. Functional dissection of the neural crest regulatory potential of the fugu hoxa2a and hoxa2b genes identify the previously unknown cis-element NC5, which is implicated in generating the differential activity of the enhancers from these genes. The NC5 region plays a similar role in the ability of this enhancer to mediate reporter expression in mice, suggesting it is a conserved component involved in control of neural crest expression of Hoxa2 in vertebrate craniofacial development.

  18. Triadic (ecological, neural, cognitive) niche construction: a scenario of human brain evolution extrapolating tool use and language from the control of reaching actions.

    Science.gov (United States)

    Iriki, Atsushi; Taoka, Miki

    2012-01-12

    Hominin evolution has involved a continuous process of addition of new kinds of cognitive capacity, including those relating to manufacture and use of tools and to the establishment of linguistic faculties. The dramatic expansion of the brain that accompanied additions of new functional areas would have supported such continuous evolution. Extended brain functions would have driven rapid and drastic changes in the hominin ecological niche, which in turn demanded further brain resources to adapt to it. In this way, humans have constructed a novel niche in each of the ecological, cognitive and neural domains, whose interactions accelerated their individual evolution through a process of triadic niche construction. Human higher cognitive activity can therefore be viewed holistically as one component in a terrestrial ecosystem. The brain's functional characteristics seem to play a key role in this triadic interaction. We advance a speculative argument about the origins of its neurobiological mechanisms, as an extension (with wider scope) of the evolutionary principles of adaptive function in the animal nervous system. The brain mechanisms that subserve tool use may bridge the gap between gesture and language--the site of such integration seems to be the parietal and extending opercular cortices.

  19. Innoversity in knowledge-for-action and adaptation to climate change: the first steps of an 'evidence-based climatic health' transfrontier training program

    Directory of Open Access Journals (Sweden)

    Véronique Lapaige

    2010-12-01

    Full Text Available Véronique Lapaige1–3, Hélène Essiembre41Department of Psychiatry, University of Montreal, Montreal, QC, Canada; 2Fernand-Seguin Research Centre, Montreal, QC, Canada; 3Quebec National Public Health Institute; 4Industrial and Organizational Program, Department of Psychology, University of Montreal, Montreal, QC, CanadaAbstract: It has become increasingly clear to the international scientific community that climate change is real and has important consequences for human health. To meet these new challenges, the World Health Organization recommends reinforcing the adaptive capacity of health systems. One of the possible avenues in this respect is to promote awareness and knowledge translation in climatic health, at both the local and global scales. Within such perspective, two major themes have emerged in the field of public health research: 1 the development of advanced training adapted to 'global environment' change and to the specific needs of various groups of actors (doctors, nurses, public health practitioners, health care managers, public service managers, local communities, etc and 2 the development of strategies for implementing research results and applying various types of evidence to the management of public health issues affected by climate change. Progress on these two fronts will depend on maximum innovation in transdisciplinary and transsectoral collaborations. The general purpose of this article is to present the program of a new research and learning chair designed for this double set of developmental objectives – a chair that emphasizes 'innoversity' (the dynamic relationship between innovation and diversity and 'transfrontier ecolearning for adaptive actions'. The Écoapprentissages, santé mentale et climat collaborative research chair (University of Montreal and Quebec National Public Health Institute based in Montreal is a center for 'transdisciplinary research' on the transfrontier knowledge-for-action that can aid

  20. Neural dynamics based on the recognition of neural fingerprints

    Directory of Open Access Journals (Sweden)

    José Luis eCarrillo-Medina

    2015-03-01

    Full Text Available Experimental evidence has revealed the existence of characteristic spiking features in different neural signals, e.g. individual neural signatures identifying the emitter or functional signatures characterizing specific tasks. These neural fingerprints may play a critical role in neural information processing, since they allow receptors to discriminate or contextualize incoming stimuli. This could be a powerful strategy for neural systems that greatly enhances the encoding and processing capacity of these networks. Nevertheless, the study of information processing based on the identification of specific neural fingerprints has attracted little attention. In this work, we study (i the emerging collective dynamics of a network of neurons that communicate with each other by exchange of neural fingerprints and (ii the influence of the network topology on the self-organizing properties within the network. Complex collective dynamics emerge in the network in the presence of stimuli. Predefined inputs, i.e. specific neural fingerprints, are detected and encoded into coexisting patterns of activity that propagate throughout the network with different spatial organization. The patterns evoked by a stimulus can survive after the stimulation is over, which provides memory mechanisms to the network. The results presented in this paper suggest that neural information processing based on neural fingerprints can be a plausible, flexible and powerful strategy.

  1. Molecular mapping of the origin of postnatal spinal cord ependymal cells: evidence that adult ependymal cells are derived from Nkx6.1+ ventral neural progenitor cells.

    Science.gov (United States)

    Fu, Hui; Qi, Yingchuan; Tan, Min; Cai, Jun; Hu, Xuemei; Liu, Zijing; Jensen, Jan; Qiu, Mengsheng

    2003-02-10

    Recent studies have suggested that the ependymal cells lining the central canal of postnatal spinal cord possess certain properties of neural stem cells. However, the embryonic origin and developmental potential of the postnatal spinal cord ependymal cells remain to be defined. In this report, we investigated the developmental origin of postnatal spinal ependymal cells by studying the dynamic expression of several neural progenitor genes that are initially expressed in distinct domains of neuroepithelium in young embryos. At later stages of development, as the ventricular zone of the embryonic spinal cord is reduced, expression of Nkx6.1 progenitor gene is constantly detected in ependymal cells throughout chick and mouse development. Expression of other neural progenitor genes that lie either dorsal or ventral to the Nkx6.1+ domain is gradually decreased and eventually disappeared. These results suggest that the remaining neuroepithelial cells at later stages of animal life are derived from the Nkx6.1+ ventral neuroepithelial cells. Expression of Nkx6.1 in the remaining neuroepithelium is closely associated with, and regulated by, Shh expression in the floor plate. In addition, we suggested that the Nkx6.1+ ependymal cells in adult mouse spinal cords may retain the proliferative property of neural stem cells.

  2. Evidence from pupillometry and fMRI indicates reduced neural response during vicarious social pain but not physical pain in autism

    NARCIS (Netherlands)

    Krach, Sören; Kamp-Becker, Inge; Einhäuser, Wolfgang; Sommer, Jens; Frässle, Stefan; Jansen, Andreas; Rademacher, Lena; Müller-Pinzler, Laura; Gazzola, V.; Paulus, Frieder M

    2015-01-01

    Autism spectrum disorder (ASD) is characterized by substantial social deficits. The notion that dysfunctions in neural circuits involved in sharing another's affect explain these deficits is appealing, but has received only modest experimental support. Here we evaluated a complex paradigm on the vic

  3. Priorities for action on the social determinants of health: Empirical evidence on the strongest associations with life expectancy in 54 low-income countries, 1990-2012.

    Science.gov (United States)

    Hauck, K; Martin, S; Smith, P C

    2016-10-01

    The WHO Commission on the Social Determinants of Health set out an impressive collection of policy proposals on the social determinants of health. However, a serious weakness for securing implementation is the difficulty for policymakers in identifying priorities for action. The objective of this study is to determine a small set of the most influential determinants using existing data and an empirical approach. 45 Indicators from the World Bank's World Development Indicators are selected to measure attainment for the determinants proposed by the Commission. Panel data models of life expectancy at birth for 54 low-income countries over the years 1990-2012 (1188 country-years) are estimated. Each determinant is subjected to a robustness test using Extreme Bound Analysis, to determine the stability of its estimated impact on life expectancy. For 20 robust and significant determinants the magnitude of association with life expectancy is determined. The largest average increases in life expectancy at 14.5 months per capita is associated with a one standard deviation reduction in HIV prevalence among children, followed by advances in gender equality at 9.4 months. Improvements in life expectancy between 6 and 9 months are associated with agricultural production, political stability, access to clean water and sanitation, good governance, and primary school enrolment. Improvements below 6 months are associated with increases in private health expenditure and overseas development assistance, and control of armed conflict and HIV prevalence among men. There is no evidence that national income, public spending on healthcare and education, secondary schooling, terms of international trade, employment, debt service and relief, out-of-pocket expenditures, agricultural ex- or imports, lifestock production, foreign investment, urbanization or environmental degradation are robustly associated with population health. Results provide support for the relevance of some proposed

  4. The neural crest and neural crest cells: discovery and significance for theories of embryonic organization

    Indian Academy of Sciences (India)

    Brian K Hall

    2008-12-01

    The neural crest has long fascinated developmental biologists, and, increasingly over the past decades, evolutionary and evolutionary developmental biologists. The neural crest is the name given to the fold of ectoderm at the junction between neural and epidermal ectoderm in neurula-stage vertebrate embryos. In this sense, the neural crest is a morphological term akin to head fold or limb bud. This region of the dorsal neural tube consists of neural crest cells, a special population(s) of cell, that give rise to an astonishing number of cell types and to an equally astonishing number of tissues and organs. Neural crest cell contributions may be direct — providing cells — or indirect — providing a necessary, often inductive, environment in which other cells develop. The enormous range of cell types produced provides an important source of evidence of the neural crest as a germ layer, bringing the number of germ layers to four — ectoderm, endoderm, mesoderm, and neural crest. In this paper I provide a brief overview of the major phases of investigation into the neural crest and the major players involved, discuss how the origin of the neural crest relates to the origin of the nervous system in vertebrate embryos, discuss the impact on the germ-layer theory of the discovery of the neural crest and of secondary neurulation, and present evidence of the neural crest as the fourth germ layer. A companion paper (Hall, Evol. Biol. 2008) deals with the evolutionary origins of the neural crest and neural crest cells.

  5. Perception, action, and Roelofs effect: a mere illusion of dissociation.

    Directory of Open Access Journals (Sweden)

    Paul Dassonville

    2004-11-01

    Full Text Available A prominent and influential hypothesis of vision suggests the existence of two separate visual systems within the brain, one creating our perception of the world and another guiding our actions within it. The induced Roelofs effect has been described as providing strong evidence for this perception/action dissociation: When a small visual target is surrounded by a large frame positioned so that the frame's center is offset from the observer's midline, the perceived location of the target is shifted in the direction opposite the frame's offset. In spite of this perceptual mislocalization, however, the observer can accurately guide movements to the target location. Thus, perception is prone to the illusion while actions seem immune. Here we demonstrate that the Roelofs illusion is caused by a frame-induced transient distortion of the observer's apparent midline. We further demonstrate that actions guided to targets within this same distorted egocentric reference frame are fully expected to be accurate, since the errors of target localization will exactly cancel the errors of motor guidance. These findings provide a mechanistic explanation for the various perceptual and motor effects of the induced Roelofs illusion without requiring the existence of separate neural systems for perception and action. Given this, the behavioral dissociation that accompanies the Roelofs effect cannot be considered evidence of a dissociation of perception and action. This indicates a general need to re-evaluate the broad class of evidence purported to support this hypothesized dissociation.

  6. Pleiotropic Actions of Peroxisome Proliferator-Activated Receptors (PPARs in Dysregulated Metabolic Homeostasis, Inflammation and Cancer: Current Evidence and Future Perspectives

    Directory of Open Access Journals (Sweden)

    Antonio Simone Laganà

    2016-06-01

    Full Text Available Background: Peroxisome proliferator-activated receptors (PPARs have demonstrated a lot of important effects in the regulation of glucose and lipid metabolism and in the correct functioning of adipose tissue. Recently, many studies have evaluated a possible effect of PPARs on tumor cells. The purpose of this review is to describe the effects of PPARs, their action and their future prospective; Methods: Narrative review aimed to synthesize cutting-edge evidence retrieved from searches of computerized databases; Results: PPARs play a key role in metabolic diseases, which include several cardiovascular diseases, insulin resistance, type 2 diabetes, metabolic syndrome, impaired immunity and the increasing risk of cancer; in particular, PPARα and PPARβ/δ mainly enable energy combustion, while PPARγ contributes to energy storage by enhancing adipogenesis; Conclusion: PPAR agonists could represent interesting types of molecules that can treat not only metabolic diseases, but also inflammation and cancer. Additional research is needed for the identification of high-affinity, high-specificity agonists for the treatment of obesity, type 2 diabetes (T2DM and other metabolic diseases. Further studies are needed also to elucidate the role of PPARs in cancer.

  7. Pleiotropic Actions of Peroxisome Proliferator-Activated Receptors (PPARs) in Dysregulated Metabolic Homeostasis, Inflammation and Cancer: Current Evidence and Future Perspectives

    Science.gov (United States)

    Laganà, Antonio Simone; Vitale, Salvatore Giovanni; Nigro, Angela; Sofo, Vincenza; Salmeri, Francesca Maria; Rossetti, Paola; Rapisarda, Agnese Maria Chiara; La Vignera, Sandro; Condorelli, Rosita Angela; Rizzo, Gianluca; Buscema, Massimo

    2016-01-01

    Background: Peroxisome proliferator-activated receptors (PPARs) have demonstrated a lot of important effects in the regulation of glucose and lipid metabolism and in the correct functioning of adipose tissue. Recently, many studies have evaluated a possible effect of PPARs on tumor cells. The purpose of this review is to describe the effects of PPARs, their action and their future prospective; Methods: Narrative review aimed to synthesize cutting-edge evidence retrieved from searches of computerized databases; Results: PPARs play a key role in metabolic diseases, which include several cardiovascular diseases, insulin resistance, type 2 diabetes, metabolic syndrome, impaired immunity and the increasing risk of cancer; in particular, PPARα and PPARβ/δ mainly enable energy combustion, while PPARγ contributes to energy storage by enhancing adipogenesis; Conclusion: PPAR agonists could represent interesting types of molecules that can treat not only metabolic diseases, but also inflammation and cancer. Additional research is needed for the identification of high-affinity, high-specificity agonists for the treatment of obesity, type 2 diabetes (T2DM) and other metabolic diseases. Further studies are needed also to elucidate the role of PPARs in cancer. PMID:27347932

  8. Further evidences for the mode of action of the larvicidal m-pentadecadienyl-phenol isolated from Myracrodruon urundeuva seeds against Aedes aegypti.

    Science.gov (United States)

    Souza, Terezinha M; Menezes, Erika S Bezerra; Oliveira, Rodrigo V; Almeida Filho, Luiz Carlos P; Martins, Jorge M; Moreno, Frederico B; Monteiro-Moreira, Ana Cristina O; Moura, Arlindo A Araripe; Carvalho, Ana F Urano

    2015-12-01

    Nowadays, dengue fever is considered the most important arbovirosis worldwide and its control is still based upon combating the vector Aedes aegypti. Besides monitoring of mosquito populations resistant to conventional insecticides, the search for new environmentally safe insecticides and conduction of molecular studies focusing on the elucidation of mode of action and possible resistance mechanisms are considered the key for a sustainable management of the mosquito vector. Thus, the present work aimed to assess changes in protein expression of 3rd-instar larvae of Ae. aegypti after exposure to the natural insecticide m-pentadecadienyl-phenol. Bidimensional electrophoresis followed by mass spectrometry resulted in identification of 12 proteins differentially expressed between control and treated groups. Larvae exposed to the toxic compound for 24h showed elevated detoxification response (glutathione-S-transferase), increased levels of stress-related proteins (HSP70) as well as evidence of lysosome stabilization to enable survival. Furthermore, expression of proteins involved in protection of peritrophic membrane and metabolism of lipids indicated systemic effect of toxic effects in treated larvae.

  9. Distribution of Müller stem cells within the neural retina: evidence for the existence of a ciliary margin-like zone in the adult human eye.

    Science.gov (United States)

    Bhatia, Bhairavi; Singhal, Shweta; Lawrence, Jean M; Khaw, Peng T; Limb, G Astrid

    2009-09-01

    Much interest has been generated by the identification of neural stem cells in the human neural retina and ciliary body. However, it is not clear whether stem cells identified in these ocular compartments are of the same origin or whether they ontogenically derive from different cell populations. This study examined the in situ anatomical distribution of these cells within the neural retina and ciliary body, as well as their ability to proliferate in response to EGF. Human retinae and ciliary body were examined for co-expression of Nestin, cellular retinaldehyde binding (CRALBP) or Vimentin, and the stem cell markers SOX2, CHX10, NOTCH1 and SHH. Retinal explants were cultured with epidermal growth factor (EGF) to assess retinal cell proliferation. Intense Nestin and CRALBP staining was observed in the neural retinal margin, where cells formed bundles of spindle cells (resembling glial cells) that lacked lamination and co-stained for SOX2, CHX10 and SHH. This staining differentiated the neural retina from the ciliary epithelium, which expressed SOX2, CHX10 and NOTCH1 but not Nestin or CRALBP. Nestin and CRALBP expression decreased towards the posterior retina, where it anatomically identified a population of Müller glia. All Vimentin positive Müller glia co-stained for SOX2, but only few Vimentin positive cells expressed Nestin and SOX2. Cells of the retinal margin and the inner nuclear layer (INL), where the soma of Müller glia predominate, re-entered the cell cycle upon retinal explant culture with EGF. Lack of lamination and abundance of Müller glia expressing stem cell markers in the marginal region of the adult human retina resemble the ciliary marginal zone (CMZ) of fish and amphibians. The findings that cells in this CM-like zone, as well in the inner nuclear layer proliferate in response to EGF suggest that the adult human retina has regenerative potential. Identification of factors that may promote retinal regeneration in the adult human eye would

  10. Modeling the value of strategic actions in the superior colliculus

    Directory of Open Access Journals (Sweden)

    Dhushan Thevarajah

    2010-02-01

    Full Text Available In learning models of strategic game play, an agent constructs a valuation (action value over possible future choices as a function of past actions and rewards. Choices are then stochastic functions of these action values. Our goal is to uncover a neural signal that correlates with the action value posited by behavioral learning models. We measured activity from neurons in the superior colliculus (SC, a midbrain region involved in planning saccadic eye movements, in monkeys while they performed two saccade tasks. In the strategic task, monkeys competed against a computer in a saccade version of the mixed-strategy game “matching-pennies”. In the instructed task, stochastic saccades were elicited through explicit instruction rather than free choices. In both tasks, neuronal activity and behavior were shaped by past actions and rewards with more recent events exerting a larger influence. Further, SC activity predicted upcoming choices during the strategic task and upcoming reaction times during the instructed task. Finally, we found that neuronal activity in both tasks correlated with an established learning model, the Experience Weighted Attraction model of action valuation (Ho, Camerer, and Chong, 2007. Collectively, our results provide evidence that action values hypothesized by learning models are represented in the motor planning regions of the brain in a manner that could be used to select strategic actions.

  11. Evidence from pharmacology and pathophysiology suggests that chemicals with dissimilar mechanisms of action could be of bigger concern in the toxicological risk assessment of chemical mixtures than chemicals with a similar mechanism of action

    DEFF Research Database (Denmark)

    Hadrup, Niels

    2014-01-01

    mechanisms of action, similar modes of action or with common target organs. In the European Union, efforts are currently being made to subgroup chemicals according to this need. However, it remains to be determined whether this is the best strategy to obtain data for risk assessment. In conditions...... such as cancer or HIV, it is generally recognised that pharmacological combination therapy targeting different mechanisms of action is more effective than a strategy where only one mechanism is targeted. Moreover, in diseases such as acute myocardial infarction and congestive heart failure, several organ systems...

  12. Imaging the neural mechanisms of TMS neglect-like bias in healthy volunteers with the interleaved TMS/fMRI technique: preliminary evidence

    Directory of Open Access Journals (Sweden)

    Raffaella eRicci

    2012-12-01

    Full Text Available Applying a precisely timed pulse of Transcranial Magnetic Stimulation (TMS over the right posterior parietal cortex (PPC can produce temporary visuo-spatial neglect-like effects. Although the TMS is applied over PPC, it is not clear what other brain regions are involved. We applied TMS within a functional Magnetic Resonance Imaging (fMRI scanner to investigate brain activity during TMS induction of neglect-like bias in three healthy volunteers, while they performed a line bisection judgment task (i.e. the landmark task. Single-pulse TMS at 115% of motor threshold was applied 150 ms after the visual stimulus onset. Participants completed two different TMS/fMRI sessions while performing this task: one session while single-pulse TMS was intermittently and time-locked applied to the right PPC and a control session with TMS positioned over the vertex. Perceptual rightward bias was observed when TMS was delivered over the right PPC. During neglect-like behavior, the fMRI maps showed decreased neural activity within parieto-frontal areas which are often lesioned or dysfunctional in patients with left neglect. Vertex TMS induced behavioral effects compatible with leftward response bias and increased BOLD signal in the left caudate (a site which has been linked to response bias. These results are discussed in relation to recent findings on neural networks subserving attention in space.

  13. Imaging the neural mechanisms of TMS neglect-like bias in healthy volunteers with the interleaved TMS/fMRI technique: preliminary evidence.

    Science.gov (United States)

    Ricci, Raffaella; Salatino, Adriana; Li, Xingbao; Funk, Agnes P; Logan, Sarah L; Mu, Qiwen; Johnson, Kevin A; Bohning, Daryl E; George, Mark S

    2012-01-01

    Applying a precisely timed pulse of transcranial magnetic stimulation (TMS) over the right posterior parietal cortex (PPC) can produce temporary visuo-spatial neglect-like effects. Although the TMS is applied over PPC, it is not clear what other brain regions are involved. We applied TMS within a functional magnetic resonance imaging (fMRI) scanner to investigate brain activity during TMS induction of neglect-like bias in three healthy volunteers, while they performed a line bisection judgment task (i.e., the landmark task). Single-pulse TMS at 115% of motor threshold was applied 150 ms after the visual stimulus onset. Participants completed two different TMS/fMRI sessions while performing this task: one session while single-pulse TMS was intermittently and time-locked applied to the right PPC and a control session with TMS positioned over the vertex. Perceptual rightward bias was observed when TMS was delivered over the right PPC. During neglect-like behavior, the fMRI maps showed decreased neural activity within parieto-frontal areas, which are often lesioned or dysfunctional in patients with left neglect. Vertex TMS induced behavioral effects compatible with leftward response bias and increased BOLD signal in the left caudate (a site which has been linked to response bias). These results are discussed in relation to recent findings on neural networks subserving attention in space.

  14. Neural Circuits Trained with Standard Reinforcement Learning Can Accumulate Probabilistic Information during Decision Making.

    Science.gov (United States)

    Kurzawa, Nils; Summerfield, Christopher; Bogacz, Rafal

    2017-02-01

    Much experimental evidence suggests that during decision making, neural circuits accumulate evidence supporting alternative options. A computational model well describing this accumulation for choices between two options assumes that the brain integrates the log ratios of the likelihoods of the sensory inputs given the two options. Several models have been proposed for how neural circuits can learn these log-likelihood ratios from experience, but all of these models introduced novel and specially dedicated synaptic plasticity rules. Here we show that for a certain wide class of tasks, the log-likelihood ratios are approximately linearly proportional to the expected rewards for selecting actions. Therefore, a simple model based on standard reinforcement learning rules is able to estimate the log-likelihood ratios from experience and on each trial accumulate the log-likelihood ratios associated with presented stimuli while selecting an action. The simulations of the model replicate experimental data on both behavior and neural activity in tasks requiring accumulation of probabilistic cues. Our results suggest that there is no need for the brain to support dedicated plasticity rules, as the standard mechanisms proposed to describe reinforcement learning can enable the neural circuits to perform efficient probabilistic inference.

  15. Power effects on cognitive control: Turning conflict into action.

    Science.gov (United States)

    Schmid, Petra C; Kleiman, Tali; Amodio, David M

    2015-06-01

    Power is known to promote effective goal pursuit, especially when it requires one to overcome distractions or bias. We proposed that this effect involves the ability to engage and implement cognitive control. In Study 1, we demonstrated that power enhances behavioral performance on a response conflict task and that it does so by enhancing controlled processing rather than by reducing automatic processing. In Study 2, we used an event-related potential index of anterior cingulate activity to test whether power effects on control were due to enhanced conflict sensitivity or action implementation. Power did not significantly affect neural sensitivity to conflict; rather, high power was associated with a stronger link between conflict processing and intended action, relative to low power. These findings suggest a new perspective on how social factors can affect controlled processing and offer new evidence regarding the transition between conflict detection and the implementation of action control.

  16. Understanding the Goals of Everyday Instrumental Actions Is Primarily Linked to Object, Not Motor-Kinematic, Information: Evidence from fMRI

    Science.gov (United States)

    Nicholson, Toby; Roser, Matt; Bach, Patric

    2017-01-01

    Prior research conceptualised action understanding primarily as a kinematic matching of observed actions to own motor representations but has ignored the role of object information. The current study utilized fMRI to identify (a) regions uniquely involved in encoding the goal of others’ actions, and (b) to test whether these goal understanding processes draw more strongly on regions involved in encoding object semantics or movement kinematics. Participants watched sequences of instrumental actions while attending to either the actions’ goal (goal task), the movements performed (movement task) or the objects used (object task). The results confirmed, first, a unique role of the inferior frontal gyrus, middle temporal gyrus and medial frontal gyrus in action goal understanding. Second, they show for the first time that activation in the goal task overlaps directly with object- but not movement-related activation. Moreover, subsequent parametric analyses revealed that movement-related regions become activated only when goals are unclear, or observers have little action experience. In contrast to motor theories of action understanding, these data suggest that objects—rather than movement kinematics—carry the key information about others’ actions. Kinematic information is additionally recruited when goals are ambiguous or unfamiliar. PMID:28081175

  17. Neural processing of race during imitation: self-similarity versus social status.

    Science.gov (United States)

    Losin, Elizabeth A Reynolds; Cross, Katy A; Iacoboni, Marco; Dapretto, Mirella

    2014-04-01

    People preferentially imitate others who are similar to them or have high social status. Such imitative biases are thought to have evolved because they increase the efficiency of cultural acquisition. Here we focused on distinguishing between self-similarity and social status as two candidate mechanisms underlying neural responses to a person's race during imitation. We used fMRI to measure neural responses when 20 African American (AA) and 20 European American (EA) young adults imitated AA, EA and Chinese American (CA) models and also passively observed their gestures and faces. We found that both AA and EA participants exhibited more activity in lateral frontoparietal and visual regions when imitating AAs compared with EAs or CAs. These results suggest that racial self-similarity is not likely to modulate neural responses to race during imitation, in contrast with findings from previous neuroimaging studies of face perception and action observation. Furthermore, AA and EA participants associated AAs with lower social status than EAs or CAs, suggesting that the social status associated with different racial groups may instead modulate neural activity during imitation of individuals from those groups. Taken together, these findings suggest that neural responses to race during imitation are driven by socially learned associations rather than self-similarity. This may reflect the adaptive role of imitation in social learning, where learning from higher status models can be more beneficial. This study provides neural evidence consistent with evolutionary theories of cultural acquisition.

  18. CD24 expression identifies teratogen-sensitive fetal neural stem cell subpopulations: evidence from developmental ethanol exposure and orthotopic cell transfer models.

    Directory of Open Access Journals (Sweden)

    Joseph D Tingling

    Full Text Available BACKGROUND: Ethanol is a potent teratogen. Its adverse neural effects are partly mediated by disrupting fetal neurogenesis. The teratogenic process is poorly understood, and vulnerable neurogenic stages have not been identified. Identifying these is a prerequisite for therapeutic interventions to mitigate effects of teratogen exposures. METHODS: We used flow cytometry and qRT-PCR to screen fetal mouse-derived neurosphere cultures for ethanol-sensitive neural stem cell (NSC subpopulations, to study NSC renewal and differentiation. The identity of vulnerable NSC populations was validated in vivo, using a maternal ethanol exposure model. Finally, the effect of ethanol exposure on the ability of vulnerable NSC subpopulations to integrate into the fetal neurogenic environment was assessed following ultrasound guided, adoptive transfer. RESULTS: Ethanol decreased NSC mRNAs for c-kit, Musashi-1and GFAP. The CD24(+ NSC population, specifically the CD24(+CD15(+ double-positive subpopulation, was selectively decreased by ethanol. Maternal ethanol exposure also resulted in decreased fetal forebrain CD24 expression. Ethanol pre-exposed CD24(+ cells exhibited increased proliferation, and deficits in cell-autonomous and cue-directed neuronal differentiation, and following orthotopic transplantation into naïve fetuses, were unable to integrate into neurogenic niches. CD24(depleted cells retained neurosphere regeneration capacity, but following ethanol exposure, generated increased numbers of CD24(+ cells relative to controls. CONCLUSIONS: Neuronal lineage committed CD24(+ cells exhibit specific vulnerability, and ethanol exposure persistently impairs this population's cell-autonomous differentiation capacity. CD24(+ cells may additionally serve as quorum sensors within neurogenic niches; their loss, leading to compensatory NSC activation, perhaps depleting renewal capacity. These data collectively advance a mechanistic hypothesis for teratogenesis leading to

  19. The representation of response effector and response location in episodic memory for newly acquired actions: evidence from retrieval-induced forgetting.

    Science.gov (United States)

    Reppa, Irene; Worth, E Rhian; Greville, W James; Saunders, Jo

    2013-06-01

    Information retrieval can cause forgetting for related but non-retrieved information. Such retrieval-induced forgetting (RIF) has been previously found for semantically and episodically related information. The current study used RIF to examine whether response effector and location are encoded explicitly in action memory. Participants learned unique touchscreen responses to ten novel objects. Correct actions to each object involved left-hand or right-hand pushing of one of four possible object buttons. After learning, participants practiced two of the ten object-specific sequences. Unpracticed actions could share hand only, button only, both hand and button, or neither hand nor button, with the practiced actions. Subsequent testing showed significant RIF (in retrieval accuracy and speed measures) for actions that shared hand only, button only, or both hand and button with the practiced action. The results have implications for understanding the representations mediating episodic action memory, and for the potential of RIF as a tool for elucidating feature-based representations in this and other domains.

  20. Sensorimotor learning biases choice behavior: a learning neural field model for decision making.

    Directory of Open Access Journals (Sweden)

    Christian Klaes

    Full Text Available According to a prominent view of sensorimotor processing in primates, selection and specification of possible actions are not sequential operations. Rather, a decision for an action emerges from competition between different movement plans, which are specified and selected in parallel. For action choices which are based on ambiguous sensory input, the frontoparietal sensorimotor areas are considered part of the common underlying neural substrate for selection and specification of action. These areas have been shown capable of encoding alternative spatial motor goals in parallel during movement planning, and show signatures of competitive value-based selection among these goals. Since the same network is also involved in learning sensorimotor associations, competitive action selection (decision making should not only be driven by the sensory evidence and expected reward in favor of either action, but also by the subject's learning history of different sensorimotor associations. Previous computational models of competitive neural decision making used predefined associations between sensory input and corresponding motor output. Such hard-wiring does not allow modeling of how decisions are influenced by sensorimotor learning or by changing reward contingencies. We present a dynamic neural field model which learns arbitrary sensorimotor associations with a reward-driven Hebbian learning algorithm. We show that the model accurately simulates the dynamics of action selection with different reward contingencies, as observed in monkey cortical recordings, and that it correctly predicted the pattern of choice errors in a control experiment. With our adaptive model we demonstrate how network plasticity, which is required for association learning and adaptation to new reward contingencies, can influence choice behavior. The field model provides an integrated and dynamic account for the operations of sensorimotor integration, working memory and action

  1. The role of BDNF in depression on the basis of its location in the neural circuitry

    Institute of Scientific and Technical Information of China (English)

    Hui YU; Zhe-yu CHEN

    2011-01-01

    Depression is one of the most prevalent and life-threatening forms of mental illnesses and the neural circuitry underlying depression remains incompletely understood. Most attention in the field has focused on hippocampal and frontal cortical regions for their roles in depression and antidepressant action. While these regions no doubt play important roles in the mental illness, there is compelling evi-dence that other brain regions are also involved. Brain-derived neurotrophic factor (BDNF) is broadly expressed in the developing and adult mammalian brain and has been implicated in development, neural regeneration, synaptic transmission, synaptic plasticity and neurogenesis. Recently BDNF has been shown to play an important role in the pathophysiology of depression, however there are con-troversial reports about the effects of BDNF on depression. Here, we present an overview of the current knowledge concerning BDNF actions and associated intracellular signaling in hippocampus, prefrontal cortex, nucleus accumbens (NAc) and amygdala as their rela-tion to depression.

  2. Feature Weight Tuning for Recursive Neural Networks

    OpenAIRE

    2014-01-01

    This paper addresses how a recursive neural network model can automatically leave out useless information and emphasize important evidence, in other words, to perform "weight tuning" for higher-level representation acquisition. We propose two models, Weighted Neural Network (WNN) and Binary-Expectation Neural Network (BENN), which automatically control how much one specific unit contributes to the higher-level representation. The proposed model can be viewed as incorporating a more powerful c...

  3. Folate receptor alpha is necessary for neural plate cell apical constriction during Xenopus neural tube formation.

    Science.gov (United States)

    Balashova, Olga A; Visina, Olesya; Borodinsky, Laura N

    2017-03-02

    Folate supplementation prevents up to 70% of neural tube defects (NTDs), which result from a failure of neural tube closure during embryogenesis. The elucidation of the mechanisms underlying folate action has been challenging. This study introduces Xenopus laevis as a model to determine the cellular and molecular mechanisms involved in folate action during neural tube formation. We show that knockdown of folate receptor-α (FRα) impairs neural tube formation and leads to NTDs. FRα knockdown in neural plate cells only is necessary and sufficient to induce NTDs. FRα-deficient neural plate cells fail to constrict, resulting in widening of the neural plate midline and defective neural tube closure. Pharmacological inhibition of folate action by methotrexate during neurulation induces NTDs by inhibiting folate interaction with its uptake systems. Our findings support a model for folate receptor interacting with cell adhesion molecules, thus regulating apical cell membrane remodeling and cytoskeletal dynamics necessary for neural plate folding. Further studies in this organism may unveil novel cellular and molecular events mediated by folate and lead to new means for preventing NTDs.

  4. Introduction. Modelling natural action selection.

    Science.gov (United States)

    Prescott, Tony J; Bryson, Joanna J; Seth, Anil K

    2007-09-29

    Action selection is the task of resolving conflicts between competing behavioural alternatives. This theme issue is dedicated to advancing our understanding of the behavioural patterns and neural substrates supporting action selection in animals, including humans. The scope of problems investigated includes: (i) whether biological action selection is optimal (and, if so, what is optimized), (ii) the neural substrates for action selection in the vertebrate brain, (iii) the role of perceptual selection in decision-making, and (iv) the interaction of group and individual action selection. A second aim of this issue is to advance methodological practice with respect to modelling natural action section. A wide variety of computational modelling techniques are therefore employed ranging from formal mathematical approaches through to computational neuroscience, connectionism and agent-based modelling. The research described has broad implications for both natural and artificial sciences. One example, highlighted here, is its application to medical science where models of the neural substrates for action selection are contributing to the understanding of brain disorders such as Parkinson's disease, schizophrenia and attention deficit/hyperactivity disorder.

  5. Forecasting returns on a stock market using Artificial Neural Networks and GARCH family models: Evidence of stock market S&P 500

    Directory of Open Access Journals (Sweden)

    Nadhem Selmi

    2015-04-01

    Full Text Available In the area of financial stock market forecasting, many studies have focused on application of Artificial Neural Networks (ANNs. Due to its high rate of uncertainty and volatility, the stock markets returns forecasting by conventional methods became a difficult task. The ANNs is a relatively new and have been reported as good methods to predict financial stock market levels and can model flexible linear or non-linear relationship among variables. The aim of the study is to employ an ANN models to estimate and predict the dynamic volatility of the daily of S&P500 market returns. Results of ANN models will be compared with time series model using GARCH family models. The use of the novel model for conditional stock markets returns volatility can handle the vast amount of nonlinear data, simulate their relationship and give a moderate solution for the hard problem. The forecasts of stock index returns in the paper will be evaluated and compared, considering the MSE, RMSE and MAE forecasts statistic.

  6. Neural Events in the Reinforcement Contingency

    Science.gov (United States)

    Silva, Maria Teresa Araujo; Goncalves, Fabio Leyser; Garcia-Mijares, Miriam

    2007-01-01

    When neural events are analyzed as stimuli and responses, functional relations among them and among overt stimuli and responses can be unveiled. The integration of neuroscience and the experimental analysis of behavior is beginning to provide empirical evidence of involvement of neural events in the three-term contingency relating discriminative…

  7. Adaptive Neurons For Artificial Neural Networks

    Science.gov (United States)

    Tawel, Raoul

    1990-01-01

    Training time decreases dramatically. In improved mathematical model of neural-network processor, temperature of neurons (in addition to connection strengths, also called weights, of synapses) varied during supervised-learning phase of operation according to mathematical formalism and not heuristic rule. Evidence that biological neural networks also process information at neuronal level.

  8. Task-Irrelevant Expectation Violations in Sequential Manual Actions: Evidence for a "Check-after-Surprise" Mode of Visual Attention and Eye-Hand Decoupling.

    Science.gov (United States)

    Foerster, Rebecca M

    2016-01-01

    When performing sequential manual actions (e.g., cooking), visual information is prioritized according to the task determining where and when to attend, look, and act. In well-practiced sequential actions, long-term memory (LTM)-based expectations specify which action targets might be found where and when. We have previously demonstrated (Foerster and Schneider, 2015b) that violations of such expectations that are task-relevant (e.g., target location change) cause a regression from a memory-based mode of attentional selection to visual search. How might task-irrelevant expectation violations in such well-practiced sequential manual actions modify attentional selection? This question was investigated by a computerized version of the number-connection test. Participants clicked on nine spatially distributed numbered target circles in ascending order while eye movements were recorded as proxy for covert attention. Target's visual features and locations stayed constant for 65 prechange-trials, allowing practicing the manual action sequence. Consecutively, a task-irrelevant expectation violation occurred and stayed for 20 change-trials. Specifically, action target number 4 appeared in a different font. In 15 reversion-trials, number 4 returned to the original font. During the first task-irrelevant change trial, manual clicking was slower and eye scanpaths were larger and contained more fixations. The additional fixations were mainly checking fixations on the changed target while acting on later targets. Whereas the eyes repeatedly revisited the task-irrelevant change, cursor-paths remained completely unaffected. Effects lasted for 2-3 change trials and did not reappear during reversion. In conclusion, an unexpected task-irrelevant change on a task-defining feature of a well-practiced manual sequence leads to eye-hand decoupling and a "check-after-surprise" mode of attentional selection.

  9. Visual motion imagery neurofeedback based on the hMT+/V5 complex: evidence for a feedback-specific neural circuit involving neocortical and cerebellar regions

    Science.gov (United States)

    Banca, Paula; Sousa, Teresa; Catarina Duarte, Isabel; Castelo-Branco, Miguel

    2015-12-01

    Objective. Current approaches in neurofeedback/brain-computer interface research often focus on identifying, on a subject-by-subject basis, the neural regions that are best suited for self-driven modulation. It is known that the hMT+/V5 complex, an early visual cortical region, is recruited during explicit and implicit motion imagery, in addition to real motion perception. This study tests the feasibility of training healthy volunteers to regulate the level of activation in their hMT+/V5 complex using real-time fMRI neurofeedback and visual motion imagery strategies. Approach. We functionally localized the hMT+/V5 complex to further use as a target region for neurofeedback. An uniform strategy based on motion imagery was used to guide subjects to neuromodulate hMT+/V5. Main results. We found that 15/20 participants achieved successful neurofeedback. This modulation led to the recruitment of a specific network as further assessed by psychophysiological interaction analysis. This specific circuit, including hMT+/V5, putative V6 and medial cerebellum was activated for successful neurofeedback runs. The putamen and anterior insula were recruited for both successful and non-successful runs. Significance. Our findings indicate that hMT+/V5 is a region that can be modulated by focused imagery and that a specific cortico-cerebellar circuit is recruited during visual motion imagery leading to successful neurofeedback. These findings contribute to the debate on the relative potential of extrinsic (sensory) versus intrinsic (default-mode) brain regions in the clinical application of neurofeedback paradigms. This novel circuit might be a good target for future neurofeedback approaches that aim, for example, the training of focused attention in disorders such as ADHD.

  10. Sentential context modulates the involvement of the motor cortex in action language processing: an FMRI study.

    Science.gov (United States)

    Schuil, Karen D I; Smits, Marion; Zwaan, Rolf A

    2013-01-01

    Theories of embodied cognition propose that language comprehension is based on perceptual and motor processes. More specifically, it is hypothesized that neurons processing verbs describing bodily actions, and those that process the corresponding physical actions, fire simultaneously during action verb learning. Thus the concept and motor activation become strongly linked. According to this view, the language-induced activation of the neural substrates for action is automatic. By contrast, a weak view of embodied cognition proposes that activation of these motor regions is modulated by context. In recent studies it was found that action verbs in literal sentences activate the motor system, while mixed results were observed for action verbs in non-literal sentences. Thus, whether the recruitment of motor regions is automatic or context dependent remains a question. We investigated functional magnetic resonance imaging activation in response to non-literal and literal sentences including arm and leg related actions. The sentence structure was such that the action verb was the last word in the subordinate clause. Thus, the constraining context was presented well before the verb. Region of interest analyses showed that action verbs in literal context engage the motor regions to a greater extent than non-literal action verbs. There was no evidence for a semantic somatotopic organization of the motor cortex. Taken together, these results indicate that during comprehension, the degree to which motor regions are recruited is context dependent, supporting the weak view of embodied cognition.

  11. Generalisation of action sequences in RNNPB networks with mirror properties

    NARCIS (Netherlands)

    Cuijpers, R.H.; Stuijt, F.H.A.; Sprinkhuizen-Kuyper, I.G.

    2009-01-01

    The human mirror neuron system (MNS) is supposed to be involved in recognition of observed action sequences. However, it remains unclear how such a system could learn to recognise a large variety of action sequences. Here we investigated a neural network with mirror properties, the Recurrent Neural

  12. Organizational Actions of Metabolic Hormones

    OpenAIRE

    Bouret, Sebastien G.

    2013-01-01

    Brain development is a complex and dynamic process, and many environmental factors have been found to influence the normal development of neural pathways. Cumulative evidence suggests that metabolic hormones that regulate the hypothalamic circuits that control energy homeostasis function in much the same way that sex steroids act on sexually dimorphic circuits. For example, although the effects of the adipocyte-derived hormone leptin were originally thought to be limited to the neural control...

  13. Neural adaptations to electrical stimulation strength training

    NARCIS (Netherlands)

    Hortobagyi, Tibor; Maffiuletti, Nicola A.

    2011-01-01

    This review provides evidence for the hypothesis that electrostimulation strength training (EST) increases the force of a maximal voluntary contraction (MVC) through neural adaptations in healthy skeletal muscle. Although electrical stimulation and voluntary effort activate muscle differently, there

  14. Remedial action and feedback processing in a time-estimation task: Evidence for a role of the rostral cingulate zone in behavioral adjustments without learning

    NARCIS (Netherlands)

    Veen, F.M. van der; Röder, C.H.; Mies, G.W.; Lugt, A. van der; Smits, M.

    2011-01-01

    The present study examined the role of the rostral cingulate zone (RCZ) in feedback processing, and especially focused on effects of modality of the feedback stimulus and remedial action. Participants performed a time-estimation task in which they had to estimate a 1-second interval. After the estim

  15. Optic ataxia as a model to investigate the role of the posterior parietal cortex in visually guided action: Evidence from studies of patient M.H.

    Directory of Open Access Journals (Sweden)

    Cristiana eCavina-Pratesi

    2013-07-01

    Full Text Available Optic ataxia is a neuropsychological disorder that affects the ability to interact with objects presented in the visual modality following either unilateral or bilateral lesions of the posterior parietal cortex (PPC. Patients with optic ataxia fail to reach accurately for objects, particularly when they are presented in peripheral vision. The present review will focus on a series of experiments performed on patient M.H. Following a lesion restricted largely to the left PPC, he developed mis-reaching behaviour when using his contralesional right arm for movements directed toward the contralesional (right visual half-field. Given the clear-cut specificity of this patient’s deficit, whereby reaching actions are essentially spared when executed toward his ipsilateral space or when using his left arm, M.H. provides a valuable experiment of nature for investigating the role of the PPC in performing different visually guided actions. In order to address this, we used kinematic measurement techniques to investigate M.H.’s reaching and grasping behaviour in various tasks. Our experiments support the idea that optic ataxia is highly function-specific: it affects a specific sub-category of visually guided actions (reaching but not grasping, regardless of their specific end goal (both reaching toward an object and reaching to avoid an obstacle; and finally, is independent of the limb used to perform the action (whether the arm or the leg. Critically, these results are congruent with recent functional MRI experiments in neurologically intact subjects which suggest that the PPC is organized in a function-specific, rather than effector-specific, manner with different sub-portions of its mantle devoted to guiding actions according to their specific end-goal (reaching, grasping or looking, rather than according to the effector used to perform them (leg, arm, hand or eyes.

  16. Regulation of the nascent brain vascular network by neural progenitors.

    Science.gov (United States)

    Santhosh, Devi; Huang, Zhen

    2015-11-01

    Neural progenitors are central players in the development of the brain neural circuitry. They not only produce the diverse neuronal and glial cell types in the brain, but also guide their migration in this process. Recent evidence indicates that neural progenitors also play a critical role in the development of the brain vascular network. At an early stage, neural progenitors have been found to facilitate the ingression of blood vessels from outside the neural tube, through VEGF and canonical Wnt signaling. Subsequently, neural progenitors directly communicate with endothelial cells to stabilize nascent brain vessels, in part through down-regulating Wnt pathway activity. Furthermore, neural progenitors promote nascent brain vessel integrity, through integrin αvβ8-dependent TGFβ signaling. In this review, we will discuss the evidence for, as well as questions that remain, regarding these novel roles of neural progenitors and the underlying mechanisms in their regulation of the nascent brain vascular network.

  17. Lack of Evidence That Neural Empathic Responses Are Blunted in Excessive Users of Violent Video Games: An fMRI Study

    Science.gov (United States)

    Szycik, Gregor R.; Mohammadi, Bahram; Münte, Thomas F.; te Wildt, Bert T.

    2017-01-01

    The use of violent video games has been often linked to increase of aggressive behavior. According to the General Aggression Model, one of the central mechanisms for this aggressiveness inducing impact is an emotional desensitization process resulting from long lasting repeated violent game playing. This desensitization should evidence itself in a lack of empathy. Recent research has focused primarily on acute, short term impact of violent media use but only little is known about long term effects. In this study 15 excessive users of violent games and control subjects matched for age and education viewed pictures depicting emotional and neutral situations with and without social interaction while fMRI activations were obtained. While the typical pattern of activations for empathy and theory of mind networks was seen, both groups showed no differences in brain responses. We interpret our results as evidence against the desensitization hypothesis and suggest that the impact of violent media on emotional processing may be rather acute and short-lived. PMID:28337156

  18. Neural Networks

    Directory of Open Access Journals (Sweden)

    Schwindling Jerome

    2010-04-01

    Full Text Available This course presents an overview of the concepts of the neural networks and their aplication in the framework of High energy physics analyses. After a brief introduction on the concept of neural networks, the concept is explained in the frame of neuro-biology, introducing the concept of multi-layer perceptron, learning and their use as data classifer. The concept is then presented in a second part using in more details the mathematical approach focussing on typical use cases faced in particle physics. Finally, the last part presents the best way to use such statistical tools in view of event classifers, putting the emphasis on the setup of the multi-layer perceptron. The full article (15 p. corresponding to this lecture is written in french and is provided in the proceedings of the book SOS 2008.

  19. Action semantics modulate action prediction.

    Science.gov (United States)

    Springer, Anne; Prinz, Wolfgang

    2010-11-01

    Previous studies have demonstrated that action prediction involves an internal action simulation that runs time-locked to the real action. The present study replicates and extends these findings by indicating a real-time simulation process (Graf et al., 2007), which can be differentiated from a similarity-based evaluation of internal action representations. Moreover, results showed that action semantics modulate action prediction accuracy. The semantic effect was specified by the processing of action verbs and concrete nouns (Experiment 1) and, more specifically, by the dynamics described by action verbs (Experiment 2) and the speed described by the verbs (e.g., "to catch" vs. "to grasp" vs. "to stretch"; Experiment 3). These results propose a linkage between action simulation and action semantics as two yet unrelated domains, a view that coincides with a recent notion of a close link between motor processes and the understanding of action language.

  20. Simulated experiment evidences of the corrosion and reform actions of H2S to carbonate reservoirs: an example of Feixianguan Formation, east Sichuan

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The reservoir of Feixianguan Formation of the Lower Triassic in the Sichuan Basin is the deepest buried carbonate reservoir in China, with developed secondary corrosion holes, high quantities carbonate reservoir, maximum effective carbonate reservoir thickness. Also Feixianguan gas reservoir has the highest quantities of H2S. Research discovers that there are close relationships between the formation of reservoir and H2S. The mutual actions between acidity fluid and carbonate promoted the forming of secondary carbonate holes. Through the experiment of corrosion of the samples of Feixianguan carbonate reservoir in saturated aqueous solution of hydrogen sulfide, the porosity and permeability increased greatly, porosity increased 2% and permeability increased nearly two quantity degrees, also the density became light, which confirm the corrosion and reform actions of H2S to carbonate.

  1. Evidence for involvement of c-Src in the anti-apoptotic action of nitric oxide in serum-deprived RINm5F cells.

    Science.gov (United States)

    Tejedo, J R; Ramírez, R; Cahuana, G M; Rincón, P; Sobrino, F; Bedoya, F J

    2001-11-01

    The mechanism by which nitric oxide (NO) protects from apoptosis is a matter of debate. We have shown previously that phosphorylation of tyrosine residues participates in the protection from apoptosis in insulin-producing RINm5F cells (Inorg. Chem. Commun. 3 (2000) 32). Since NO has been reported to activate the tyrosine kinase c-Src and this kinase is involved in the activation of protein kinase G (PKG) in some cell systems, we aimed at studying the contribution of c-Src and PKG systems in anti-apoptotic actions of NO in serum-deprived RINm5F cells. Here we report that exposure of serum-deprived cells to 10 microM DETA/NO results in protection from degradation of the anti-apoptotic protein Bcl-2, together with a reduction of cytochrome c release from mitochondria and caspase-3 inhibition. Studies with the inhibitors ODQ and KT-5823 revealed that these actions are dependent on both activation of guanylate cyclase and PKG. DETA/NO was also able to induce autophosphorylation and activation c-Src protein both in vivo and in vitro and active c-Src was able to induce tyrosine phosphorylation of Bcl-2 in vitro. The c-Src kinase inhibitor PP1 abrogated the actions of DETA/NO on cGMP formation, PKG activation, caspase activation, cytochrome c release from mitochondria, and Bcl-2 phosphorylation and degradation in serum-deprived cells. We thus propose that activation of c-Src is an early step in the chain of events that signal cGMP-dependent anti-apoptotic actions of NO in mitocohondria.

  2. Determining the mode of action of anti-mycobacterial C17 diyne natural products using expression profiling: evidence for fatty acid biosynthesis inhibition

    OpenAIRE

    Li, Haoxin; Cowie, Andrew; JOHNSON, JOHN A.; Webster, Duncan; Martyniuk, Christopher J.; Gray, Christopher A.

    2016-01-01

    Background The treatment of microbial infections is becoming increasingly challenging because of limited therapeutic options and the growing number of pathogenic strains that are resistant to current antibiotics. There is an urgent need to identify molecules with novel modes of action to facilitate the development of new and more effective therapeutic agents. The anti-mycobacterial activity of the C17 diyne natural products falcarinol and panaxydol has been described previously; however, thei...

  3. Integrating verbal and nonverbal communication in a dynamic neural field architecture for human-robot interaction

    Directory of Open Access Journals (Sweden)

    Estela Bicho

    2010-05-01

    Full Text Available How do humans coordinate their intentions, goals and motor behaviors when performing joint action tasks? Recent experimental evidence suggests that resonance processes in the observer's motor system are crucially involved in our ability to understand actions of others', to infer their goals and even to comprehend their action-related language. In this paper, we present a control architecture for human-robot collaboration that exploits this close perception-action linkage as a means to achieve more natural and efficient communication grounded in sensorimotor experiences. The architecture is formalized by a coupled system of dynamic neural fields representing a distributed network of neural populations that encode in their activation patterns goals, actions and shared task knowledge. We validate the verbal and non-verbal communication skills of the robot in a joint assembly task in which the human-robot team has to construct toy objects from their components. The experiments focus on the robot’s capacity to anticipate the user’s needs and to detect and communicate unexpected events that may occur during joint task execution.

  4. Cross-resistance of an amsacrine-resistant human leukemia line to topoisomerase II reactive DNA intercalating agents. Evidence for two topoisomerase II directed drug actions

    Energy Technology Data Exchange (ETDEWEB)

    Zwelling, L.A.; Mayes, J.; Hinds, M.; Chan, D.; Altschuler, E.; Carroll, B.; Parker, E.; Deisseroth, K.; Radcliffe, A.; Seligman, M.; Li, Li; Farquhar, D. (Univ. of Texas M.D. Anderson Cancer Center, Houston (USA))

    1991-04-23

    HL-60/AMSA is a human leukemia cell line that is 50-100-fold more resistant than its drug-sensitive HL-60 parent line to the cytotoxic actions of the DNA intercalator amsacrine (m-AMSA). HL-60/AMSA topoisomerase II is also resistant to the inhibitory actions of m-AMSA. HL-60/AMSA cells and topoisomerase II are cross-resistant to anthracycline and ellipticine intercalators but relatively sensitive to the nonintercalating topoisomerase II reactive epipodophyllotoxin etoposide. The authors now demonstrate that HL-60/AMSA and its topoisomerase II are cross-resistant to the DNA intercalators mitoxantrone and amonafide, thus strongly indicating that HL-60/AMSA and its topoisomerase II are resistant to topoisomerase II reactive intercalators but not to nonintercalators. At high concentrations, mitoxantrone and amonafide were also found to inhibit their own, m-AMSA's, and etoposide's abilities to stabilize topoisomerase II-DNA complexes. These results suggest that the cytotoxicity of m-AMSA and etoposide is initiated primarily by the stabilization of the topoisomerase II-DNA complex. Other topoisomerase II reactive drugs may inhibit the enzyme at other steps in the topoisomerization cycle, particularly at elevated concentrations. Under these conditions, these latter drugs may not produce protein-associated DNA cleavage while still inhibiting topoisomerase II function as well as the actions of other topoisomerase II reactive drugs.

  5. Cocaine-induced cardiovascular effects: lack of evidence for a central nervous system site of action based on hemodynamic studies with cocaine methiodide.

    Science.gov (United States)

    Dickerson, L W; Rodak, D J; Kuhn, F E; Wahlstrom, S K; Tessel, R E; Visner, M S; Schaer, G L; Gillis, R A

    1999-01-01

    It has been suggested that cocaine acts directly in the brain to enhance central sympathetic outflow. However, some studies suggested that the cardiovascular effects of cocaine are related to a peripheral action. To characterize further the site of cocaine's cardiovascular effect, we compared the hemodynamic effects of cocaine (2 mg/kg, i.v. bolus) with those observed after administration of an equimolar dose (2.62 mg/kg, i.v. bolus) of cocaine methiodide, a quaternary derivative of cocaine that does not penetrate the blood-brain barrier, by using sufentanil-sedated dogs. Cocaine produced significant (p < 0.05) increases in heart rate (+37+/-11 beats/min), mean arterial pressure (+55+/-11 mm Hg), left ventricular end-diastolic pressure (+5.3+/-1.0 mm Hg), and cardiac output (+2.4+/-0.9 L/min). Cocaine methiodide produced increases in heart rate (+57+/-11 beats/min), mean arterial pressure (+45+/-11 mm Hg), left ventricular end-diastolic pressure (+3.4+/-1.0 mm Hg), and cardiac output (1.1+/-0.9 L/min), which were not significantly different from those observed with cocaine. Because opiate sedation potentially might have attenuated central sympathetic outflow, we further confirmed the qualitative similarity of the actions of cocaine and cocaine methiodide on heart rate and blood pressure in unsedated, conscious dogs. Our data suggest that the cardiovascular effects of cocaine result primarily from a peripheral site of action.

  6. Cholinergic systems mediate action from movement to higher consciousness.

    Science.gov (United States)

    Woolf, Nancy J; Butcher, Larry L

    2011-08-10

    There is a fundamental link between cholinergic neurotransmitter function and overt and covert actions. Major cholinergic systems include peripheral motor neurons organizing skeletal muscle movements into overt behaviors and cholinergic neurons in the basal forebrain and mesopontine regions that mediate covert actions realized as states of consciousness, arousal, selective attention, perception, and memory. Cholinergic interneurons in the striatum appear to integrate conscious and unconscious actions. Neural network models involving cholinergic neurons, as well as neurons using other neurotransmitters, emphasize connective circuitry as being responsible for both motor programs and neural correlates of higher consciousness. This, however, is only a partial description. At a more fundamental level lie intracellular mechanisms involving the cytoskeleton, which are common to both muscle contraction and neuroplastic responses in targets of central cholinergic cells attendant with higher cognition. Acetylcholine, acting through nicotinic receptors, triggers interactions between cytoskeletal proteins in skeletal muscle cells, as has been long known. There is also evidence that acetylcholine released at central sites acts through muscarinic and nicotinic receptors to initiate responses in actin and microtubule proteins. These effects and their implications for cholinergic involvement in higher cognition are explored in this review.

  7. FGF Signaling Transforms Non-neural Ectoderm into Neural Crest

    OpenAIRE

    Yardley, Nathan; García-Castro, Martín I.

    2012-01-01

    The neural crest arises at the border between the neural plate and the adjacent non-neural ectoderm. It has been suggested that both neural and non-neural ectoderm can contribute to the neural crest. Several studies have examined the molecular mechanisms that regulate neural crest induction in neuralized tissues or the neural plate border. Here, using the chick as a model system, we address the molecular mechanisms by which non-neural ectoderm generates neural crest. We report that in respons...

  8. Rapid neural discrimination of communicative gestures.

    Science.gov (United States)

    Redcay, Elizabeth; Carlson, Thomas A

    2015-04-01

    Humans are biased toward social interaction. Behaviorally, this bias is evident in the rapid effects that self-relevant communicative signals have on attention and perceptual systems. The processing of communicative cues recruits a wide network of brain regions, including mentalizing systems. Relatively less work, however, has examined the timing of the processing of self-relevant communicative cues. In the present study, we used multivariate pattern analysis (decoding) approach to the analysis of magnetoencephalography (MEG) to study the processing dynamics of social-communicative actions. Twenty-four participants viewed images of a woman performing actions that varied on a continuum of communicative factors including self-relevance (to the participant) and emotional valence, while their brain activity was recorded using MEG. Controlling for low-level visual factors, we found early discrimination of emotional valence (70 ms) and self-relevant communicative signals (100 ms). These data offer neural support for the robust and rapid effects of self-relevant communicative cues on behavior.

  9. Co-lateralized bilingual mechanisms for reading in single and dual language contexts: evidence from visual half-field processing of action words in proficient bilinguals

    Directory of Open Access Journals (Sweden)

    Marlena eKrefta

    2015-08-01

    Full Text Available When reading, proficient bilinguals seem to engage the same cognitive circuits regardless of the language in use. Yet, whether or not such ‘bilingual’ mechanisms would be lateralized in the same way in distinct – single or dual – language contexts is a question for debate. To fill this gap, we tested 18 highly proficient Polish (L1 – English (L2 childhood bilinguals whose task was to read aloud one of the two laterally presented action verbs, one stimulus per visual half field. While in the single-language blocks only L1 or L2 words were shown, in the subsequent mixed-language blocks words from both languages were concurrently displayed. All stimuli were presented for 217 ms followed by masks in which letters were replaced with hash marks. Since in non-simultaneous bilinguals the control of language, skilled actions (including reading, and representations of action concepts are typically left lateralized, the vast majority of our participants showed the expected, significant right visual field advantage for L1 and L2, both for accuracy and response times. The observed effects were nevertheless associated with substantial variability in the strength of the lateralization of the mechanisms involved. Moreover, although it could be predicted that participants’ performance should be better in a single-language context, accuracy was significantly higher and response times were significantly shorter in a dual-language context, irrespective of the language tested. Finally, for both accuracy and response times, there were significant positive correlations between the laterality indices (LIs of both languages independent of the context, with a significantly greater left-sided advantage for L1 vs. L2 in the mixed-language blocks, based on LIs calculated for response times. Thus, despite similar representations of the two languages in the bilingual brain, these results also point to the functional separation of L1 and L2 in the dual

  10. Spin-mediated consciousness theory: possible roles of neural membrane nuclear spin ensembles and paramagnetic oxygen.

    Science.gov (United States)

    Hu, Huping; Wu, Maoxin

    2004-01-01

    A novel theory of consciousness is proposed in this paper. We postulate that consciousness is intrinsically connected to quantum spin since the latter is the origin of quantum effects in both Bohm and Hestenes quantum formulism and a fundamental quantum process associated with the structure of space-time. That is, spin is the "mind-pixel". The unity of mind is achieved by entanglement of the mind-pixels. Applying these ideas to the particular structures and dynamics of the brain, we theorize that human brain works as follows: through action potential modulated nuclear spin interactions and paramagnetic O2/NO driven activations, the nuclear spins inside neural membranes and proteins form various entangled quantum states some of which survive decoherence through quantum Zeno effects or in decoherence-free subspaces and then collapse contextually via irreversible and non-computable means producing consciousness and, in turn, the collective spin dynamics associated with said collapses have effects through spin chemistry on classical neural activities thus influencing the neural networks of the brain. Our proposal calls for extension of associative encoding of neural memories to the dynamical structures of neural membranes and proteins. Thus, according our theory, the nuclear spin ensembles are the "mind-screen" with nuclear spins as its pixels, the neural membranes and proteins are the mind-screen and memory matrices, and the biologically available paramagnetic species such as O2 and NO are pixel-activating agents. Together, they form the neural substrates of consciousness. We also present supporting evidence and make important predictions. We stress that our theory is experimentally verifiable with present technologies. Further, experimental realizations of intra-/inter-molecular nuclear spin coherence and entanglement, macroscopic entanglement of spin ensembles and NMR quantum computation, all in room temperatures, strongly suggest the possibility of a spin

  11. The minimalist grammar of action.

    Science.gov (United States)

    Pastra, Katerina; Aloimonos, Yiannis

    2012-01-12

    Language and action have been found to share a common neural basis and in particular a common 'syntax', an analogous hierarchical and compositional organization. While language structure analysis has led to the formulation of different grammatical formalisms and associated discriminative or generative computational models, the structure of action is still elusive and so are the related computational models. However, structuring action has important implications on action learning and generalization, in both human cognition research and computation. In this study, we present a biologically inspired generative grammar of action, which employs the structure-building operations and principles of Chomsky's Minimalist Programme as a reference model. In this grammar, action terminals combine hierarchically into temporal sequences of actions of increasing complexity; the actions are bound with the involved tools and affected objects and are governed by certain goals. We show, how the tool role and the affected-object role of an entity within an action drives the derivation of the action syntax in this grammar and controls recursion, merge and move, the latter being mechanisms that manifest themselves not only in human language, but in human action too.

  12. Improved probabilistic inference as a general learning mechanism with action video games.

    Science.gov (United States)

    Green, C Shawn; Pouget, Alexandre; Bavelier, Daphne

    2010-09-14

    Action video game play benefits performance in an array of sensory, perceptual, and attentional tasks that go well beyond the specifics of game play [1-9]. That a training regimen may induce improvements in so many different skills is notable because the majority of studies on training-induced learning report improvements on the trained task but limited transfer to other, even closely related, tasks ([10], but see also [11-13]). Here we ask whether improved probabilistic inference may explain such broad transfer. By using a visual perceptual decision making task [14, 15], the present study shows for the first time that action video game experience does indeed improve probabilistic inference. A neural model of this task [16] establishes how changing a single parameter, namely the strength of the connections between the neural layer providing the momentary evidence and the layer integrating the evidence over time, captures improvements in action-gamers behavior. These results were established in a visual, but also in a novel auditory, task, indicating generalization across modalities. Thus, improved probabilistic inference provides a general mechanism for why action video game playing enhances performance in a wide variety of tasks. In addition, this mechanism may serve as a signature of training regimens that are likely to produce transfer of learning.

  13. Neural Correlates of Task-Irrelevant First and Second Language Emotion Words — Evidence from the Face-Word Stroop Task

    Directory of Open Access Journals (Sweden)

    Lin Fan

    2016-11-01

    Full Text Available Emotionally valenced words have thus far not been empirically examined in a bilingual population with the emotional face-word Stroop paradigm. Chinese-English bilinguals were asked to identify the facial expressions of emotion with their first (L1 or second (L2 language task-irrelevant emotion words superimposed on the face pictures. We attempted to examine how the emotional content of words modulates behavioral performance and cerebral functioning in the bilinguals’ two languages. The results indicated that there were significant congruency effects for both L1 and L2 emotion words, and that identifiable differences in the magnitude of Stroop effect between the two languages were also observed, suggesting L1 is more capable of activating the emotional response to word stimuli. For event-related potentials (ERPs data, an N350-550 effect was observed only in L1 task with greater negativity for incongruent than congruent trials. The size of N350-550 effect differed across languages, whereas no identifiable language distinction was observed in the effect of conflict slow potential (conflict SP. Finally, more pronounced negative amplitude at 230-330 ms was observed in L1 than in L2, but only for incongruent trials. This negativity, likened to an orthographic decoding N250, may reflect the extent of attention to emotion word processing at word-form level, while N350-550 reflects a complicated set of processes in the conflict processing. Overall, the face-word congruency effect has reflected identifiable language distinction at 230-330 and 350-550 ms, which provides supporting evidence for the theoretical proposals assuming attenuated emotionality of L2 processing.

  14. Neural Correlates of Task-Irrelevant First and Second Language Emotion Words – Evidence from the Emotional Face–Word Stroop Task

    Science.gov (United States)

    Fan, Lin; Xu, Qiang; Wang, Xiaoxi; Zhang, Feng; Yang, Yaping; Liu, Xiaoping

    2016-01-01

    Emotionally valenced words have thus far not been empirically examined in a bilingual population with the emotional face–word Stroop paradigm. Chinese-English bilinguals were asked to identify the facial expressions of emotion with their first (L1) or second (L2) language task-irrelevant emotion words superimposed on the face pictures. We attempted to examine how the emotional content of words modulated behavioral performance and cerebral functioning in the bilinguals’ two languages. The results indicated that there were significant congruency effects for both L1 and L2 emotion words, and that identifiable differences in the magnitude of the Stroop effect between the two languages were also observed, suggesting L1 is more capable of activating the emotional response to word stimuli. For event-related potentials data, an N350–550 effect was observed only in the L1 task with greater negativity for incongruent than congruent trials. The size of the N350–550 effect differed across languages, whereas no identifiable language distinction was observed in the effect of conflict slow potential (conflict SP). Finally, more pronounced negative amplitude at 230–330 ms was observed in L1 than in L2, but only for incongruent trials. This negativity, likened to an orthographic decoding N250, may reflect the extent of attention to emotion word processing at word-form level, while the N350–550 reflects a complicated set of processes in the conflict processing. Overall, the face–word congruency effect has reflected identifiable language distinction at 230–330 and 350-550 ms, which provides supporting evidence for the theoretical proposals assuming attenuated emotionality of L2 processing. PMID:27847485

  15. Neural Network Applications

    NARCIS (Netherlands)

    Vonk, E.; Jain, L.C.; Veelenturf, L.P.J.

    1995-01-01

    Artificial neural networks, also called neural networks, have been used successfully in many fields including engineering, science and business. This paper presents the implementation of several neural network simulators and their applications in character recognition and other engineering areas

  16. Changes of right-hemispheric activation after constraint-induced, intensive language action therapy in chronic aphasia: fMRI evidence from auditory semantic processing

    Directory of Open Access Journals (Sweden)

    Bettina eMohr

    2014-11-01

    Full Text Available The role of the two hemispheres in the neurorehabilitation of language is still under dispute. This study explored the changes in language-evoked brain activation over a two-week treatment interval with intensive constraint induced aphasia therapy (CIAT, which is also called intensive language action therapy (ILAT. Functional magnetic resonance imaging (fMRI was used to assess brain activation in perilesional left hemispheric and in homotopic right hemispheric areas during passive listening to high and low-ambiguity sentences and non-speech control stimuli in chronic non-fluent aphasia patients. All patients demonstrated significant clinical improvements of language functions after therapy. In an event-related fMRI experiment, a significant increase of BOLD signals was manifest in right inferior frontal and temporal areas. This activation increase was stronger for highly ambiguous sentences than for unambiguous ones. These results suggest that the known language improvements brought about by intensive constraint-induced language action therapy at least in part relies on circuits within the right-hemispheric homologues of left-perisylvian language areas, which are most strongly activated in the processing of semantically complex language.

  17. Changes of right-hemispheric activation after constraint-induced, intensive language action therapy in chronic aphasia: fMRI evidence from auditory semantic processing.

    Science.gov (United States)

    Mohr, Bettina; Difrancesco, Stephanie; Harrington, Karen; Evans, Samuel; Pulvermüller, Friedemann

    2014-01-01

    The role of the two hemispheres in the neurorehabilitation of language is still under dispute. This study explored the changes in language-evoked brain activation over a 2-week treatment interval with intensive constraint induced aphasia therapy (CIAT), which is also called intensive language action therapy (ILAT). Functional magnetic resonance imaging (fMRI) was used to assess brain activation in perilesional left hemispheric and in homotopic right hemispheric areas during passive listening to high and low-ambiguity sentences and non-speech control stimuli in chronic non-fluent aphasia patients. All patients demonstrated significant clinical improvements of language functions after therapy. In an event-related fMRI experiment, a significant increase of BOLD signal was manifest in right inferior frontal and temporal areas. This activation increase was stronger for highly ambiguous sentences than for unambiguous ones. These results suggest that the known language improvements brought about by intensive constraint-induced language action therapy at least in part relies on circuits within the right-hemispheric homologs of left-perisylvian language areas, which are most strongly activated in the processing of semantically complex language.

  18. Incentive memory: evidence the basolateral amygdala encodes and the insular cortex retrieves outcome values to guide choice between goal-directed actions.

    Science.gov (United States)

    Parkes, Shauna L; Balleine, Bernard W

    2013-05-15

    Choice between goal-directed actions is determined by the relative value of their consequences. Such values are encoded during incentive learning and later retrieved to guide performance. Although the basolateral amygdala (BLA) and the gustatory region of insular cortex (IC) have been implicated in these processes, their relative contribution is still a matter of debate. Here we assessed whether these structures interact during incentive learning and retrieval to guide choice. In these experiments, rats were trained on two actions for distinct outcomes after which one of the two outcomes was devalued by specific satiety immediately before a choice extinction test. We first confirmed that, relative to appropriate controls, outcome devaluation recruited both the BLA and IC based on activation of the immediate early gene Arc; however, we found that infusion of the NMDAr antagonist ifenprodil into the BLA only abolished outcome devaluation when given before devaluation. In contrast, ifenprodil infusion into the IC was effective whether made before devaluation or test. We hypothesized that the BLA encodes and the IC retrieves incentive value for choice and, to test this, developed a novel sequential disconnection procedure. Blocking NMDAr activation unilaterally in the BLA before devaluation and then contralaterally in the IC before test abolished selective devaluation. In contrast, reversing the order of these infusions left devaluation intact. These results confirm that the BLA and IC form a circuit mediating the encoding and retrieval of outcome values, with the BLA encoding and the IC retrieving such values to guide choice.

  19. From action to language: comparative perspectives on primate tool use, gesture and the evolution of human language.

    Science.gov (United States)

    Steele, James; Ferrari, Pier Francesco; Fogassi, Leonardo

    2012-01-12

    The papers in this Special Issue examine tool use and manual gestures in primates as a window on the evolution of the human capacity for language. Neurophysiological research has supported the hypothesis of a close association between some aspects of human action organization and of language representation, in both phonology and semantics. Tool use provides an excellent experimental context to investigate analogies between action organization and linguistic syntax. Contributors report and contextualize experimental evidence from monkeys, great apes, humans and fossil hominins, and consider the nature and the extent of overlaps between the neural representations of tool use, manual gestures and linguistic processes.

  20. Action video game training reduces the Simon Effect.

    Science.gov (United States)

    Hutchinson, Claire V; Barrett, Doug J K; Nitka, Aleksander; Raynes, Kerry

    2016-04-01

    A number of studies have shown that training on action video games improves various aspects of visual cognition including selective attention and inhibitory control. Here, we demonstrate that action video game play can also reduce the Simon Effect, and, hence, may have the potential to improve response selection during the planning and execution of goal-directed action. Non-game-players were randomly assigned to one of four groups; two trained on a first-person-shooter game (Call of Duty) on either Microsoft Xbox or Nintendo DS, one trained on a visual training game for Nintendo DS, and a control group who received no training. Response times were used to contrast performance before and after training on a behavioral assay designed to manipulate stimulus-response compatibility (the Simon Task). The results revealed significantly faster response times and a reduced cost of stimulus-response incompatibility in the groups trained on the first-person-shooter game. No benefit of training was observed in the control group or the group trained on the visual training game. These findings are consistent with previous evidence that action game play elicits plastic changes in the neural circuits that serve attentional control, and suggest training may facilitate goal-directed action by improving players' ability to resolve conflict during response selection and execution.

  1. Using fuzzy logic to integrate neural networks and knowledge-based systems

    Science.gov (United States)

    Yen, John

    1991-01-01

    Outlined here is a novel hybrid architecture that uses fuzzy logic to integrate neural networks and knowledge-based systems. The author's approach offers important synergistic benefits to neural nets, approximate reasoning, and symbolic processing. Fuzzy inference rules extend symbolic systems with approximate reasoning capabilities, which are used for integrating and interpreting the outputs of neural networks. The symbolic system captures meta-level information about neural networks and defines its interaction with neural networks through a set of control tasks. Fuzzy action rules provide a robust mechanism for recognizing the situations in which neural networks require certain control actions. The neural nets, on the other hand, offer flexible classification and adaptive learning capabilities, which are crucial for dynamic and noisy environments. By combining neural nets and symbolic systems at their system levels through the use of fuzzy logic, the author's approach alleviates current difficulties in reconciling differences between low-level data processing mechanisms of neural nets and artificial intelligence systems.

  2. Representation of actions in rats: the role of cerebellum in learning spatial performances by observation.

    Science.gov (United States)

    Leggio, M G; Molinari, M; Neri, P; Graziano, A; Mandolesi, L; Petrosini, L

    2000-02-29

    Experimental evidence demonstrates that cerebellar networks are involved in spatial learning, controlling the acquisition of exploration strategies without blocking motor execution of the task. Action learning by observation has been considered somehow related to motor physiology, because it provides a way of learning performances that is almost as effective as the actual execution of actions. Neuroimaging studies demonstrate that observation of movements performed by others, imagination of actions, and actual execution of motor performances share common neural substrates and that the cerebellum is among these shared areas. The present paper analyzes the effects of observation in learning a spatial task, focusing on the cerebellar role in learning a spatial ability through observation. We allowed normal rats to observe 200 Morris water maze trials performed by companion rats. After this observation training, "observer" rats underwent a hemicerebellectomy and then were tested in the Morris water maze. In spite of the cerebellar lesion, they displayed no spatial defects, exhibiting exploration abilities comparable to controls. When the cerebellar lesion preceded observation training, a complete lack of spatial observational learning was observed. Thus, as demonstrated already for the acquisition of spatial procedures through actual execution, cerebellar circuits appear to play a key role in the acquisition of spatial procedures also through observation. In conclusion, the present results provide strong support for a common neural basis in the observation of actions that are to be reproduced as well as in the actual production of the same actions.

  3. Action physics

    Science.gov (United States)

    McGinness, Lachlan P.; Savage, C. M.

    2016-09-01

    More than a decade ago, Edwin Taylor issued a "call to action" that presented the case for basing introductory university mechanics teaching around the principle of stationary action [E. F. Taylor, Am. J. Phys. 71, 423-425 (2003)]. We report on our response to that call in the form of an investigation of the teaching and learning of the stationary action formulation of physics in a first-year university course. Our action physics instruction proceeded from the many-paths approach to quantum physics to ray optics, classical mechanics, and relativity. Despite the challenges presented by action physics, students reported it to be accessible, interesting, motivational, and valuable.

  4. Complementary Actions

    Directory of Open Access Journals (Sweden)

    Luisa eSartori

    2015-05-01

    Full Text Available Complementary colors are color pairs which, when combined in the right proportions, produce white or black. Complementary actions refer here to forms of social interaction wherein individuals adapt their joint actions according to a common aim. Notably, complementary actions are incongruent actions. But being incongruent is not sufficient to be complementary (i.e., to complete the action of another person. Successful complementary interactions are founded on the abilities: (i to simulate another person’s movements, (ii to predict another person’s future action/s, (iii to produce an appropriate incongruent response which differ, while interacting, with observed ones, and (iv to complete the social interaction by integrating the predicted effects of one’s own action with those of another person. This definition clearly alludes to the functional importance of complementary actions in the perception–action cycle and prompts us to scrutinize what is taking place behind the scenes. Preliminary data on this topic have been provided by recent cutting-edge studies utilizing different research methods. This mini-review aims to provide an up-to-date overview of the processes and the specific activations underlying complementary actions.

  5. Neural crest contributions to the lamprey head

    Science.gov (United States)

    McCauley, David W.; Bronner-Fraser, Marianne

    2003-01-01

    The neural crest is a vertebrate-specific cell population that contributes to the facial skeleton and other derivatives. We have performed focal DiI injection into the cranial neural tube of the developing lamprey in order to follow the migratory pathways of discrete groups of cells from origin to destination and to compare neural crest migratory pathways in a basal vertebrate to those of gnathostomes. The results show that the general pathways of cranial neural crest migration are conserved throughout the vertebrates, with cells migrating in streams analogous to the mandibular and hyoid streams. Caudal branchial neural crest cells migrate ventrally as a sheet of cells from the hindbrain and super-pharyngeal region of the neural tube and form a cylinder surrounding a core of mesoderm in each pharyngeal arch, similar to that seen in zebrafish and axolotl. In addition to these similarities, we also uncovered important differences. Migration into the presumptive caudal branchial arches of the lamprey involves both rostral and caudal movements of neural crest cells that have not been described in gnathostomes, suggesting that barriers that constrain rostrocaudal movement of cranial neural crest cells may have arisen after the agnathan/gnathostome split. Accordingly, neural crest cells from a single axial level contributed to multiple arches and there was extensive mixing between populations. There was no apparent filling of neural crest derivatives in a ventral-to-dorsal order, as has been observed in higher vertebrates, nor did we find evidence of a neural crest contribution to cranial sensory ganglia. These results suggest that migratory constraints and additional neural crest derivatives arose later in gnathostome evolution.

  6. Estimation of network structure for signal propagations by the analysis of multichannel action potentials in cultured neural networks; Ta channel katsudo den`i kaiseki ni yoru baiyo shinkei kairomonai kofun denpa keiro no suitei

    Energy Technology Data Exchange (ETDEWEB)

    Konno, N.; Fukami, T.; Shiina, T. [University of Tsukuba, Tsukuba (Japan); Jinbo, Y. [Nippon Telegraph and Telephone Corp., Tokyo (Japan)

    1998-07-01

    We have fabricated a 64 embedded microelectrode-array substrate using semiconductor technology to investigate the biological signal processing in brain by using cultured neural networks of fetal rat neocortex in vitro. We analyzed temporal and spatial neural networks patterns cultured on electrode-array substrate and attempted to examine the network structure constituted by neurons and the propagating patterns of electrical activity induced by the electric stimulus. In the experiments, each microelectrode size was 30 {mu}m squared and 150{mu} m spaced. For stimulation, one of the electrodes was selected and current pulses were applied through an isolated circuit. After the network was cultured in about 50 days, responses of neurons to electric stimulus were monitored extracellularly through 64-channel electrode array. Data recorded at each electrode consist of several spike trains generated by different cells. Therefore, these trains were separated by using wavelet transform and template matching for each electrode. We referred the temporal patterns of generated spikes for each electrode to as `spike sequences`. Next, we compared With the spike sequences among multichannel data and visualized the Cultured neural networks structure by identifying the directions of propagations and cell connections. 15 refs., 9 figs.

  7. Sentential context modulates the involvement of the motor cortex in action language processing: An fMRI study

    Directory of Open Access Journals (Sweden)

    Karen D.I. Schuil

    2013-04-01

    Full Text Available Theories of embodied cognition propose that language comprehension is based on perceptual and motor processes. More specifically, it is hypothesized that neurons processing verbs describing bodily actions, and those that process the corresponding physical actions, fire simultaneously during action verb learning. Thus the concept and motor activation become strongly linked. According to this view, the language-induced activation of the neural substrates for action is automatic. By contrast, a moderate view of embodied cognition proposes that activation of these motor regions is modulated by context. In recent studies it was found that action verbs in literal sentences activate the motor system, while mixed results were observed for action verbs in nonliteral sentences. Thus, whether the recruitment of motor regions is automatic or context dependent remains a question. We investigated functional magnetic resonance imaging activation in response to nonliteral and literal sentences including arm and leg related actions. The sentence structure was such that the action verb was the last word in the subordinate clause. Thus, the constraining context was presented well before the verb. Region of interest analyses showed that action verbs in literal context engage the motor regions to a greater extent than nonliteral action verbs. There was no evidence for a semantic somatotopic organization of the motor cortex. Taken together, these results indicate that during comprehension, the degree to which motor regions are recruited is context dependent, supporting the weak view of embodied cognition.

  8. Action representation: crosstalk between semantics and pragmatics.

    Science.gov (United States)

    Prinz, Wolfgang

    2014-03-01

    Marc Jeannerod pioneered a representational approach to movement and action. In his approach, motor representations provide both, declarative knowledge about action and procedural knowledge for action (action semantics and action pragmatics, respectively). Recent evidence from language comprehension and action simulation supports the claim that action pragmatics and action semantics draw on common representational resources, thus challenging the traditional divide between declarative and procedural action knowledge. To account for these observations, three kinds of theoretical frameworks are discussed: (i) semantics is grounded in pragmatics, (ii) pragmatics is anchored in semantics, and (iii) pragmatics is part and parcel of semantics.

  9. The Consortium for Evidence Based Research in Rural Educational Settings (CEBRRES): Applying Collaborative Action Research as a Means of Enhancing the Development of Rural Middle School Science Teachers

    Science.gov (United States)

    Wulff, A. H.

    2006-05-01

    Kentucky ranks third in the U.S. in need of rural education attention. Rural schools in Kentucky serve nearly 40% of the total student population, and graduation rates and NAEP scores are low. A two-year pilot study is being completed addressing psychological, social, and content knowledge based constructs, as they apply to science and mathematics achievement in rural environments. The goals are to identify the key aspects of rural teachers knowledge and skills, use a framework to describe how knowledge and skills develop in the rural classroom, apply a useful model of intervention to promote teacher development and increased student learning. If proven successful the knowledge can be incorporated into the practice of current teaching and preservice pedagogical methods. The problem that was identified and addressed by CEBRRES is the high level of student disengagement and the shortage of rigorous stimulating curriculum models. The action taken was the development and implementation of model eliciting activities. Teachers at the target school were expected to utilize action research methodology to execute model-eliciting activities in the classroom, and then communicate results in forms that are useful for other teachers. Benefits to teachers included stipends, increased science content depth and breadth, support to achieve "highly qualified teacher status", extensive professional development, and technology, equipment, and supplies for their school. Survey instruments were devised to address school perceptions (61% worry that they are not doing well enough in school), future plans (80% expect to attend college vs. the current 47.5%), various self concepts, academic self concepts (23% feel that learning is difficult for them), and family self concepts. Science was identified by the students as the subject that interests them the most, followed by math, yet Kentucky ranks near the bottom of the U.S. in math and science training in the workplace. Geology

  10. How the mode of action affects evidence of planning and movement kinematics in aging: End-state comfort in older adults.

    Science.gov (United States)

    Scharoun, Sara M; Gonzalez, Dave A; Roy, Eric A; Bryden, Pamela J

    2016-05-01

    Motor deficits are commonly observed with age; however, it has been argued that older adults are more adept when acting in natural tasks and do not differ from young adults in these contexts. This study assessed end-state comfort and movement kinematics in a familiar task to examine this further. Left- and right-handed older adults picked up a glass (upright or overturned) as if to pour water in four modes of action (pantomime, pantomime with image/cup as a guide, actual grasping). With increasing age, a longer deceleration phase (in pantomime without a stimulus) and less end-state comfort (in pantomime without a stimulus and image as a guide) was displayed as the amount of contextual information available to guide movement decreased. Changes in movement strategies likely reflect an increased reliance on feedback control and demonstration of a more cautious movement. A secondary aim of this study was to assess hand preference and performance, considering conflicting reports of manual asymmetries with age. Performance differences in the Grooved Pegboard place task indicate left handers may display a shift towards right handedness in some, but not all cases. Summarizing, this study supports age-related differences in planning and control processes in a familiar task, and changes in manual asymmetries with age in left handers.

  11. The potent opioid agonist, (+)-cis-3-methylfentanyl binds pseudoirreversibly to the opioid receptor complex in vitro and in vivo: Evidence for a novel mechanism of action

    Energy Technology Data Exchange (ETDEWEB)

    Band, L.; Xu, Heng; Bykov, V.; Rothman, R.B.; Kim, Chongho; Newman, A.; Jacobson, A.E.; Rice, K.C. (NIDDK, Bethesda, MD (USA)); Greig, N. (NIA, Bethesda, MD (USA))

    1990-01-01

    The present study demonstrates that pretreatment of rat brain membranes with (+)-cis-3-methylfentanyl ((+)-cis-MF), followed by extensive washing of the membranes, produces a wash-resistant decreasing in the binding of ({sup 3}H)-(D-ala{sup 2}, D-leu{sup 5})enkephalin to the d binding site of the opioid receptor complex ({delta}{sub cx} binding site). Intravenous administration of (+)-cis-MF (50 {mu}g/kg) to rats produced a pronounced catalepsy and also produced a wash-resistant masking of {delta}{sub cx} and {mu} binding sites in membranes prepared 120 min post-injection. Administration of 1 mg/kg i.v. of the opioid antagonist, 6-desoxy-6{beta}-fluoronaltrexone (cycloFOXY), 100 min after the injection of (+)-cis-MF (20 min prior to the preparation of membranes) completely reversed the catatonia and restored masked {delta}{sub cx} binding sites to control levels. This was not observed with (+)-cycloFOXY. The implications of these and other findings for the mechanism of action of (+)-cis-MF and models of the opioid receptors are discussed.

  12. Neural substrates of semantic memory.

    Science.gov (United States)

    Hart, John; Anand, Raksha; Zoccoli, Sandra; Maguire, Mandy; Gamino, Jacque; Tillman, Gail; King, Richard; Kraut, Michael A

    2007-09-01

    Semantic memory is described as the storage of knowledge, concepts, and information that is common and relatively consistent across individuals (e.g., memory of what is a cup). These memories are stored in multiple sensorimotor modalities and cognitive systems throughout the brain (e.g., how a cup is held and manipulated, the texture of a cup's surface, its shape, its function, that is related to beverages such as coffee, and so on). Our ability to engage in purposeful interactions with our environment is dependent on the ability to understand the meaning and significance of the objects and actions around us that are stored in semantic memory. Theories of the neural basis of the semantic memory of objects have produced sophisticated models that have incorporated to varying degrees the results of cognitive and neural investigations. The models are grouped into those that are (1) cognitive models, where the neural data are used to reveal dissociations in semantic memory after a brain lesion occurs; (2) models that incorporate both cognitive and neuroanatomical information; and (3) models that use cognitive, neuroanatomic, and neurophysiological data. This review highlights the advances and issues that have emerged from these models and points to future directions that provide opportunities to extend these models. The models of object memory generally describe how category and/or feature representations encode for object memory, and the semantic operations engaged in object processing. The incorporation of data derived from multiple modalities of investigation can lead to detailed neural specifications of semantic memory organization. The addition of neurophysiological data can potentially provide further elaboration of models to include semantic neural mechanisms. Future directions should incorporate available and newly developed techniques to better inform the neural underpinning of semantic memory models.

  13. Serotonin, neural markers, and memory.

    Science.gov (United States)

    Meneses, Alfredo

    2015-01-01

    Diverse neuropsychiatric disorders present dysfunctional memory and no effective treatment exits for them; likely as result of the absence of neural markers associated to memory. Neurotransmitter systems and signaling pathways have been implicated in memory and dysfunctional memory; however, their role is poorly understood. Hence, neural markers and cerebral functions and dysfunctions are revised. To our knowledge no previous systematic works have been published addressing these issues. The interactions among behavioral tasks, control groups and molecular changes and/or pharmacological effects are mentioned. Neurotransmitter receptors and signaling pathways, during normal and abnormally functioning memory with an emphasis on the behavioral aspects of memory are revised. With focus on serotonin, since as it is a well characterized neurotransmitter, with multiple pharmacological tools, and well characterized downstream signaling in mammals' species. 5-HT1A, 5-HT4, 5-HT5, 5-HT6, and 5-HT7 receptors as well as SERT (serotonin transporter) seem to be useful neural markers and/or therapeutic targets. Certainly, if the mentioned evidence is replicated, then the translatability from preclinical and clinical studies to neural changes might be confirmed. Hypothesis and theories might provide appropriate limits and perspectives of evidence.

  14. Serotonin, neural markers and memory

    Directory of Open Access Journals (Sweden)

    Alfredo eMeneses

    2015-07-01

    Full Text Available Diverse neuropsychiatric disorders present dysfunctional memory and no effective treatment exits for them; likely as result of the absence of neural markers associated to memory. Neurotransmitter systems and signaling pathways have been implicated in memory and dysfunctional memory; however, their role is poorly understood. Hence, neural markers and cerebral functions and dysfunctions are revised. To our knowledge no previous systematic works have been published addressing these issues. The interactions among behavioral tasks, control groups and molecular changes and/or pharmacological effects are mentioned. Neurotransmitter receptors and signaling pathways, during normal and abnormally functioning memory with an emphasis on the behavioral aspects of memory are revised. With focus on serotonin, since as it is a well characterized neurotransmitter, with multiple pharmacological tools, and well characterized downstream signaling in mammals’ species. 5-HT1A, 5-HT4, 5-HT5, 5-HT6 and 5-HT7 receptors as well as SERT (serotonin transporter seem to be useful neural markers and/or therapeutic targets. Certainly, if the mentioned evidence is replicated, then the translatability from preclinical and clinical studies to neural changes might be confirmed. Hypothesis and theories might provide appropriate limits and perspectives of evidence

  15. Contractility of isolated bovine ventricular myocytes is enhanced by intracellular injection of cardioactive glycosides. Evidence for an intracellular mode of action.

    Science.gov (United States)

    Isenberg, G

    1984-01-01

    The contractions of isolated bovine left ventricular myocytes were evaluated by optically measuring the extent of unloaded shortening (ES), the maximal rate of shortening (MRS) and the maximal rate of re-lengthening (MRL). Ouabain, digoxin or digitoxin were intracellularly injected by 2 sec long pressure pulses via the microelectrodes. Their i.c. concentration was estimated to be 2-5 nM. Within 1-4 min after the injection, ES, MRS and MRL increased by more than 2-fold. The contractility renormalized within the following 20 min. Injection of solutions without glycosides did not increase the contractility. An interaction of the injected glycoside with the e.c. ouabain receptor could be largely excluded because a) the amount of the released glycoside was too small for e.c. effects, b) 500 nM e.c. antidigoxin, c) 20 mM [K]o or d) covalent binding of digoxin to HSA did not prevent the increase in contractility due to the i.c. injections. Since contractility also increased when the injections were performed at Na-free conditions, [Na]i-load is not necessary for the effect of i.e. glycosides. The increased contractility due to the injected glycosides was not observed when the contractility prior to the injection was already potentiated, e.g. by greater than 3.6 mM [Ca]o or by stimulation at frequencies greater than 1.25 Hz. The results are interpreted by the hypothesis that the i.c. glycosides facilitate the release of activator calcium from the SR. The possible i.c. modes of action are discussed as well as the idea that e.c. applied glycosides internalize and mediate inotropy via the i.e. mechanism.

  16. Labeling of Oxidizable Proteins with a Photoactivatable Analog of the Antitumor Agent DMXAA: Evidence for Redox Signaling in Its Mode of Action

    Directory of Open Access Journals (Sweden)

    Romy Brauer

    2010-09-01

    Full Text Available The signaling pathway(s and molecular target(s for 5,6-dimethylxanthenone-4-acetic acid (DMXAA, a tumor vascular disrupting agent in late stages of clinical development, are still undefined. As an approach toward identifying potential targets for DMXAA, a tritiated azido-analog of DMXAA was used to probe for cellular binding proteins. More than 20 cytosolic proteins from murine splenocytes, RAW 264.7 cells, and the HECPP immortalized endothelial cells were photoaffinity-labeled. Although no protein domain, fold, or binding site for a specific ligand was found to be shared by all the candidate proteins, essentially all were noted to be oxidizable proteins, implicating a role for redox signaling in the action of DMXAA. Consistent with this hypothesis, DMXAA caused an increase in concentrations of reactive oxygen species (ROS in RAW264.7 cells during the first 2 hours. This increase in ROS was suppressed in the presence of the antioxidant, N-acetyl-L-cysteine, which also suppressed DMXAA-induced cytokine production in the RAW 264.7 cells with no effects on cell viability. Short interfering RNA (siRNA-mediated knockdown of one of the photoaffinity-labeled proteins, superoxide dismutase 1, an ROS scavenger, resulted in an increase in tumor necrosis factor-α production by RAW 264.7 cells in response to DMXAA compared with negative or positive controls transfected with nontargeting or lamin A/C-targeting siRNA molecules, respectively. The results from these lines of study all suggest that redox signaling plays a central role in cytokine induction by DMXAA.

  17. Neural Induction, Neural Fate Stabilization, and Neural Stem Cells

    Directory of Open Access Journals (Sweden)

    Sally A. Moody

    2002-01-01

    Full Text Available The promise of stem cell therapy is expected to greatly benefit the treatment of neurodegenerative diseases. An underlying biological reason for the progressive functional losses associated with these diseases is the extremely low natural rate of self-repair in the nervous system. Although the mature CNS harbors a limited number of self-renewing stem cells, these make a significant contribution to only a few areas of brain. Therefore, it is particularly important to understand how to manipulate embryonic stem cells and adult neural stem cells so their descendants can repopulate and functionally repair damaged brain regions. A large knowledge base has been gathered about the normal processes of neural development. The time has come for this information to be applied to the problems of obtaining sufficient, neurally committed stem cells for clinical use. In this article we review the process of neural induction, by which the embryonic ectodermal cells are directed to form the neural plate, and the process of neural�fate stabilization, by which neural plate cells expand in number and consolidate their neural fate. We will present the current knowledge of the transcription factors and signaling molecules that are known to be involved in these processes. We will discuss how these factors may be relevant to manipulating embryonic stem cells to express a neural fate and to produce large numbers of neurally committed, yet undifferentiated, stem cells for transplantation therapies.

  18. Neuroart: picturing the neuroscience of intentional actions in art and science

    Science.gov (United States)

    Siler, Todd

    2015-01-01

    Intentional actions cover a broad spectrum of human behaviors involving consciousness, creativity, innovative thinking, problem-solving, critical thinking, and other related cognitive processes self-evident in the arts and sciences. The author discusses the brain activity associated with action intentions, connecting this activity with the creative process. Focusing on one seminal artwork created and exhibited over a period of three decades, Thought Assemblies (1979–82, 2014), he describes how this symbolic art interprets the neuropsychological processes of intuition and analytical reasoning. It explores numerous basic questions concerning observed interactions between artistic and scientific inquiries, conceptions, perceptions, and representations connecting mind and nature. Pointing to some key neural mechanisms responsible for forming and implementing intentions, he considers why and how we create, discover, invent, and innovate. He suggests ways of metaphorical thinking and symbolic modeling that can help integrate the neuroscience of intentional actions with the neuroscience of creativity, art and neuroaesthetics. PMID:26257629

  19. Neuroart: picturing the neuroscience of intentional actions in art and science.

    Science.gov (United States)

    Siler, Todd

    2015-01-01

    Intentional actions cover a broad spectrum of human behaviors involving consciousness, creativity, innovative thinking, problem-solving, critical thinking, and other related cognitive processes self-evident in the arts and sciences. The author discusses the brain activity associated with action intentions, connecting this activity with the creative process. Focusing on one seminal artwork created and exhibited over a period of three decades, Thought Assemblies (1979-82, 2014), he describes how this symbolic art interprets the neuropsychological processes of intuition and analytical reasoning. It explores numerous basic questions concerning observed interactions between artistic and scientific inquiries, conceptions, perceptions, and representations connecting mind and nature. Pointing to some key neural mechanisms responsible for forming and implementing intentions, he considers why and how we create, discover, invent, and innovate. He suggests ways of metaphorical thinking and symbolic modeling that can help integrate the neuroscience of intentional actions with the neuroscience of creativity, art and neuroaesthetics.

  20. Radioactive fallout and neural tube defects

    Directory of Open Access Journals (Sweden)

    Nejat Akar

    2015-10-01

    Full Text Available Possible link between radioactivity and the occurrence of neural tube defects is a long lasting debate since the Chernobyl nuclear fallout in 1986. A recent report on the incidence of neural defects in the west coast of USA, following Fukushima disaster, brought another evidence for effect of radioactive fallout on the occurrence of NTD’s. Here a literature review was performed focusing on this special subject.

  1. Designing neural networks that process mean values of random variables

    Energy Technology Data Exchange (ETDEWEB)

    Barber, Michael J. [AIT Austrian Institute of Technology, Innovation Systems Department, 1220 Vienna (Austria); Clark, John W. [Department of Physics and McDonnell Center for the Space Sciences, Washington University, St. Louis, MO 63130 (United States); Centro de Ciências Matemáticas, Universidade de Madeira, 9000-390 Funchal (Portugal)

    2014-06-13

    We develop a class of neural networks derived from probabilistic models posed in the form of Bayesian networks. Making biologically and technically plausible assumptions about the nature of the probabilistic models to be represented in the networks, we derive neural networks exhibiting standard dynamics that require no training to determine the synaptic weights, that perform accurate calculation of the mean values of the relevant random variables, that can pool multiple sources of evidence, and that deal appropriately with ambivalent, inconsistent, or contradictory evidence. - Highlights: • High-level neural computations are specified by Bayesian belief networks of random variables. • Probability densities of random variables are encoded in activities of populations of neurons. • Top-down algorithm generates specific neural network implementation of given computation. • Resulting “neural belief networks” process mean values of random variables. • Such networks pool multiple sources of evidence and deal properly with inconsistent evidence.

  2. Hippocampal signatures of episodic memory: Evidence from single-unit recording studies

    Directory of Open Access Journals (Sweden)

    Amy L Griffin

    2013-05-01

    Full Text Available What hippocampal neural firing patterns signal memory and, more importantly, how is this memory code used by associated structures to translate a memory into a decision or action? Candidate hippocampal activity patterns will be discussed including (1 trajectory-specific firing of place cells with place fields on an overlapping segment of two (or more distinct trajectories (2 prospective firing of hippocampal neurons that signal an upcoming event or action, and (3 place cell remapping to changes in environment and task. To date, there has not compelling evidence for any of these activity patterns being the neural substrate of episodic memory. New findings suggest that learning and memory processes are emergent properties of interregional interactions and not localized within any one discrete brain region. Therefore, the next step in understanding how remapping and trajectory coding participate in memory coding may be to investigate how these activity patterns relate to activity in anatomically-connected structures such as the prefrontal cortex.

  3. Antidepressant-like action of the ethanolic extract from Tabebuia avellanedae in mice: evidence for the involvement of the monoaminergic system.

    Science.gov (United States)

    Freitas, Andiara E; Budni, Josiane; Lobato, Kelly R; Binfaré, Ricardo W; Machado, Daniele G; Jacinto, Jardel; Veronezi, Patrícia O; Pizzolatti, Moacir G; Rodrigues, Ana Lúcia S

    2010-03-17

    The antidepressant-like effect of the ethanolic extract obtained from barks of Tabebuia avellanedae, a plant widely employed in folk medicine, was investigated in two predictive models of depression: forced swimming test (FST) and tail suspension test (TST) in mice. Additionally, the mechanisms involved in this antidepressant-like action and the effects of the association of the extract with the antidepressants fluoxetine, desipramine and bupropion in the TST were investigated. The extract from T. avellanedae produced an antidepressant-like effect, in the FST (100 mg/kg, p.o.) and in the TST (10-300 mg/kg, p.o.), without accompanying changes in ambulation when assessed in the open-field test. The anti-immobility effect of the extract (30 mg/kg, p.o.) in the TST was prevented by pre-treatment of mice with ketanserin (5 mg/kg, i.p., a preferential 5-HT(2A) receptor antagonist), prazosin (1 mg/kg, i.p., an alpha(1)-adrenoceptor antagonist), yohimbine (1 mg/kg, i.p., an alpha(2)-adrenoceptor antagonist), propranolol (2 mg/kg, i.p., a beta-adrenoceptor antagonist), sulpiride (50 mg/kg, i.p., a dopamine D(2) receptor antagonist) and SCH23390 (0.05 mg/kg, s.c., a dopamine D(1) receptor antagonist). The combined administration of a subeffective dose of WAY100635 (0.1 mg/kg, s.c., a selective 5-HT(1A) receptor antagonist) and a subeffective dose of the extract (1 mg/kg, p.o.) produced a significant reduction in the immobility time in the TST. In addition, the combination of fluoxetine (1 mg/kg, p.o.), desipramine (0.1 mg/kg, p.o.), or bupropion (1 mg/kg, p.o.) with a subeffective dose of the extract (1 mg/kg, p.o.) produced a synergistic antidepressant-like effect in the TST, without causing hyperlocomotion in the open-field test. It may be concluded that the extract from T. avellanedae produces an antidepressant-like effect in the FST and in the TST that is dependent on the monoaminergic system. Taken together, our results suggest that T. avellanedae deserves further

  4. Infrared neural stimulation (INS) inhibits electrically evoked neural responses in the deaf white cat

    Science.gov (United States)

    Richter, Claus-Peter; Rajguru, Suhrud M.; Robinson, Alan; Young, Hunter K.

    2014-03-01

    Infrared neural stimulation (INS) has been used in the past to evoke neural activity from hearing and partially deaf animals. All the responses were excitatory. In Aplysia californica, Duke and coworkers demonstrated that INS also inhibits neural responses [1], which similar observations were made in the vestibular system [2, 3]. In deaf white cats that have cochleae with largely reduced spiral ganglion neuron counts and a significant degeneration of the organ of Corti, no cochlear compound action potentials could be observed during INS alone. However, the combined electrical and optical stimulation demonstrated inhibitory responses during irradiation with infrared light.

  5. The membrane disordering effect of ethanol on neural crest cells in vitro and the protective role of GM1 ganglioside.

    Science.gov (United States)

    Chen, S Y; Yang, B; Jacobson, K; Sulik, K K

    1996-01-01

    The teratogenic effect of ethanol appears to be related to excessive cell death in selected cell populations including craniofacial neural crest. Because there is a large body of evidence suggesting that a primary site of action of ethanol is at the membrane level, the current study was designed to examine and attempt to ameliorate ethanol-induced neural crest cell membrane changes that proceed cell death. To this end, neural crest cells were grown as primary cultures from mouse cranial neural tube be explants. In these cultured cells, the relationships between changes in membrane lipid lateral mobility (a measure of membrane fluidity) as determined using the technique of fluorescence recovery after photobleaching (FRAP), ethanol-induced cell death, and the protective role of GM1 ganglioside were examined. A dose-response study showed that treatment with 50, 100, 150, or 200 mM ethanol respectively, for 24 h was positively correlated with membrane lipid lateral mobility and negatively correlated with cell viability. Pre- or co-treatment of the cells with GM1 ganglioside diminished the ethanol-induced increases in membrane fluidity and decreases in cell viability. The results of this study suggest that change in membrane fluidity can account, in part, for ethanol-induced neural crest cell death and that the protection conferred by GM1 ganglioside may result from membrane stabilization and subsequent preservation of the biophysical properties and biological function of the ethanol-exposed cell membranes.

  6. Additive Feed Forward Control with Neural Networks

    DEFF Research Database (Denmark)

    Sørensen, O.

    1999-01-01

    This paper demonstrates a method to control a non-linear, multivariable, noisy process using trained neural networks. The basis for the method is a trained neural network controller acting as the inverse process model. A training method for obtaining such an inverse process model is applied....... A suitable 'shaped' (low-pass filtered) reference is used to overcome problems with excessive control action when using a controller acting as the inverse process model. The control concept is Additive Feed Forward Control, where the trained neural network controller, acting as the inverse process model......, is placed in a supplementary pure feed-forward path to an existing feedback controller. This concept benefits from the fact, that an existing, traditional designed, feedback controller can be retained without any modifications, and after training the connection of the neural network feed-forward controller...

  7. From Knowledge to Action

    DEFF Research Database (Denmark)

    Hjelmar, Ulf; Møller, Anne Mette

    2016-01-01

    of a greater process of bringing knowledge to action, encompassing the social and organisational contexts of research utilisation. The article concludes by stating that knowledge portals have the potential to be effective instruments in knowledge-to-action processes. The two main challenges, however......In recent years, focus has been on the utilisation of research-based knowledge and evidence in social work policy and practice in order to make it more effective. A part of this process has been the launch of knowledge portals to make use of knowledge from research. In this article, we investigate...... how knowledge portals about vulnerable children and youth present knowledge and evidence, and how they try to work as ?knowledge brokers? or intermediaries of evidence. We argue that knowledge portals are not merely channels for dissemination of knowledge. Knowledge portals could be considered as part...

  8. Effects of focal prefrontal cortex lesions on electrophysiological indices of executive attention and action control.

    Science.gov (United States)

    Solbakk, Anne-Kristin; Løvstad, Marianne

    2014-06-01

    The human capacity to maintain an overarching control over mental states and behavior relies on multiple, distributed and dynamically interacting brain networks, in which prefrontal cortex (PFC) plays a critical role. PFC exerts top-down executive control over subcortical and posterior cortical areas via extensive reciprocal connections. The orbital, lateral, and medial PFC subdivisions are associated with distinct executive functions, but their precise roles in large-scale neural networks remain to be determined. The main objective of our research program is to specify cognitive and neural mechanisms that govern executive control functions. We study effects of focal PFC lesions on behavioral and electrophysiological correlates of attention and action control utilizing experiments that relate to real-life requirements for executive control. We provide a selective review of studies on the impact of lesions to PFC subregions on novelty processing, anticipatory attention, and action preparation and motor inhibition. The studies provide evidence for the contribution of both lateral, dorsomedial and orbital PFC in novelty processing and dynamic contextual updating. We also report evidence for a role of lateral PFC in motor preparation and anticipatory attention. In contrast to the common view that orbitofrontal cortex plays a general role in inhibitory control, we report findings indicating an involvement in action outcome monitoring rather than in behavioral inhibition as such. We argue that improved understanding of how basic aspects of attentional control and inhibition is regulated in the brain, will shed light on the complex behavioral, cognitive and emotional problems experienced by patients with executive dysfunction.

  9. The developmental cognitive neuroscience of action: semantics, motor resonance and social processing.

    Science.gov (United States)

    Ní Choisdealbha, Áine; Reid, Vincent

    2014-06-01

    The widespread use of EEG methods and the introduction of new brain imaging methods such as near-infrared spectroscopy have made cognitive neuroscience research with infants more feasible, resulting in an explosion of new findings. Among the long-established study of the neural correlates of face and speech perception in infancy, there has been an abundance of recent research on infant perception and production of action and concomitant neurocognitive development. In this review, three significant strands of developmental action research are discussed. The first strand focuses on the relationship of diverse social cognitive processes, including the perception of goals and animacy, and the development of precursors to theory of mind, to action perception. The second investigates the role of motor resonance and mirror systems in early action development. The third strand focuses on the extraction of meaning from action by infants and discusses how semantic processing of action emerges early in life. Although these strands of research are pursued separately, many of the findings from each strand inform all three theoretical frameworks. This review will evaluate the evidence for a synthesised account of infant action development.

  10. Action Research Empowers School Librarians

    Science.gov (United States)

    Robins, Jennifer

    2015-01-01

    Successful school library programs occur through careful planning and reflection. This reflective process is improved when it is applied in a systematic way through action research. The action research described in this paper enabled school librarians to reflect based on evidence, using data they had collected. This study presents examples of the…

  11. 基于小波神经网络和D-S证据理论的电力变压器故障诊断研究%Study on Power Transformers Fault Diagnosis Based on Wavelet Neural Network and D-S Evidence Theory

    Institute of Scientific and Technical Information of China (English)

    梁流铭; 陈伟根; 岳彦峰

    2008-01-01

    Transformer faults are quite complicated phenomena and can occur due to a variety of reasons. There have been several methods for transformer fault synthetic diagnosis, but each of them has its own limitations in real fault diagnosis applications. In order to overcome those shortcomings in the existing methods, a new transformer fault diagnosis method based on a wavelet neural network optimized by adaptive genetic algorithm (AGA) and an improved D-S evidence theory fusion technique is proposed in this paper. The proposed method combines the oil chromatogram data and the off-line electrical test data of transformers to carry out fault diagnosis. Based on the fusion mechanism of D-S evidence theory, the comprehensive reliability of evidence is constructed by considering the evidence importance, the outputs of the neural network and the expert experience. The new method increases the objectivity of the basic probability assignment (BPA) and reduces the basic probability assigned for uncertain and unimportant information. The case study results of using the proposed method show that it has a good performance of fault diagnosis for transformers.

  12. The neural basis of altruistic punishment.

    Science.gov (United States)

    de Quervain, Dominique J-F; Fischbacher, Urs; Treyer, Valerie; Schellhammer, Melanie; Schnyder, Ulrich; Buck, Alfred; Fehr, Ernst

    2004-08-27

    Many people voluntarily incur costs to punish violations of social norms. Evolutionary models and empirical evidence indicate that such altruistic punishment has been a decisive force in the evolution of human cooperation. We used H2 15O positron emission tomography to examine the neural basis for altruistic punishment of defectors in an economic exchange. Subjects could punish defection either symbolically or effectively. Symbolic punishment did not reduce the defector's economic payoff, whereas effective punishment did reduce the payoff. We scanned the subjects' brains while they learned about the defector's abuse of trust and determined the punishment. Effective punishment, as compared with symbolic punishment, activated the dorsal striatum, which has been implicated in the processing of rewards that accrue as a result of goal-directed actions. Moreover, subjects with stronger activations in the dorsal striatum were willing to incur greater costs in order to punish. Our findings support the hypothesis that people derive satisfaction from punishing norm violations and that the activation in the dorsal striatum reflects the anticipated satisfaction from punishing defectors.

  13. Neural Tube Defects

    Science.gov (United States)

    Neural tube defects are birth defects of the brain, spine, or spinal cord. They happen in the ... that she is pregnant. The two most common neural tube defects are spina bifida and anencephaly. In ...

  14. Morphological neural networks

    Energy Technology Data Exchange (ETDEWEB)

    Ritter, G.X.; Sussner, P. [Univ. of Florida, Gainesville, FL (United States)

    1996-12-31

    The theory of artificial neural networks has been successfully applied to a wide variety of pattern recognition problems. In this theory, the first step in computing the next state of a neuron or in performing the next layer neural network computation involves the linear operation of multiplying neural values by their synaptic strengths and adding the results. Thresholding usually follows the linear operation in order to provide for nonlinearity of the network. In this paper we introduce a novel class of neural networks, called morphological neural networks, in which the operations of multiplication and addition are replaced by addition and maximum (or minimum), respectively. By taking the maximum (or minimum) of sums instead of the sum of products, morphological network computation is nonlinear before thresholding. As a consequence, the properties of morphological neural networks are drastically different than those of traditional neural network models. In this paper we consider some of these differences and provide some particular examples of morphological neural network.

  15. Artificial Neural Networks

    OpenAIRE

    Chung-Ming Kuan

    2006-01-01

    Artificial neural networks (ANNs) constitute a class of flexible nonlinear models designed to mimic biological neural systems. In this entry, we introduce ANN using familiar econometric terminology and provide an overview of ANN modeling approach and its implementation methods.

  16. Neural tissue-spheres

    DEFF Research Database (Denmark)

    Andersen, Rikke K; Johansen, Mathias; Blaabjerg, Morten

    2007-01-01

    By combining new and established protocols we have developed a procedure for isolation and propagation of neural precursor cells from the forebrain subventricular zone (SVZ) of newborn rats. Small tissue blocks of the SVZ were dissected and propagated en bloc as free-floating neural tissue...... content, thus allowing experimental studies of neural precursor cells and their niche...

  17. READING A NEURAL CODE

    NARCIS (Netherlands)

    BIALEK, W; RIEKE, F; VANSTEVENINCK, RRD; WARLAND, D

    1991-01-01

    Traditional approaches to neural coding characterize the encoding of known stimuli in average neural responses. Organisms face nearly the opposite task - extracting information about an unknown time-dependent stimulus from short segments of a spike train. Here the neural code was characterized from

  18. Generalized classifier neural network.

    Science.gov (United States)

    Ozyildirim, Buse Melis; Avci, Mutlu

    2013-03-01

    In this work a new radial basis function based classification neural network named as generalized classifier neural network, is proposed. The proposed generalized classifier neural network has five layers, unlike other radial basis function based neural networks such as generalized regression neural network and probabilistic neural network. They are input, pattern, summation, normalization and output layers. In addition to topological difference, the proposed neural network has gradient descent based optimization of smoothing parameter approach and diverge effect term added calculation improvements. Diverge effect term is an improvement on summation layer calculation to supply additional separation ability and flexibility. Performance of generalized classifier neural network is compared with that of the probabilistic neural network, multilayer perceptron algorithm and radial basis function neural network on 9 different data sets and with that of generalized regression neural network on 3 different data sets include only two classes in MATLAB environment. Better classification performance up to %89 is observed. Improved classification performances proved the effectivity of the proposed neural network.

  19. Evidence for the involvement of the serotonergic, noradrenergic, and dopaminergic systems in the antidepressant-like action of riparin III obtained from Aniba riparia (Nees) Mez (Lauraceae) in mice.

    Science.gov (United States)

    Melo, Carla Thiciane Vasconcelos; de Carvalho, Alyne Mara Rodrigues; Moura, Brinell Arcanjo; Teixeira, Caroline Porto Leite; Vasconcelos, Leonardo Freire; Feitosa, Mariana Lima; de Oliveira, Gersilene Valente; Barbosa-Filho, José Maria; Chavez Gutierrez, Stanley Juan; de França Fonteles, Marta Maria; Vasconcelos, Silvânia Maria Mendes; de Sousa, Francisca Cléa Florenço

    2013-02-01

    Previous work has shown that intraperitoneal administration of riparin III (ripIII) reduces immobility time in the forced swimming test (FST), which suggests potential antidepressant activity. As the mechanism of action is not completely understood, this study is aimed at investigating the antidepressant-like action of ripIII. Following intraperitoneal administration of ripIII at doses of 25 and 50 mg/kg, there were decreases in the immobility time in the FST and tail suspension test without accompanying changes in ambulation (data not shown). The pretreatment of mice with sulpiride (50 mg/kg, i.p.), prazosin (1 mg/kg, i.p.), yohimbine (1 mg/kg, i.p.), and p-chlorophenylalanine (PCPA, 100 mg/kg, i.p. for, four consecutive days) significantly prevented the anti-immobility effect of ripIII in the FST. On the other hand, the anti-immobility effect of ripIII (50 mg/kg, v.o.) was not altered by pretreatment of mice with SCH23390 (15 μg/kg, i.p.) Furthermore, ripIII potentiated the sleeping latency and sleeping time of the pentobarbital-induced sleeping time test and also potentiated apomorphine (16 mg/kg, i.p.)-induced hypothermia in mice. In conclusion, the present study provides evidence that the antidepressant-like effect of ripIII is dependent on its interaction with the serotonergic, noradrenergic (α₁- and α₂- receptors), and dopaminergic (dopamine D₂ receptors) systems.

  20. Neurobiology: Setting the Set Point for Neural Homeostasis.

    Science.gov (United States)

    Truszkowski, Torrey L S; Aizenman, Carlos D

    2015-12-07

    Neural homeostasis allows neural networks to maintain a dynamic range around a given set point. How this set point is determined remains unknown. New evidence shows that alterations of activity during a critical developmental period can alter the homeostatic set point, resulting in epilepsy-like activity.

  1. Preventing neural tube defects in Europe : A missed opportunity

    NARCIS (Netherlands)

    Busby, A; Armstrong, B; Dolk, H; Armstrong, N; Haeusler, M; Berghold, A; Gillerot, Y; Baguette, A; Gjerga, R; Barisic, [No Value; Christiansen, M; Goujard, J; Steinbicker, [No Value; Rosch, C; McDonnell, R; Scarano, G; Calzolari, E; Neville, A; Cocchi, G; Bianca, S; Gatt, M; De Walle, H; Braz, P; Latos-Bielenska, A; Gener, B; Portillor, [No Value; Addor, MC; Abramsky, L; Ritvanen, A; Robert-Gnansia, E; Daltveit, AK; Aneren, G; Olars, B; Edwards, G

    2005-01-01

    Each year, more than 4500 pregnancies in the European Union are affected by neural tube defects (NTD). Unambiguous evidence of the effectiveness of peri conceptional folic acid in preventing the majority of neural tube defects has been available since 1991. We report on trends in the total prevalenc

  2. Neural computation and the computational theory of cognition.

    Science.gov (United States)

    Piccinini, Gualtiero; Bahar, Sonya

    2013-04-01

    We begin by distinguishing computationalism from a number of other theses that are sometimes conflated with it. We also distinguish between several important kinds of computation: computation in a generic sense, digital computation, and analog computation. Then, we defend a weak version of computationalism-neural processes are computations in the generic sense. After that, we reject on empirical grounds the common assimilation of neural computation to either analog or digital computation, concluding that neural computation is sui generis. Analog computation requires continuous signals; digital computation requires strings of digits. But current neuroscientific evidence indicates that typical neural signals, such as spike trains, are graded like continuous signals but are constituted by discrete functional elements (spikes); thus, typical neural signals are neither continuous signals nor strings of digits. It follows that neural computation is sui generis. Finally, we highlight three important consequences of a proper understanding of neural computation for the theory of cognition. First, understanding neural computation requires a specially designed mathematical theory (or theories) rather than the mathematical theories of analog or digital computation. Second, several popular views about neural computation turn out to be incorrect. Third, computational theories of cognition that rely on non-neural notions of computation ought to be replaced or reinterpreted in terms of neural computation.

  3. Neural Codes: Firing Rates and beyond

    Science.gov (United States)

    Gerstner, Wulfram; Kreiter, Andreas K.; Markram, Henry; Herz, Andreas V. M.

    1997-11-01

    Computational neuroscience has contributed significantly to our understanding of higher brain function by combining experimental neurobiology, psychophysics, modeling, and mathematical analysis. This article reviews recent advances in a key area: neural coding and information processing. It is shown that synapses are capable of supporting computations based on highly structured temporal codes. Such codes could provide a substrate for unambiguous representations of complex stimuli and be used to solve difficult cognitive tasks, such as the binding problem. Unsupervised learning rules could generate the circuitry required for precise temporal codes. Together, these results indicate that neural systems perform a rich repertoire of computations based on action potential timing.

  4. Equal Opportunity Laws, Affirmative Action and Asymmetric Tournaments:Some Experimental Evidence%机会公平、倾斜政策与不对称锦标赛:一项实验研究

    Institute of Scientific and Technical Information of China (English)

    闫威; 陈长怀

    2012-01-01

    employees with low abilities? If the affirmative action program has been put into practice, will the objective of equality be achieved at the cost of efficiency loss? In this paper, based on the seminal work by Schotter and Weigelt ( 1992) , we experimentally study the impact of equal opportunity law and affirmative action on agents' effort. Our study differs from the previous research in two ways. First, we recruit Chinese students as subjects in seven experiments. This design can provide new evidence and promote research interests among domestic scholars. Second, in contrast with findings in Schotter and Weigelt's study ( 1992) our experimental results suggest the implementation of affirmative action programs do not increase subjects' effort and their total output. This finding is quite different from that of most studies on affirmative action or weakens most literature based on Schotter and Weigelt's study.In the first part, following the basic tournament models established by Lazear & Rosen (1981) and Schotter & Weigelt (1992) the equilibrium efforts are derived respectively for the unfair tournament model, uneven tournament model and affirmative action model. A brief discussion on those models and some research inferences are presented to provide the baseline for empirical analysis. The second part gives a detailed explanation of the experimental design and experimental procedures adopted in this study. We recruited 130 subjects from students attending economics or management courses at Chongqing University. Seven experiments were designed and carried out to study the behavior modes of subjects in different tournament settings. There are two main parameters in these " experiments, kanda , representing the degree of unfairness and asymmetry respectively in a certain tournament. To be more specific, each experiment differs from the other one by a change in only one parameter. Experiment 1 is a fair and symmetrical benchmark experiment. In order to investigate the impact

  5. Neural induction and factors that stabilize a neural fate

    OpenAIRE

    Rogers, Crystal; Moody, Sally A.; Casey, Elena

    2009-01-01

    The neural ectoderm of vertebrates forms when the BMP signaling pathway is suppressed. Herein we review the molecules that directly antagonize extracellular BMP and the signaling pathways that further contribute to reduce BMP activity in the neural ectoderm. Downstream of neural induction, a large number of “neural fate stabilizing” (NFS) transcription factors are expressed in the presumptive neural ectoderm, developing neural tube, and ultimately in neural stem cells. Herein we review what i...

  6. Consciousness and neural plasticity

    DEFF Research Database (Denmark)

    In contemporary consciousness studies the phenomenon of neural plasticity has received little attention despite the fact that neural plasticity is of still increased interest in neuroscience. We will, however, argue that neural plasticity could be of great importance to consciousness studies....... If consciousness is related to neural processes it seems, at least prima facie, that the ability of the neural structures to change should be reflected in a theory of this relationship "Neural plasticity" refers to the fact that the brain can change due to its own activity. The brain is not static but rather...... the relation between consciousness and brain functions. If consciousness is connected to specific brain structures (as a function or in identity) what happens to consciousness when those specific underlying structures change? It is therefore possible that the understanding and theories of neural plasticity can...

  7. China's Actions

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    @@ China's National Development and Reform Commission publicized the country's policies and actions for addressing climate change in a report released on November 26,2009.The report highlighted China's efforts in cutting greenhouse gas emissions in 2009 by: (1)Rigorously checking the blind expansion of its energy-and pollution-intensive industries.

  8. Do mirror neurons subserve action understanding?

    Science.gov (United States)

    Hickok, Gregory

    2013-04-12

    Mirror neurons were once widely believed to support action understanding via motor simulation of the observed actions. Recent evidence regarding the functional properties of mirror neurons in monkeys as well as much neuropsychological evidence in humans has shown that this is not the case.

  9. Chaotic diagonal recurrent neural network

    Institute of Scientific and Technical Information of China (English)

    Wang Xing-Yuan; Zhang Yi

    2012-01-01

    We propose a novel neural network based on a diagonal recurrent neural network and chaos,and its structure andlearning algorithm are designed.The multilayer feedforward neural network,diagonal recurrent neural network,and chaotic diagonal recurrent neural network are used to approach the cubic symmetry map.The simulation results show that the approximation capability of the chaotic diagonal recurrent neural network is better than the other two neural networks.

  10. The neural processes underlying perceptual decision making in humans: recent progress and future directions.

    Science.gov (United States)

    Kelly, Simon P; O'Connell, Redmond G

    2015-01-01

    In the last two decades, animal neurophysiology research has made great strides towards explaining how the brain can enable adaptive action in the face of noisy sensory information. In particular, this work has identified neural signals that perform the role of a 'decision variable' which integrates sensory information in favor of a particular outcome up to an action-triggering threshold, consistent with long-standing predictions from mathematical psychology. This has provoked an intensive search for similar neural processes at work in the human brain. In this paper we review the progress that has been made in tracing the dynamics of perceptual decision formation in humans using functional imaging and electrophysiology. We highlight some of the limitations that non-invasive recording techniques place on our ability to make definitive judgments regarding the role that specific signals play in decision making. Finally, we provide an overview of our own work in this area which has focussed on two perceptual tasks - intensity change detection and motion discrimination - performed under continuous-monitoring conditions, and highlight the insights gained thus far. We show that through simple paradigm design features such as avoiding sudden intensity transients at evidence onset, a neural instantiation of the theoretical decision variable can be directly traced in the form of a centro-parietal positivity (CPP) in the standard event-related potential (ERP). We recapitulate evidence for the domain-general nature of the CPP process, being divorced from the sensory and motor requirements of the task, and re-plot data of both tasks highlighting this aspect as well as its relationship to decision outcome and reaction time. We discuss the implications of these findings for mechanistically principled research on normal and abnormal decision making in humans.

  11. Differentiation state determines neural effects on microvascular endothelial cells

    Energy Technology Data Exchange (ETDEWEB)

    Muffley, Lara A., E-mail: muffley@u.washington.edu [University of Washington, Campus Box 359796, 300 9th Avenue, Seattle, WA 98104 (United States); Pan, Shin-Chen, E-mail: pansc@mail.ncku.edu.tw [University of Washington, Campus Box 359796, 300 9th Avenue, Seattle, WA 98104 (United States); Smith, Andria N., E-mail: gnaunderwater@gmail.com [University of Washington, Campus Box 359796, 300 9th Avenue, Seattle, WA 98104 (United States); Ga, Maricar, E-mail: marga16@uw.edu [University of Washington, Campus Box 359796, 300 9th Avenue, Seattle, WA 98104 (United States); Hocking, Anne M., E-mail: ahocking@u.washington.edu [University of Washington, Campus Box 359796, 300 9th Avenue, Seattle, WA 98104 (United States); Gibran, Nicole S., E-mail: nicoleg@u.washington.edu [University of Washington, Campus Box 359796, 300 9th Avenue, Seattle, WA 98104 (United States)

    2012-10-01

    Growing evidence indicates that nerves and capillaries interact paracrinely in uninjured skin and cutaneous wounds. Although mature neurons are the predominant neural cell in the skin, neural progenitor cells have also been detected in uninjured adult skin. The aim of this study was to characterize differential paracrine effects of neural progenitor cells and mature sensory neurons on dermal microvascular endothelial cells. Our results suggest that neural progenitor cells and mature sensory neurons have unique secretory profiles and distinct effects on dermal microvascular endothelial cell proliferation, migration, and nitric oxide production. Neural progenitor cells and dorsal root ganglion neurons secrete different proteins related to angiogenesis. Specific to neural progenitor cells were dipeptidyl peptidase-4, IGFBP-2, pentraxin-3, serpin f1, TIMP-1, TIMP-4 and VEGF. In contrast, endostatin, FGF-1, MCP-1 and thrombospondin-2 were specific to dorsal root ganglion neurons. Microvascular endothelial cell proliferation was inhibited by dorsal root ganglion neurons but unaffected by neural progenitor cells. In contrast, microvascular endothelial cell migration in a scratch wound assay was inhibited by neural progenitor cells and unaffected by dorsal root ganglion neurons. In addition, nitric oxide production by microvascular endothelial cells was increased by dorsal root ganglion neurons but unaffected by neural progenitor cells. -- Highlights: Black-Right-Pointing-Pointer Dorsal root ganglion neurons, not neural progenitor cells, regulate microvascular endothelial cell proliferation. Black-Right-Pointing-Pointer Neural progenitor cells, not dorsal root ganglion neurons, regulate microvascular endothelial cell migration. Black-Right-Pointing-Pointer Neural progenitor cells and dorsal root ganglion neurons do not effect microvascular endothelial tube formation. Black-Right-Pointing-Pointer Dorsal root ganglion neurons, not neural progenitor cells, regulate

  12. 'Catching the waves' - slow cortical potentials as moderator of voluntary action.

    Science.gov (United States)

    Schmidt, Stefan; Jo, Han-Gue; Wittmann, Marc; Hinterberger, Thilo

    2016-09-01

    The readiness potential is an ongoing negativity in the EEG preceding a self-initiated movement by approximately 1.5s. So far it has predominantly been interpreted as a preparatory signal with a causal link to the upcoming movement. Here a different hypothesis is suggested which we call the selective slow cortical potential sampling hypothesis. In this review of recent research results we argue that the initiation of a voluntary action is more likely during negative fluctuations of the slow cortical potential and that the sampling and averaging of many trials leads to the observed negativity. That is, empirical evidence indicates that the early readiness potential is not a neural correlate of preconscious motor preparation and thus a determinant of action. Our hypothesis thereafter challenges the classic interpretation of the Libet experiment which is often taken as proof that there is no free will. We furthermore suggest that slow cortical potentials are related to an urge to act but are not a neural indicator of the decision process of action initiation.

  13. Neural reuse in the organization and development of the brain.

    Science.gov (United States)

    Anderson, Michael L

    2016-03-01

    Neural reuse is the process by which neural elements originally developed for one purpose are put to many different subsequent uses. In this brief review I will outline the role of neural reuse in the development of the brain. Special attention will be paid to elucidating and differentiating between two different mechanisms of neurocognitive development: Hebbian plasticity, the importance of which is already well known, and a neural search mechanism that supports the establishment of new functional partnerships in the brain. I describe how these two mechanisms work in concert throughout development to produce the functional architecture we observe in the adult brain; outline the evidence for the importance of neural reuse; offer suggestions for some clinical implications of neural reuse; and point to future research directions.

  14. A neural signature of hierarchical reinforcement learning.

    Science.gov (United States)

    Ribas-Fernandes, José J F; Solway, Alec; Diuk, Carlos; McGuire, Joseph T; Barto, Andrew G; Niv, Yael; Botvinick, Matthew M

    2011-07-28

    Human behavior displays hierarchical structure: simple actions cohere into subtask sequences, which work together to accomplish overall task goals. Although the neural substrates of such hierarchy have been the target of increasing research, they remain poorly understood. We propose that the computations supporting hierarchical behavior may relate to those in hierarchical reinforcement learning (HRL), a machine-learning framework that extends reinforcement-learning mechanisms into hierarchical domains. To test this, we leveraged a distinctive prediction arising from HRL. In ordinary reinforcement learning, reward prediction errors are computed when there is an unanticipated change in the prospects for accomplishing overall task goals. HRL entails that prediction errors should also occur in relation to task subgoals. In three neuroimaging studies we observed neural responses consistent with such subgoal-related reward prediction errors, within structures previously implicated in reinforcement learning. The results reported support the relevance of HRL to the neural processes underlying hierarchical behavior.

  15. Neural activity, memory, and dementias: serotonergic markers.

    Science.gov (United States)

    Meneses, Alfredo

    2017-04-01

    Dysfunctional memory seems to be a key component of diverse dementias and other neuropsychiatric disorders; unfortunately, no effective treatment exists for this, probably because of the absence of neural biomarkers accompanying it. Diverse neurotransmission systems have been implicated in memory, including serotonin or 5-hydroxytryptamine (5-HT). There are multiple serotonergic pharmacological tools, well-characterized downstream signaling in mammals' species and neural markers providing new insights into memory functions and dysfunctions. Serotonin in mammal species has multiple neural markers, including receptors (5-HT1-7), serotonin transporter, and volume transmission, which are present in brain areas involved in memory. Memory, amnesia, and forgetting modify serotonergic markers; this influence is bidirectional. Evidence shows insights and therapeutic targets and diverse approaches support the translatability of using neural markers and cerebral functions and dysfunctions, including memory formation and amnesia. For instance, 5-HT2A/2B/2C, 5-HT4, and 5-HT6 receptors are involved in tau protein hyperphosphorylation in Alzheimer's disease. In addition, at least, 5-HT1A, 5-HT4, 5-HT6, and 5-HT7 receptors as well as serotonin transporter seem to be useful neural markers and therapeutic targets. Hence, available evidence supports the notion that several mechanisms cooperate to achieve synaptic plasticity or memory, including changes in the number of neurotransmitter receptors and transporters. Considering that memory is a key component of dementias, hence reversing or reducing memory deficits might positively affect them?

  16. Interhemispheric inhibition during mental actions of different complexity.

    Directory of Open Access Journals (Sweden)

    Nicolas Gueugneau

    Full Text Available Several investigations suggest that actual and mental actions trigger similar neural substrates. Yet, neurophysiological evidences on the nature of interhemispheric interactions during mental movements are still meagre. Here, we asked whether the content of mental images, investigated by task complexity, is finely represented in the inhibitory interactions between the two primary motor cortices (M1s. Subjects' left M1 was stimulated by means of transcranial magnetic stimulation (TMS while they were performing actual or mental movements of increasing complexity with their right hand and exerting a maximum isometric force with their left thumb and index. Thus, we simultaneously assessed the corticospinal excitability in the right opponent pollicis muscle (OP and the ipsilateral silent period (iSP in the left OP during actual and mental movements. Corticospinal excitability in right OP increased during actual and mental movements, but task complexity-dependent changes were only observed during actual movements. Interhemispheric motor inhibition in the left OP was similarly modulated by task complexity in both mental and actual movements. Precisely, the duration and the area of the iSP increased with task complexity in both movement conditions. Our findings suggest that mental and actual movements share similar inhibitory neural circuits between the two homologous primary motor cortex areas.

  17. Expanding the mirror : vicarious activity for actions, emotions, and sensations

    NARCIS (Netherlands)

    Keysers, Christian; Gazzola, Valeria

    2009-01-01

    We often empathically share the states of others. The discovery of 'mirror neurons' suggested a neural mechanism for monkeys to share the actions of others. Here we expand this view by showing that mirror neurons for actions not only exist in the premotor cortex or in monkeys and that vicarious acti

  18. Pharmacogenetics of neural injury recovery.

    Science.gov (United States)

    Pearson-Fuhrhop, Kristin M; Cramer, Steven C

    2013-10-01

    Relatively few pharmacological agents are part of routine care for neural injury, although several are used or under consideration in acute stroke, chronic stroke, traumatic brain injury and secondary stroke prevention. Tissue plasminogen activator is approved for the treatment of acute ischemic stroke, and genetic variants may impact the efficacy and safety of this drug. In the chronic phase of stroke, several drugs such as L-dopa, fluoxetine and donepezil are under investigation for enhancing rehabilitation therapy, with varying levels of evidence. One potential reason for the mixed efficacy displayed by these drugs may be the influence of genetic factors that were not considered in prior studies. An understanding of the genetics impacting the efficacy of dopaminergic, serotonergic and cholinergic drugs may allow clinicians to target these potential therapies to those patients most likely to benefit. In the setting of stroke prevention, which is directly linked to neural injury recovery, the most highly studied pharmacogenomic interactions pertain to clopidogrel and warfarin. Incorporating pharmacogenomics into neural injury recovery has the potential to maximize the benefit of several current and potential pharmacological therapies and to refine the choice of pharmacological agent that may be used to enhance benefits from rehabilitation therapy.

  19. Neural mechanisms of mental fatigue.

    Science.gov (United States)

    Ishii, Akira; Tanaka, Masaaki; Watanabe, Yasuyoshi

    2014-01-01

    Fatigue is defined as a decline in the ability and efficiency of mental and/or physical activities that is caused by excessive mental and/or physical activities. Fatigue can be classified as physical or mental. Mental fatigue manifests as potentially impaired cognitive function and is one of the most significant causes of accidents in modern society. Recently, it has been shown that the neural mechanisms of mental fatigue related to cognitive task performance are more complex than previously thought and that mental fatigue is not caused only by impaired activity in task-related brain regions. There is accumulating evidence supporting the existence of mental facilitation and inhibition systems. These systems are involved in the neural mechanisms of mental fatigue, modulating the activity of task-related brain regions to regulate cognitive task performance. In this review, we propose a new conceptual model: the dual regulation system of mental fatigue. This model contributes to our understanding of the neural mechanisms of mental fatigue and the regulatory mechanisms of cognitive task performance in the presence of mental fatigue.

  20. Brain basis of communicative actions in language.

    Science.gov (United States)

    Egorova, Natalia; Shtyrov, Yury; Pulvermüller, Friedemann

    2016-01-15

    Although language is a key tool for communication in social interaction, most studies in the neuroscience of language have focused on language structures such as words and sentences. Here, the neural correlates of speech acts, that is, the actions performed by using language, were investigated with functional magnetic resonance imaging (fMRI). Participants were shown videos, in which the same critical utterances were used in different communicative contexts, to Name objects, or to Request them from communication partners. Understanding of critical utterances as Requests was accompanied by activation in bilateral premotor, left inferior frontal and temporo-parietal cortical areas known to support action-related and social interactive knowledge. Naming, however, activated the left angular gyrus implicated in linking information about word forms and related reference objects mentioned in critical utterances. These findings show that understanding of utterances as different communicative actions is reflected in distinct brain activation patterns, and thus suggest different neural substrates for different speech act types.

  1. Death and rebirth of neural activity in sparse inhibitory networks

    OpenAIRE

    Angulo-Garcia, David; Luccioli, Stefano; Olmi, Simona; Torcini, Alessandro

    2016-01-01

    In this paper, we clarify the mechanisms underlying a general phenomenon present in pulse-coupled heterogeneous inhibitory networks: inhibition can induce not only suppression of the neural activity, as expected, but it can also promote neural reactivation. In particular, for globally coupled systems, the number of firing neurons monotonically reduces upon increasing the strength of inhibition (neurons' death). However, the random pruning of the connections is able to reverse the action of in...

  2. A neural flow estimator

    DEFF Research Database (Denmark)

    Jørgensen, Ivan Harald Holger; Bogason, Gudmundur; Bruun, Erik

    1995-01-01

    This paper proposes a new way to estimate the flow in a micromechanical flow channel. A neural network is used to estimate the delay of random temperature fluctuations induced in a fluid. The design and implementation of a hardware efficient neural flow estimator is described. The system...... is implemented using switched-current technique and is capable of estimating flow in the μl/s range. The neural estimator is built around a multiplierless neural network, containing 96 synaptic weights which are updated using the LMS1-algorithm. An experimental chip has been designed that operates at 5 V...

  3. Neural Systems Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — As part of the Electrical and Computer Engineering Department and The Institute for System Research, the Neural Systems Laboratory studies the functionality of the...

  4. Kernel Temporal Differences for Neural Decoding

    Directory of Open Access Journals (Sweden)

    Jihye Bae

    2015-01-01

    Full Text Available We study the feasibility and capability of the kernel temporal difference (KTD(λ algorithm for neural decoding. KTD(λ is an online, kernel-based learning algorithm, which has been introduced to estimate value functions in reinforcement learning. This algorithm combines kernel-based representations with the temporal difference approach to learning. One of our key observations is that by using strictly positive definite kernels, algorithm’s convergence can be guaranteed for policy evaluation. The algorithm’s nonlinear functional approximation capabilities are shown in both simulations of policy evaluation and neural decoding problems (policy improvement. KTD can handle high-dimensional neural states containing spatial-temporal information at a reasonable computational complexity allowing real-time applications. When the algorithm seeks a proper mapping between a monkey’s neural states and desired positions of a computer cursor or a robot arm, in both open-loop and closed-loop experiments, it can effectively learn the neural state to action mapping. Finally, a visualization of the coadaptation process between the decoder and the subject shows the algorithm’s capabilities in reinforcement learning brain machine interfaces.

  5. The neural substrate of gesture recognition.

    Science.gov (United States)

    Villarreal, Mirta; Fridman, Esteban A; Amengual, Alejandra; Falasco, German; Gerschcovich, Eliana Roldan; Gerscovich, Eliana Roldan; Ulloa, Erlinda R; Leiguarda, Ramon C

    2008-01-01

    Previous studies have linked action recognition with a particular pool of neurons located in the ventral premotor cortex, the posterior parietal cortex and the superior temporal sulcus (the mirror neuron system). However, it is still unclear if transitive and intransitive gestures share the same neural substrates during action-recognition processes. In the present study, we used event-related functional magnetic resonance imaging (fMRI) to assess the cortical areas active during recognition of pantomimed transitive actions, intransitive gestures, and meaningless control actions. Perception of all types of gestures engaged the right pre-supplementary motor area (pre-SMA), and bilaterally in the posterior superior temporal cortex, the posterior parietal cortex, occipitotemporal regions and visual cortices. Activation of the posterior superior temporal sulcus/superior temporal gyrus region was found in both hemispheres during recognition of transitive and intransitive gestures, and in the right hemisphere during the control condition; the middle temporal gyrus showed activation in the left hemisphere when subjects recognized transitive and intransitive gestures; activation of the left inferior parietal lobe and intraparietal sulcus (IPS) was mainly observed in the left hemisphere during recognition of the three conditions. The most striking finding was the greater activation of the left inferior frontal gyrus (IFG) during recognition of intransitive actions. Results show that a similar neural substrate, albeit, with a distinct engagement underlies the cognitive processing of transitive and intransitive gestures recognition. These findings suggest that selective disruptions in these circuits may lead to distinct clinical deficits.

  6. A Fuzzy-Neural Network Control of Nonlinear Dynamic Systems

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    In this paper,an adaptive dynamic control scheme based on a fuzzy neural network is presented,that presents utilizes both feed-forward and feedback controller elements.The former of the two elements comprises a neural network with both identification and control role,and the latter is a fuzzy neural algorithm,which is introduced to provide additional control enhancement.The feedforward controller provides only coarse control,whereas the feedback oontroller can generate on-line conditional proposition rule automatically to improve the overall control action.These properties make the design very versatile and applicable to a range of industrial applications.

  7. Generalized Potential of Adult Neural Stem Cells

    Science.gov (United States)

    Clarke, Diana L.; Johansson, Clas B.; Wilbertz, Johannes; Veress, Biborka; Nilsson, Erik; Karlström, Helena; Lendahl, Urban; Frisén, Jonas

    2000-06-01

    The differentiation potential of stem cells in tissues of the adult has been thought to be limited to cell lineages present in the organ from which they were derived, but there is evidence that some stem cells may have a broader differentiation repertoire. We show here that neural stem cells from the adult mouse brain can contribute to the formation of chimeric chick and mouse embryos and give rise to cells of all germ layers. This demonstrates that an adult neural stem cell has a very broad developmental capacity and may potentially be used to generate a variety of cell types for transplantation in different diseases.

  8. Neural Networks: Implementations and Applications

    NARCIS (Netherlands)

    Vonk, E.; Veelenturf, L.P.J.; Jain, L.C.

    1996-01-01

    Artificial neural networks, also called neural networks, have been used successfully in many fields including engineering, science and business. This paper presents the implementation of several neural network simulators and their applications in character recognition and other engineering areas

  9. What Are Neural Tube Defects?

    Science.gov (United States)

    ... NICHD Research Information Clinical Trials Resources and Publications Neural Tube Defects (NTDs): Condition Information Skip sharing on social media links Share this: Page Content What are neural tube defects? Neural (pronounced NOOR-uhl ) tube defects are ...

  10. Action Learning: Avoiding Conflict or Enabling Action

    Science.gov (United States)

    Corley, Aileen; Thorne, Ann

    2006-01-01

    Action learning is based on the premise that action and learning are inextricably entwined and it is this potential, to enable action, which has contributed to the growth of action learning within education and management development programmes. However has this growth in action learning lead to an evolution or a dilution of Revan's classical…

  11. Primary neural leprosy: systematic review

    Directory of Open Access Journals (Sweden)

    Jose Antonio Garbino

    2013-06-01

    Full Text Available The authors proposed a systematic review on the current concepts of primary neural leprosy by consulting the following online databases: MEDLINE, Lilacs/SciELO, and Embase. Selected studies were classified based on the degree of recommendation and levels of scientific evidence according to the “Oxford Centre for Evidence-based Medicine”. The following aspects were reviewed: cutaneous clinical and laboratorial investigations, i.e. skin clinical exam, smears, and biopsy, and Mitsuda's reaction; neurological investigation (anamnesis, electromyography and nerve biopsy; serological investigation and molecular testing, i.e. serological testing for the detection of the phenolic glycolipid 1 (PGL-I and the polymerase chain reaction (PCR; and treatment (classification criteria for the definition of specific treatment, steroid treatment, and cure criteria.

  12. Critical Branching Neural Networks

    Science.gov (United States)

    Kello, Christopher T.

    2013-01-01

    It is now well-established that intrinsic variations in human neural and behavioral activity tend to exhibit scaling laws in their fluctuations and distributions. The meaning of these scaling laws is an ongoing matter of debate between isolable causes versus pervasive causes. A spiking neural network model is presented that self-tunes to critical…

  13. Kunstige neurale net

    DEFF Research Database (Denmark)

    Hørning, Annette

    1994-01-01

    Artiklen beskæftiger sig med muligheden for at anvende kunstige neurale net i forbindelse med datamatisk procession af naturligt sprog, specielt automatisk talegenkendelse.......Artiklen beskæftiger sig med muligheden for at anvende kunstige neurale net i forbindelse med datamatisk procession af naturligt sprog, specielt automatisk talegenkendelse....

  14. Is neural Darwinism Darwinism?

    Science.gov (United States)

    van Belle, T

    1997-01-01

    Neural Darwinism is a theory of cognition developed by Gerald Edelman along with George Reeke and Olaf Sporns at Rockefeller University. As its name suggests, neural Darwinism is modeled after biological Darwinism, and its authors assert that the two processes are strongly analogous. both operate on variation in a population, amplifying the more adaptive individuals. However, from a computational perspective, neural Darwinism is quite different from other models of natural selection, such as genetic algorithms. The individuals of neural Darwinism do not replicate, thus robbing the process of the capacity to explore new solutions over time and ultimately reducing it to a random search. Because neural Darwinism does not have the computational power of a truly Darwinian process, it is misleading to label it as such. to illustrate this disparity in adaptive power, one of Edelman's early computer experiments, Darwin I, is revisited, and it is shown that adding replication greatly improves the adaptive power of the system.

  15. Do Neural Avalanches Indicate Criticality After All?

    CERN Document Server

    Dehghani, Mohammad; Shahbazi, Farhad

    2016-01-01

    Neural avalanches in size and duration exhibit a power law distribution illustrating as a straight line when plotted on the logarithmic scales. The power-law exponent is interpreted as the signature of criticality and it is assumed that the resting brain operates near criticality. However, there is no clear evidence that supports this assumption, and even there are extensive research studies conflicting one another. The model of the current paper is an extension of a previous publication wherein we used an integrate-and-fire model on a regular lattice with periodic boundary conditions and introduced the temporal complexity as a genuine signature of criticality. However, in that model the power-law distribution of neural avalanches were manifestation of super-criticality rather than criticality. Here, however, we show that replacing the discrete noise in the model with a Gaussian noise and continuous time solution of the equation leads to coincidence of temporal complexity and spatiotemporal patterns of neural...

  16. Action experience and action discovery in medicated individuals with Parkinson’s disease

    Directory of Open Access Journals (Sweden)

    Jeffery G. Bednark

    2016-08-01

    Full Text Available Parkinson’s disease (PD is a neurodegenerative disorder that markedly affects voluntary action. While regular dopamine treatment can help restore motor function, dopamine also influences cognitive portions of the action system. Previous studies have demonstrated that dopamine medication boosts action-effect associations, which are crucial for the discovery of new voluntary actions. In the present study, we investigated whether neural processes involved in the discovery of new actions are altered in PD participants on regular dopamine treatment, compared to healthy age-match controls. We recorded brain electroencephalography (EEG activity while PD patients and age-matched controls performed action discovery and action control tasks. We found that the novelty P3, a component normally present when there is uncertainty about the occurrence of the sensory effect, was enhanced in PD patients. However, action discovery was maintained in PD patients, and the novelty P3 demonstrated normal learning-related reductions. Crucially, we found that in PD patients the causal association between an action and its resulting sensory outcome did not modulate the amplitude of the feedback correct-related positivity (fCRP, an EEG component sensitive to the association between an action and its resulting effect. Collectively, these preliminary results suggest that the formation of long-term action-outcome representations may be maintained in PD patients on regular dopamine treatment, but the initial experience of action-effect association may be affected.

  17. Some neural effects of adenosin.

    Science.gov (United States)

    Haulică, I; Brănişteanu, D D; Petrescu, G H

    1978-01-01

    The possible neural effects of adenosine were investigated by using electrophysiological techniques at the level of some central and peripheral synapses. The evoked potentials in the somatosensorial cerebral cortex are influenced according to both the type of administration and the level of the electrical stimulation. While the local application does not induce significant alterations, the intrathalamic injections and the perfusion of the IIIrd cerebral ventricle do change the distribution of activated units at the level of different cortical layers especially during the peripheral stimulation. The frequency of spontaneous miniature discharges intracellularly recorded in the neuromuscular junction (mepp) is significantly depressed by adenosine. This effect is calcium- and dose-dependent. The end plate potentials (EPP) were also depressed. The statistical binomial analysis of the phenomenon indicated that adenosine induces a decrease if the presynaptic pool of the available transmitter. The data obtained demonstrate a presynaptic inhibitory action of adenosine beside its known vascular and metaholic effects.

  18. An Instruction Language for Self-Construction in the Context of Neural Networks

    OpenAIRE

    Frederic eZubler; Andreas eHauri; Sabina ePfister; Whatley, Adrian M; Matthew eCook; Rodney eDouglas

    2011-01-01

    Biological systems are based on an entirely different concept of construction than human artifacts. They construct themselves by a process of self-organization that is a systematic spatio-temporal generation of, and interaction between, various specialized cell types. We propose a framework for designing gene-like codes for guiding the self-construction of neural networks. The description of neural development is formalized by defining a set of primitive actions taken locally by neural precur...

  19. Neuro-immune interactions of neural stem cell transplants: from animal disease models to human trials.

    Science.gov (United States)

    Giusto, Elena; Donegà, Matteo; Cossetti, Chiara; Pluchino, Stefano

    2014-10-01

    Stem cell technology is a promising branch of regenerative medicine that is aimed at developing new approaches for the treatment of severely debilitating human diseases, including those affecting the central nervous system (CNS). Despite the increasing understanding of the mechanisms governing their biology, the application of stem cell therapeutics remains challenging. The initial idea that stem cell transplants work in vivo via the replacement of endogenous cells lost or damaged owing to disease has been challenged by accumulating evidence of their therapeutic plasticity. This new concept covers the remarkable immune regulatory and tissue trophic effects that transplanted stem cells exert at the level of the neural microenvironment to promote tissue healing via combination of immune modulatory and tissue protective actions, while retaining predominantly undifferentiated features. Among a number of promising candidate stem cell sources, neural stem/precursor cells (NPCs) are under extensive investigation with regard to their therapeutic plasticity after transplantation. The significant impact in vivo of experimental NPC therapies in animal models of inflammatory CNS diseases has raised great expectations that these stem cells, or the manipulation of the mechanisms behind their therapeutic impact, could soon be translated to human studies. This review aims to provide an update on the most recent evidence of therapeutically-relevant neuro-immune interactions following NPC transplants in animal models of multiple sclerosis, cerebral stroke and traumas of the spinal cord, and consideration of the forthcoming challenges related to the early translation of some of these exciting experimental outcomes into clinical medicines.

  20. Independent Neural Computation of Value from Other People's Confidence.

    Science.gov (United States)

    Campbell-Meiklejohn, Daniel; Simonsen, Arndis; Frith, Chris D; Daw, Nathaniel D

    2017-01-18

    Expectation of reward can be shaped by the observation of actions and expressions of other people in one's environment. A person's apparent confidence in the likely reward of an action, for instance, makes qualities of their evidence, not observed directly, socially accessible. This strategy is computationally distinguished from associative learning methods that rely on direct observation, by its use of inference from indirect evidence. In twenty-three healthy human subjects, we isolated effects of first-hand experience, other people's choices, and the mediating effect of their confidence, on decision-making and neural correlates of value within ventromedial prefrontal cortex (vmPFC). Value derived from first-hand experience and other people's choices (regardless of confidence) were indiscriminately represented across vmPFC. However, value computed from agent choices weighted by their associated confidence was represented with specificity for ventromedial area 10. This pattern corresponds to shifts of connectivity and overlapping cognitive processes along a posterior-anterior vmPFC axis. Task behavior and self-reported self-reliance for decision-making in other social contexts correlated. The tendency to conform in other social contexts corresponded to increased activation in cortical regions previously shown to respond to social conflict in proportion to subsequent conformity (Campbell-Meiklejohn et al., 2010). The tendency to self-monitor predicted a selectively enhanced response to accordance with others in the right temporoparietal junction (rTPJ). The findings anatomically decompose vmPFC value representations according to computational requirements and provide biological insight into the social transmission of preference and reassurance gained from the confidence of others.

  1. The Cellular Prion Protein Controls Notch Signaling in Neural Stem/Progenitor Cells.

    Science.gov (United States)

    Martin-Lannerée, Séverine; Halliez, Sophie; Hirsch, Théo Z; Hernandez-Rapp, Julia; Passet, Bruno; Tomkiewicz, Céline; Villa-Diaz, Ana; Torres, Juan-Maria; Launay, Jean-Marie; Béringue, Vincent; Vilotte, Jean-Luc; Mouillet-Richard, Sophie

    2017-03-01

    The prion protein is infamous for its involvement in a group of neurodegenerative diseases known as Transmissible Spongiform Encephalopathies. In the longstanding quest to decipher the physiological function of its cellular isoform, PrP(C) , the discovery of its participation to the self-renewal of hematopoietic and neural stem cells has cast a new spotlight on its potential role in stem cell biology. However, still little is known on the cellular and molecular mechanisms at play. Here, by combining in vitro and in vivo murine models of PrP(C) depletion, we establish that PrP(C) deficiency severely affects the Notch pathway, which plays a major role in neural stem cell maintenance. We document that the absence of PrP(C) in a neuroepithelial cell line or in primary neurospheres is associated with drastically reduced expression of Notch ligands and receptors, resulting in decreased levels of Notch target genes. Similar alterations of the Notch pathway are recovered in the neuroepithelium of Prnp(-/-) embryos during a developmental window encompassing neural tube closure. In addition, in line with Notch defects, our data show that the absence of PrP(C) results in altered expression of Nestin and Olig2 as well as N-cadherin distribution. We further provide evidence that PrP(C) controls the expression of the epidermal growth factor receptor (EGFR) downstream from Notch. Finally, we unveil a negative feedback action of EGFR on both Notch and PrP(C) . As a whole, our study delineates a molecular scenario through which PrP(C) takes part to the self-renewal of neural stem and progenitor cells. Stem Cells 2017;35:754-765.

  2. Dynamics of neural cryptography.

    Science.gov (United States)

    Ruttor, Andreas; Kinzel, Wolfgang; Kanter, Ido

    2007-05-01

    Synchronization of neural networks has been used for public channel protocols in cryptography. In the case of tree parity machines the dynamics of both bidirectional synchronization and unidirectional learning is driven by attractive and repulsive stochastic forces. Thus it can be described well by a random walk model for the overlap between participating neural networks. For that purpose transition probabilities and scaling laws for the step sizes are derived analytically. Both these calculations as well as numerical simulations show that bidirectional interaction leads to full synchronization on average. In contrast, successful learning is only possible by means of fluctuations. Consequently, synchronization is much faster than learning, which is essential for the security of the neural key-exchange protocol. However, this qualitative difference between bidirectional and unidirectional interaction vanishes if tree parity machines with more than three hidden units are used, so that those neural networks are not suitable for neural cryptography. In addition, the effective number of keys which can be generated by the neural key-exchange protocol is calculated using the entropy of the weight distribution. As this quantity increases exponentially with the system size, brute-force attacks on neural cryptography can easily be made unfeasible.

  3. Botulinum toxins: mechanisms of action, antinociception and clinical applications.

    Science.gov (United States)

    Wheeler, Anthony; Smith, Howard S

    2013-04-05

    Botulinum toxin (BoNT) is a potent neurotoxin that is produced by the gram-positive, spore-forming, anaerobic bacterium, Clostridum botulinum. There are 7 known immunologically distinct serotypes of BoNT: types A, B, C1, D, E, F, and G. Clostridum neurotoxins are produced as a single inactive polypeptide chain of 150kDa, which is cleaved by tissue proteinases into an active di-chain molecule: a heavy chain (H) of ∼100 kDa and a light chain (L) of ∼50 kDa held together by a single disulfide bond. Each serotype demonstrates its own varied mechanisms of action and duration of effect. The heavy chain of each BoNT serotype binds to its specific neuronal ecto-acceptor, whereby, membrane translocation and endocytosis by intracellular synaptic vesicles occurs. The light chain acts to cleave SNAP-25, which inhibits synaptic exocytosis, and therefore, disables neural transmission. The action of BoNT to block the release of acetylcholine botulinum toxin at the neuromuscular junction is best understood, however, most experts acknowledge that this effect alone appears inadequate to explain the entirety of the neurotoxin's apparent analgesic activity. Consequently, scientific and clinical evidence has emerged that suggests multiple antinociceptive mechanisms for botulinum toxins in a variety of painful disorders, including: chronic musculoskeletal, neurological, pelvic, perineal, osteoarticular, and some headache conditions.

  4. The neural mechanisms of learning from competitors.

    Science.gov (United States)

    Howard-Jones, Paul A; Bogacz, Rafal; Yoo, Jee H; Leonards, Ute; Demetriou, Skevi

    2010-11-01

    Learning from competitors poses a challenge for existing theories of reward-based learning, which assume that rewarded actions are more likely to be executed in the future. Such a learning mechanism would disadvantage a player in a competitive situation because, since the competitor's loss is the player's gain, reward might become associated with an action the player should themselves avoid. Using fMRI, we investigated the neural activity of humans competing with a computer in a foraging task. We observed neural activity that represented the variables required for learning from competitors: the actions of the competitor (in the player's motor and premotor cortex) and the reward prediction error arising from the competitor's feedback. In particular, regions positively correlated with the unexpected loss of the competitor (which was beneficial to the player) included the striatum and those regions previously implicated in response inhibition. Our results suggest that learning in such contexts may involve the competitor's unexpected losses activating regions of the player's brain that subserve response inhibition, as the player learns to avoid the actions that produced them.

  5. Social status modulates neural activity in the mentalizing network.

    Science.gov (United States)

    Muscatell, Keely A; Morelli, Sylvia A; Falk, Emily B; Way, Baldwin M; Pfeifer, Jennifer H; Galinsky, Adam D; Lieberman, Matthew D; Dapretto, Mirella; Eisenberger, Naomi I

    2012-04-15

    The current research explored the neural mechanisms linking social status to perceptions of the social world. Two fMRI studies provide converging evidence that individuals lower in social status are more likely to engage neural circuitry often involved in 'mentalizing' or thinking about others' thoughts and feelings. Study 1 found that college students' perception of their social status in the university community was related to neural activity in the mentalizing network (e.g., DMPFC, MPFC, precuneus/PCC) while encoding social information, with lower social status predicting greater neural activity in this network. Study 2 demonstrated that socioeconomic status, an objective indicator of global standing, predicted adolescents' neural activity during the processing of threatening faces, with individuals lower in social status displaying greater activity in the DMPFC, previously associated with mentalizing, and the amygdala, previously associated with emotion/salience processing. These studies demonstrate that social status is fundamentally and neurocognitively linked to how people process and navigate their social worlds.

  6. AUV fuzzy neural BDI

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    The typical BDI (belief desire intention) model of agent is not efficiently computable and the strict logic expression is not easily applicable to the AUV (autonomous underwater vehicle) domain with uncertainties. In this paper, an AUV fuzzy neural BDI model is proposed. The model is a fuzzy neural network composed of five layers: input ( beliefs and desires) , fuzzification, commitment, fuzzy intention, and defuzzification layer. In the model, the fuzzy commitment rules and neural network are combined to form intentions from beliefs and desires. The model is demonstrated by solving PEG (pursuit-evasion game), and the simulation result is satisfactory.

  7. ANT Advanced Neural Tool

    Energy Technology Data Exchange (ETDEWEB)

    Labrador, I.; Carrasco, R.; Martinez, L.

    1996-07-01

    This paper describes a practical introduction to the use of Artificial Neural Networks. Artificial Neural Nets are often used as an alternative to the traditional symbolic manipulation and first order logic used in Artificial Intelligence, due the high degree of difficulty to solve problems that can not be handled by programmers using algorithmic strategies. As a particular case of Neural Net a Multilayer Perception developed by programming in C language on OS9 real time operating system is presented. A detailed description about the program structure and practical use are included. Finally, several application examples that have been treated with the tool are presented, and some suggestions about hardware implementations. (Author) 15 refs.

  8. Attentional selection in visual perception, memory and action: a quest for cross-domain integration.

    Science.gov (United States)

    Schneider, Werner X; Einhäuser, Wolfgang; Horstmann, Gernot

    2013-10-19

    For decades, the cognitive and neural sciences have benefitted greatly from a separation of mind and brain into distinct functional domains. The tremendous success of this approach notwithstanding, it is self-evident that such a view is incomplete. Goal-directed behaviour of an organism requires the joint functioning of perception, memory and sensorimotor control. A prime candidate for achieving integration across these functional domains are attentional processes. Consequently, this Theme Issue brings together studies of attentional selection from many fields, both experimental and theoretical, that are united in their quest to find overreaching integrative principles of attention between perception, memory and action. In all domains, attention is understood as combination of competition and priority control ('bias'), with the task as a decisive driving factor to ensure coherent goal-directed behaviour and cognition. Using vision as the predominant model system for attentional selection, many studies of this Theme Issue focus special emphasis on eye movements as a selection process that is both a fundamental action and serves a key function in perception. The Theme Issue spans a wide range of methods, from measuring human behaviour in the real word to recordings of single neurons in the non-human primate brain. We firmly believe that combining such a breadth in approaches is necessary not only for attentional selection, but also to take the next decisive step in all of the cognitive and neural sciences: to understand cognition and behaviour beyond isolated domains.

  9. The Criticality Hypothesis in Neural Systems

    Science.gov (United States)

    Karimipanah, Yahya

    There is mounting evidence that neural networks of the cerebral cortex exhibit scale invariant dynamics. At the larger scale, fMRI recordings have shown evidence for spatiotemporal long range correlations. On the other hand, at the smaller scales this scale invariance is marked by the power law distribution of the size and duration of spontaneous bursts of activity, which are referred as neuronal avalanches. The existence of such avalanches has been confirmed by several studies in vitro and in vivo, among different species and across multiple scales, from spatial scale of MEG and EEG down to single cell resolution. This prevalent scale free nature of cortical activity suggests the hypothesis that the cortex resides at a critical state between two phases of order (short-lasting activity) and disorder (long-lasting activity). In addition, it has been shown, both theoretically and experimentally, that being at criticality brings about certain functional advantages for information processing. However, despite the plenty of evidence and plausibility of the neural criticality hypothesis, still very little is known on how the brain may leverage such criticality to facilitate neural coding. Moreover, the emergent functions that may arise from critical dynamics is poorly understood. In the first part of this thesis, we review several pieces of evidence for the neural criticality hypothesis at different scales, as well as some of the most popular theories of self-organized criticality (SOC). Thereafter, we will focus on the most prominent evidence from small scales, namely neuronal avalanches. We will explore the effect of adaptation and how it can maintain scale free dynamics even at the presence of external stimuli. Using calcium imaging we also experimentally demonstrate the existence of scale free activity at the cellular resolution in vivo. Moreover, by exploring the subsampling issue in neural data, we will find some fundamental constraints of the conventional methods

  10. Neural networks and graph theory

    Institute of Scientific and Technical Information of China (English)

    许进; 保铮

    2002-01-01

    The relationships between artificial neural networks and graph theory are considered in detail. The applications of artificial neural networks to many difficult problems of graph theory, especially NP-complete problems, and the applications of graph theory to artificial neural networks are discussed. For example graph theory is used to study the pattern classification problem on the discrete type feedforward neural networks, and the stability analysis of feedback artificial neural networks etc.

  11. Hidden neural networks

    DEFF Research Database (Denmark)

    Krogh, Anders Stærmose; Riis, Søren Kamaric

    1999-01-01

    A general framework for hybrids of hidden Markov models (HMMs) and neural networks (NNs) called hidden neural networks (HNNs) is described. The article begins by reviewing standard HMMs and estimation by conditional maximum likelihood, which is used by the HNN. In the HNN, the usual HMM probability...... parameters are replaced by the outputs of state-specific neural networks. As opposed to many other hybrids, the HNN is normalized globally and therefore has a valid probabilistic interpretation. All parameters in the HNN are estimated simultaneously according to the discriminative conditional maximum...... likelihood criterion. The HNN can be viewed as an undirected probabilistic independence network (a graphical model), where the neural networks provide a compact representation of the clique functions. An evaluation of the HNN on the task of recognizing broad phoneme classes in the TIMIT database shows clear...

  12. Critical branching neural networks.

    Science.gov (United States)

    Kello, Christopher T

    2013-01-01

    It is now well-established that intrinsic variations in human neural and behavioral activity tend to exhibit scaling laws in their fluctuations and distributions. The meaning of these scaling laws is an ongoing matter of debate between isolable causes versus pervasive causes. A spiking neural network model is presented that self-tunes to critical branching and, in doing so, simulates observed scaling laws as pervasive to neural and behavioral activity. These scaling laws are related to neural and cognitive functions, in that critical branching is shown to yield spiking activity with maximal memory and encoding capacities when analyzed using reservoir computing techniques. The model is also shown to account for findings of pervasive 1/f scaling in speech and cued response behaviors that are difficult to explain by isolable causes. Issues and questions raised by the model and its results are discussed from the perspectives of physics, neuroscience, computer and information sciences, and psychological and cognitive sciences.

  13. Neural Oscillators Programming Simplified

    Directory of Open Access Journals (Sweden)

    Patrick McDowell

    2012-01-01

    Full Text Available The neurological mechanism used for generating rhythmic patterns for functions such as swallowing, walking, and chewing has been modeled computationally by the neural oscillator. It has been widely studied by biologists to model various aspects of organisms and by computer scientists and robotics engineers as a method for controlling and coordinating the gaits of walking robots. Although there has been significant study in this area, it is difficult to find basic guidelines for programming neural oscillators. In this paper, the authors approach neural oscillators from a programmer’s point of view, providing background and examples for developing neural oscillators to generate rhythmic patterns that can be used in biological modeling and robotics applications.

  14. Terminology versus action (Editorial

    Directory of Open Access Journals (Sweden)

    Lindsay Glynn

    2006-12-01

    Full Text Available I have heard it said, as many of us have, that evidence based library and information practice is an area dominated and led by librarians in the health sciences. It is a logical leap to say that medical librarians may be more familiar with the evidence based model of practice because of their need to be familiar, on some level, with evidence based medicine. The idea of making a decision based on the appropriate evidence is as familiar to a medical librarianas is how to effectively search PubMed. How pervasive is the influence of the medical profession on this area? Being a librarian looking for quick information, I turned to Google. The results on the first two pages from a Google search for evidence based practice are 100% health/medicine related. Being a good librarian, I refined my search to see how the results would differ, and I added the term library to the search. This time there were 75% health/medicine results and 5% representing evidence based library and information practice (eblip. Note that a high percentage of the health/medicine hits were library webpages on evidence based medicine. Being an obsessive‐compulsive librarian, I changed my search strategy again by replacing library with librarianship. This time there were 30% health/medicine results and 65% eblip. A final search for evidence based information had this journal as the top hit. Being a busy librarian with a lot of work to do, I stopped right there. OK, so the terminology appears to point strongly in one direction and weighs heavily on the health sciences penetration. Let’s leave terminology aside for a moment and look at action. Since Evidence Based Library and Information Practice is the first journal on this topic, the list of contributors and their backgrounds should give an indication on whether or not there is a concentration of medical librarians. Approximately two thirds of the articles that we have published are non‐health/medicine related. Only 29% of our

  15. The Potential Neural Mechanisms of Acute Indirect Vibration

    OpenAIRE

    Cochrane, Darryl J.

    2011-01-01

    There is strong evidence to suggest that acute indirect vibration acts on muscle to enhance force, power, flexibility, balance and proprioception suggesting neural enhancement. Nevertheless, the neural mechanism(s) of vibration and its potentiating effect have received little attention. One proposal suggests that spinal reflexes enhance muscle contraction through a reflex activity known as tonic vibration stretch reflex (TVR), which increases muscle activation. However, TVR is based on direct...

  16. Neural Signaling Metabolites May Modulate Energy Use in Hibernation.

    Science.gov (United States)

    Drew, Kelly L; Frare, Carla; Rice, Sarah A

    2017-01-01

    Despite an epidemic in obesity and metabolic syndrome limited means exist to effect adiposity or metabolic rate other than life style changes. Here we review evidence that neural signaling metabolites may modulate thermoregulatory pathways and offer novel means to fine tune energy use. We extend prior reviews on mechanisms that regulate thermogenesis and energy use in hibernation by focusing primarily on the neural signaling metabolites adenosine, AMP and glutamate.

  17. A new framework for cortico-striatal plasticity: behavioural theory meets in vitro data at the reinforcement-action interface.

    Directory of Open Access Journals (Sweden)

    Kevin N Gurney

    2015-01-01

    Full Text Available Operant learning requires that reinforcement signals interact with action representations at a suitable neural interface. Much evidence suggests that this occurs when phasic dopamine, acting as a reinforcement prediction error, gates plasticity at cortico-striatal synapses, and thereby changes the future likelihood of selecting the action(s coded by striatal neurons. But this hypothesis faces serious challenges. First, cortico-striatal plasticity is inexplicably complex, depending on spike timing, dopamine level, and dopamine receptor type. Second, there is a credit assignment problem-action selection signals occur long before the consequent dopamine reinforcement signal. Third, the two types of striatal output neuron have apparently opposite effects on action selection. Whether these factors rule out the interface hypothesis and how they interact to produce reinforcement learning is unknown. We present a computational framework that addresses these challenges. We first predict the expected activity changes over an operant task for both types of action-coding striatal neuron, and show they co-operate to promote action selection in learning and compete to promote action suppression in extinction. Separately, we derive a complete model of dopamine and spike-timing dependent cortico-striatal plasticity from in vitro data. We then show this model produces the predicted activity changes necessary for learning and extinction in an operant task, a remarkable convergence of a bottom-up data-driven plasticity model with the top-down behavioural requirements of learning theory. Moreover, we show the complex dependencies of cortico-striatal plasticity are not only sufficient but necessary for learning and extinction. Validating the model, we show it can account for behavioural data describing extinction, renewal, and reacquisition, and replicate in vitro experimental data on cortico-striatal plasticity. By bridging the levels between the single synapse and

  18. A new framework for cortico-striatal plasticity: behavioural theory meets in vitro data at the reinforcement-action interface.

    Science.gov (United States)

    Gurney, Kevin N; Humphries, Mark D; Redgrave, Peter

    2015-01-01

    Operant learning requires that reinforcement signals interact with action representations at a suitable neural interface. Much evidence suggests that this occurs when phasic dopamine, acting as a reinforcement prediction error, gates plasticity at cortico-striatal synapses, and thereby changes the future likelihood of selecting the action(s) coded by striatal neurons. But this hypothesis faces serious challenges. First, cortico-striatal plasticity is inexplicably complex, depending on spike timing, dopamine level, and dopamine receptor type. Second, there is a credit assignment problem-action selection signals occur long before the consequent dopamine reinforcement signal. Third, the two types of striatal output neuron have apparently opposite effects on action selection. Whether these factors rule out the interface hypothesis and how they interact to produce reinforcement learning is unknown. We present a computational framework that addresses these challenges. We first predict the expected activity changes over an operant task for both types of action-coding striatal neuron, and show they co-operate to promote action selection in learning and compete to promote action suppression in extinction. Separately, we derive a complete model of dopamine and spike-timing dependent cortico-striatal plasticity from in vitro data. We then show this model produces the predicted activity changes necessary for learning and extinction in an operant task, a remarkable convergence of a bottom-up data-driven plasticity model with the top-down behavioural requirements of learning theory. Moreover, we show the complex dependencies of cortico-striatal plasticity are not only sufficient but necessary for learning and extinction. Validating the model, we show it can account for behavioural data describing extinction, renewal, and reacquisition, and replicate in vitro experimental data on cortico-striatal plasticity. By bridging the levels between the single synapse and behaviour, our

  19. A double dissociation between the meanings of action verbs and locative prepositions.

    Science.gov (United States)

    Kemmerer, David; Tranel, Daniel

    2003-10-01

    Abstract We describe two patients who manifested opposite patterns of performance on test batteries that evaluated production, comprehension, and semantic analysis of action verbs on the one hand (e.g. smile, wave, run ) and locative prepositions on the other (e.g. in, on, over ). JP failed all of the verb tests but passed all of the preposition tests, suggesting impaired knowledge of the meanings of action verbs but intact knowledge of the meanings of locative prepositions. In contrast, RR exhibited the reverse dissociation: he passed many of the verb tests but failed all of the preposition tests, suggesting mostly intact knowledge of the meanings of action verbs but impaired knowledge of the meanings of locative prepositions. This behavioral double dissociation reflects the fact that the two categories of words differ along several conceptual parameters. To a large extent, the patients exhibited a neuroanatomical double dissociation as well, since JP's lesion is predominantly in the left frontal operculum whereas RR's is predominantly in the left inferior parietal lobe and the posterior superior temporal region. This constitutes preliminary evidence that the meanings of action verbs and locative prepositions are represented by partially independent neural networks in the brain.

  20. Imaging the Neural Symphony.

    Science.gov (United States)

    Svoboda, Karel

    2016-01-01

    Since the start of the new millennium, a method called two-photon microscopy has allowed scientists to peer farther into the brain than ever before. Our author, one of the pioneers in the development of this new technology, writes that "directly observing the dynamics of neural networks in an intact brain has become one of the holy grails of brain research." His article describes the advances that led to this remarkable breakthrough-one that is helping neuroscientists better understand neural networks.

  1. Building a Neural Computer

    OpenAIRE

    1998-01-01

    In the work of [Siegelmann 95] it was showed that Artificial Recursive Neural Networks have the same computing power as Turing machines. A Turing machine can be programmed in a proper high-level language - the language of partial recursive functions. In this paper we present the implementation of a compiler that directly translates high-level Turing machine programs to Artificial Recursive Neural Networks. The application contains a simulator that can be used to test the resulting networks. W...

  2. Neural cryptography with feedback.

    Science.gov (United States)

    Ruttor, Andreas; Kinzel, Wolfgang; Shacham, Lanir; Kanter, Ido

    2004-04-01

    Neural cryptography is based on a competition between attractive and repulsive stochastic forces. A feedback mechanism is added to neural cryptography which increases the repulsive forces. Using numerical simulations and an analytic approach, the probability of a successful attack is calculated for different model parameters. Scaling laws are derived which show that feedback improves the security of the system. In addition, a network with feedback generates a pseudorandom bit sequence which can be used to encrypt and decrypt a secret message.

  3. The Endocannabinoid System and Its Role in Regulating the Intrinsic Neural Circuitry of the Gastrointestinal Tract.

    Science.gov (United States)

    Trautmann, Samantha M; Sharkey, Keith A

    2015-01-01

    Endocannabinoids are important neuromodulators in the central nervous system. They regulate central transmission through pre- and postsynaptic actions on neurons and indirectly through effects on glial cells. Cannabinoids (CBs) also regulate neurotransmission in the enteric nervous system (ENS) of the gastrointestinal (GI) tract. The ENS consists of intrinsic primary afferent neurons, interneurons, and motor neurons arranged in two ganglionated plexuses which control all the functions of the gut. Increasing evidence suggests that endocannabinoids are potent neuromodulators in the ENS. In this review, we will highlight key observations on the localization of CB receptors and molecules involved in the synthesis and degradation of endocannabinoids in the ENS. We will discuss endocannabinoid signaling mechanisms, endocannabinoid tone and concepts of CB receptor metaplasticity in the ENS. We will also touch on some examples of enteric neural signaling in relation neuromuscular, secretomotor, and enteroendocrine transmission in the ENS. Finally, we will briefly discuss some key future directions.

  4. Neural reactivation links unconscious thought to decision-making performance.

    Science.gov (United States)

    Creswell, John David; Bursley, James K; Satpute, Ajay B

    2013-12-01

    Brief periods of unconscious thought (UT) have been shown to improve decision making compared with making an immediate decision (ID). We reveal a neural mechanism for UT in decision making using blood oxygen level-dependent (BOLD) functional magnetic resonance imaging. Participants (N = 33) encoded information on a set of consumer products (e.g. 48 attributes describing four different cars), and we manipulated whether participants (i) consciously thought about this information (conscious thought), (ii) completed a difficult 2-back working memory task (UT) or (iii) made an immediate decision about the consumer products (ID) in a within-subjects blocked design. To differentiate UT neural activity from 2-back working memory neural activity, participants completed an independent 2-back task and this neural activity was subtracted from neural activity occurring during the UT 2-back task. Consistent with a neural reactivation account, we found that the same regions activated during the encoding of complex decision information (right dorsolateral prefrontal cortex and left intermediate visual cortex) continued to be activated during a subsequent 2-min UT period. Moreover, neural reactivation in these regions was predictive of subsequent behavioral decision-making performance after the UT period. These results provide initial evidence for post-encoding unconscious neural reactivation in facilitating decision making.

  5. The neural subjective frame: from bodily signals to perceptual consciousness.

    Science.gov (United States)

    Park, Hyeong-Dong; Tallon-Baudry, Catherine

    2014-05-05

    The report 'I saw the stimulus' operationally defines visual consciousness, but where does the 'I' come from? To account for the subjective dimension of perceptual experience, we introduce the concept of the neural subjective frame. The neural subjective frame would be based on the constantly updated neural maps of the internal state of the body and constitute a neural referential from which first person experience can be created. We propose to root the neural subjective frame in the neural representation of visceral information which is transmitted through multiple anatomical pathways to a number of target sites, including posterior insula, ventral anterior cingulate cortex, amygdala and somatosensory cortex. We review existing experimental evidence showing that the processing of external stimuli can interact with visceral function. The neural subjective frame is a low-level building block of subjective experience which is not explicitly experienced by itself which is necessary but not sufficient for perceptual experience. It could also underlie other types of subjective experiences such as self-consciousness and emotional feelings. Because the neural subjective frame is tightly linked to homeostatic regulations involved in vigilance, it could also make a link between state and content consciousness.

  6. Ideomotor feedback control in a recurrent neural network.

    Science.gov (United States)

    Galtier, Mathieu

    2015-06-01

    The architecture of a neural network controlling an unknown environment is presented. It is based on a randomly connected recurrent neural network from which both perception and action are simultaneously read and fed back. There are two concurrent learning rules implementing a sort of ideomotor control: (i) perception is learned along the principle that the network should predict reliably its incoming stimuli; (ii) action is learned along the principle that the prediction of the network should match a target time series. The coherent behavior of the neural network in its environment is a consequence of the interaction between the two principles. Numerical simulations show a promising performance of the approach, which can be turned into a local and better "biologically plausible" algorithm.

  7. Neural locus of color afterimages.

    Science.gov (United States)

    Zaidi, Qasim; Ennis, Robert; Cao, Dingcai; Lee, Barry

    2012-02-07

    After fixating on a colored pattern, observers see a similar pattern in complementary colors when the stimulus is removed [1-6]. Afterimages were important in disproving the theory that visual rays emanate from the eye, in demonstrating interocular interactions, and in revealing the independence of binocular vision from eye movements. Afterimages also prove invaluable in exploring selective attention, filling in, and consciousness. Proposed physiological mechanisms for color afterimages range from bleaching of cone photopigments to cortical adaptation [4-9], but direct neural measurements have not been reported. We introduce a time-varying method for evoking afterimages, which provides precise measurements of adaptation and a direct link between visual percepts and neural responses [10]. We then use in vivo electrophysiological recordings to show that all three classes of primate retinal ganglion cells exhibit subtractive adaptation to prolonged stimuli, with much slower time constants than those expected of photoreceptors. At the cessation of the stimulus, ganglion cells generate rebound responses that can provide afterimage signals for later neurons. Our results indicate that afterimage signals are generated in the retina but may be modified like other retinal signals by cortical processes, so that evidence presented for cortical generation of color afterimages is explainable by spatiotemporal factors that modify all signals.

  8. Event-driven neural integration and synchronicity in analog VLSI.

    Science.gov (United States)

    Yu, Theodore; Park, Jongkil; Joshi, Siddharth; Maier, Christoph; Cauwenberghs, Gert

    2012-01-01

    Synchrony and temporal coding in the central nervous system, as the source of local field potentials and complex neural dynamics, arises from precise timing relationships between spike action population events across neuronal assemblies. Recently it has been shown that coincidence detection based on spike event timing also presents a robust neural code invariant to additive incoherent noise from desynchronized and unrelated inputs. We present spike-based coincidence detection using integrate-and-fire neural membrane dynamics along with pooled conductance-based synaptic dynamics in a hierarchical address-event architecture. Within this architecture, we encode each synaptic event with parameters that govern synaptic connectivity, synaptic strength, and axonal delay with additional global configurable parameters that govern neural and synaptic temporal dynamics. Spike-based coincidence detection is observed and analyzed in measurements on a log-domain analog VLSI implementation of the integrate-and-fire neuron and conductance-based synapse dynamics.

  9. Chaotifying delayed recurrent neural networks via impulsive effects

    Science.gov (United States)

    Şaylı, Mustafa; Yılmaz, Enes

    2016-02-01

    In this paper, chaotification of delayed recurrent neural networks via chaotically changing moments of impulsive actions is considered. Sufficient conditions for the presence of Li-Yorke chaos with its ingredients proximality, frequent separation, and existence of infinitely many periodic solutions are theoretically proved. Finally, effectiveness of our theoretical results is illustrated by an example with numerical simulations.

  10. Visual intelligence using neural-symbolic learning and reasoning

    NARCIS (Netherlands)

    Penning, H.L.H. de

    2011-01-01

    The DARPA Mind’s Eye program seeks to develop in machines a capability that currently exists only in animals: visual intelligence. This short paper describes the initial results of a Neural-Symbolic approach for action recognition and description to be demonstrated at the 7th international workshop

  11. Fluctuation-Driven Neural Dynamics Reproduce Drosophila Locomotor Patterns.

    Directory of Open Access Journals (Sweden)

    Andrea Maesani

    2015-11-01

    Full Text Available The neural mechanisms determining the timing of even simple actions, such as when to walk or rest, are largely mysterious. One intriguing, but untested, hypothesis posits a role for ongoing activity fluctuations in neurons of central action selection circuits that drive animal behavior from moment to moment. To examine how fluctuating activity can contribute to action timing, we paired high-resolution measurements of freely walking Drosophila melanogaster with data-driven neural network modeling and dynamical systems analysis. We generated fluctuation-driven network models whose outputs-locomotor bouts-matched those measured from sensory-deprived Drosophila. From these models, we identified those that could also reproduce a second, unrelated dataset: the complex time-course of odor-evoked walking for genetically diverse Drosophila strains. Dynamical models that best reproduced both Drosophila basal and odor-evoked locomotor patterns exhibited specific characteristics. First, ongoing fluctuations were required. In a stochastic resonance-like manner, these fluctuations allowed neural activity to escape stable equilibria and to exceed a threshold for locomotion. Second, odor-induced shifts of equilibria in these models caused a depression in locomotor frequency following olfactory stimulation. Our models predict that activity fluctuations in action selection circuits cause behavioral output to more closely match sensory drive and may therefore enhance navigation in complex sensory environments. Together these data reveal how simple neural dynamics, when coupled with activity fluctuations, can give rise to complex patterns of animal behavior.

  12. "Remember Me": Memory and Action in "Hamlet".

    Science.gov (United States)

    Andrews, Michael Cameron

    1981-01-01

    Examines the relationship between Hamlet's commitments to the past and his failure to translate these commitments into action, as he permits himself to be deflected by preoccupation with the future consequences of his action. Cites supportive evidence from the text. (DMM)

  13. A Possible Neural Representation of Mathematical Group Structures.

    Science.gov (United States)

    Pomi, Andrés

    2016-09-01

    Every cognitive activity has a neural representation in the brain. When humans deal with abstract mathematical structures, for instance finite groups, certain patterns of activity are occurring in the brain that constitute their neural representation. A formal neurocognitive theory must account for all the activities developed by our brain and provide a possible neural representation for them. Associative memories are neural network models that have a good chance of achieving a universal representation of cognitive phenomena. In this work, we present a possible neural representation of mathematical group structures based on associative memory models that store finite groups through their Cayley graphs. A context-dependent associative memory stores the transitions between elements of the group when multiplied by each generator of a given presentation of the group. Under a convenient election of the vector basis mapping the elements of the group in the neural activity, the input of a vector corresponding to a generator of the group collapses the context-dependent rectangular matrix into a virtual square permutation matrix that is the matrix representation of the generator. This neural representation corresponds to the regular representation of the group, in which to each element is assigned a permutation matrix. This action of the generator on the memory matrix can also be seen as the dissection of the corresponding monochromatic subgraph of the Cayley graph of the group, and the adjacency matrix of this subgraph is the permutation matrix corresponding to the generator.

  14. Estimation of the chemical-induced eye injury using a weight-of-evidence (WoE) battery of 21 artificial neural network (ANN) c-QSAR models (QSAR-21): part I: irritation potential.

    Science.gov (United States)

    Verma, Rajeshwar P; Matthews, Edwin J

    2015-03-01

    Evaluation of potential chemical-induced eye injury through irritation and corrosion is required to ensure occupational and consumer safety for industrial, household and cosmetic ingredient chemicals. The historical method for evaluating eye irritant and corrosion potential of chemicals is the rabbit Draize test. However, the Draize test is controversial and its use is diminishing - the EU 7th Amendment to the Cosmetic Directive (76/768/EEC) and recast Regulation now bans marketing of new cosmetics having animal testing of their ingredients and requires non-animal alternative tests for safety assessments. Thus, in silico and/or in vitro tests are advocated. QSAR models for eye irritation have been reported for several small (congeneric) data sets; however, large global models have not been described. This report describes FDA/CFSAN's development of 21 ANN c-QSAR models (QSAR-21) to predict eye irritation using the ADMET Predictor program and a diverse training data set of 2928 chemicals. The 21 models had external (20% test set) and internal validation and average training/verification/test set statistics were: 88/88/85(%) sensitivity and 82/82/82(%) specificity, respectively. The new method utilized multiple artificial neural network (ANN) molecular descriptor selection functionalities to maximize the applicability domain of the battery. The eye irritation models will be used to provide information to fill the critical data gaps for the safety assessment of cosmetic ingredient chemicals.

  15. The endocannabinoid system drives neural progenitor proliferation.

    Science.gov (United States)

    Aguado, Tania; Monory, Krisztina; Palazuelos, Javier; Stella, Nephi; Cravatt, Benjamin; Lutz, Beat; Marsicano, Giovanni; Kokaia, Zaal; Guzmán, Manuel; Galve-Roperh, Ismael

    2005-10-01

    The discovery of multipotent neural progenitor (NP) cells has provided strong support for the existence of neurogenesis in the adult brain. However, the signals controlling NP proliferation remain elusive. Endocannabinoids, the endogenous counterparts of marijuana-derived cannabinoids, act as neuromodulators via presynaptic CB1 receptors and also control neural cell death and survival. Here we show that progenitor cells express a functional endocannabinoid system that actively regulates cell proliferation both in vitro and in vivo. Specifically, NPs produce endocannabinoids and express the CB1 receptor and the endocannabinoid-inactivating enzyme fatty acid amide hydrolase (FAAH). CB1 receptor activation promotes cell proliferation and neurosphere generation, an action that is abrogated in CB1-deficient NPs. Accordingly, proliferation of hippocampal NPs is increased in FAAH-deficient mice. Our results demonstrate that endocannabinoids constitute a new group of signaling cues that regulate NP proliferation and thus open novel therapeutic avenues for manipulation of NP cell fate in the adult brain.

  16. Universality and individuality in a neural code

    CERN Document Server

    Schneidman, E; Tishby, N; De Ruyter van Steveninck, R R; Bialek, W; Schneidman, Elad; Brenner, Naama; Tishby, Naftali; De Ruyter van Steveninck, Rob R.; Bialek, William

    2000-01-01

    The problem of neural coding is to understand how sequences of action potentials (spikes) are related to sensory stimuli, motor outputs, or (ultimately) thoughts and intentions. One clear question is whether the same coding rules are used by different neurons, or by corresponding neurons in different individuals. We present a quantitative formulation of this problem using ideas from information theory, and apply this approach to the analysis of experiments in the fly visual system. We find significant individual differences in the structure of the code, particularly in the way that temporal patterns of spikes are used to convey information beyond that available from variations in spike rate. On the other hand, all the flies in our ensemble exhibit a high coding efficiency, so that every spike carries the same amount of information in all the individuals. Thus the neural code has a quantifiable mixture of individuality and universality.

  17. Morphogenetic action through flux-limited spreading

    Science.gov (United States)

    Verbeni, M.; Sánchez, O.; Mollica, E.; Siegl-Cachedenier, I.; Carleton, A.; Guerrero, I.; Ruiz i Altaba, A.; Soler, J.

    2013-12-01

    A central question in biology is how secreted morphogens act to induce different cellular responses within a group of cells in a concentration-dependent manner. Modeling morphogenetic output in multicellular systems has so far employed linear diffusion, which is the normal type of diffusion associated with Brownian processes. However, there is evidence that at least some morphogens, such as Hedgehog (Hh) molecules, may not freely diffuse. Moreover, the mathematical analysis of such models necessarily implies unrealistic instantaneous spreading of morphogen molecules, which are derived from the assumptions of Brownian motion in its continuous formulation. A strict mathematical model considering Fick's diffusion law predicts morphogen exposure of the whole tissue at the same time. Such a strict model thus does not describe true biological patterns, even if similar and attractive patterns appear as results of applying such simple model. To eliminate non-biological behaviors from diffusion models we introduce flux-limited spreading (FLS), which implies a restricted velocity for morphogen propagation and a nonlinear mechanism of transport. Using FLS and focusing on intercellular Hh-Gli signaling, we model a morphogen gradient and highlight the propagation velocity of morphogen particles as a new key biological parameter. This model is then applied to the formation and action of the Sonic Hh (Shh) gradient in the vertebrate embryonic neural tube using our experimental data on Hh spreading in heterologous systems together with published data. Unlike linear diffusion models, FLS modeling predicts concentration fronts and the evolution of gradient dynamics and responses over time. In addition to spreading restrictions by extracellular binding partners, we suggest that the constraints imposed by direct bridges of information transfer such as nanotubes or cytonemes underlie FLS. Indeed, we detect and measure morphogen particle velocity in such cell extensions in different

  18. Gain control of gamma frequency activation by a novel feed forward disinhibitory loop: implications for normal and epileptic neural activity

    Directory of Open Access Journals (Sweden)

    Zeinab eBirjandian

    2013-11-01

    Full Text Available The inhibition of excitatory (pyramidal neurons directly dampens their activity resulting in a suppression of neural network output. The inhibition of inhibitory cells is more complex. Inhibitory drive is known to gate neural network synchrony, but there is also a widely held view that it may augment excitability by reducing inhibitory cell activity, a process termed disinhibition. Surprisingly, however, disinhibition has never been demonstrated to be an important mechanism that augments or drives the activity of excitatory neurons in a functioning neural circuit. Using voltage sensitive dye imaging (VSDI we show that 20-80 Hz stimulus trains, (beta-gamma activation, of the olfactory cortex pyramidal cells in layer II leads to a subsequent reduction in inhibitory interneuron activity that augments the efficacy of the initial stimulus. This disinhibition occurs with a lag of about 150-250 ms after the initial excitation of the layer 2 pyramidal cell layer. In addition activation of the endopiriform nucleus also arises just before the disinhibitory phase with a lag of about 40-80 ms. Preventing the spread of action potentials from layer II stopped the excitation of the endopiriform nucleus, abolished the disinhibitory activity and reduced the excitation of layer II cells. After the induction of experimental epilepsy the disinhibition was more intense with a concomitant increase in excitatory cell activity. Our observations provide the first evidence of feed forward disinhibition loop that augments excitatory neurotransmission, a mechanism that could play an important role in the development of epileptic seizures.

  19. [Plant lectins and embryonic tissue factors as probes for studying the mechanisms of neural induction in amphibians].

    Science.gov (United States)

    Mikhaĭlov, A T; Gorgoliuk, N A

    1992-01-01

    Using various experimental techniques, we have demonstrated that animal pole ectoderm (APE) of Rana temporaria embryos at the stage of early gastrula is a good target tissue for testing the neuralizing (N) factors. In this respect R. temporaria APE is comparable with APE of some other amphibian species. We found that concanavalin A (con A), phytohemagglutinin (PHA) and embryonic brain-derived neuralizing factor (EBDNF; a factor extracted from the chick embryonic brain and partially purified) have a pronounced N-effect on the APE of R. temporaria. In order to analyse possible mechanisms of N-action of these factors, we have cultured APE explants for 3 or 18 h in the medium containing various concentrations of con A, PHA of EBDNF. All these factors could produce neuralization in 50% explants. However, the optimal concentration and time of exposure were different. This is an evidence for different mechanisms of reception and transmission of a N-signal in each particular case. It appears that the APE consists of several cell subpopulations which differ in their threshold sensitivity to the N-effect of studied agents.

  20. Between thoughts and actions: motivationally salient cues invigorate mental action in the human brain.

    Science.gov (United States)

    Mendelsohn, Avi; Pine, Alex; Schiller, Daniela

    2014-01-08

    The maintenance of goal-directed behavior relies upon a cascade of covert mental actions including motor imagery and planning. Here we investigated how cues imbued with motivational salience can invigorate motor imagery networks preceding action. We adapted the Pavlovian-to-instrumental (PIT) paradigm to explore this by substituting motor action with motor imagery. Thus, reward was contingent upon a given level of imagery-induced neural activity using real-time fMRI. We found that the concomitant presentation of reward-related cues during motor imagery not only enhanced neural responses in motivational centers (ventral striatum and extended amygdala) but also exerted a motivational effect in the imagery network itself. Moreover, functional connectivity between ventral striatum (but not extended amygdala) and motor cortex was heightened during imagery in the presence of the reward-related cue. The concurrent activation of "value" and "action" networks may illuminate the neural process that links motivational cues to desires and urges to obtain goals.

  1. Neural networks in seismic discrimination

    Energy Technology Data Exchange (ETDEWEB)

    Dowla, F.U.

    1995-01-01

    Neural networks are powerful and elegant computational tools that can be used in the analysis of geophysical signals. At Lawrence Livermore National Laboratory, we have developed neural networks to solve problems in seismic discrimination, event classification, and seismic and hydrodynamic yield estimation. Other researchers have used neural networks for seismic phase identification. We are currently developing neural networks to estimate depths of seismic events using regional seismograms. In this paper different types of network architecture and representation techniques are discussed. We address the important problem of designing neural networks with good generalization capabilities. Examples of neural networks for treaty verification applications are also described.

  2. Neural regulation of the stress response: glucocorticoid feedback mechanisms

    Directory of Open Access Journals (Sweden)

    J.P. Herman

    2012-04-01

    Full Text Available The mammalian stress response is an integrated physiological and psychological reaction to real or perceived adversity. Glucocorticoids are an important component of this response, acting to redistribute energy resources to both optimize survival in the face of challenge and to restore homeostasis after the immediate challenge has subsided. Release of glucocorticoids is mediated by the hypothalamo-pituitary-adrenal (HPA axis, driven by a neural signal originating in the paraventricular nucleus (PVN. Stress levels of glucocorticoids bind to glucocorticoid receptors in multiple body compartments, including the brain, and consequently have wide-reaching actions. For this reason, glucocorticoids serve a vital function in negative feedback inhibition of their own secretion. Negative feedback inhibition is mediated by a diverse collection of mechanisms, including fast, non-genomic feedback at the level of the PVN, stress-shut-off at the level of the limbic system, and attenuation of ascending excitatory input through destabilization of mRNAs encoding neuropeptide drivers of the HPA axis. In addition, there is evidence that glucocorticoids participate in stress activation via feed-forward mechanisms at the level of the amygdala. Feedback deficits are associated with numerous disease states, underscoring the necessity for adequate control of glucocorticoid homeostasis. Thus, rather than having a single, defined feedback ‘switch’, control of the stress response requires a wide-reaching feedback ‘network’ that coordinates HPA activity to suit the overall needs of multiple body systems.

  3. Modulation of arm reaching movements during processing of arm/hand-related action verbs with and without emotional connotation.

    Directory of Open Access Journals (Sweden)

    Silvia Spadacenta

    Full Text Available The theory of embodied language states that language comprehension relies on an internal reenactment of the sensorimotor experience associated with the processed word or sentence. Most evidence in support of this hypothesis had been collected using linguistic material without any emotional connotation. For instance, it had been shown that processing of arm-related verbs, but not of those leg-related verbs, affects the planning and execution of reaching movements; however, at present it is unknown whether this effect is further modulated by verbs evoking an emotional experience. Showing such a modulation might shed light on a very debated issue, i.e. the way in which the emotional meaning of a word is processed. To this end, we assessed whether processing arm/hand-related verbs describing actions with negative connotations (e.g. to stab affects reaching movements differently from arm/hand-related verbs describing actions with neutral connotation (e.g. to comb. We exploited a go/no-go paradigm in which healthy participants were required to perform arm-reaching movements toward a target when verbs expressing emotional hand actions, neutral hand actions or foot actions were shown, and to refrain from moving when no-effector-related verbs were presented. Reaction times and percentages of errors increased when the verb involved the same effector as used to give the response. However, we also found that the size of this interference decreased when the arm/hand-related verbs had a negative emotional connotation. Crucially, we show that such modulation only occurred when the verb semantics had to be retrieved. These results suggest that the comprehension of negatively valenced verbs might require the simultaneous reenactment of the neural circuitry associated with the processing of the emotion evoked by their meaning and of the neural circuitry associated with their motor features.

  4. Modulation of arm reaching movements during processing of arm/hand-related action verbs with and without emotional connotation.

    Science.gov (United States)

    Spadacenta, Silvia; Gallese, Vittorio; Fragola, Michele; Mirabella, Giovanni

    2014-01-01

    The theory of embodied language states that language comprehension relies on an internal reenactment of the sensorimotor experience associated with the processed word or sentence. Most evidence in support of this hypothesis had been collected using linguistic material without any emotional connotation. For instance, it had been shown that processing of arm-related verbs, but not of those leg-related verbs, affects the planning and execution of reaching movements; however, at present it is unknown whether this effect is further modulated by verbs evoking an emotional experience. Showing such a modulation might shed light on a very debated issue, i.e. the way in which the emotional meaning of a word is processed. To this end, we assessed whether processing arm/hand-related verbs describing actions with negative connotations (e.g. to stab) affects reaching movements differently from arm/hand-related verbs describing actions with neutral connotation (e.g. to comb). We exploited a go/no-go paradigm in which healthy participants were required to perform arm-reaching movements toward a target when verbs expressing emotional hand actions, neutral hand actions or foot actions were shown, and to refrain from moving when no-effector-related verbs were presented. Reaction times and percentages of errors increased when the verb involved the same effector as used to give the response. However, we also found that the size of this interference decreased when the arm/hand-related verbs had a negative emotional connotation. Crucially, we show that such modulation only occurred when the verb semantics had to be retrieved. These results suggest that the comprehension of negatively valenced verbs might require the simultaneous reenactment of the neural circuitry associated with the processing of the emotion evoked by their meaning and of the neural circuitry associated with their motor features.

  5. Are corporations people too? The neural correlates of moral judgments about companies and individuals.

    Science.gov (United States)

    Plitt, Mark; Savjani, Ricky R; Eagleman, David M

    2015-04-01

    To investigate whether the legal concept of "corporate personhood" mirrors an inherent similarity in the neural processing of the actions of corporations and people, we measured brain responses to vignettes about corporations and people while participants underwent functional magnetic resonance imaging. We found that anti-social actions of corporations elicited more intense negative emotions and that pro-social actions of people elicited more intense positive emotions. However, the networks underlying the moral decisions about corporations and people are strikingly similar, including regions of the canonical theory of mind network. In analyzing the activity in these networks, we found differences in the emotional processing of these two types of vignettes: neutral actions of corporations showed neural correlates that more closely resembled negative actions than positive actions. Collectively, these findings indicate that our brains understand and analyze the actions of corporations and people very similarly, with a small emotional bias against corporations.

  6. Insect Bio-inspired Neural Network Provides New Evidence on How Simple Feature Detectors Can Enable Complex Visual Generalization and Stimulus Location Invariance in the Miniature Brain of Honeybees

    Science.gov (United States)

    Fernando, Chrisantha

    2017-01-01

    The ability to generalize over naturally occurring variation in cues indicating food or predation risk is highly useful for efficient decision-making in many animals. Honeybees have remarkable visual cognitive abilities, allowing them to classify visual patterns by common features despite having a relatively miniature brain. Here we ask the question whether generalization requires complex visual recognition or whether it can also be achieved with relatively simple neuronal mechanisms. We produced several simple models inspired by the known anatomical structures and neuronal responses within the bee brain and subsequently compared their ability to generalize achromatic patterns to the observed behavioural performance of honeybees on these cues. Neural networks with just eight large-field orientation-sensitive input neurons from the optic ganglia and a single layer of simple neuronal connectivity within the mushroom bodies (learning centres) show performances remarkably similar to a large proportion of the empirical results without requiring any form of learning, or fine-tuning of neuronal parameters to replicate these results. Indeed, a model simply combining sensory input from both eyes onto single mushroom body neurons returned correct discriminations even with partial occlusion of the patterns and an impressive invariance to the location of the test patterns on the eyes. This model also replicated surprising failures of bees to discriminate certain seemingly highly different patterns, providing novel and useful insights into the inner workings facilitating and limiting the utilisation of visual cues in honeybees. Our results reveal that reliable generalization of visual information can be achieved through simple neuronal circuitry that is biologically plausible and can easily be accommodated in a tiny insect brain. PMID:28158189

  7. Insect Bio-inspired Neural Network Provides New Evidence on How Simple Feature Detectors Can Enable Complex Visual Generalization and Stimulus Location Invariance in the Miniature Brain of Honeybees.

    Science.gov (United States)

    Roper, Mark; Fernando, Chrisantha; Chittka, Lars

    2017-02-01

    The ability to generalize over naturally occurring variation in cues indicating food or predation risk is highly useful for efficient decision-making in many animals. Honeybees have remarkable visual cognitive abilities, allowing them to classify visual patterns by common features despite having a relatively miniature brain. Here we ask the question whether generalization requires complex visual recognition or whether it can also be achieved with relatively simple neuronal mechanisms. We produced several simple models inspired by the known anatomical structures and neuronal responses within the bee brain and subsequently compared their ability to generalize achromatic patterns to the observed behavioural performance of honeybees on these cues. Neural networks with just eight large-field orientation-sensitive input neurons from the optic ganglia and a single layer of simple neuronal connectivity within the mushroom bodies (learning centres) show performances remarkably similar to a large proportion of the empirical results without requiring any form of learning, or fine-tuning of neuronal parameters to replicate these results. Indeed, a model simply combining sensory input from both eyes onto single mushroom body neurons returned correct discriminations even with partial occlusion of the patterns and an impressive invariance to the location of the test patterns on the eyes. This model also replicated surprising failures of bees to discriminate certain seemingly highly different patterns, providing novel and useful insights into the inner workings facilitating and limiting the utilisation of visual cues in honeybees. Our results reveal that reliable generalization of visual information can be achieved through simple neuronal circuitry that is biologically plausible and can easily be accommodated in a tiny insect brain.

  8. Translating science into action

    DEFF Research Database (Denmark)

    Jürgensen, Nanna; Petersen, Poul E; Ogawa, Hiroshi

    2012-01-01

    findings into effective and sustainable programs for groups and populations. The advances in oral health science have not yet benefitted the poor and disadvantaged population groups around the world to the fullest extent possible and this has led to inequalities in periodontal health as well as in other...... is emphasized. Research on other population-directed strategies and their implications on public health would be instrumental to integrated prevention of chronic disease and periodontal disease. Community interventions and delivery of preventive oral care by oral health services may have positive outcomes...... for periodontal health but periodontal research needs to be further strengthened by the provision of sound evidence. It is somewhat remarkable that research on true population-directed actions in prevention of periodontal disease is most unusual. The high need for reorientation of periodontal research toward...

  9. Contextual behavior and neural circuits

    Directory of Open Access Journals (Sweden)

    Inah eLee

    2013-05-01

    Full Text Available Animals including humans engage in goal-directed behavior flexibly in response to items and their background, which is called contextual behavior in this review. Although the concept of context has long been studied, there are differences among researchers in defining and experimenting with the concept. The current review aims to provide a categorical framework within which not only the neural mechanisms of contextual information processing but also the contextual behavior can be studied in more concrete ways. For this purpose, we categorize contextual behavior into three subcategories as follows by considering the types of interactions among context, item, and response: contextual response selection, contextual item selection, and contextual item-response selection. Contextual response selection refers to the animal emitting different types of responses to the same item depending on the context in the background. Contextual item selection occurs when there are multiple items that need to be chosen in a contextual manner. Finally, when multiple items and multiple contexts are involved, contextual item-response selection takes place whereby the animal either choose an item or inhibit such a response depending on item-context paired association. The literature suggests that the rhinal cortical regions and the hippocampal formation play key roles in mnemonically categorizing and recognizing contextual representations and the associated items. In addition, it appears that the fronto-striatal cortical loops in connection with the contextual information-processing areas critically control the flexible deployment of adaptive action sets and motor responses for maximizing goals. We suggest that contextual information processing should be investigated in experimental settings where contextual stimuli and resulting behaviors are clearly defined and measurable, considering the dynamic top-down and bottom-up interactions among the neural systems for

  10. Contextual behavior and neural circuits

    Science.gov (United States)

    Lee, Inah; Lee, Choong-Hee

    2013-01-01

    Animals including humans engage in goal-directed behavior flexibly in response to items and their background, which is called contextual behavior in this review. Although the concept of context has long been studied, there are differences among researchers in defining and experimenting with the concept. The current review aims to provide a categorical framework within which not only the neural mechanisms of contextual information processing but also the contextual behavior can be studied in more concrete ways. For this purpose, we categorize contextual behavior into three subcategories as follows by considering the types of interactions among context, item, and response: contextual response selection, contextual item selection, and contextual item–response selection. Contextual response selection refers to the animal emitting different types of responses to the same item depending on the context in the background. Contextual item selection occurs when there are multiple items that need to be chosen in a contextual manner. Finally, when multiple items and multiple contexts are involved, contextual item–response selection takes place whereby the animal either chooses an item or inhibits such a response depending on item–context paired association. The literature suggests that the rhinal cortical regions and the hippocampal formation play key roles in mnemonically categorizing and recognizing contextual representations and the associated items. In addition, it appears that the fronto-striatal cortical loops in connection with the contextual information-processing areas critically control the flexible deployment of adaptive action sets and motor responses for maximizing goals. We suggest that contextual information processing should be investigated in experimental settings where contextual stimuli and resulting behaviors are clearly defined and measurable, considering the dynamic top-down and bottom-up interactions among the neural systems for contextual behavior

  11. Study on Fault Diagnosis Methods of Rolling Bearing Based on BP Neural Network and D-S Evidence Theory%基于BP神经网络和D-S证据理论的滚动轴承故障诊断方法研究

    Institute of Scientific and Technical Information of China (English)

    徐卫晓; 谭继文; 文妍

    2014-01-01

    针对单一传感器对滚动轴承故障信息的识别具有不确定性的缺陷,提出了基于BP神经网络与D⁃S证据理论的多传感器信息融合的方法。将BP神经网络的输出结果进行归一化处理作为各焦元的基本概率分配,轴承的5种故障类型作为系统的识别框架,根据Dempster合成法则进行决策级融合。试验结果表明,利用该方法对轴承的内圈磨损、外圈磨损、滚珠磨损等故障进行试验诊断,提高了故障诊断的准确率,验证了该方法的可行性。%Aimed at the defect of uncertainty of single sensor for the rolling bearing fault information recognition, the method of multi⁃sensor information fusion was proposed based on the BP neural network and the D⁃S evidence theory. Output results of BP neural network were normalized as the focal element of the basic probability assignment, five kinds of fault types of rolling bearing were identi⁃fied as a system framework, and decision level fusion was made according to Dempster combination rule. The test results show that using the method in experiments of fault diagnosis for bearing inner ring wear, outer ring wear and ball bearing wear has improved the accuracy of fault diagnosis, and verified its feasibility.

  12. Rule Extraction:Using Neural Networks or for Neural Networks?

    Institute of Scientific and Technical Information of China (English)

    Zhi-Hua Zhou

    2004-01-01

    In the research of rule extraction from neural networks, fidelity describes how well the rules mimic the behavior of a neural network while accuracy describes how well the rules can be generalized. This paper identifies the fidelity-accuracy dilemma. It argues to distinguish rule extraction using neural networks and rule extraction for neural networks according to their different goals, where fidelity and accuracy should be excluded from the rule quality evaluation framework, respectively.

  13. Wittgenstein running: neural mechanisms of collective intentionality and we-mode.

    Science.gov (United States)

    Becchio, Cristina; Bertone, Cesare

    2004-03-01

    In this paper we discuss the problem of the neural conditions of shared attitudes and intentions: which neural mechanisms underlie "we-mode" processes or serve as precursors to such processes? Neurophysiological and neuropsychological evidence suggests that in different areas of the brain neural representations are shared by several individuals. This situation, on the one hand, creates a potential problem for correct attribution. On the other hand, it may provide the conditions for shared attitudes and intentions.

  14. Fuzzy Multiresolution Neural Networks

    Science.gov (United States)

    Ying, Li; Qigang, Shang; Na, Lei

    A fuzzy multi-resolution neural network (FMRANN) based on particle swarm algorithm is proposed to approximate arbitrary nonlinear function. The active function of the FMRANN consists of not only the wavelet functions, but also the scaling functions, whose translation parameters and dilation parameters are adjustable. A set of fuzzy rules are involved in the FMRANN. Each rule either corresponding to a subset consists of scaling functions, or corresponding to a sub-wavelet neural network consists of wavelets with same dilation parameters. Incorporating the time-frequency localization and multi-resolution properties of wavelets with the ability of self-learning of fuzzy neural network, the approximation ability of FMRANN can be remarkable improved. A particle swarm algorithm is adopted to learn the translation and dilation parameters of the wavelets and adjusting the shape of membership functions. Simulation examples are presented to validate the effectiveness of FMRANN.

  15. Vicarious neural processing of outcomes during observational learning.

    Directory of Open Access Journals (Sweden)

    Elisabetta Monfardini

    Full Text Available Learning what behaviour is appropriate in a specific context by observing the actions of others and their outcomes is a key constituent of human cognition, because it saves time and energy and reduces exposure to potentially dangerous situations. Observational learning of associative rules relies on the ability to map the actions of others onto our own, process outcomes, and combine these sources of information. Here, we combined newly developed experimental tasks and functional magnetic resonance imaging (fMRI to investigate the neural mechanisms that govern such observational learning. Results show that the neural systems involved in individual trial-and-error learning and in action observation and execution both participate in observational learning. In addition, we identified brain areas that specifically activate for others' incorrect outcomes during learning in the posterior medial frontal cortex (pMFC, the anterior insula and the posterior superior temporal sulcus (pSTS.

  16. Deep learning in neural networks: an overview.

    Science.gov (United States)

    Schmidhuber, Jürgen

    2015-01-01

    In recent years, deep artificial neural networks (including recurrent ones) have won numerous contests in pattern recognition and machine learning. This historical survey compactly summarizes relevant work, much of it from the previous millennium. Shallow and Deep Learners are distinguished by the depth of their credit assignment paths, which are chains of possibly learnable, causal links between actions and effects. I review deep supervised learning (also recapitulating the history of backpropagation), unsupervised learning, reinforcement learning & evolutionary computation, and indirect search for short programs encoding deep and large networks.

  17. Signi fi cance of Neural Crest in Tooth Development: The Molecular Signature

    Directory of Open Access Journals (Sweden)

    VP Jayasekharan

    2014-07-01

    Full Text Available The neural crest originates from cells located along the lateral margins of the neural plate. Neural crest cells arise as the result of an inductive action by the non-neural ectoderm adjacent to the neural plate and possibly by nearby mesoderm as well. As the neural tube forms, a group of cells separate from the neuro- ectoderm. These cells have the capacity to migrate and differen- tiate extensively within the developing embryo and they are the basis of structures such as spinal sensory ganglia, sympathetic neurons, Schwann cells, pigment cells and meninges. Speci fi c interactions occur during the development of tooth and recent research has concentrated more on the molecular aspects of these interactions. Thus, it is highly imperative to understand and digress the complex mechanisms involved in these processes

  18. Introduction to Artificial Neural Networks

    DEFF Research Database (Denmark)

    Larsen, Jan

    1999-01-01

    The note addresses introduction to signal analysis and classification based on artificial feed-forward neural networks.......The note addresses introduction to signal analysis and classification based on artificial feed-forward neural networks....

  19. Deep neural network with weight sparsity control and pre-training extracts hierarchical features and enhances classification performance: Evidence from whole-brain resting-state functional connectivity patterns of schizophrenia.

    Science.gov (United States)

    Kim, Junghoe; Calhoun, Vince D; Shim, Eunsoo; Lee, Jong-Hwan

    2016-01-01

    Functional connectivity (FC) patterns obtained from resting-state functional magnetic resonance imaging data are commonly employed to study neuropsychiatric conditions by using pattern classifiers such as the support vector machine (SVM). Meanwhile, a deep neural network (DNN) with multiple hidden layers has shown its ability to systematically extract lower-to-higher level information of image and speech data from lower-to-higher hidden layers, markedly enhancing classification accuracy. The objective of this study was to adopt the DNN for whole-brain resting-state FC pattern classification of schizophrenia (SZ) patients vs. healthy controls (HCs) and identification of aberrant FC patterns associated with SZ. We hypothesized that the lower-to-higher level features learned via the DNN would significantly enhance the classification accuracy, and proposed an adaptive learning algorithm to explicitly control the weight sparsity in each hidden layer via L1-norm regularization. Furthermore, the weights were initialized via stacked autoencoder based pre-training to further improve the classification performance. Classification accuracy was systematically evaluated as a function of (1) the number of hidden layers/nodes, (2) the use of L1-norm regularization, (3) the use of the pre-training, (4) the use of framewise displacement (FD) removal, and (5) the use of anatomical/functional parcellation. Using FC patterns from anatomically parcellated regions without FD removal, an error rate of 14.2% was achieved by employing three hidden layers and 50 hidden nodes with both L1-norm regularization and pre-training, which was substantially lower than the error rate from the SVM (22.3%). Moreover, the trained DNN weights (i.e., the learned features) were found to represent the hierarchical organization of aberrant FC patterns in SZ compared with HC. Specifically, pairs of nodes extracted from the lower hidden layer represented sparse FC patterns implicated in SZ, which was

  20. 耳针作用的形态学基础-来自HRP神经示踪法的证据%Morphological Basis of Auricular Acupuncture Effects: Evidences from Neural Tracer Method of HRP

    Institute of Scientific and Technical Information of China (English)

    梅志刚; 朱兵; 何伟; 高昕妍

    2009-01-01

    Objective To observe projections of nervus auricularis vagi in brain stem of oblongata level,and to study the mechanism of auricular acupuncture. Methods Ten SD rats were used in this experiment, a skin incision was performed in the region of auricular concha of each rat, forty microliters of a 30% solution of horseradish peroxidase (HRP) in normal saline were subcuta-neously injected into the cut central end of auricular branch of vagus nerve, then distribution of the labeled neurons in the primary brain stem was observed using HRP retrograde tracing technique. Results Labeled neurons and fibers were seen in the nucleus of solitary tract, dorsal nucleus of vagus nerve and other nucleus besides nucleus of spinal tract of trigeminal. Conclusion There exists neural projection to NTS and DMV from the terminal of auricular vagus branch, maybe effect of auricular acupuncture is completed through auricular - vagal reflexes.%目的 观察支配耳甲区迷走神经在延髓水平中枢的投射情况,探讨耳针作用机理.方法 健康成年SD大鼠10只,外耳道口方向分离耳甲皮肤与皮下组织,微量注射器缝内注射40 μl 浓度为30%的HRP神经示踪剂,神经示踪技术观察标记细胞在延脑水平核团分布情况.结果 除了在三叉神经脊束核外,在孤束核和迷走神经运动背核以及其他核团也发现了标记神经元或神经纤维.结论 耳甲区迷走神经分支与迷走初级中枢有神经联系,耳甲穴位针刺效应很可能是通过耳-迷走反射途径实现的.

  1. Evidence that limbic neural plasticity in the right hemisphere mediates partial kindling induced lasting increases in anxiety-like behavior: effects of low frequency stimulation (quenching?) on long term potentiation of amygdala efferents and behavior following kindling.

    Science.gov (United States)

    Adamec, R E

    1999-08-21

    lasting increases in defensiveness and amygdalo-PAG LTP with FG-7142. The parallel between the present findings and the FG-7142 experiments suggests that lasting changes in defensive response are dependent on LTP of right amygdala efferents to the PAG, however produced. The findings suggest further that the spectrum of behavioral changes produced by partial kindling are dependent on changes in a variety of neural circuits, and that amygdala efferent transmission changes are responsible for changes in defensive behavior, but not predatory attack behavior. Clinical implications are discussed.

  2. NRC Significant Enforcement Actions

    Data.gov (United States)

    Nuclear Regulatory Commission — This dataset provides a list of Nuclear Regulartory Commission (NRC) issued significant enforcement actions. These actions, referred to as "escalated", are issued by...

  3. Neural mechanisms of proactive and reactive inhibitory control : Studies in healthy volunteers and schizophrenia patients

    NARCIS (Netherlands)

    Zandbelt, B.B.

    2011-01-01

    The neural underpinnings of our ability to restrain actions in advance (i.e. proactive inhibition) and stop actions in reaction to some event (i.e. reactive inhibition) remain largely unknown. In this thesis we used neuroimaging (functional magnetic resonance imaging, fMRI) and brain stimulation (tr

  4. Generation of diverse neural cell types through direct conversion

    Institute of Scientific and Technical Information of China (English)

    Gayle; F; Petersen; Padraig; M; Strappe

    2016-01-01

    A characteristic of neurological disorders is the loss of critical populations of cells that the body is unable to replace,thus there has been much interest in identifying methods of generating clinically relevant numbers of cells to replace those that have been damaged or lost.The process of neural direct conversion,in which cells of one lineage are converted into cells of a neural lineage without first inducing pluripotency,shows great potential,with evidence of the generation of a range of functional neural cell types both in vitro and in vivo,through viral and non-viral delivery of exogenous factors,as well as chemical induction methods.Induced neural cells have been proposed as an attractive alternative to neural cells derived from embryonic or induced pluripotent stem cells,with prospective roles in the investigation of neurological disorders,including neurodegenerative disease modelling,drug screening,and cellular replacement for regenerative medicine applications,however further investigations into improving the efficacy and safety of these methods need to be performed before neural direct conversion becomes a clinically viable option.In this review,we describe the generation of diverse neural cell types via direct conversion of somatic cells,with comparison against stem cell-based approaches,as well as discussion of their potential research and clinical applications.

  5. High school music classes enhance the neural processing of speech.

    Science.gov (United States)

    Tierney, Adam; Krizman, Jennifer; Skoe, Erika; Johnston, Kathleen; Kraus, Nina

    2013-01-01

    Should music be a priority in public education? One argument for teaching music in school is that private music instruction relates to enhanced language abilities and neural function. However, the directionality of this relationship is unclear and it is unknown whether school-based music training can produce these enhancements. Here we show that 2 years of group music classes in high school enhance the neural encoding of speech. To tease apart the relationships between music and neural function, we tested high school students participating in either music or fitness-based training. These groups were matched at the onset of training on neural timing, reading ability, and IQ. Auditory brainstem responses were collected to a synthesized speech sound presented in background noise. After 2 years of training, the neural responses of the music training group were earlier than at pre-training, while the neural timing of students in the fitness training group was unchanged. These results represent the strongest evidence to date that in-school music education can cause enhanced speech encoding. The neural benefits of musical training are, therefore, not limited to expensive private instruction early in childhood but can be elicited by cost-effective group instruction during adolescence.

  6. Affirmative Action at Work

    Directory of Open Access Journals (Sweden)

    Jack McKillip

    2001-04-01

    Full Text Available IMGIP and ICEOP are minority graduate fellowship programs sponsored by the State of Illinois in order to increase the number of minority faculty and professional staff at Illinois institutions of higher education through graduate fellowships, networking and mentoring support. Nearly 850 fellowships have been awarded since 1986. A performance audit examined immediate (areas of graduate study, ethnicity of awards, intermediate (graduation areas and rates, and long-range results (academic job placement. The primary source for the audit was the database maintained by the programs' administrative office. These data were compared with data sets maintained by the Illinois Board of Higher Education and with national benchmarks (NSF and Ford Foundation Minority Graduate Fellowships. Findings revealed: (a the IMGIP and ICEOP programs led to major diversification of minority doctoral study in Illinois; (b a high percentage of all fellows graduated, both absolutely and in relation to national benchmarks, and fellows made up a large percentage of doctoral degrees awarded to minorities by Illinois institutions (e.g., 46% of doctorates in the hard sciences awarded to African Americans from 1988-1998; and (c fellows made up an important proportion of all minority faculty in Illinois (9%. Most ICEOP doctoral fellows and many other fellows have taken academic positions. The audit revealed outcomes-based evidence of a successful affirmative action program in higher education—evidence that is not otherwise available.

  7. Generalized Adaptive Artificial Neural Networks

    Science.gov (United States)

    Tawel, Raoul

    1993-01-01

    Mathematical model of supervised learning by artificial neural network provides for simultaneous adjustments of both temperatures of neurons and synaptic weights, and includes feedback as well as feedforward synaptic connections. Extension of mathematical model described in "Adaptive Neurons For Artificial Neural Networks" (NPO-17803). Dynamics of neural network represented in new model by less-restrictive continuous formalism.

  8. The Neuroscience of Storing and Molding Tool Action Concepts: how plastic is grounded cognition?

    Directory of Open Access Journals (Sweden)

    J.C. Mizelle

    2010-11-01

    Full Text Available Choosing how to use tools to accomplish a task is a natural and seemingly trivial aspect of our lives, yet engages complex neural mechanisms. Recently, work in healthy populations has led to the idea that tool knowledge is grounded to allow for appropriate recall based on some level of personal history. This grounding has presumed neural loci for tool use, centered on parieto-temporo-frontal areas to fuse perception and action representations into one dynamic system. A challenge for this idea is related to one of its great benefits. For such a system to exist, it must be very plastic, to allow for the introduction of novel tools or concepts of tool use and modification of existing ones. Thus, learning new tool usage (familiar tools in new situations and new tools in familiar situations must involve mapping into this grounded network while marinating existing rules for tool usage. This plasticity may present a challenging breadth of encoding that needs to be optimally stored and accessed. The aim of this work is to explore the challenges of plasticity related to changing or incorporating representations of tool action within the theory of grounded cognition and propose a modular model of tool-object goal related accomplishment. While considering the neuroscience evidence for this approach, we will focus on the requisite plasticity for this system. Further, we will highlight challenges for flexibility and organization of already grounded tool actions and provide thoughts on future research to better evaluate mechanisms of encoding in the theory of grounded cognition.

  9. Neural Circuitry of the Bilingual Mental Lexicon: Effect of Age of Second Language Acquisition

    Science.gov (United States)

    Isel, Frederic; Baumgaertner, Annette; Thran, Johannes; Meisel, Jurgen M.; Buchel, Christian

    2010-01-01

    Numerous studies have proposed that changes of the human language faculty caused by neural maturation can explain the substantial differences in ultimate attainment of grammatical competences between first language (L1) acquirers and second language (L2) learners. However, little evidence on the effect of neural maturation on the attainment of…

  10. Adult neural stem cells-Functional potential and therapeutic applications

    Institute of Scientific and Technical Information of China (English)

    YANG Lin; ZHU Jianhong

    2004-01-01

    The adult brain has been thought traditionally as a structure with a very limited regenerative capacity. It is now evident that neurogenesis in adult mammalian brain is a prevailing phenomenon. Neural stem cells with the ability to self-renew, differentiate into neurons, astrocytes and oligodendrocytes reside in some regions of the adult brain. Adult neurogenesis can be stimulated by many physiological factors including pregnancy. More strikingly, newborn neurons in hippocampus integrally function with local neurons, thus neural stem cells might play important roles in memory and learning function. It seems that neural stem cells could transdifferentiate into other tissues, such as blood cells and muscles. Although there are some impediments in this field, some attempts have been made to employ adult neural stem cells in the cell replacement therapy for traumatic and ischemic brain injuries.

  11. A Spiking Neural Learning Classifier System

    CERN Document Server

    Howard, Gerard; Lanzi, Pier-Luca

    2012-01-01

    Learning Classifier Systems (LCS) are population-based reinforcement learners used in a wide variety of applications. This paper presents a LCS where each traditional rule is represented by a spiking neural network, a type of network with dynamic internal state. We employ a constructivist model of growth of both neurons and dendrites that realise flexible learning by evolving structures of sufficient complexity to solve a well-known problem involving continuous, real-valued inputs. Additionally, we extend the system to enable temporal state decomposition. By allowing our LCS to chain together sequences of heterogeneous actions into macro-actions, it is shown to perform optimally in a problem where traditional methods can fail to find a solution in a reasonable amount of time. Our final system is tested on a simulated robotics platform.

  12. Neural Network Ensembles

    DEFF Research Database (Denmark)

    Hansen, Lars Kai; Salamon, Peter

    1990-01-01

    We propose several means for improving the performance an training of neural networks for classification. We use crossvalidation as a tool for optimizing network parameters and architecture. We show further that the remaining generalization error can be reduced by invoking ensembles of similar...

  13. Template learning of cellular neural network using genetic programming.

    Science.gov (United States)

    Radwan, Elsayed; Tazaki, Eiichiro

    2004-08-01

    A new learning algorithm for space invariant Uncoupled Cellular Neural Network is introduced. Learning is formulated as an optimization problem. Genetic Programming has been selected for creating new knowledge because they allow the system to find new rules both near to good ones and far from them, looking for unknown good control actions. According to the lattice Cellular Neural Network architecture, Genetic Programming will be used in deriving the Cloning Template. Exploration of any stable domain is possible by the current approach. Details of the algorithm are discussed and several application results are shown.

  14. [Folic acid: Primary prevention of neural tube defects. Literature Review].

    Science.gov (United States)

    Llamas Centeno, M J; Miguélez Lago, C

    2016-03-01

    Neural tube defects (NTD) are the most common congenital malformations of the nervous system, they have a multifactorial etiology, are caused by exposure to chemical, physical or biological toxic agents, factors deficiency, diabetes, obesity, hyperthermia, genetic alterations and unknown causes. Some of these factors are associated with malnutrition by interfering with the folic acid metabolic pathway, the vitamin responsible for neural tube closure. Its deficit produce anomalies that can cause abortions, stillbirths or newborn serious injuries that cause disability, impaired quality of life and require expensive treatments to try to alleviate in some way the alterations produced in the embryo. Folic acid deficiency is considered the ultimate cause of the production of neural tube defects, it is clear the reduction in the incidence of Espina Bifida after administration of folic acid before conception, this leads us to want to further study the action of folic acid and its application in the primary prevention of neural tube defects. More than 40 countries have made the fortification of flour with folate, achieving encouraging data of decrease in the prevalence of neural tube defects. This paper attempts to make a literature review, which clarify the current situation and future of the prevention of neural tube defects.

  15. Neural correlates of humor detection and appreciation.

    Science.gov (United States)

    Moran, Joseph M; Wig, Gagan S; Adams, Reginald B; Janata, Petr; Kelley, William M

    2004-03-01

    Humor is a uniquely human quality whose neural substrates remain enigmatic. The present report combined dynamic, real-life content and event-related functional magnetic resonance imaging (fMRI) to dissociate humor detection ("getting the joke") from humor appreciation (the affective experience of mirth). During scanning, subjects viewed full-length episodes of the television sitcoms Seinfeld or The Simpsons. Brain activity time-locked to humor detection moments revealed increases in left inferior frontal and posterior temporal cortices, whereas brain activity time-locked to moments of humor appreciation revealed increases in bilateral regions of insular cortex and the amygdala. These findings provide evidence that humor depends critically upon extant neural systems important for resolving incongruities (humor detection) and for the expression of affect (humor appreciation).

  16. Robot soccer action selection based on Q learning

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    This paper researches robot soccer action selection based on Q learning . The robot learn to activate particular behavior given their current situation and reward signal. We adopt neural network to implementations of Q learning for their generalization properties and limited computer memory requirements

  17. The natural variation of a neural code.

    Science.gov (United States)

    Kfir, Yoav; Renan, Ittai; Schneidman, Elad; Segev, Ronen

    2012-01-01

    The way information is represented by sequences of action potentials of spiking neurons is determined by the input each neuron receives, but also by its biophysics, and the specifics of the circuit in which it is embedded. Even the "code" of identified neurons can vary considerably from individual to individual. Here we compared the neural codes of the identified H1 neuron in the visual systems of two families of flies, blow flies and flesh flies, and explored the effect of the sensory environment that the flies were exposed to during development on the H1 code. We found that the two families differed considerably in the temporal structure of the code, its content and energetic efficiency, as well as the temporal delay of neural response. The differences in the environmental conditions during the flies' development had no significant effect. Our results may thus reflect an instance of a family-specific design of the neural code. They may also suggest that individual variability in information processing by this specific neuron, in terms of both form and content, is regulated genetically.

  18. Reading Neural Encodings using Phase Space Methods

    CERN Document Server

    Abarbanel, Henry D I; Abarbanel, Henry D I; Tumer, Evren C.

    2003-01-01

    Environmental signals sensed by nervous systems are often represented in spike trains carried from sensory neurons to higher neural functions where decisions and functional actions occur. Information about the environmental stimulus is contained (encoded) in the train of spikes. We show how to "read" the encoding using state space methods of nonlinear dynamics. We create a mapping from spike signals which are output from the neural processing system back to an estimate of the analog input signal. This mapping is realized locally in a reconstructed state space embodying both the dynamics of the source of the sensory signal and the dynamics of the neural circuit doing the processing. We explore this idea using a Hodgkin-Huxley conductance based neuron model and input from a low dimensional dynamical system, the Lorenz system. We show that one may accurately learn the dynamical input/output connection and estimate with high precision the details of the input signals from spike timing output alone. This form of "...

  19. A common neural code for similar conscious experiences in different individuals.

    Science.gov (United States)

    Naci, Lorina; Cusack, Rhodri; Anello, Mimma; Owen, Adrian M

    2014-09-30

    The interpretation of human consciousness from brain activity, without recourse to speech or action, is one of the most provoking and challenging frontiers of modern neuroscience. We asked whether there is a common neural code that underpins similar conscious experiences, which could be used to decode these experiences in the absence of behavior. To this end, we used richly evocative stimulation (an engaging movie) portraying real-world events to elicit a similar conscious experience in different people. Common neural correlates of conscious experience were quantified and related to measurable, quantitative and qualitative, executive components of the movie through two additional behavioral investigations. The movie's executive demands drove synchronized brain activity across healthy participants' frontal and parietal cortices in regions known to support executive function. Moreover, the timing of activity in these regions was predicted by participants' highly similar qualitative experience of the movie's moment-to-moment executive demands, suggesting that synchronization of activity across participants underpinned their similar experience. Thus we demonstrate, for the first time to our knowledge, that a neural index based on executive function reliably predicted every healthy individual's similar conscious experience in response to real-world events unfolding over time.