WorldWideScience

Sample records for human attention evidence

  1. Attentional Bias for Uncertain Cues of Shock in Human Fear Conditioning: Evidence for Attentional Learning Theory

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    Stephan Koenig

    2017-05-01

    Full Text Available We conducted a human fear conditioning experiment in which three different color cues were followed by an aversive electric shock on 0, 50, and 100% of the trials, and thus induced low (L, partial (P, and high (H shock expectancy, respectively. The cues differed with respect to the strength of their shock association (L < P < H and the uncertainty of their prediction (L < P > H. During conditioning we measured pupil dilation and ocular fixations to index differences in the attentional processing of the cues. After conditioning, the shock-associated colors were introduced as irrelevant distracters during visual search for a shape target while shocks were no longer administered and we analyzed the cues’ potential to capture and hold overt attention automatically. Our findings suggest that fear conditioning creates an automatic attention bias for the conditioned cues that depends on their correlation with the aversive outcome. This bias was exclusively linked to the strength of the cues’ shock association for the early attentional processing of cues in the visual periphery, but additionally was influenced by the uncertainty of the shock prediction after participants fixated on the cues. These findings are in accord with attentional learning theories that formalize how associative learning shapes automatic attention.

  2. Attentional Bias for Uncertain Cues of Shock in Human Fear Conditioning: Evidence for Attentional Learning Theory

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    Koenig, Stephan; Uengoer, Metin; Lachnit, Harald

    2017-01-01

    We conducted a human fear conditioning experiment in which three different color cues were followed by an aversive electric shock on 0, 50, and 100% of the trials, and thus induced low (L), partial (P), and high (H) shock expectancy, respectively. The cues differed with respect to the strength of their shock association (L H). During conditioning we measured pupil dilation and ocular fixations to index differences in the attentional processing of the cues. After conditioning, the shock-associated colors were introduced as irrelevant distracters during visual search for a shape target while shocks were no longer administered and we analyzed the cues’ potential to capture and hold overt attention automatically. Our findings suggest that fear conditioning creates an automatic attention bias for the conditioned cues that depends on their correlation with the aversive outcome. This bias was exclusively linked to the strength of the cues’ shock association for the early attentional processing of cues in the visual periphery, but additionally was influenced by the uncertainty of the shock prediction after participants fixated on the cues. These findings are in accord with attentional learning theories that formalize how associative learning shapes automatic attention. PMID:28588466

  3. Social Class and the Motivational Relevance of Other Human Beings: Evidence From Visual Attention.

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    Dietze, Pia; Knowles, Eric D

    2016-11-01

    We theorize that people's social class affects their appraisals of others' motivational relevance-the degree to which others are seen as potentially rewarding, threatening, or otherwise worth attending to. Supporting this account, three studies indicate that social classes differ in the amount of attention their members direct toward other human beings. In Study 1, wearable technology was used to film the visual fields of pedestrians on city streets; higher-class participants looked less at other people than did lower-class participants. In Studies 2a and 2b, participants' eye movements were tracked while they viewed street scenes; higher class was associated with reduced attention to people in the images. In Study 3, a change-detection procedure assessed the degree to which human faces spontaneously attract visual attention; faces proved less effective at drawing the attention of high-class than low-class participants, which implies that class affects spontaneous relevance appraisals. The measurement and conceptualization of social class are discussed. © The Author(s) 2016.

  4. Exposure to Mobile Phone-Emitted Electromagnetic Fields and Human Attention: No Evidence of a Causal Relationship

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    Giuseppe Curcio

    2018-02-01

    Full Text Available In the past 20 years of research regarding effects of mobile phone-derived electromagnetic fields (EMFs on human cognition, attention has been one of the first and most extensively investigated functions. Different domains investigated covered selective, sustained, and divided attention. Here, the most relevant studies on this topic have been reviewed and discussed. A total of 43 studies are reported and summarized: of these, 31 indicated a total absence of statistically significant difference between real and sham signal, 9 showed a partial improvement of attentional performance (mainly increase in speed of performance and/or improvement of accuracy as a function of real exposure, while the remaining 3 showed inconsistent results (i.e., increased speed in some tasks and slowing in others or even a worsening in performance (reduced speed and/or deteriorated accuracy. These results are independent of the specific attentional domain investigated. This scenario allows to conclude that there is a substantial lack of evidence about a negative influence of non-ionizing radiations on attention functioning. Nonetheless, published literature is very heterogeneous under the point of view of methodology (type of signal, exposure time, blinding, dosimetry (accurate evaluation of specific absorption rate-SAR or emitted power, and statistical analyses, making arduous a conclusive generalization to everyday life. Some remarks and suggestions regarding future research are proposed.

  5. Exposure to Mobile Phone-Emitted Electromagnetic Fields and Human Attention: No Evidence of a Causal Relationship.

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    Curcio, Giuseppe

    2018-01-01

    In the past 20 years of research regarding effects of mobile phone-derived electromagnetic fields (EMFs) on human cognition, attention has been one of the first and most extensively investigated functions. Different domains investigated covered selective, sustained, and divided attention. Here, the most relevant studies on this topic have been reviewed and discussed. A total of 43 studies are reported and summarized: of these, 31 indicated a total absence of statistically significant difference between real and sham signal, 9 showed a partial improvement of attentional performance (mainly increase in speed of performance and/or improvement of accuracy) as a function of real exposure, while the remaining 3 showed inconsistent results (i.e., increased speed in some tasks and slowing in others) or even a worsening in performance (reduced speed and/or deteriorated accuracy). These results are independent of the specific attentional domain investigated. This scenario allows to conclude that there is a substantial lack of evidence about a negative influence of non-ionizing radiations on attention functioning. Nonetheless, published literature is very heterogeneous under the point of view of methodology (type of signal, exposure time, blinding), dosimetry (accurate evaluation of specific absorption rate-SAR or emitted power), and statistical analyses, making arduous a conclusive generalization to everyday life. Some remarks and suggestions regarding future research are proposed.

  6. The attentional blink reveals serial working memory encoding: evidence from virtual and human event-related potentials.

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    Craston, Patrick; Wyble, Brad; Chennu, Srivas; Bowman, Howard

    2009-03-01

    Observers often miss a second target (T2) if it follows an identified first target item (T1) within half a second in rapid serial visual presentation (RSVP), a finding termed the attentional blink. If two targets are presented in immediate succession, however, accuracy is excellent (Lag 1 sparing). The resource sharing hypothesis proposes a dynamic distribution of resources over a time span of up to 600 msec during the attentional blink. In contrast, the ST(2) model argues that working memory encoding is serial during the attentional blink and that, due to joint consolidation, Lag 1 is the only case where resources are shared. Experiment 1 investigates the P3 ERP component evoked by targets in RSVP. The results suggest that, in this context, P3 amplitude is an indication of bottom-up strength rather than a measure of cognitive resource allocation. Experiment 2, employing a two-target paradigm, suggests that T1 consolidation is not affected by the presentation of T2 during the attentional blink. However, if targets are presented in immediate succession (Lag 1 sparing), they are jointly encoded into working memory. We use the ST(2) model's neural network implementation, which replicates a range of behavioral results related to the attentional blink, to generate "virtual ERPs" by summing across activation traces. We compare virtual to human ERPs and show how the results suggest a serial nature of working memory encoding as implied by the ST(2) model.

  7. Bridging the gap between physiology and behavior: evidence from the sSoTS model of human visual attention.

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    Mavritsaki, Eirini; Heinke, Dietmar; Allen, Harriet; Deco, Gustavo; Humphreys, Glyn W

    2011-01-01

    We present the case for a role of biologically plausible neural network modeling in bridging the gap between physiology and behavior. We argue that spiking-level networks can allow "vertical" translation between physiological properties of neural systems and emergent "whole-system" performance-enabling psychological results to be simulated from implemented networks and also inferences to be made from simulations concerning processing at a neural level. These models also emphasize particular factors (e.g., the dynamics of performance in relation to real-time neuronal processing) that are not highlighted in other approaches and that can be tested empirically. We illustrate our argument from neural-level models that select stimuli by biased competition. We show that a model with biased competition dynamics can simulate data ranging from physiological studies of single-cell activity (Study 1) to whole-system behavior in human visual search (Study 2), while also capturing effects at an intermediate level, including performance breakdown after neural lesion (Study 3) and data from brain imaging (Study 4). We also show that, at each level of analysis, novel predictions can be derived from the biologically plausible parameters adopted, which we proceed to test (Study 5). We argue that, at least for studying the dynamics of visual attention, the approach productively links single-cell to psychological data.

  8. Human treadmill walking needs attention

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    Daniel Olivier

    2006-08-01

    Full Text Available Abstract Background The aim of the study was to assess the attentional requirements of steady state treadmill walking in human subjects using a dual task paradigm. The extent of decrement of a secondary (cognitive RT task provides a measure of the attentional resources required to maintain performance of the primary (locomotor task. Varying the level of difficulty of the reaction time (RT task is used to verify the priority of allocation of attentional resources. Methods 11 healthy adult subjects were required to walk while simultaneously performing a RT task. Participants were instructed to bite a pressure transducer placed in the mouth as quickly as possible in response to an unpredictable electrical stimulation applied on the back of the neck. Each subject was tested under five different experimental conditions: simple RT task alone and while walking, recognition RT task alone and while walking, walking alone. A foot switch system composed of a pressure sensitive sensor was placed under the heel and forefoot of each foot to determine the gait cycle duration. Results Gait cycle duration was unchanged (p > 0.05 by the addition of the RT task. Regardless of the level of difficulty of the RT task, the RTs were longer during treadmill walking than in sitting conditions (p 0.05 was found between the attentional demand of the walking task and the decrement of performance found in the RT task under varying levels of difficulty. This finding suggests that the healthy subjects prioritized the control of walking at the expense of cognitive performance. Conclusion We conclude that treadmill walking in young adults is not a purely automatic task. The methodology and outcome measures used in this study provide an assessment of the attentional resources required by walking on the treadmill at a steady state.

  9. Paying attention to attention: evidence for an attentional contribution to the size congruity effect.

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    Risko, Evan F; Maloney, Erin A; Fugelsang, Jonathan A

    2013-08-01

    Understanding the mechanisms supporting our comprehension of magnitude information represents a key goal in cognitive psychology. A major phenomenon employed in the pursuit of this goal has been the physical size congruity effect-namely, the observation that comparing the relative numerical sizes of two numbers is influenced by their relative physical sizes. The standard account of the physical size congruity effect attributes it to the automatic influence of the comparison of irrelevant physical magnitudes on numerical judgments. Here we develop an alternative account of this effect on the basis of the operation of attention in the typical size congruity display and the temporal dynamics of number comparison. We also provide a test of a number of predictions derived from this alternative account by combining a physical size congruity manipulation with a manipulation designed to alter the operation of attention within the typical size congruity display (i.e., a manipulation of the relative onsets of the digits). This test provides evidence consistent with an attentional contribution to the size congruity effect. Implications for our understanding of magnitude and the interactions between attention and magnitude are discussed.

  10. Evidence that emotion mediates social attention in rhesus macaques.

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    Emily J Bethell

    Full Text Available BACKGROUND: Recent work on non-human primates indicates that the allocation of social attention is mediated by characteristics of the attending animal, such as social status and genotype, as well as by the value of the target to which attention is directed. Studies of humans indicate that an individual's emotion state also plays a crucial role in mediating their social attention; for example, individuals look for longer towards aggressive faces when they are feeling more anxious, and this bias leads to increased negative arousal and distraction from other ongoing tasks. To our knowledge, no studies have tested for an effect of emotion state on allocation of social attention in any non-human species. METHODOLOGY: We presented captive adult male rhesus macaques with pairs of adult male conspecific face images - one with an aggressive expression, one with a neutral expression - and recorded gaze towards these images. Each animal was tested twice, once during a putatively stressful condition (i.e. following a veterinary health check, and once during a neutral (or potentially positive condition (i.e. a period of environmental enrichment. Initial analyses revealed that behavioural indicators of anxiety and stress were significantly higher after the health check than during enrichment, indicating that the former caused a negative shift in emotional state. PRINCIPLE FINDINGS: The macaques showed initial vigilance for aggressive faces across both conditions, but subsequent responses differed between conditions. Following the health check, initial vigilance was followed by rapid and sustained avoidance of aggressive faces. By contrast, during the period of enrichment, the macaques showed sustained attention towards the same aggressive faces. CONCLUSIONS/SIGNIFICANCE: These data provide, to our knowledge, the first evidence that shifts in emotion state mediate social attention towards and away from facial cues of emotion in a non-human animal. This work

  11. Functional evolution of new and expanded attention networks in humans.

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    Patel, Gaurav H; Yang, Danica; Jamerson, Emery C; Snyder, Lawrence H; Corbetta, Maurizio; Ferrera, Vincent P

    2015-07-28

    Macaques are often used as a model system for invasive investigations of the neural substrates of cognition. However, 25 million years of evolution separate humans and macaques from their last common ancestor, and this has likely substantially impacted the function of the cortical networks underlying cognitive processes, such as attention. We examined the homology of frontoparietal networks underlying attention by comparing functional MRI data from macaques and humans performing the same visual search task. Although there are broad similarities, we found fundamental differences between the species. First, humans have more dorsal attention network areas than macaques, indicating that in the course of evolution the human attention system has expanded compared with macaques. Second, potentially homologous areas in the dorsal attention network have markedly different biases toward representing the contralateral hemifield, indicating that the underlying neural architecture of these areas may differ in the most basic of properties, such as receptive field distribution. Third, despite clear evidence of the temporoparietal junction node of the ventral attention network in humans as elicited by this visual search task, we did not find functional evidence of a temporoparietal junction in macaques. None of these differences were the result of differences in training, experimental power, or anatomical variability between the two species. The results of this study indicate that macaque data should be applied to human models of cognition cautiously, and demonstrate how evolution may shape cortical networks.

  12. On the instability and constraints of the interaction between number representation and spatial attention in healthy humans: A concise review of the literature and new experimental evidence.

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    Fattorini, E; Pinto, M; Merola, S; D'Onofrio, M; Doricchi, F

    2016-01-01

    The relationship between number and space representation is still one of the most debated topics in studies of mathematical cognition. Here we offer a concise review of two important behavioral effects that have pointed out the use of a spatially left-to-right oriented mental number line (MNL) in healthy participants: the SNARC effect and the attentional SNARC effect (Att-SNARC). Following a brief summary of seminal investigations on the introspective properties of the MNL, we review recent empirical evidence and theories on the functional origin of the SNARC effect, where upon left/right response choices faster reaction times are found for small numbers with left-side responses and for large numbers with right-side responses. Then we offer a summary of the studies that have investigated whether the mere perception of visual Arabic numbers presented at central fixation can engender spatially congruent lateral shifts of attention, ie, leftward for small numbers and rightward for large ones, ie, the Att-SNARC effect. Finally, we summarize four experiments that tested whether the Att-SNARC depends on an active rather than passive processing of centrally presented digit cues. In line with other recent studies, these experiment do not replicate the original Att-SNARC and show that the mere perception of Arabic numerals does not trigger automatic shifts of attention. These shifts are instead found when the task requires the explicit left/right spatial coding of digit cues, ie, Spatial Att-SNARC (Fattorini et al., 2015b). Nonetheless, the reliability of the Spatial Att-SNARC effect seems not as strong as that of conventional SNARC effects where left/right codes are mapped onto responses rather than directly mapped on digit cues. Comparing the magnitude of digits to a numerical reference, ie, "5," also produced a Magnitude Comparison Att-SNARC that was weaker than the spatial one. However, the reliability of this Magnitude Comparison Att-SNARC should be considered with

  13. Human attention filters for single colors

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    Sun, Peng; Chubb, Charles; Wright, Charles E.; Sperling, George

    2016-01-01

    The visual images in the eyes contain much more information than the brain can process. An important selection mechanism is feature-based attention (FBA). FBA is best described by attention filters that specify precisely the extent to which items containing attended features are selectively processed and the extent to which items that do not contain the attended features are attenuated. The centroid-judgment paradigm enables quick, precise measurements of such human perceptual attention filters, analogous to transmission measurements of photographic color filters. Subjects use a mouse to locate the centroid—the center of gravity—of a briefly displayed cloud of dots and receive precise feedback. A subset of dots is distinguished by some characteristic, such as a different color, and subjects judge the centroid of only the distinguished subset (e.g., dots of a particular color). The analysis efficiently determines the precise weight in the judged centroid of dots of every color in the display (i.e., the attention filter for the particular attended color in that context). We report 32 attention filters for single colors. Attention filters that discriminate one saturated hue from among seven other equiluminant distractor hues are extraordinarily selective, achieving attended/unattended weight ratios >20:1. Attention filters for selecting a color that differs in saturation or lightness from distractors are much less selective than attention filters for hue (given equal discriminability of the colors), and their filter selectivities are proportional to the discriminability distance of neighboring colors, whereas in the same range hue attention-filter selectivity is virtually independent of discriminabilty. PMID:27791040

  14. Spatial coordinate systems for tactile spatial attention depend on developmental vision: evidence from event-related potentials in sighted and congenitally blind adult humans.

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    Röder, Brigitte; Föcker, Julia; Hötting, Kirsten; Spence, Charles

    2008-08-01

    Changes in limb posture (such as crossing the hands) can impair people's performance in tasks such as those involving temporal order judgements, when one tactile stimulus is presented to either hand. This crossed hands deficit has been attributed to a conflict between externally and anatomically anchored reference systems when people localize tactile stimuli. Interestingly, however, the performance of congenitally blind adults does not seem to be affected by crossing the hands, suggesting a default use of an anatomically rather than an externally anchored reference system for tactile localization. In the present study, 12 congenitally blind and 12 sighted adults were instructed to attend to either the left or the right hand on a trial-by-trial basis in order to detect rare deviants (consisting of a double touch) at that hand, while ignoring both deviants at the other hand and frequent standard stimuli (consisting of a single touch) presented to either hand. Only the sighted participants performed less accurately when they crossed their hands. Concurrent electroencephalogram recordings revealed an early contralateral attention positivity, followed by an attention negativity in the sighted group when they adopted the uncrossed hands posture. For the crossed hand posture, only the attention negativity was observed with reduced amplitude in the sighted group. By contrast, the congenitally blind group displayed an event-related potential attention negativity that did not vary when the posture of their hands was changed. These results demonstrate that the default use of an external frame of reference for tactile localization seems to depend on developmental vision.

  15. Attention to spoken word planning: Chronometric and neuroimaging evidence

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    Roelofs, A.P.A.

    2008-01-01

    This article reviews chronometric and neuroimaging evidence on attention to spoken word planning, using the WEAVER++ model as theoretical framework. First, chronometric studies on the time to initiate vocal responding and gaze shifting suggest that spoken word planning may require some attention,

  16. Contingent capture of visual-spatial attention depends on capacity-limited central mechanisms: evidence from human electrophysiology and the psychological refractory period.

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    Brisson, Benoit; Leblanc, Emilie; Jolicoeur, Pierre

    2009-02-01

    It has recently been demonstrated that a lateralized distractor that matches the individual's top-down control settings elicits an N2pc wave, an electrophysiological index of the focus of visual-spatial attention, indicating that contingent capture has a visual-spatial locus. Here, we investigated whether contingent capture required capacity-limited central resources by incorporating a contingent capture task as the second task of a psychological refractory period (PRP) dual-task paradigm. The N2pc was used to monitor where observers were attending while they performed concurrent central processing known to cause the PRP effect. The N2pc elicited by the lateralized distractor that matched the top-down control settings was attenuated in high concurrent central load conditions, indicating that although involuntary, the deployment of visual-spatial attention occurring during contingent capture depends on capacity-limited central resources.

  17. Faces capture attention: Evidence from Inhibition-of-return

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    Theeuwes, J.; van der Stigchel, S.

    2006-01-01

    The human face is a visual pattern of great social and biological importance. While previous studies have shown that attention may be preferentially directed and engaged longer by faces, the current study presents a new methodology to test the notion that faces can capture attention. The present

  18. Moving attention - Evidence for time-invariant shifts of visual selective attention

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    Remington, R.; Pierce, L.

    1984-01-01

    Two experiments measured the time to shift spatial selective attention across the visual field to targets 2 or 10 deg from central fixation. A central arrow cued the most likely target location. The direction of attention was inferred from reaction times to expected, unexpected, and neutral locations. The development of a spatial attentional set with time was examined by presenting target probes at varying times after the cue. There were no effects of distance on the time course of the attentional set. Reaction times for far locations were slower than for near, but the effects of attention were evident by 150 msec in both cases. Spatial attention does not shift with a characteristic, fixed velocity. Rather, velocity is proportional to distance, resulting in a movement time that is invariant over the distances tested.

  19. Attentive novelty detection in humans is governed by pre-attentive sensory memory.

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    Tiitinen, H; May, P; Reinikainen, K; Näätänen, R

    1994-11-03

    Being able to detect unusual, possibly dangerous events in the environment is a fundamental ability that helps ensure the survival of biological organisms. Novelty detection requires a memory system that models (builds neural representations of) events in the environment, so that changes are detected because they violate the predictions of the model. The earliest physiologically measurable brain response to novel auditory stimuli is the mismatch negativity, MMN, a component of the event-related potential. It is elicited when a predictable series of unvarying stimuli is unexpectedly followed by a deviating stimulus. As the occurrence of MMN is not usually affected by the direction of attention, MMN reflects the operation of automatic sensory (echoic) memory, the earliest memory system that builds traces of the acoustic environment against which new stimuli can be compared. The dependence of attentive novelty detection on earlier, pre-attentive processes, however, has remained elusive. Previous, related studies seem to suggest a relationship between MMN and attentive processes, although no conclusive evidence has so far been shown. Here we address novelty detection in humans both on a physiological and behavioural level, and show how attentive novelty detection is governed by a pre-attentive sensory memory mechanism.

  20. Visual attentional load influences plasticity in the human motor cortex.

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    Kamke, Marc R; Hall, Michelle G; Lye, Hayley F; Sale, Martin V; Fenlon, Laura R; Carroll, Timothy J; Riek, Stephan; Mattingley, Jason B

    2012-05-16

    Neural plasticity plays a critical role in learning, memory, and recovery from injury to the nervous system. Although much is known about the physical and physiological determinants of plasticity, little is known about the influence of cognitive factors. In this study, we investigated whether selective attention plays a role in modifying changes in neural excitability reflecting long-term potentiation (LTP)-like plasticity. We induced LTP-like effects in the hand area of the human motor cortex using transcranial magnetic stimulation (TMS). During the induction of plasticity, participants engaged in a visual detection task with either low or high attentional demands. Changes in neural excitability were assessed by measuring motor-evoked potentials in a small hand muscle before and after the TMS procedures. In separate experiments plasticity was induced either by paired associative stimulation (PAS) or intermittent theta-burst stimulation (iTBS). Because these procedures induce different forms of LTP-like effects, they allowed us to investigate the generality of any attentional influence on plasticity. In both experiments reliable changes in motor cortex excitability were evident under low-load conditions, but this effect was eliminated under high-attentional load. In a third experiment we investigated whether the attentional task was associated with ongoing changes in the excitability of motor cortex, but found no difference in evoked potentials across the levels of attentional load. Our findings indicate that in addition to their role in modifying sensory processing, mechanisms of attention can also be a potent modulator of cortical plasticity.

  1. Electrophysiological evidence for spatiotemporal flexibility in the ventrolateral attention network.

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    Jelena Ristic

    Full Text Available Successful completion of many everyday tasks depends on interactions between voluntary attention, which acts to maintain current goals, and reflexive attention, which enables responding to unexpected events by interrupting the current focus of attention. Past studies, which have mostly examined each attentional mechanism in isolation, indicate that volitional and reflexive orienting depend on two functionally specialized cortical networks in the human brain. Here we investigated how the interplay between these two cortical networks affects sensory processing and the resulting overt behavior. By combining measurements of human performance and electrocortical recordings with a novel analytical technique for estimating spatiotemporal activity in the human cortex, we found that the subregions that comprise the reflexive ventrolateral attention network dissociate both spatially and temporally as a function of the nature of the sensory information and current task demands. Moreover, we found that together with the magnitude of the early sensory gain, the spatiotemporal neural dynamics accounted for the high amount of the variance in the behavioral data. Collectively these data support the conclusion that the ventrolateral attention network is recruited flexibly to support complex behaviors.

  2. Economic principles motivating social attention in humans.

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    Hayden, Benjamin Y; Parikh, Purak C; Deaner, Robert O; Platt, Michael L

    2007-07-22

    We know little about the processes by which we evaluate the opportunity to look at another person. We propose that behavioural economics provides a powerful approach to understanding this basic aspect of social attention. We hypothesized that the decision process culminating in attention to another person follows the same economic principles that govern choices about rewards such as food, drinks and money. Specifically, such rewards are discounted as a function of time, are tradable for other rewards, and reinforce work. Behavioural and neurobiological evidence suggests that looking at other people can also be described as rewarding, but to what extent these economic principles apply to social orienting remains unknown. Here, we show that the opportunity to view pictures of the opposite sex is discounted by delay to viewing, substitutes for money and reinforces work. The reward value of photos of the opposite sex varied with physical attractiveness and was greater in men, suggesting differential utility of acquiring visual information about the opposite sex in men and women. Together, these results demonstrate that choosing whom to look at follows a general set of economic principles, implicating shared neural mechanisms in both social and non-social decision making.

  3. On the Electrophysiological Evidence for the Capture of Visual Attention

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    McDonald, John J.; Green, Jessica J.; Jannati, Ali; Di Lollo, Vincent

    2013-01-01

    The presence of a salient distractor interferes with visual search. According to the salience-driven selection hypothesis, this interference is because of an initial deployment of attention to the distractor. Three event-related potential (ERP) findings have been regarded as evidence for this hypothesis: (a) salient distractors were found to…

  4. Attention.

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    Callahan, Patrick M; Terry, Alvin V

    2015-01-01

    The ability to focus one's attention on important environmental stimuli while ignoring irrelevant stimuli is fundamental to human cognition and intellectual function. Attention is inextricably linked to perception, learning and memory, and executive function; however, it is often impaired in a variety of neuropsychiatric disorders, including Alzheimer's disease, schizophrenia, depression, and attention deficit hyperactivity disorder (ADHD). Accordingly, attention is considered as an important therapeutic target in these disorders. The purpose of this chapter is to provide an overview of the most common behavioral paradigms of attention that have been used in animals (particularly rodents) and to review the literature where these tasks have been employed to elucidate neurobiological substrates of attention as well as to evaluate novel pharmacological agents for their potential as treatments for disorders of attention. These paradigms include two tasks of sustained attention that were developed as rodent analogues of the human Continuous Performance Task (CPT), the Five-Choice Serial Reaction Time Task (5-CSRTT) and the more recently introduced Five-Choice Continuous Performance Task (5C-CPT), and the Signal Detection Task (SDT) which was designed to emphasize temporal components of attention.

  5. Endogenous spatial attention: evidence for intact functioning in adults with autism

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    Grubb, Michael A.; Behrmann, Marlene; Egan, Ryan; Minshew, Nancy J.; Carrasco, Marisa; Heeger, David J.

    2012-01-01

    Lay Abstract Attention allows us to selectively process the vast amount of information with which we are confronted. Focusing on a certain location of the visual scene (visual spatial attention) enables the prioritization of some aspects of information while ignoring others. Rapid manipulation of the attention field (i.e., the location and spread of visual spatial attention) is a critical aspect of human cognition, and previous research on spatial attention in individuals with autism spectrum disorders (ASD) has produced inconsistent results. In a series of three experiments, we evaluated claims in the literature that individuals with ASD exhibit a deficit in voluntarily controlling the deployment and size of the spatial attention field. We measured how well participants perform a visual discrimination task (accuracy) and how quickly they do so (reaction time), with and without spatial uncertainty (i.e., the lack of predictability concerning the spatial position of the upcoming stimulus). We found that high–functioning adults with autism exhibited slower reactions times overall with spatial uncertainty, but the effects of attention on performance accuracies and reaction times were indistinguishable between individuals with autism and typically developing individuals, in all three experiments. These results provide evidence of intact endogenous spatial attention function in high–functioning adults with ASD, suggesting that atypical endogenous spatial attention cannot be a latent characteristic of autism in general. Scientific Abstract Rapid manipulation of the attention field (i.e., the location and spread of visual spatial attention) is a critical aspect of human cognition, and previous research on spatial attention in individuals with autism spectrum disorders (ASD) has produced inconsistent results. In a series of three psychophysical experiments, we evaluated claims in the literature that individuals with ASD exhibit a deficit in voluntarily controlling the

  6. Hierarchical nonlinear dynamics of human attention.

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    Rabinovich, Mikhail I; Tristan, Irma; Varona, Pablo

    2015-08-01

    Attention is the process of focusing mental resources on a specific cognitive/behavioral task. Such brain dynamics involves different partially overlapping brain functional networks whose interconnections change in time according to the performance stage, and can be stimulus-driven or induced by an intrinsically generated goal. The corresponding activity can be described by different families of spatiotemporal discrete patterns or sequential dynamic modes. Since mental resources are finite, attention modalities compete with each other at all levels of the hierarchy, from perception to decision making and behavior. Cognitive activity is a dynamical process and attention possesses some universal dynamical characteristics. Thus, it is time to apply nonlinear dynamical theory for the description and prediction of hierarchical attentional tasks. Such theory has to include the analyses of attentional control stability, the time cost of attention switching, the finite capacity of informational resources in the brain, and the normal and pathological bifurcations of attention sequential dynamics. In this paper we have integrated today's knowledge, models and results in these directions. Copyright © 2015 Elsevier Ltd. All rights reserved.

  7. Animacy and attentional processes: Evidence from the Stroop task.

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    Bugaiska, Aurélia; Grégoire, Laurent; Camblats, Anna-Malika; Gelin, Margaux; Méot, Alain; Bonin, Patrick

    2018-04-01

    In visual perception, evidence has shown that attention is captured earlier and held longer by animate than inanimate stimuli. The former are also remembered better than the latter. Thus, as far as attentional processes are concerned, animate entities have a privileged status over inanimate entities. We tested this hypothesis further using an adaptation of the Stroop paradigm. Adults had to categorise the colours of words that referred to either animate or inanimate concepts. In two experiments, we found that it took longer to process the ink colour of animate than inanimate words. Indeed, this effect was found when the words were presented in an oral animacy Stroop task (Experiment 1) and in a manual animacy Stroop task (Experiment 2). Using ex-Gaussian analyses and examining the distribution of RTs as a function of vincentiles per animacy condition, we did not find a specific localisation of the animacy effect. The findings are interpreted as providing further evidence that animates are prioritised in processing because their fitness value is higher than that of inanimates.

  8. Culture and attention: evidence from brain and behavior.

    Science.gov (United States)

    Ketay, Sarah; Aron, Arthur; Hedden, Trey

    2009-01-01

    Research has demonstrated that our experiences, including the culture in which we are raised, shape how we attend to and perceive the world. Behavioral studies have found that individuals raised in Western cultures tend toward analytic processing and prefer tasks emphasizing independent contexts rather than tasks emphasizing interdependent contexts. The opposite is true for individuals raised in East Asian cultures, who tend toward holistic processing and prefer tasks emphasizing interdependent contexts. Recently, cognitive neuroscientists have extended these behavioral findings to examine the brain activity of individuals from different cultures during the performance of cognitive tasks. Results from these initial studies indicate that culture may shape how the brain processes even very abstract stimuli and may influence the features of the environment to which individuals attend. The present chapter reviews evidence that culture influences attention and related systems, which, in turn, impact other cognitive and social processes and their neural correlates.

  9. Diverting attention suppresses human amygdala responses to faces

    Directory of Open Access Journals (Sweden)

    Carmen eMorawetz

    2010-12-01

    Full Text Available Recent neuroimaging studies disagree as to whether the processing of emotion-laden visual stimuli is dependent upon the availability of attentional resources or entirely capacity-free. Two main factors have been proposed to be responsible for the discrepancies: the differences in the perceptual attentional demands of the tasks used to divert attentional resources from emotional stimuli and the spatial location of the affective stimuli in the visual field. To date, no neuroimaging report addressed these two issues in the same set of subjects. Therefore, the aim of the study was to investigate the effects of high and low attentional load as well as different stimulus locations on face processing in the amygdala using fMRI to provide further evidence for one of the two opposing theories. We were able for the first time to directly test the interaction of attentional load and spatial location. The results revealed a strong attenuation of amygdala activity when the attentional load was high. The eccentricity of the emotional stimuli did not affect responses in the amygdala and no interaction effect between attentional load and spatial location was found. We conclude that the processing of emotional stimuli in the amygdala is strongly dependent on the availability of attentional resources without a preferred processing of stimuli presented in the periphery and provide firm evidence for the concept of the attentional load theory of emotional processing in the amygdala.

  10. Further evidence for a deficit in switching attention in schizophrenia.

    Science.gov (United States)

    Smith, G L; Large, M M; Kavanagh, D J; Karayanidis, F; Barrett, N A; Michie, P T; O'Sullivan, B T

    1998-08-01

    In this study, sustained, selective, divided, and switching attention, and reloading of working memory were investigated in schizophrenia by using a newly developed Visual Attention Battery (VAB). Twenty-four outpatients with schizophrenia and 24 control participants were studied using the VAB. Performance on VAB components was correlated with performance of standard tests. Patients with schizophrenia were significantly impaired on VAB tasks that required switching of attention and reloading of working memory but had normal performance on tasks involving sustained attention or attention to multiple stimulus features. Switching attention and reloading of working memory were highly correlated with Trails (B-A) score for patients. The decline in performance on the switching-attention task in patients with schizophrenia met criteria for a differential deficit in switching attention. Future research should examine the neurophysiological basis of the switching deficit and its sensitivity and specificity to schizophrenia.

  11. Frequency-specific attentional modulation in human primary auditory cortex and midbrain.

    Science.gov (United States)

    Riecke, Lars; Peters, Judith C; Valente, Giancarlo; Poser, Benedikt A; Kemper, Valentin G; Formisano, Elia; Sorger, Bettina

    2018-07-01

    Paying selective attention to an audio frequency selectively enhances activity within primary auditory cortex (PAC) at the tonotopic site (frequency channel) representing that frequency. Animal PAC neurons achieve this 'frequency-specific attentional spotlight' by adapting their frequency tuning, yet comparable evidence in humans is scarce. Moreover, whether the spotlight operates in human midbrain is unknown. To address these issues, we studied the spectral tuning of frequency channels in human PAC and inferior colliculus (IC), using 7-T functional magnetic resonance imaging (FMRI) and frequency mapping, while participants focused on different frequency-specific sounds. We found that shifts in frequency-specific attention alter the response gain, but not tuning profile, of PAC frequency channels. The gain modulation was strongest in low-frequency channels and varied near-monotonically across the tonotopic axis, giving rise to the attentional spotlight. We observed less prominent, non-tonotopic spatial patterns of attentional modulation in IC. These results indicate that the frequency-specific attentional spotlight in human PAC as measured with FMRI arises primarily from tonotopic gain modulation, rather than adapted frequency tuning. Moreover, frequency-specific attentional modulation of afferent sound processing in human IC seems to be considerably weaker, suggesting that the spotlight diminishes toward this lower-order processing stage. Our study sheds light on how the human auditory pathway adapts to the different demands of selective hearing. Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.

  12. Tracking the allocation of attention using human pupillary oscillations

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    Marnix eNaber

    2013-12-01

    Full Text Available The muscles that control the pupil are richly innervated by the autonomic nervous system. While there are central pathways that drive pupil dilations in relation to arousal, there is no anatomical evidence that cortical centers involved with visual selective attention innervate the pupil. In this study, we show that such connections must exist. Specifically, we demonstrate a novel Pupil Frequency Tagging (PFT method, where oscillatory changes in stimulus brightness over time are mirrored by pupil constrictions and dilations. We find that the luminance induced pupil oscillations are enhanced when covert attention is directed to the flicker stimulus and when targets are correctly detected in an attentional tracking task. These results suggest that the amplitudes of pupil responses closely follow the allocation of focal visual attention and the encoding of stimuli. PFT provides a new opportunity to study top down visual attention itself as well as identifying the pathways and mechanisms that support this unexpected phenomenon.

  13. Endogenous attention modulates attentional and motor interference from distractors: Evidence from behavioral and electrophysiological results.

    Directory of Open Access Journals (Sweden)

    Elisa eMartín-Arévalo

    2015-02-01

    Full Text Available Selective visual attention enhances the processing of relevant stimuli and filters out irrelevant stimuli and/or distractors. However, irrelevant information is sometimes processed, as demonstrated by the Simon effect (Simon & Rudell, 1967. We examined whether fully irrelevant distractors (task and target-irrelevant produce interference (measured as the Simon effect, and whether endogenous orienting modulated this interference. Despite being fully irrelevant, distractors were attentionally coded (as reflected by the distractor-related N2pc component, and interfered with the processing of the target response (as reflected by the target-related LRP component. Distractor’s attentional capture depended on endogenous attention, and their interference with target responses was modulated by both endogenous attention and distractor location repetition. These results demonstrate both endogenous attentional and motor modulations over the Simon effect produced by fully irrelevant distractors.

  14. Absence of evidence or evidence of absence: reflecting on therapeutic implementations of attentional bias modification.

    Science.gov (United States)

    Clarke, Patrick J F; Notebaert, Lies; MacLeod, Colin

    2014-01-15

    Attentional bias modification (ABM) represents one of a number of cognitive bias modification techniques which are beginning to show promise as therapeutic interventions for emotional pathology. Numerous studies with both clinical and non-clinical populations have now demonstrated that ABM can reduce emotional vulnerability. However, some recent studies have failed to achieve change in either selective attention or emotional vulnerability using ABM methodologies, including a recent randomised controlled trial by Carlbring et al. Some have sought to represent such absence of evidence as a sound basis not to further pursue ABM as an online intervention. While these findings obviously raise questions about the specific conditions under which ABM procedures will produce therapeutic benefits, we suggest that the failure of some studies to modify selective attention does not challenge the theoretical and empirical basis of ABM. The present paper seeks to put these ABM failures in perspective within the broader context of attentional bias modification research. In doing so it is apparent that the current findings and future prospects of ABM are in fact very promising, suggesting that more research in this area is warranted, not less.

  15. Maternal ratings of attention problems in ADHD: evidence for the existence of a continuum

    NARCIS (Netherlands)

    Lubke, Gitta H.; Hudziak, James J.; Derks, Eske M.; van Bijsterveldt, Toos C. E. M.; Boomsma, Dorret I.

    2009-01-01

    To investigate whether items assessing attention problems provide evidence of quantitative differences or categorically distinct subtypes of attention problems (APs) and to investigate the relation of empirically derived latent classes to DSM-IV diagnoses of subtypes of

  16. Covert spatial attention is functionally intact in amblyopic human adults

    OpenAIRE

    Roberts, Mariel; Cymerman, Rachel; Smith, R. Theodore; Kiorpes, Lynne; Carrasco, Marisa

    2016-01-01

    Certain abnormalities in behavioral performance and neural signaling have been attributed to a deficit of visual attention in amblyopia, a neurodevelopmental disorder characterized by a diverse array of visual deficits following abnormal binocular childhood experience. Critically, most have inferred attention's role in their task without explicitly manipulating and measuring its effects against a baseline condition. Here, we directly investigate whether human amblyopic adults benefit from cov...

  17. Activity in human visual and parietal cortex reveals object-based attention in working memory.

    Science.gov (United States)

    Peters, Benjamin; Kaiser, Jochen; Rahm, Benjamin; Bledowski, Christoph

    2015-02-25

    Visual attention enables observers to select behaviorally relevant information based on spatial locations, features, or objects. Attentional selection is not limited to physically present visual information, but can also operate on internal representations maintained in working memory (WM) in service of higher-order cognition. However, only little is known about whether attention to WM contents follows the same principles as attention to sensory stimuli. To address this question, we investigated in humans whether the typically observed effects of object-based attention in perception are also evident for object-based attentional selection of internal object representations in WM. In full accordance with effects in visual perception, the key behavioral and neuronal characteristics of object-based attention were observed in WM. Specifically, we found that reaction times were shorter when shifting attention to memory positions located on the currently attended object compared with equidistant positions on a different object. Furthermore, functional magnetic resonance imaging and multivariate pattern analysis of visuotopic activity in visual (areas V1-V4) and parietal cortex revealed that directing attention to one position of an object held in WM also enhanced brain activation for other positions on the same object, suggesting that attentional selection in WM activates the entire object. This study demonstrated that all characteristic features of object-based attention are present in WM and thus follows the same principles as in perception. Copyright © 2015 the authors 0270-6474/15/353360-10$15.00/0.

  18. Selective attention reduces physiological noise in the external ear canals of humans. II: Visual attention

    Science.gov (United States)

    Walsh, Kyle P.; Pasanen, Edward G.; McFadden, Dennis

    2014-01-01

    Human subjects performed in several behavioral conditions requiring, or not requiring, selective attention to visual stimuli. Specifically, the attentional task was to recognize strings of digits that had been presented visually. A nonlinear version of the stimulus-frequency otoacoustic emission (SFOAE), called the nSFOAE, was collected during the visual presentation of the digits. The segment of the physiological response discussed here occurred during brief silent periods immediately following the SFOAE-evoking stimuli. For all subjects tested, the physiological-noise magnitudes were substantially weaker (less noisy) during the tasks requiring the most visual attention. Effect sizes for the differences were >2.0. Our interpretation is that cortico-olivo influences adjusted the magnitude of efferent activation during the SFOAE-evoking stimulation depending upon the attention task in effect, and then that magnitude of efferent activation persisted throughout the silent period where it also modulated the physiological noise present. Because the results were highly similar to those obtained when the behavioral conditions involved auditory attention, similar mechanisms appear to operate both across modalities and within modalities. Supplementary measurements revealed that the efferent activation was spectrally global, as it was for auditory attention. PMID:24732070

  19. Selective attention reduces physiological noise in the external ear canals of humans. I: Auditory attention

    Science.gov (United States)

    Walsh, Kyle P.; Pasanen, Edward G.; McFadden, Dennis

    2014-01-01

    In this study, a nonlinear version of the stimulus-frequency OAE (SFOAE), called the nSFOAE, was used to measure cochlear responses from human subjects while they simultaneously performed behavioral tasks requiring, or not requiring, selective auditory attention. Appended to each stimulus presentation, and included in the calculation of each nSFOAE response, was a 30-ms silent period that was used to estimate the level of the inherent physiological noise in the ear canals of our subjects during each behavioral condition. Physiological-noise magnitudes were higher (noisier) for all subjects in the inattention task, and lower (quieter) in the selective auditory-attention tasks. These noise measures initially were made at the frequency of our nSFOAE probe tone (4.0 kHz), but the same attention effects also were observed across a wide range of frequencies. We attribute the observed differences in physiological-noise magnitudes between the inattention and attention conditions to different levels of efferent activation associated with the differing attentional demands of the behavioral tasks. One hypothesis is that when the attentional demand is relatively great, efferent activation is relatively high, and a decrease in the gain of the cochlear amplifier leads to lower-amplitude cochlear activity, and thus a smaller measure of noise from the ear. PMID:24732069

  20. Adaptive Attention Allocation Support: Effects of System Conservativeness and Human Competence

    NARCIS (Netherlands)

    van Maanen, Peter-Paul; Lucassen, Teun; van Dongen, Kees; Schmorrow, Dylan D.; Fidopiastis, Cali M.

    2011-01-01

    Naval tactical picture compilation is a task for which allocation of attention to the right information at the right time is crucial. Performance on this task can be improved if a support system assists the human operator. However, there is evidence that benefits of support systems are highly

  1. Selective attentional deficit in essential tremor: Evidence from the attention network test.

    Science.gov (United States)

    Pauletti, Caterina; Mannarelli, Daniela; De Lucia, Maria Caterina; Locuratolo, Nicoletta; Currà, Antonio; Missori, Paolo; Marinelli, Lucio; Fattapposta, Francesco

    2015-11-01

    The traditional view of essential tremor (ET) as a monosymptomatic and benign disorder has been reconsidered after patients with ET have been shown to experience cognitive deficits that are also related to attention. The Attention Network Test (ANT) is a rapid, widely used test to measure the efficiency of three attentional networks, i.e. alerting, orienting and executive, by evaluating reaction times (RTs) in response to visual stimuli. The aim of this study was to investigate attentional functioning in ET patients by means of the ANT. 21 non-demented patients with ET and 21 age- and sex-matched healthy controls performed the ANT. RT was significantly longer in ET patients than in controls (p attention in ET patients, probably owing to a dysfunction in the cerebello-thalamo-cortical loop. These selective attentional deficits are not related to clinical motor symptoms, contributing to shed further light on the clinical picture of ET. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. Divided versus selective attention: evidence for common processing mechanisms.

    Science.gov (United States)

    Hahn, Britta; Wolkenberg, Frank A; Ross, Thomas J; Myers, Carol S; Heishman, Stephen J; Stein, Dan J; Kurup, Pradeep K; Stein, Elliot A

    2008-06-18

    The current study revisited the question of whether there are brain mechanisms specific to divided attention that differ from those used in selective attention. Increased neuronal activity required to simultaneously process two stimulus dimensions as compared with each separate dimension has often been observed, but rarely has activity induced by a divided attention condition exceeded the sum of activity induced by the component tasks. Healthy participants performed a selective-divided attention paradigm while undergoing functional Magnetic Resonance Imaging (fMRI). The task required participants to make a same-different judgment about either one of two simultaneously presented stimulus dimensions, or about both dimensions. Performance accuracy was equated between tasks by dynamically adjusting the stimulus display time. Blood Oxygenation Level Dependent (BOLD) signal differences between tasks were identified by whole-brain voxel-wise comparisons and by region-specific analyses of all areas modulated by the divided attention task (DIV). No region displayed greater activation or deactivation by DIV than the sum of signal change by the two selective attention tasks. Instead, regional activity followed the tasks' processing demands as reflected by reaction time. Only a left cerebellar region displayed a correlation between participants' BOLD signal intensity and reaction time that was selective for DIV. The correlation was positive, reflecting slower responding with greater activation. Overall, the findings do not support the existence of functional brain activity specific to DIV. Increased activity appears to reflect additional processing demands by introducing a secondary task, but those demands do not appear to qualitatively differ from processes of selective attention.

  3. Thalamic control of human attention driven by memory and learning.

    Science.gov (United States)

    de Bourbon-Teles, José; Bentley, Paul; Koshino, Saori; Shah, Kushal; Dutta, Agneish; Malhotra, Paresh; Egner, Tobias; Husain, Masud; Soto, David

    2014-05-05

    The role of the thalamus in high-level cognition-attention, working memory (WM), rule-based learning, and decision making-remains poorly understood, especially in comparison to that of cortical frontoparietal networks [1-3]. Studies of visual thalamus have revealed important roles for pulvinar and lateral geniculate nucleus in visuospatial perception and attention [4-10] and for mediodorsal thalamus in oculomotor control [11]. Ventrolateral thalamus contains subdivisions devoted to action control as part of a circuit involving the basal ganglia [12, 13] and motor, premotor, and prefrontal cortices [14], whereas anterior thalamus forms a memory network in connection with the hippocampus [15]. This connectivity profile suggests that ventrolateral and anterior thalamus may represent a nexus between mnemonic and control functions, such as action or attentional selection. Here, we characterize the role of thalamus in the interplay between memory and visual attention. We show that ventrolateral lesions impair the influence of WM representations on attentional deployment. A subsequent fMRI study in healthy volunteers demonstrates involvement of ventrolateral and, notably, anterior thalamus in biasing attention through WM contents. To further characterize the memory types used by the thalamus to bias attention, we performed a second fMRI study that involved learning of stimulus-stimulus associations and their retrieval from long-term memory to optimize attention in search. Responses in ventrolateral and anterior thalamic nuclei tracked learning of the predictiveness of these abstract associations and their use in directing attention. These findings demonstrate a key role for human thalamus in higher-level cognition, notably, in mnemonic biasing of attention. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

  4. The effects of attention on age-related relational memory deficits: Evidence from a novel attentional manipulation

    Science.gov (United States)

    Kim, So-Yeon; Giovanello, Kelly S.

    2011-01-01

    Healthy aging is often accompanied by episodic memory decline. Prior studies have consistently demonstrated that older adults show disproportionate deficits in relational memory (RM) relative to item memory (IM). Despite rich evidence of an age-related RM deficit, the source of this deficit remains unspecified. One of the most widely investigated factors of age-related RM impairment is a reduction in attentional resources. However, no prior studies have demonstrated that reduced attentional resources are the critical source of age-related RM deficits. Here, we utilized qualitatively different attention tasks, and tested whether reduced attention for relational processing underlies the RM deficit observed in aging. In Experiment 1, we imposed either item-detection or relation-detection attention tasks on young adults during episodic memory encoding, and found that only the concurrent attention task involving relational processing disproportionately impaired RM performance in young adults. Moreover, by ruling out the possible confound of task-difficulty on the disproportionate RM impairment, we further demonstrated that reduced relational attention is a key factor for the age-related RM deficit. In Experiment 2, we replicated the results from Experiment 1 using different materials of stimuli and found that the effect of relational attention on RM is material-general. The results of Experiment 2 also showed that reducing attentional resources for relational processing in young adults strikingly equated their RM performance to that of older adults. Thus, the current study documents the first evidence that reduced attentional resources for relational processing are a critical factor for the relational memory impairment observed in aging. PMID:21707178

  5. Attention in essential tremor: evidence from event-related potentials.

    Science.gov (United States)

    Pauletti, C; Mannarelli, D; Locuratolo, N; Vanacore, N; De Lucia, M C; Mina, C; Fattapposta, F

    2013-07-01

    Clinically subtle executive dysfunctions have recently been described in essential tremor (ET), though the presence of attentional deficits is still unclear. We investigated the psychophysiological aspects of attention in ET, using event-related potentials (ERPs). Twenty-one non-demented patients with ET and 21 age- and sex-matched healthy controls underwent a psychophysiological evaluation. P300 components and the Contingent Negative Variation (CNV) were recorded. The latencies and amplitudes of the P3a and P3b subcomponents and CNV areas were evaluated. Possible correlations between clinical parameters and ERP data were investigated. P3a latency was significantly longer in the ET group (p attentive circuits, while the memory context-updating process appears to be spared. This selective cognitive dysfunction does not appear to interfere with the attentional set linked to the expectancy evaluated during a complex choice-reaction time task, which is preserved in ET. This multitask psychophysiological approach reveals the presence of a peculiar attentional deficit in patients with ET, thus expanding the clinical features of this disease.

  6. Divided attention enhances the recognition of emotional stimuli: evidence from the attentional boost effect.

    Science.gov (United States)

    Rossi-Arnaud, Clelia; Spataro, Pietro; Costanzi, Marco; Saraulli, Daniele; Cestari, Vincenzo

    2018-01-01

    The present study examined predictions of the early-phase-elevated-attention hypothesis of the attentional boost effect (ABE), which suggests that transient increases in attention at encoding, as instantiated in the ABE paradigm, should enhance the recognition of neutral and positive items (whose encoding is mostly based on controlled processes), while having small or null effects on the recognition of negative items (whose encoding is primarily based on automatic processes). Participants were presented a sequence of negative, neutral and positive stimuli (pictures in Experiment 1, words in Experiment 2) associated to target (red) squares, distractor (green) squares or no squares (baseline condition). They were told to attend to the pictures/words and simultaneously press the spacebar of the computer when a red square appeared. In a later recognition task, stimuli associated to target squares were recognised better than stimuli associated to distractor squares, replicating the standard ABE. More importantly, we also found that: (a) the memory enhancement following target detection occurred with all types of stimuli (neutral, negative and positive) and (b) the advantage of negative stimuli over neutral stimuli was intact in the DA condition. These findings suggest that the encoding of negative stimuli depends on both controlled (attention-dependent) and automatic (attention-independent) processes.

  7. Evidence for Two Attentional Components in Visual Working Memory

    Science.gov (United States)

    Allen, Richard J.; Baddeley, Alan D.; Hitch, Graham J.

    2014-01-01

    How does executive attentional control contribute to memory for sequences of visual objects, and what does this reveal about storage and processing in working memory? Three experiments examined the impact of a concurrent executive load (backward counting) on memory for sequences of individually presented visual objects. Experiments 1 and 2 found…

  8. Sustained Selective Attention Skills of Preschool Children with Specific Language Impairment: Evidence for Separate Attentional Capacities

    Science.gov (United States)

    Spaulding, Tammie J.; Plante, Elena; Vance, Rebecca

    2008-01-01

    Purpose: The present study was designed to investigate the performance of preschool children with specific language impairment (SLI) and their typically developing (TD) peers on sustained selective attention tasks. Method: This study included 23 children diagnosed with SLI and 23 TD children matched for age, gender, and maternal education level.…

  9. Development in attention functions and social processing: Evidence from the Attention Network Test.

    Science.gov (United States)

    Federico, Francesca; Marotta, Andrea; Martella, Diana; Casagrande, Maria

    2017-06-01

    According to the attention network approach, attention is best understood in terms of three functionally and neuroanatomically distinct networks - alerting, orienting, and executive attention. Recent findings showed that social information influences the efficiency of these networks in adults. Using some social and non-social variants of the Attentional Network Test (ANT), this study was aimed to evaluate the development of the three attention networks in childhood, also assessing the development of the ability to manage social or non-social conflicting information. Sixty-six children (three groups of 6, 8, and 10 years of age) performed three variants of the original ANT, using fish, schematic, or real faces looking to the left or right as target and flanker stimuli. Results showed an improvement from 6 to 8 and 10 years of age in reaction time (RT) and accuracy, together with an improvement of executive control and a decrement in alerting. These developmental changes were not unique to social stimuli, and no differences were observed between social and no-social variants of the ANT. However, independently from the age of the children, a real face positively affected the executive control (as indexed by RTs) as compared to both a schematic face and a fish. Findings of this study suggest that attentional networks are still developing from 6 to 10 years of age and underline the importance of face information in modulating the efficiency of executive control. Statement of contribution What is already known? Younger children made more errors and slower reaction times (RTs) than older children, in line with the majority of the past selective attention studies. Younger children showed both greater conflict and alerting effect than older children. The prediction that younger children would display larger interference effects than older children was supported. What does this study add? Extending the findings observed in adults and children, independently from their age

  10. Probabilistic Mapping of Human Visual Attention from Head Pose Estimation

    Directory of Open Access Journals (Sweden)

    Andrea Veronese

    2017-10-01

    Full Text Available Effective interaction between a human and a robot requires the bidirectional perception and interpretation of actions and behavior. While actions can be identified as a directly observable activity, this might not be sufficient to deduce actions in a scene. For example, orienting our face toward a book might suggest the action toward “reading.” For a human observer, this deduction requires the direction of gaze, the object identified as a book and the intersection between gaze and book. With this in mind, we aim to estimate and map human visual attention as directed to a scene, and assess how this relates to the detection of objects and their related actions. In particular, we consider human head pose as measurement to infer the attention of a human engaged in a task and study which prior knowledge should be included in such a detection system. In a user study, we show the successful detection of attention to objects in a typical office task scenario (i.e., reading, working with a computer, studying an object. Our system requires a single external RGB camera for head pose measurements and a pre-recorded 3D point cloud of the environment.

  11. Selective attention increases choice certainty in human decision making.

    Science.gov (United States)

    Zizlsperger, Leopold; Sauvigny, Thomas; Haarmeier, Thomas

    2012-01-01

    Choice certainty is a probabilistic estimate of past performance and expected outcome. In perceptual decisions the degree of confidence correlates closely with choice accuracy and reaction times, suggesting an intimate relationship to objective performance. Here we show that spatial and feature-based attention increase human subjects' certainty more than accuracy in visual motion discrimination tasks. Our findings demonstrate for the first time a dissociation of choice accuracy and certainty with a significantly stronger influence of voluntary top-down attention on subjective performance measures than on objective performance. These results reveal a so far unknown mechanism of the selection process implemented by attention and suggest a unique biological valence of choice certainty beyond a faithful reflection of the decision process.

  12. Dangerous Animals Capture and Maintain Attention in Humans

    OpenAIRE

    Jessica L. Yorzinski; Michael J. Penkunas; Michael L. Platt; Richard G. Coss

    2014-01-01

    Predation is a major source of natural selection on primates and may have shaped attentional processes that allow primates to rapidly detect dangerous animals. Because ancestral humans were subjected to predation, a process that continues at very low frequencies, we examined the visual processes by which men and women detect dangerous animals (snakes and lions). We recorded the eye movements of participants as they detected images of a dangerous animal (target) among arrays of nondangerous an...

  13. Aging and involuntary attention capture: electrophysiological evidence for preserved attentional control with advanced age.

    Science.gov (United States)

    Lien, Mei-Ching; Gemperle, Alison; Ruthruff, Eric

    2011-03-01

    The present study examined whether people become more susceptible to capture by salient objects as they age. Participants searched a target display for a letter in a specific color and indicated its identity. In Experiment 1, this target display was preceded by a non-informative cue display containing one target-color box, one ignored-color box, and two white boxes. On half of the trials, this cue display also contained a salient-but-irrelevant abrupt onset. To assess capture by the target-color cue, we used the N2pc component of the event-related potential, thought to reflect attentional allocation to the left or right visual field. The target-color box in the cue display produced a substantial N2pc effect for younger adults and, most importantly, this effect was not diminished by the presence of an abrupt onset. Therefore, the abrupt onset was unable to capture attention away from the target-color cue. Critically, older adults demonstrated the same resistance to capture by the abrupt onset. Experiment 2 extended these findings to irrelevant color singleton cues. Thus, we argue that the ability to attend to relevant stimuli and resist capture by salient-but-irrelevant stimuli is preserved with advancing age. (c) 2011 APA, all rights reserved.

  14. Neuroplasticity of selective attention: Research foundations and preliminary evidence for a gene by intervention interaction

    Science.gov (United States)

    Stevens, Courtney; Pakulak, Eric; Hampton Wray, Amanda; Bell, Theodore A.; Neville, Helen J.

    2017-01-01

    This article reviews the trajectory of our research program on selective attention, which has moved from basic research on the neural processes underlying selective attention to translational studies using selective attention as a neurobiological target for evidence-based interventions. We use this background to present a promising preliminary investigation of how genetic and experiential factors interact during development (i.e., gene × intervention interactions). Our findings provide evidence on how exposure to a family-based training can modify the associations between genotype (5-HTTLPR) and the neural mechanisms of selective attention in preschool children from lower socioeconomic status backgrounds. PMID:28819066

  15. Neuroplasticity of selective attention: Research foundations and preliminary evidence for a gene by intervention interaction.

    Science.gov (United States)

    Isbell, Elif; Stevens, Courtney; Pakulak, Eric; Hampton Wray, Amanda; Bell, Theodore A; Neville, Helen J

    2017-08-29

    This article reviews the trajectory of our research program on selective attention, which has moved from basic research on the neural processes underlying selective attention to translational studies using selective attention as a neurobiological target for evidence-based interventions. We use this background to present a promising preliminary investigation of how genetic and experiential factors interact during development (i.e., gene × intervention interactions). Our findings provide evidence on how exposure to a family-based training can modify the associations between genotype (5-HTTLPR) and the neural mechanisms of selective attention in preschool children from lower socioeconomic status backgrounds.

  16. Interaction of streaming and attention in human auditory cortex.

    Science.gov (United States)

    Gutschalk, Alexander; Rupp, André; Dykstra, Andrew R

    2015-01-01

    Serially presented tones are sometimes segregated into two perceptually distinct streams. An ongoing debate is whether this basic streaming phenomenon reflects automatic processes or requires attention focused to the stimuli. Here, we examined the influence of focused attention on streaming-related activity in human auditory cortex using magnetoencephalography (MEG). Listeners were presented with a dichotic paradigm in which left-ear stimuli consisted of canonical streaming stimuli (ABA_ or ABAA) and right-ear stimuli consisted of a classical oddball paradigm. In phase one, listeners were instructed to attend the right-ear oddball sequence and detect rare deviants. In phase two, they were instructed to attend the left ear streaming stimulus and report whether they heard one or two streams. The frequency difference (ΔF) of the sequences was set such that the smallest and largest ΔF conditions generally induced one- and two-stream percepts, respectively. Two intermediate ΔF conditions were chosen to elicit bistable percepts (i.e., either one or two streams). Attention enhanced the peak-to-peak amplitude of the P1-N1 complex, but only for ambiguous ΔF conditions, consistent with the notion that automatic mechanisms for streaming tightly interact with attention and that the latter is of particular importance for ambiguous sound sequences.

  17. Context-dependent control of attention capture: Evidence from proportion congruent effects.

    Science.gov (United States)

    Crump, Matthew J C; Milliken, Bruce; Leboe-McGowan, Jason; Leboe-McGowan, Launa; Gao, Xiaoqing

    2018-06-01

    There are several independent demonstrations that attentional phenomena can be controlled in a context-dependent manner by cues associated with differing attentional control demands. The present set of experiments provide converging evidence that attention-capture phenomena can be modulated in a context-dependent fashion. We determined whether methods from the proportion congruent literature (listwide and item- and context-specific proportion congruent designs) that are known to modulate distractor interference effects in Stroop and flanker tasks are capable of modulating attention capture by salient feature singletons. Across experiments we found evidence that attention capture can be modulated by listwide, item-specific, and context-specific manipulations of proportion congruent. We discuss challenges associated with interpreting results from proportion congruent studies but propose that our findings converge with existing work that has demonstrated context-dependent control of attention capture. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

  18. Concurrent Working Memory Load Can Facilitate Selective Attention: Evidence for Specialized Load

    Science.gov (United States)

    Park, Soojin; Kim, Min-Shik; Chun, Marvin M.

    2007-01-01

    Load theory predicts that concurrent working memory load impairs selective attention and increases distractor interference (N. Lavie, A. Hirst, J. W. de Fockert, & E. Viding, see record 2004-17825-003). Here, the authors present new evidence that the type of concurrent working memory load determines whether load impairs selective attention or not.…

  19. Dangerous Animals Capture and Maintain Attention in Humans

    Directory of Open Access Journals (Sweden)

    Jessica L. Yorzinski

    2014-07-01

    Full Text Available Predation is a major source of natural selection on primates and may have shaped attentional processes that allow primates to rapidly detect dangerous animals. Because ancestral humans were subjected to predation, a process that continues at very low frequencies, we examined the visual processes by which men and women detect dangerous animals (snakes and lions. We recorded the eye movements of participants as they detected images of a dangerous animal (target among arrays of nondangerous animals (distractors as well as detected images of a nondangerous animal (target among arrays of dangerous animals (distractors. We found that participants were quicker to locate targets when the targets were dangerous animals compared with nondangerous animals, even when spatial frequency and luminance were controlled. The participants were slower to locate nondangerous targets because they spent more time looking at dangerous distractors, a process known as delayed disengagement, and looked at a larger number of dangerous distractors. These results indicate that dangerous animals capture and maintain attention in humans, suggesting that historical predation has shaped some facets of visual orienting and its underlying neural architecture in modern humans.

  20. Dangerous animals capture and maintain attention in humans.

    Science.gov (United States)

    Yorzinski, Jessica L; Penkunas, Michael J; Platt, Michael L; Coss, Richard G

    2014-05-28

    Predation is a major source of natural selection on primates and may have shaped attentional processes that allow primates to rapidly detect dangerous animals. Because ancestral humans were subjected to predation, a process that continues at very low frequencies, we examined the visual processes by which men and women detect dangerous animals (snakes and lions). We recorded the eye movements of participants as they detected images of a dangerous animal (target) among arrays of nondangerous animals (distractors) as well as detected images of a nondangerous animal (target) among arrays of dangerous animals (distractors). We found that participants were quicker to locate targets when the targets were dangerous animals compared with nondangerous animals, even when spatial frequency and luminance were controlled. The participants were slower to locate nondangerous targets because they spent more time looking at dangerous distractors, a process known as delayed disengagement, and looked at a larger number of dangerous distractors. These results indicate that dangerous animals capture and maintain attention in humans, suggesting that historical predation has shaped some facets of visual orienting and its underlying neural architecture in modern humans.

  1. A Software Environment for an Adaptive Human-Aware Software Agent Supporting Attention-Demanding Tasks

    NARCIS (Netherlands)

    Bosse, T.; Memon, Z.A.; Oorburg, R.; Umair, M.; Treur, J.; de Vos, M.

    2011-01-01

    This paper presents a software environment providing human-aware ambient support for a human performing a task that demands substantial amounts of attention. The agent obtains human attention-awareness in an adaptive manner by use of a dynamical model of human attention, gaze sensoring by an

  2. Electrophysiological evidence for temporal dynamics associated with attentional processing in the zoom lens paradigm

    Directory of Open Access Journals (Sweden)

    Qing Zhang

    2018-04-01

    expansion of the attentional focus, suggesting that observers might further redistribute attentional resources according to the increased task difficulty. Conclusion These findings provide electrophysiological evidence that the neural activity of the N1 generator is the earliest marker of the zoom lens effect of visual spatial attention. Furthermore, evidence from N2pc shows that there is also a redistribution of attentional resources after the action of the zoom lens mechanism, which allows for better perform of the search task in the context of low attentional resolution. On the basis of the timing of P1, N1, and N2pc, our findings provide compelling evidence that visuospatial attention processing in the zoom lens paradigm involves multi-stage dynamic processing.

  3. Evidence of inbreeding depression on human height

    NARCIS (Netherlands)

    R. McQuillan (Ruth); N. Eklund (Niina); N. Pirastu (Nicola); M. Kuningas (Maris); B.P. McEvoy (Brian); T. Esko (Tõnu); T. Corre (Tanguy); G. Davies (Gail); M. Kaakinen (Marika); L.-P. Lyytikäinen (Leo-Pekka); K. Kristiansson (Kati); A.S. Havulinna (Aki); M. Gögele (Martin); V. Vitart (Veronique); A. Tenesa (Albert); Y.S. Aulchenko (Yurii); C. Hayward (Caroline); A. Johansson (Åsa); M. Boban (Mladen); S. Ulivi (Shelia); A. Robino (Antonietta); V. Boraska (Vesna); W. Igl (Wilmar); S.H. Wild (Sarah); L. Zgaga (Lina); N. Amin (Najaf); E. Theodoratou (Evropi); O. Polasek (Ozren); S. Girotto; L.M. Lopez (Lorna); C. Sala (Cinzia); J. Lahti (Jari); T. Laatikainen (Tiina); I. Prokopenko (Inga); M. Kals (Mart); J. Viikari (Jorma); J. Yang (Joanna); A. Pouta (Anneli); K. Estrada Gil (Karol); A. Hofman (Albert); N.B. Freimer (Nelson); N.G. Martin (Nicholas); M. Kähönen (Mika); L. Milani (Lili); M. Heliovaara (Markku); E. Vartiainen (Erkki); K. Räikkönen (Katri); C. Masciullo (Corrado); J.M. Starr (John); A.A. Hicks (Andrew); L. Esposito (Laura); I. Kolcic (Ivana); S.M. Farrington (Susan); B.A. Oostra (Ben); T. Zemunik (Tatijana); H. Campbell (Harry); M. Kirin (Mirna); M. Pehlic (Marina); F. Faletra (Flavio); D.J. Porteous (David J.); G. Pistis (Giorgio); E. Widen (Elisabeth); V. Salomaa (Veikko); S. Koskinen (Seppo); K. Fischer (Krista); T. Lehtimäki (Terho); A.C. Heath (Andrew); M.I. McCarthy (Mark); F. Rivadeneira Ramirez (Fernando); G.W. Montgomery (Grant); H.W. Tiemeier (Henning); A.L. Hartikainen; P.A.F. Madden (Pamela); P. d' Adamo (Pio); N. Hastie (Nick); U. Gyllensten (Ulf); A.F. Wright (Alan); C.M. van Duijn (Cornelia); M.G. Dunlop (Malcolm); I. Rudan (Igor); P. Gasparini (Paolo); P.P. Pramstaller (Peter Paul); I.J. Deary (Ian); D. Toniolo (Daniela); K. Hagen (Knut); A. Jula (Antti); O. Raitakari (Olli); A. Metspalu (Andres); M. Perola (Markus); M.-R. Jarvelin (Marjo-Riitta); A.G. Uitterlinden (André); P.M. Visscher (Peter); J.F. Wilson (James)

    2012-01-01

    textabstractStature is a classical and highly heritable complex trait, with 80%-90% of variation explained by genetic factors. In recent years, genome-wide association studies (GWAS) have successfully identified many common additive variants influencing human height; however, little attention has

  4. Autonomous spacecraft landing through human pre-attentive vision

    International Nuclear Information System (INIS)

    Schiavone, Giuseppina; Izzo, Dario; Simões, Luís F; De Croon, Guido C H E

    2012-01-01

    In this work, we exploit a computational model of human pre-attentive vision to guide the descent of a spacecraft on extraterrestrial bodies. Providing the spacecraft with high degrees of autonomy is a challenge for future space missions. Up to present, major effort in this research field has been concentrated in hazard avoidance algorithms and landmark detection, often by reference to a priori maps, ranked by scientists according to specific scientific criteria. Here, we present a bio-inspired approach based on the human ability to quickly select intrinsically salient targets in the visual scene; this ability is fundamental for fast decision-making processes in unpredictable and unknown circumstances. The proposed system integrates a simple model of the spacecraft and optimality principles which guarantee minimum fuel consumption during the landing procedure; detected salient sites are used for retargeting the spacecraft trajectory, under safety and reachability conditions. We compare the decisions taken by the proposed algorithm with that of a number of human subjects tested under the same conditions. Our results show how the developed algorithm is indistinguishable from the human subjects with respect to areas, occurrence and timing of the retargeting. (paper)

  5. Contextual control of attentional allocation in human discrimination learning.

    Science.gov (United States)

    Uengoer, Metin; Lachnit, Harald; Lotz, Anja; Koenig, Stephan; Pearce, John M

    2013-01-01

    In 3 human predictive learning experiments, we investigated whether the allocation of attention can come under the control of contextual stimuli. In each experiment, participants initially received a conditional discrimination for which one set of cues was trained as relevant in Context 1 and irrelevant in Context 2, and another set was relevant in Context 2 and irrelevant in Context 1. For Experiments 1 and 2, we observed that a second discrimination based on cues that had previously been trained as relevant in Context 1 during the conditional discrimination was acquired more rapidly in Context 1 than in Context 2. Experiment 3 revealed a similar outcome when new stimuli from the original dimensions were used in the test stage. Our results support the view that the associability of a stimulus can be controlled by the stimuli that accompany it.

  6. Implicit learning modulates attention capture: evidence from an item-specific proportion congruency manipulation

    OpenAIRE

    Thomson, David R.; Willoughby, Karen; Milliken, Bruce

    2014-01-01

    A host of research has now shown that our explicit goals and intentions can, in large part, overcome the capture of visual attention by objects that differ from their surroundings in terms of size, shape, or color. Surprisingly however, there is little evidence for the role of implicit learning in mitigating capture effects despite the fact that such learning has been shown to strongly affect behavior in a host of other performance domains. Here, we employ a modified attention capture paradig...

  7. The role of dopamine in human addiction: from reward to motivated attention.

    Science.gov (United States)

    Franken, Ingmar H A; Booij, Jan; van den Brink, Wim

    2005-12-05

    There is general consensus among preclinical researchers that dopamine plays an important role in the development and persistence of addiction. However, the precise role of dopamine in addictive behaviors is far from clear and only a few clinical studies on the role of dopamine in human addiction have been conducted so far. The present paper reviews studies addressing the role of dopamine in humans. There is substantial and consistent evidence that dopamine is involved in the experience of drug reward in humans. Dopamine may also be involved in motivational processes such as drug craving. However, given the inconsistent findings of studies using dopamine receptor (ant)agonists, the role of dopamine in the experience of craving is far from resolved. Recent theories claiming that dopamine signals salience and makes the brain paying attention to biological relevant stimuli may provide an interesting framework for explaining addictive behaviors. There is accumulating evidence that patients with drug and alcohol addiction have an aberrant focus on drug-related stimuli. Although there is some preliminary support for the role of dopamine in these attention processes, more studies have to be carried out in order to test the validity of these theories in human subjects.

  8. Neural mechanisms of human perceptual choice under focused and divided attention.

    Science.gov (United States)

    Wyart, Valentin; Myers, Nicholas E; Summerfield, Christopher

    2015-02-25

    Perceptual decisions occur after the evaluation and integration of momentary sensory inputs, and dividing attention between spatially disparate sources of information impairs decision performance. However, it remains unknown whether dividing attention degrades the precision of sensory signals, precludes their conversion into decision signals, or dampens the integration of decision information toward an appropriate response. Here we recorded human electroencephalographic (EEG) activity while participants categorized one of two simultaneous and independent streams of visual gratings according to their average tilt. By analyzing trial-by-trial correlations between EEG activity and the information offered by each sample, we obtained converging behavioral and neural evidence that dividing attention between left and right visual fields does not dampen the encoding of sensory or decision information. Under divided attention, momentary decision information from both visual streams was encoded in slow parietal signals without interference but was lost downstream during their integration as reflected in motor mu- and beta-band (10-30 Hz) signals, resulting in a "leaky" accumulation process that conferred greater behavioral influence to more recent samples. By contrast, sensory inputs that were explicitly cued as irrelevant were not converted into decision signals. These findings reveal that a late cognitive bottleneck on information integration limits decision performance under divided attention, and places new capacity constraints on decision-theoretic models of information integration under cognitive load. Copyright © 2015 the authors 0270-6474/15/353485-14$15.00/0.

  9. Neural mechanisms of human perceptual choice under focused and divided attention

    Science.gov (United States)

    Wyart, Valentin; Myers, Nicholas E.; Summerfield, Christopher

    2015-01-01

    Perceptual decisions occur after evaluation and integration of momentary sensory inputs, and dividing attention between spatially disparate sources of information impairs decision performance. However, it remains unknown whether dividing attention degrades the precision of sensory signals, precludes their conversion into decision signals, or dampens the integration of decision information towards an appropriate response. Here we recorded human electroencephalographic (EEG) activity whilst participants categorised one of two simultaneous and independent streams of visual gratings according to their average tilt. By analyzing trial-by-trial correlations between EEG activity and the information offered by each sample, we obtained converging behavioural and neural evidence that dividing attention between left and right visual fields does not dampen the encoding of sensory or decision information. Under divided attention, momentary decision information from both visual streams was encoded in slow parietal signals without interference but was lost downstream during their integration as reflected in motor mu- and beta-band (10–30 Hz) signals, resulting in a ‘leaky’ accumulation process which conferred greater behavioural influence to more recent samples. By contrast, sensory inputs that were explicitly cued as irrelevant were not converted into decision signals. These findings reveal that a late cognitive bottleneck on information integration limits decision performance under divided attention, and place new capacity constraints on decision-theoretic models of information integration under cognitive load. PMID:25716848

  10. Electrophysiological Evidence of Atypical Motivation and Reward Processing in Children with Attention-Deficit Hyperactivity Disorder

    Science.gov (United States)

    Holroyd, Clay B.; Baker, Travis E.; Kerns, Kimberly A.; Muller, Ulrich

    2008-01-01

    Behavioral and neurophysiological evidence suggest that attention-deficit hyperactivity disorder (ADHD) is characterized by the impact of abnormal reward prediction error signals carried by the midbrain dopamine system on frontal brain areas that implement cognitive control. To investigate this issue, we recorded the event-related brain potential…

  11. Attentional Bias to Beauty with Evolutionary Benefits: Evidence from Aesthetic Appraisal of Landscape Architecture

    Science.gov (United States)

    Zhang, Wei; Tang, Xiaoxiang; He, Xianyou; Lai, Shuxian

    2018-01-01

    Substantial evidence suggests that beauty is associated with the survival and reproduction of organisms. Landscape architecture is composed of a series of natural elements that have significant evolutionary implications. The present study used one pilot material ratings and three experiments to examine the mechanisms of aesthetic appraisals of landscape architecture. The results confirmed that landscape architecture elicited a sense of beauty and captured visual attention more easily than other types of architecture during explicit aesthetic rating task (Experiment 1) and implicit aesthetic perception task (dot-probe paradigm, Experiment 2). Furthermore, the spatial cueing paradigm revealed that response latencies were significantly faster for landscape architecture than non-landscape architecture on valid trials, but there was no significant difference in this contrast on invalid trials at 150-ms stimulus onset asynchrony (SOA, Experiment 3a). At 500-ms SOA (Experiment 3b), participants responded significantly faster for landscape architecture on valid trials, but reacted significantly slower for landscape architecture on invalid trials. The findings indicated that the beauty of landscape architecture can be perceived implicitly, and only faster orienting of attention, but not delayed disengagement of attention was generated at early stages of the processing of landscape architecture. However, the attentional bias at later stages of attentional processes may be resulted from both faster orienting of attention and delayed disengagement of attention from landscape architecture photographs. PMID:29467696

  12. Attentional Bias to Beauty with Evolutionary Benefits: Evidence from Aesthetic Appraisal of Landscape Architecture.

    Science.gov (United States)

    Zhang, Wei; Tang, Xiaoxiang; He, Xianyou; Lai, Shuxian

    2018-01-01

    Substantial evidence suggests that beauty is associated with the survival and reproduction of organisms. Landscape architecture is composed of a series of natural elements that have significant evolutionary implications. The present study used one pilot material ratings and three experiments to examine the mechanisms of aesthetic appraisals of landscape architecture. The results confirmed that landscape architecture elicited a sense of beauty and captured visual attention more easily than other types of architecture during explicit aesthetic rating task (Experiment 1) and implicit aesthetic perception task (dot-probe paradigm, Experiment 2). Furthermore, the spatial cueing paradigm revealed that response latencies were significantly faster for landscape architecture than non-landscape architecture on valid trials, but there was no significant difference in this contrast on invalid trials at 150-ms stimulus onset asynchrony (SOA, Experiment 3a). At 500-ms SOA (Experiment 3b), participants responded significantly faster for landscape architecture on valid trials, but reacted significantly slower for landscape architecture on invalid trials. The findings indicated that the beauty of landscape architecture can be perceived implicitly, and only faster orienting of attention, but not delayed disengagement of attention was generated at early stages of the processing of landscape architecture. However, the attentional bias at later stages of attentional processes may be resulted from both faster orienting of attention and delayed disengagement of attention from landscape architecture photographs.

  13. Spatiotopic coding of BOLD signal in human visual cortex depends on spatial attention.

    Directory of Open Access Journals (Sweden)

    Sofia Crespi

    Full Text Available The neural substrate of the phenomenological experience of a stable visual world remains obscure. One possible mechanism would be to construct spatiotopic neural maps where the response is selective to the position of the stimulus in external space, rather than to retinal eccentricities, but evidence for these maps has been inconsistent. Here we show, with fMRI, that when human subjects perform concomitantly a demanding attentive task on stimuli displayed at the fovea, BOLD responses evoked by moving stimuli irrelevant to the task were mostly tuned in retinotopic coordinates. However, under more unconstrained conditions, where subjects could attend easily to the motion stimuli, BOLD responses were tuned not in retinal but in external coordinates (spatiotopic selectivity in many visual areas, including MT, MST, LO and V6, agreeing with our previous fMRI study. These results indicate that spatial attention may play an important role in mediating spatiotopic selectivity.

  14. Tonic noradrenergic activity modulates explorative behavior and attentional set shifting: Evidence from pupillometry and gaze pattern analysis.

    Science.gov (United States)

    Pajkossy, Péter; Szőllősi, Ágnes; Demeter, Gyula; Racsmány, Mihály

    2017-12-01

    A constant task for every living organism is to decide whether to exploit rewards associated with current behavior or to explore the environment for more rewarding options. Current empirical evidence indicates that exploitation is related to phasic whereas exploration is related to tonic firing mode of noradrenergic neurons in the locus coeruleus. In humans, this exploration-exploitation trade-off is subserved by the ability to flexibly switch attention between task-related and task-irrelevant information. Here, we investigated whether this function, called attentional set shifting, is related to exploration and tonic noradrenergic discharge. We measured pretrial baseline pupil dilation, proved to be strongly correlated with the activity of the locus coeruleus, while human participants took part in well-known tasks of attentional set shifting. Study 1 used the Wisconsin Card Sorting Task, whereas in Study 2, the Intra/Extradimensional Set Shifting Task was used. Both tasks require participants to choose between different compound stimuli based on feedback provided for their previous decisions. During the task, stimulus-reward contingencies change periodically, thus participants are repeatedly required to reassess which stimulus features are relevant (i.e., they shift their attentional set). Our results showed that baseline pupil diameter steadily decreased when the stimulus-reward contingencies were stable, whereas they suddenly increased when these contingencies changed. Analysis of looking patterns also confirmed the presence of exploratory behavior during attentional set shifting. Thus, our results suggest that tonic firing mode of noradrenergic neurons in the locus coeruleus is implicated in attentional set shifting, as it regulates the amount of exploration. © 2017 Society for Psychophysiological Research.

  15. 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. Copyright © 2015 Elsevier B.V. All rights reserved.

  16. Human cortical activity evoked by contextual processing in attentional orienting.

    Science.gov (United States)

    Zhao, Shuo; Li, Chunlin; Uono, Shota; Yoshimura, Sayaka; Toichi, Motomi

    2017-06-07

    The ability to assess another person's direction of attention is paramount in social communication, many studies have reported a similar pattern between gaze and arrow cues in attention orienting. Neuroimaging research has also demonstrated no qualitative differences in attention to gaze and arrow cues. However, these studies were implemented under simple experiment conditions. Researchers have highlighted the importance of contextual processing (i.e., the semantic congruence between cue and target) in attentional orienting, showing that attentional orienting by social gaze or arrow cues could be modulated through contextual processing. Here, we examine the neural activity of attentional orienting by gaze and arrow cues in response to contextual processing using functional magnetic resonance imaging. The results demonstrated that the influence of neural activity through contextual processing to attentional orienting occurred under invalid conditions (when the cue and target were incongruent versus congruent) in the ventral frontoparietal network, although we did not identify any differences in the neural substrates of attentional orienting in contextual processing between gaze and arrow cues. These results support behavioural data of attentional orienting modulated by contextual processing based on the neurocognitive architecture.

  17. Preferential access to emotion under attentional blink: evidence for threshold phenomenon

    Directory of Open Access Journals (Sweden)

    Szczepanowski Remigiusz

    2015-03-01

    Full Text Available The present study provides evidence that the activation strength produced by emotional stimuli must pass a threshold level in order to be consciously perceived, contrary to the assumption of continuous quality of representation. An analysis of receiver operating characteristics (ROC for attentional blink performance was used to distinguish between two (continuous vs. threshold models of emotion perception by inspecting two different ROC’s shapes. Across all conditions, the results showed that performance in the attentional blink task was better described by the two-limbs ROC predicted by the Krantz threshold model than by the curvilinear ROC implied by the signal-detection theory.

  18. Watch out! Magnetoencephalographic evidence for early modulation of attention orienting by fearful gaze cueing.

    Directory of Open Access Journals (Sweden)

    Fanny Lachat

    Full Text Available Others' gaze and emotional facial expression are important cues for the process of attention orienting. Here, we investigated with magnetoencephalography (MEG whether the combination of averted gaze and fearful expression may elicit a selectively early effect of attention orienting on the brain responses to targets. We used the direction of gaze of centrally presented fearful and happy faces as the spatial attention orienting cue in a Posner-like paradigm where the subjects had to detect a target checkerboard presented at gazed-at (valid trials or non gazed-at (invalid trials locations of the screen. We showed that the combination of averted gaze and fearful expression resulted in a very early attention orienting effect in the form of additional parietal activity between 55 and 70 ms for the valid versus invalid targets following fearful gaze cues. No such effect was obtained for the targets following happy gaze cues. This early cue-target validity effect selective of fearful gaze cues involved the left superior parietal region and the left lateral middle occipital region. These findings provide the first evidence for an effect of attention orienting induced by fearful gaze in the time range of C1. In doing so, they demonstrate the selective impact of combined gaze and fearful expression cues in the process of attention orienting.

  19. Spatially distributed encoding of covert attentional shifts in human thalamus

    DEFF Research Database (Denmark)

    Hulme, Oliver J; Whiteley, Louise Emma; Shipp, Stewart

    2010-01-01

    /central-intralaminar (oculomotor thalamus), caudal intralaminar/parafascicular, suprageniculate/limitans, and medial pulvinar/lateral posterior. Hence, the cortical network generating a top-down control signal for relocating attention acts in concert with a spatially selective thalamic apparatus-the set of active nuclei mirroring...... the thalamic territory of cortical "eye-field" areas, thus supporting theories which propose the visuomotor origins of covert attentional selection.......Spatial attention modulates signal processing within visual nuclei of the thalamus--but do other nuclei govern the locus of attention in top-down mode? We examined functional MRI (fMRI) data from three subjects performing a task requiring covert attention to 1 of 16 positions in a circular array...

  20. [Pay attention to the human health risk of drinking low mineral water].

    Science.gov (United States)

    Shu, Weiqun

    2015-10-01

    The consumption of low mineral drinking water has been increasing around the world with the shortage of water resources and the development of advanced water treatment technologies. Evidences from systematic document reviews, ecological epidemiological observations, and experimental drinking water intervention studies indicate that lack of minerals in drinking water may cause direct or indirect harm to human health, among which, the associations of magnesium in water with cardiovascular disease, as well as calcium in water with osteoporosis, are well proved by sufficient evidence. This article points out that it is urgent to pay more attention to the issues about establishment of health risk evaluation system on susceptible consuming population, establishment of lab evaluation system on water quality and health effect for non-traditional drinking water, and program of safety mineralization for demineralized or desalinated water and so on.

  1. Attentional Bias in Human Category Learning: The Case of Deep Learning.

    Science.gov (United States)

    Hanson, Catherine; Caglar, Leyla Roskan; Hanson, Stephen José

    2018-01-01

    Category learning performance is influenced by both the nature of the category's structure and the way category features are processed during learning. Shepard (1964, 1987) showed that stimuli can have structures with features that are statistically uncorrelated (separable) or statistically correlated (integral) within categories. Humans find it much easier to learn categories having separable features, especially when attention to only a subset of relevant features is required, and harder to learn categories having integral features, which require consideration of all of the available features and integration of all the relevant category features satisfying the category rule (Garner, 1974). In contrast to humans, a single hidden layer backpropagation (BP) neural network has been shown to learn both separable and integral categories equally easily, independent of the category rule (Kruschke, 1993). This "failure" to replicate human category performance appeared to be strong evidence that connectionist networks were incapable of modeling human attentional bias. We tested the presumed limitations of attentional bias in networks in two ways: (1) by having networks learn categories with exemplars that have high feature complexity in contrast to the low dimensional stimuli previously used, and (2) by investigating whether a Deep Learning (DL) network, which has demonstrated humanlike performance in many different kinds of tasks (language translation, autonomous driving, etc.), would display human-like attentional bias during category learning. We were able to show a number of interesting results. First, we replicated the failure of BP to differentially process integral and separable category structures when low dimensional stimuli are used (Garner, 1974; Kruschke, 1993). Second, we show that using the same low dimensional stimuli, Deep Learning (DL), unlike BP but similar to humans, learns separable category structures more quickly than integral category structures

  2. Attentional Bias in Human Category Learning: The Case of Deep Learning

    Directory of Open Access Journals (Sweden)

    Catherine Hanson

    2018-04-01

    Full Text Available Category learning performance is influenced by both the nature of the category's structure and the way category features are processed during learning. Shepard (1964, 1987 showed that stimuli can have structures with features that are statistically uncorrelated (separable or statistically correlated (integral within categories. Humans find it much easier to learn categories having separable features, especially when attention to only a subset of relevant features is required, and harder to learn categories having integral features, which require consideration of all of the available features and integration of all the relevant category features satisfying the category rule (Garner, 1974. In contrast to humans, a single hidden layer backpropagation (BP neural network has been shown to learn both separable and integral categories equally easily, independent of the category rule (Kruschke, 1993. This “failure” to replicate human category performance appeared to be strong evidence that connectionist networks were incapable of modeling human attentional bias. We tested the presumed limitations of attentional bias in networks in two ways: (1 by having networks learn categories with exemplars that have high feature complexity in contrast to the low dimensional stimuli previously used, and (2 by investigating whether a Deep Learning (DL network, which has demonstrated humanlike performance in many different kinds of tasks (language translation, autonomous driving, etc., would display human-like attentional bias during category learning. We were able to show a number of interesting results. First, we replicated the failure of BP to differentially process integral and separable category structures when low dimensional stimuli are used (Garner, 1974; Kruschke, 1993. Second, we show that using the same low dimensional stimuli, Deep Learning (DL, unlike BP but similar to humans, learns separable category structures more quickly than integral category

  3. No Evidence for a Food-Related Attention Bias after Thought Suppression

    Directory of Open Access Journals (Sweden)

    Barbara Soetens

    2008-01-01

    Full Text Available The aim of this study was to investigate whether food-related thought suppression results in an attention bias for food cues. Fifty-nine female students took part in the experiment. All completed a modified exogenous cueing task containing pictures of foods and toys with a similar valence (presentation duration: 250 ms and 1050 ms. Half of the participants were instructed to suppress thoughts about food and the other half was given control instructions, prior to completing the exogenous cueing task. No evidence was found for an enhanced cue validity effect for food cues after food-related thought suppression. Hence, the preliminary results do not provide support for the hypothesis that thought suppression is sufficient to yield an attention bias. Since the study was the first to employ an exogenous cueing task to study the attentional processing of food cues, replication is warranted.

  4. A right-ear bias of auditory selective attention is evident in alpha oscillations.

    Science.gov (United States)

    Payne, Lisa; Rogers, Chad S; Wingfield, Arthur; Sekuler, Robert

    2017-04-01

    Auditory selective attention makes it possible to pick out one speech stream that is embedded in a multispeaker environment. We adapted a cued dichotic listening task to examine suppression of a speech stream lateralized to the nonattended ear, and to evaluate the effects of attention on the right ear's well-known advantage in the perception of linguistic stimuli. After being cued to attend to input from either their left or right ear, participants heard two different four-word streams presented simultaneously to the separate ears. Following each dichotic presentation, participants judged whether a spoken probe word had been in the attended ear's stream. We used EEG signals to track participants' spatial lateralization of auditory attention, which is marked by interhemispheric differences in EEG alpha (8-14 Hz) power. A right-ear advantage (REA) was evident in faster response times and greater sensitivity in distinguishing attended from unattended words. Consistent with the REA, we found strongest parietal and right frontotemporal alpha modulation during the attend-right condition. These findings provide evidence for a link between selective attention and the REA during directed dichotic listening. © 2016 Society for Psychophysiological Research.

  5. Thalamic Control of Human Attention Driven by Memory and Learning

    OpenAIRE

    de Bourbon-Teles, José; Bentley, Paul; Koshino, Saori; Shah, Kushal; Dutta, Agneish; Malhotra, Paresh; Egner, Tobias; Husain, Masud; Soto, David

    2014-01-01

    Summary The role of the thalamus in high-level cognition—attention, working memory (WM), rule-based learning, and decision making—remains poorly understood, especially in comparison to that of cortical frontoparietal networks [1–3]. Studies of visual thalamus have revealed important roles for pulvinar and lateral geniculate nucleus in visuospatial perception and attention [4–10] and for mediodorsal thalamus in oculomotor control [11]. Ventrolateral thalamus contains subdivisions devoted to ac...

  6. Attention, predictions and expectations, and their violation: attentional control in the human brain

    OpenAIRE

    Vossel, Simone; Geng, Joy J.; Friston, Karl J.

    2014-01-01

    In the complex scenes of everyday life, our brains must select from among many competing inputs for perceptual synthesis—so that only the most relevant are fully processed and irrelevant (distracting) information is suppressed. At the same time, we must remain responsive to salient events outside our current focus of attention—and balancing these two processing modes is a fundamental task our brain constantly needs to solve.This Research Topic examines how attentional control is guided by sen...

  7. Time to guide: evidence for delayed attentional guidance in contextual cueing \\ud

    OpenAIRE

    Kunar, Melina A.; Flusberg, Stephen J.; Wolfe, Jeremy M

    2008-01-01

    Contextual cueing experiments show that, when displays are repeated, reaction times (RTs) to find a target decrease over time even when the observers are not aware of the repetition. Recent evidence suggests that this benefit in standard contextual cueing tasks is not likely to be due to an improvement in attentional guidance (Kunar, Flusberg, Horowitz, & Wolfe, 2007). Nevertheless, we ask whether guidance can help participants find the target in a repeated display, if they are given sufficie...

  8. The association of attention deficit hyperactivity disorder with socioeconomic disadvantage: alternative explanations and evidence

    OpenAIRE

    Russell, Ginny; Ford, Tamsin; Rosenberg, Rachel; Kelly, Susan

    2013-01-01

    Background Studies throughout Northern Europe, the United States and Australia have found an association between childhood attention deficit hyperactivity disorder (ADHD) and family socioeconomic disadvantage. We report further evidence for the association and review potential causal pathways that might explain the link. Method Secondary analysis of a UK birth cohort (the Millennium Cohort Study, N = 19,519) was used to model the association of ADHD with socioeconomic disadvantage and assess ...

  9. Multimodal neuroimaging evidence linking memory and attention systems during visual search cued by context.

    Science.gov (United States)

    Kasper, Ryan W; Grafton, Scott T; Eckstein, Miguel P; Giesbrecht, Barry

    2015-03-01

    Visual search can be facilitated by the learning of spatial configurations that predict the location of a target among distractors. Neuropsychological and functional magnetic resonance imaging (fMRI) evidence implicates the medial temporal lobe (MTL) memory system in this contextual cueing effect, and electroencephalography (EEG) studies have identified the involvement of visual cortical regions related to attention. This work investigated two questions: (1) how memory and attention systems are related in contextual cueing; and (2) how these systems are involved in both short- and long-term contextual learning. In one session, EEG and fMRI data were acquired simultaneously in a contextual cueing task. In a second session conducted 1 week later, EEG data were recorded in isolation. The fMRI results revealed MTL contextual modulations that were correlated with short- and long-term behavioral context enhancements and attention-related effects measured with EEG. An fMRI-seeded EEG source analysis revealed that the MTL contributed the most variance to the variability in the attention enhancements measured with EEG. These results support the notion that memory and attention systems interact to facilitate search when spatial context is implicitly learned. © 2015 New York Academy of Sciences.

  10. Sad facial cues inhibit temporal attention: evidence from an event-related potential study.

    Science.gov (United States)

    Kong, Xianxian; Chen, Xiaoqiang; Tan, Bo; Zhao, Dandan; Jin, Zhenlan; Li, Ling

    2013-06-19

    We examined the influence of different emotional cues (happy or sad) on temporal attention (short or long interval) using behavioral as well as event-related potential recordings during a Stroop task. Emotional stimuli cued short and long time intervals, inducing 'sad-short', 'sad-long', 'happy-short', and 'happy-long' conditions. Following the intervals, participants performed a numeric Stroop task. Behavioral results showed the temporal attention effects in the sad-long, happy-long, and happy-short conditions, in which valid cues quickened the reaction times, but not in the sad-short condition. N2 event-related potential components showed sad cues to have decreased activity for short intervals compared with long intervals, whereas happy cues did not. Taken together, these findings provide evidence for different modulation of sad and happy facial cues on temporal attention. Furthermore, sad cues inhibit temporal attention, resulting in longer reaction time and decreased neural activity in the short interval by diverting more attentional resources.

  11. Lifespan development of attentiveness in domestic dogs: drawing parallels with humans

    Directory of Open Access Journals (Sweden)

    Lisa Jessica Wallis

    2014-02-01

    Full Text Available Attention is pivotal to consciousness, perception, cognition, and working memory in all mammals, and therefore changes in attention over the lifespan are likely to influence development and aging of all of these functions. Due to their evolutionary and developmental history, the dog is being recognised as an important species for modelling human healthspan, aging and associated diseases. In this study, we investigated the normal lifespan development of attentiveness of pet dogs in naturalistic situations, and compared the resulting cross-sectional developmental trajectories with data from previous studies in humans. We tested a sample of 145 Border collies (six months to 14 years with humans and objects or food as attention attractors, in order to assess their attentional capture, sustained and selective attention and sensorimotor abilities. Our results reveal differences in task relevance in sustained attentional performance when watching a human or a moving object, which may be explained by life-long learning processes involving such stimuli. During task-switching we found that dogs’ selective attention and sensorimotor abilities showed differences between age groups, with performance peaking at middle age. Dogs’ sensorimotor abilities showed a quadratic distribution with age and were correlated with selective attention performance. Our results support the hypothesis that the development and senescence of sensorimotor and attentional control may be fundamentally interrelated. Additionally, attentional capture, sustained attention and sensorimotor control developmental trajectories paralleled those found in humans. Given that the development of attention is similar across humans and dogs, we propose that the same regulatory mechanisms are likely to be present in both species. Finally, this cross-sectional study provides the first description of age group changes in attention over the lifespan of pet dogs.

  12. Dissociating location-specific inhibition and attention shifts: evidence against the disengagement account of contingent capture.

    Science.gov (United States)

    Anderson, Brian A; Folk, Charles L

    2012-08-01

    The study of attentional capture has provided a rich context for assessing the relative influence of top-down and bottom-up factors in visual perception. Some have argued that attentional capture by a salient, irrelevant stimulus is contingent on top-down attentional set (e.g., Folk, Remington, & Johnston, Journal of Experimental Psychology: Human Perception and Performance 18:1030-1044, 1992). Others, however, have argued that capture is driven entirely by bottom-up salience and that top-down factors influence the postallocation speed of disengagement from the irrelevant stimulus (e.g., Theeuwes, Acta Psychologica 135:77-99, 2010a). In support of this speed-of-disengagement hypothesis, recent findings from the modified spatial-cuing paradigm show that cues carrying a no-go target property produce reverse, or negative, cuing effects, consistent with inhibition of the cue location from which attention has been very quickly disengaged (Belopolsky, Schreij, & Theeuwes, Perception, & Psychophysics, 72, 326-341, 2010). Across six experiments, we show that this inhibitory process can be dissociated from shifts of spatial attention and is, thus, not a reliable marker of capture. We conclude that the data are inconsistent with the predictions of the disengagement hypothesis.

  13. Human mutagens: evidence from paternal exposure

    International Nuclear Information System (INIS)

    Narod, S.A.; Douglas, G.R.; Nestmann, E.R.; Blakey, D.H.

    1988-01-01

    The importance of inherited mutations as a cause of human disease has been established clearly through examples of well-defined genetic anomalies, such as Down syndrome and retinoblastoma. Furthermore, it is suspected that environmental contaminants induce mutations resulting in increased risk for such defects in subsequent generations of persons exposed. The present lack of direct evidence for induced inherited genetic disorders in human beings hampers the development of risk estimation techniques for extrapolation from animal models. The most extensive prospective epidemiologic studies of inherited genetic effects have involved survivors of atomic bomb detonations and patients treated with cancer chemotherapy. In neither case has a significant elevation in inherited genetic effects or cancer been detected in the offspring of exposed individuals. Epidemiologic studies of subjects receiving chronic exposure may be confounded by the effect of maternal exposure during pregnancy. Consideration of only paternal exposure can minimize the confounding influence of teratogenicity, enhancing the resolving power of studies for inherited effects. Using this approach, retrospective (case-control) studies of childhood cancer patients have provided limited but suggestive evidence for inheritance of induced effects. Endpoints, such as congenital malformations and spontaneous abortion following paternal exposure, can also be considered as indicators of heritable mutagenic effects. For example, there is limited evidence suggesting that paternal exposure to anaesthetic gases may cause miscarriage and congenital abnormalities as a result of induced male germ cell mutations. 104 references

  14. Attention problems and Attention-Deficit/Hyperactivity Disorder in discordant and concordant monozygotic twins: Evidence of environmental mediators.

    NARCIS (Netherlands)

    Lehn, H.; Derks, E.M.; Hudziak, J.; Heutink, P.; van Beijsterveldt, C.E.M.; Boomsma, D.I.

    2007-01-01

    OBJECTIVE: To study familial and nonfamilial environmental influences on attention problems and attention-deficit/hyperactivity disorder (ADHD) in monozygotic twins discordant and concordant-high and low for these traits. METHOD: Ninety-five twin pairs from The Netherlands Twin Register were

  15. Usability of a theory of visual attention (TVA) for parameter-based measurement of attention I: evidence from normal subjects

    DEFF Research Database (Denmark)

    Finke, Kathrin; Bublak, Peter; Krummenacher, Joseph

    2005-01-01

    four separable attentional components: processing speed, working memory storage capacity, spatial distribution of attention, and top-down control. A number of studies (Duncan et al., 1999; Habekost & Bundesen, 2003; Peers et al., 2005) have already demonstrated the clinical relevance......The present study investigated the usability of whole and partial report of briefly displayed letter arrays as a diagnostic tool for the assessment of attentional functions. The tool is based on Bundesen's (1990, 1998, 2002; Bundesen et al., 2005) theory of visual attention (TVA), which assumes...... of these parameters. The present study was designed to examine whether (a) a shortened procedure bears sufficient accuracy and reliability, (b) whether the procedures reveal attentional constructs with clinical relevance, and (c) whether the mathematically independent parameters are also empirically independent...

  16. The association of attention deficit hyperactivity disorder with socioeconomic disadvantage: alternative explanations and evidence.

    Science.gov (United States)

    Russell, Ginny; Ford, Tamsin; Rosenberg, Rachel; Kelly, Susan

    2014-05-01

    Studies throughout Northern Europe, the United States and Australia have found an association between childhood attention deficit hyperactivity disorder (ADHD) and family socioeconomic disadvantage. We report further evidence for the association and review potential causal pathways that might explain the link. Secondary analysis of a UK birth cohort (the Millennium Cohort Study, N = 19,519) was used to model the association of ADHD with socioeconomic disadvantage and assess evidence for several potential explanatory pathways. The case definition of ADHD was a parent-report of whether ADHD had been identified by a medical doctor or health professional when children were 7 years old. ADHD was associated with a range of indicators of social and economic disadvantage including poverty, housing tenure, maternal education, income, lone parenthood and younger motherhood. There was no evidence to suggest childhood ADHD was a causal factor of socioeconomic disadvantage: income did not decrease for parents of children with ADHD compared to controls over the 7-year study period. No clinical bias towards labelling ADHD in low SES groups was detected. There was evidence to suggest that parent attachment/family conflict mediated the relationship between ADHD and SES. Although genetic and neurological determinants may be the primary predictors of difficulties with activity level and attention, aetiology appears to be influenced by socioeconomic situation. © 2013 The Authors Journal of Child Psychology and Psychiatry published by John Wiley & Sons Ltd on behalf of Association for Child and Adolescent Mental Health.

  17. Motivational intensity modulates attentional scope: evidence from behavioral and ERP studies.

    Science.gov (United States)

    Liu, Lei; Zhang, Guangnan; Zhou, Renlai; Wang, Zuowei

    2014-10-01

    Previous studies have found that affective states with high motivational intensity narrow attentional scope, whereas affective states with low motivational intensity broaden attentional scope. This conclusion, however, is based on fragmented evidence based on several separate studies. The present study tests this conclusion within a single study using both behavioral (Experiment 1) and neurophysiological (Experiment 2) measures. Experiment 1 showed that individuals had the global precedence effect in the neutral affective state. However, the global precedence effect was reduced for affective states with high motivational intensity, whereas the global precedence effect was not significantly enhanced for those with low motivational intensity. Experiment 2 replicated these results with event-related potential (ERP) recording. ERP results showed that affective states with high motivational intensity induced smaller N2 and greater late positive potential (LPP) amplitudes than low motivational intensity and neutral affective states. However, no differences were found between the low motivational intensity and neutral affective states. Furthermore, smaller LPP predicted the tendency a global attentional focus in the frontal and central areas and larger LPP predicted a narrowed focus in the frontal area. The findings suggested that high motivational intensity of affective states can affect attentional scope.

  18. Involuntary transfer of a top-down attentional set into the focus of attention: evidence from a contingent attentional capture paradigm.

    Science.gov (United States)

    Moore, Katherine Sledge; Weissman, Daniel H

    2010-08-01

    In the present study, we investigated whether involuntarily directing attention to a target-colored distractor causes the corresponding attentional set to enter a limited-capacity focus of attention, thereby facilitating the identification of a subsequent target whose color matches the same attentional set. As predicted, in Experiment 1, contingent attentional capture effects from a target-colored distractor were only one half to one third as large when subsequent target identification relied on the same (vs. a different) attentional set. In Experiment 2, this effect was eliminated when all of the target colors matched the same attentional set, arguing against bottom-up perceptual priming of the distractor's color as an alternative account of our findings. In Experiment 3, this effect was reversed when a target-colored distractor appeared after the target, ruling out a feature-based interference account of our findings. We conclude that capacity limitations in working memory strongly influence contingent attentional capture when multiple attentional sets guide selection.

  19. Inhibitory processes and cognitive flexibility: evidence for the theory of attentional inertia

    Directory of Open Access Journals (Sweden)

    Isabel Introzzi

    2015-07-01

    Full Text Available The aim of this study was to discriminate the differential contribution of different inhibitory processes -perceptual, cognitive and behavioral inhibition- to switching cost effect associated with alternation cognitive tasks. A correlational design was used. Several experimental paradigms (e.g., Stop signal, visual search, Stemberg´s experimental and Simon paradigm were adapted and included in a computerized program called TAC (Introzzi & Canet Juric, 2014 to the assessment of the different cognitive processes. The final sample consisted of 45 adults (18-50 years. Perceptual and behavioral inhibition shows moderate and low correlations with attentional cost, cognitive inhibition shows no relation with flexibility and only perceptual inhibition predicts switching costs effects, suggesting that different inhibitory processes contribute differentially to switch cost. This could be interpreted as evidence to Attentional Inertia Theory main argument which postulates that inhibition plays an essential role in the ability to flexibly switch between tasks and/or representations.

  20. Bilingualism and increased attention to speech: Evidence from event-related potentials.

    Science.gov (United States)

    Kuipers, Jan Rouke; Thierry, Guillaume

    2015-10-01

    A number of studies have shown that from an early age, bilinguals outperform their monolingual peers on executive control tasks. We previously found that bilingual children and adults also display greater attention to unexpected language switches within speech. Here, we investigated the effect of a bilingual upbringing on speech perception in one language. We recorded monolingual and bilingual toddlers' event-related potentials (ERPs) to spoken words preceded by pictures. Words matching the picture prime elicited an early frontal positivity in bilingual participants only, whereas later ERP amplitudes associated with semantic processing did not differ between groups. These results add to the growing body of evidence that bilingualism increases overall attention during speech perception whilst semantic integration is unaffected. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

  1. Evidence for widespread convergent evolution around human microsatellites.

    Directory of Open Access Journals (Sweden)

    Edward J Vowles

    2004-08-01

    Full Text Available Microsatellites are a major component of the human genome, and their evolution has been much studied. However, the evolution of microsatellite flanking sequences has received less attention, with reports of both high and low mutation rates and of a tendency for microsatellites to cluster. From the human genome we generated a database of many thousands of (AC(n flanking sequences within which we searched for common characteristics. Sequences flanking microsatellites of similar length show remarkable levels of convergent evolution, indicating shared mutational biases. These biases extend 25-50 bases either side of the microsatellite and may therefore affect more than 30% of the entire genome. To explore the extent and absolute strength of these effects, we quantified the observed convergence. We also compared homologous human and chimpanzee loci to look for evidence of changes in mutation rate around microsatellites. Most models of DNA sequence evolution assume that mutations are independent and occur randomly. Allowances may be made for sites mutating at different rates and for general mutation biases such as the faster rate of transitions over transversions. Our analysis suggests that these models may be inadequate, in that proximity to even very short microsatellites may alter the rate and distribution of mutations that occur. The elevated local mutation rate combined with sequence convergence, both of which we find evidence for, also provide a possible resolution for the apparently contradictory inferences of mutation rates in microsatellite flanking sequences.

  2. Evidence of inbreeding depression on human height.

    Directory of Open Access Journals (Sweden)

    Ruth McQuillan

    Full Text Available Stature is a classical and highly heritable complex trait, with 80%-90% of variation explained by genetic factors. In recent years, genome-wide association studies (GWAS have successfully identified many common additive variants influencing human height; however, little attention has been given to the potential role of recessive genetic effects. Here, we investigated genome-wide recessive effects by an analysis of inbreeding depression on adult height in over 35,000 people from 21 different population samples. We found a highly significant inverse association between height and genome-wide homozygosity, equivalent to a height reduction of up to 3 cm in the offspring of first cousins compared with the offspring of unrelated individuals, an effect which remained after controlling for the effects of socio-economic status, an important confounder (χ(2 = 83.89, df = 1; p = 5.2 × 10(-20. There was, however, a high degree of heterogeneity among populations: whereas the direction of the effect was consistent across most population samples, the effect size differed significantly among populations. It is likely that this reflects true biological heterogeneity: whether or not an effect can be observed will depend on both the variance in homozygosity in the population and the chance inheritance of individual recessive genotypes. These results predict that multiple, rare, recessive variants influence human height. Although this exploratory work focuses on height alone, the methodology developed is generally applicable to heritable quantitative traits (QT, paving the way for an investigation into inbreeding effects, and therefore genetic architecture, on a range of QT of biomedical importance.

  3. Electrophysiological evidence for cognitive control during conflict processing in visual spatial attention.

    Science.gov (United States)

    Kehrer, Stefanie; Kraft, Antje; Irlbacher, Kerstin; Koch, Stefan P; Hagendorf, Herbert; Kathmann, Norbert; Brandt, Stephan A

    2009-11-01

    Event-related potentials were measured to investigate the role of visual spatial attention mechanisms in conflict processing. We suggested that a more difficult target selection leads to stronger attentional top-down control, thereby reducing the effects of arising conflicts. This hypothesis was tested by varying the selection difficulty in a location negative priming (NP) paradigm. The difficult task resulted in prolonged responses as compared to the easy task. A behavioral NP effect was only evident in the easy task. Psychophysiologically the easy task was associated with reduced parietal N1, enhanced frontocentral N2 and N2pc components and a prolonged P3 latency for the conflict as compared to the control condition. The N2pc effect was also obvious in the difficult task. Additionally frontocentral N2 amplitudes increased and latencies of N2pc and P3 were delayed compared to the easy task. The differences at frontocentral and parietal electrodes are consistent with previous studies ascribing activity in the prefrontal and parietal cortex as the source of top-down attentional control. Thus, we propose that stronger cognitive control is involved in the difficult task, resulting in a reduced behavioral NP conflict.

  4. Implicit learning modulates attention capture: evidence from an item-specific proportion congruency manipulation.

    Science.gov (United States)

    Thomson, David R; Willoughby, Karen; Milliken, Bruce

    2014-01-01

    A host of research has now shown that our explicit goals and intentions can, in large part, overcome the capture of visual attention by objects that differ from their surroundings in terms of size, shape, or color. Surprisingly however, there is little evidence for the role of implicit learning in mitigating capture effects despite the fact that such learning has been shown to strongly affect behavior in a host of other performance domains. Here, we employ a modified attention capture paradigm, based on the work of Theeuwes (1991, 1992), in which participants must search for an odd-shaped target amongst homogeneous distracters. On each trial, there is also a salient, but irrelevant odd-colored distracter. Across the experiments reported, we intermix two search contexts: for one set of distracters (e.g., squares) the shape singleton and color singleton coincide on a majority of trials (high proportion congruent condition), whereas for the other set of distracters (e.g., circles) the shape and color singletons are highly unlikely to coincide (low proportion congruent condition). Crucially, we find that observers learn to allow the capture of attention by the salient distracter to a greater extent in the high, compared to the low proportion congruent condition, albeit only when search is sufficiently difficult. Moreover, this effect of prior experience on search behavior occurs in the absence of awareness of our proportion manipulation. We argue that low-level properties of the search displays recruit representations of prior experience in a rapid, flexible, and implicit manner.

  5. Evidence for strategic cooperation in humans.

    Science.gov (United States)

    Burton-Chellew, Maxwell N; El Mouden, Claire; West, Stuart A

    2017-06-14

    Humans may cooperate strategically, cooperating at higher levels than expected from their short-term interests, to try and stimulate others to cooperate. To test this hypothesis, we experimentally manipulated the extent an individual's behaviour is known to others, and hence whether or not strategic cooperation is possible. In contrast with many previous studies, we avoided confounding factors by preventing individuals from learning during the game about either pay-offs or about how other individuals behave. We found clear evidence for strategic cooperators-just telling some individuals that their groupmates would be informed about their behaviour led to them tripling their initial level of cooperation, from 17 to 50%. We also found that many individuals play as if they do not understand the game, and their presence obscures the detection of strategic cooperation. Identifying such players allowed us to detect and study strategic motives for cooperation in novel, more powerful, ways. © 2017 The Author(s).

  6. Attraction of position preference by spatial attention throughout human visual cortex

    NARCIS (Netherlands)

    Klein, Barrie P.; Harvey, Ben M.; Dumoulin, Serge O.

    2014-01-01

    Voluntary spatial attention concentrates neural resources at the attended location. Here, we examined the effects of spatial attention on spatial position selectivity in humans. We measured population receptive fields (pRFs) using high-field functional MRI (fMRI) (7T) while subjects performed an

  7. The Social Origins of Sustained Attention in One-Year-Old Human Infants.

    Science.gov (United States)

    Yu, Chen; Smith, Linda B

    2016-05-09

    The ability to sustain attention is a major achievement in human development and is generally believed to be the developmental product of increasing self-regulatory and endogenous (i.e., internal, top-down, voluntary) control over one's attention and cognitive systems [1-5]. Because sustained attention in late infancy is predictive of future development, and because early deficits in sustained attention are markers for later diagnoses of attentional disorders [6], sustained attention is often viewed as a constitutional and individual property of the infant [6-9]. However, humans are social animals; developmental pathways for seemingly non-social competencies evolved within the social group and therefore may be dependent on social experience [10-13]. Here, we show that social context matters for the duration of sustained attention episodes in one-year-old infants during toy play. Using head-mounted eye tracking to record moment-by-moment gaze data from both parents and infants, we found that when the social partner (parent) visually attended to the object to which infant attention was directed, infants, after the parent's look, extended their duration of visual attention to the object. Looks to the same object by two social partners is a well-studied phenomenon known as joint attention, which has been shown to be critical to early learning and to the development of social skills [14, 15]. The present findings implicate joint attention in the development of the child's own sustained attention and thus challenge the current understanding of the origins of individual differences in sustained attention, providing a new and potentially malleable developmental pathway to the self-regulation of attention. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Focus-of-attention for human activity recognition from UAVs

    NARCIS (Netherlands)

    Burghouts, G.J.; Eekeren, A.W.M. van; Dijk, J.

    2014-01-01

    This paper presents a system to extract metadata about human activities from full-motion video recorded from a UAV. The pipeline consists of these components: tracking, motion features, representation of the tracks in terms of their motion features, and classification of each track as one of the

  9. Electrophysiological Evidence of Atypical Spatial Attention in Those with a High Level of Self-Reported Autistic Traits

    Science.gov (United States)

    Dunn, Stephanie A.; Freeth, Megan; Milne, Elizabeth

    2016-01-01

    Selective attention is atypical in individuals with autism spectrum conditions. Evidence suggests this is also the case for those with high levels of autistic traits. Here we investigated the neural basis of spatial attention in those with high and low levels of self-reported autistic traits via analysis of ERP deflections associated with covert…

  10. Attentional switching in humans and flies: rivalry in large and miniature brains

    Directory of Open Access Journals (Sweden)

    Steven Mark Miller

    2012-01-01

    Full Text Available Human perception, and consequently behaviour, is driven by attention dynamics. In the special case of rivalry, where attention alternates between competing percepts, such dynamics can be measured and their determinants investigated. A recent study in the fruit fly, Drosophila melanogaster, now shows that the origins of attentional rivalry may be quite ancient. Furthermore, individual variation exists in the rate of attentional rivalry in both humans and flies, and in humans this is under substantial genetic influence. In the pathophysiological realm, slowing of rivalry rate is associated with the heritable psychiatric condition, bipolar disorder. Fly rivalry may therefore prove a powerful model to examine genetic and molecular influences on rivalry rate, and may even shed light on human cognitive and behavioural dysfunction.

  11. Attentional load modulates responses of human primary visual cortex to invisible stimuli.

    Science.gov (United States)

    Bahrami, Bahador; Lavie, Nilli; Rees, Geraint

    2007-03-20

    Visual neuroscience has long sought to determine the extent to which stimulus-evoked activity in visual cortex depends on attention and awareness. Some influential theories of consciousness maintain that the allocation of attention is restricted to conscious representations [1, 2]. However, in the load theory of attention [3], competition between task-relevant and task-irrelevant stimuli for limited-capacity attention does not depend on conscious perception of the irrelevant stimuli. The critical test is whether the level of attentional load in a relevant task would determine unconscious neural processing of invisible stimuli. Human participants were scanned with high-field fMRI while they performed a foveal task of low or high attentional load. Irrelevant, invisible monocular stimuli were simultaneously presented peripherally and were continuously suppressed by a flashing mask in the other eye [4]. Attentional load in the foveal task strongly modulated retinotopic activity evoked in primary visual cortex (V1) by the invisible stimuli. Contrary to traditional views [1, 2, 5, 6], we found that availability of attentional capacity determines neural representations related to unconscious processing of continuously suppressed stimuli in human primary visual cortex. Spillover of attention to cortical representations of invisible stimuli (under low load) cannot be a sufficient condition for their awareness.

  12. Implicit Learning Modulates Attention Capture: Evidence from an Item-Specific Proportion Congruency Manipulation

    Directory of Open Access Journals (Sweden)

    David R Thomson

    2014-06-01

    Full Text Available A host of research has now shown that our explicit goals and intentions can, in large part, overcome the capture of visual attention by objects that differ from their surroundings in terms of size, shape, or color. Surprisingly however, there is little evidence for the role of implicit learning in mitigating capture effects despite the fact that such learning has been shown to strongly affect behavior in a host of other performance domains. Here, we employ a modified attention capture paradigm, based on the work of Theeuwes (1991; 1992, in which participants must search for an odd-shaped target amongst homogeneous distracters. On each trial, there is also a salient, but irrelevant odd-colored distracter. Across the experiments reported, we intermix two search contexts: for one set of distracters (e.g. squares the shape singleton and color singleton coincide on a majority of trials (high proportion congruent condition, whereas for the other set of distracters (e.g. circles the shape and color singletons are highly unlikely to coincide (low proportion congruent condition. Crucially, we find that observers learn to allow the capture of attention by the salient distracter to a greater extent in the high, compared to the low proportion congruent condition, albeit only when search is sufficiently difficult. Moreover, this effect of prior experience on search behavior occurs in the absence of awareness of our proportion manipulation. We argue that low-level properties of the search displays recruit representations of prior experience in a rapid, flexible, and implicit manner.

  13. Endogenous attention signals evoked by threshold contrast detection in human superior colliculus.

    Science.gov (United States)

    Katyal, Sucharit; Ress, David

    2014-01-15

    Human superior colliculus (SC) responds in a retinotopically selective manner when attention is deployed on a high-contrast visual stimulus using a discrimination task. To further elucidate the role of SC in endogenous visual attention, high-resolution fMRI was used to demonstrate that SC also exhibits a retinotopically selective response for covert attention in the absence of significant visual stimulation using a threshold-contrast detection task. SC neurons have a laminar organization according to their function, with visually responsive neurons present in the superficial layers and visuomotor neurons in the intermediate layers. The results show that the response evoked by the threshold-contrast detection task is significantly deeper than the response evoked by the high-contrast speed discrimination task, reflecting a functional dissociation of the attentional enhancement of visuomotor and visual neurons, respectively. Such a functional dissociation of attention within SC laminae provides a subcortical basis for the oculomotor theory of attention.

  14. Time to Guide: Evidence for Delayed Attentional Guidance in Contextual Cueing.

    Science.gov (United States)

    Kunar, Melina A; Flusberg, Stephen J; Wolfe, Jeremy M

    2008-01-01

    Contextual cueing experiments show that, when displays are repeated, reaction times (RTs) to find a target decrease over time even when the observers are not aware of the repetition. Recent evidence suggests that this benefit in standard contextual cueing tasks is not likely to be due to an improvement in attentional guidance (Kunar, Flusberg, Horowitz & Wolfe, 2007). Nevertheless, we ask whether guidance can help participants find the target in a repeated display, if they are given sufficient time to encode the display. In Experiment 1 we increased the display complexity so that it took participants longer to find the target. Here we found a larger effect of guidance than in a condition with shorter RTs. Experiment 2 gave participants prior exposure to the display context. The data again showed that with more time participants could implement guidance to help find the target, provided that there was something in the search stimuli locations to guide attention to. The data suggest that although the benefit in a standard contextual cueing task is unlikely to be a result of guidance, guidance can play a role if it is given time to develop.

  15. Implicit attentional bias for facial emotion in dissociative seizures: Additional evidence.

    Science.gov (United States)

    Pick, Susannah; Mellers, John D C; Goldstein, Laura H

    2018-03-01

    This study sought to extend knowledge about the previously reported preconscious attentional bias (AB) for facial emotion in patients with dissociative seizures (DS) by exploring whether the finding could be replicated, while controlling for concurrent anxiety, depression, and potentially relevant cognitive impairments. Patients diagnosed with DS (n=38) were compared with healthy controls (n=43) on a pictorial emotional Stroop test, in which backwardly masked emotional faces (angry, happy, neutral) were processed implicitly. The group with DS displayed a significantly greater AB to facial emotion relative to controls; however, the bias was not specific to negative or positive emotions. The group effect could not be explained by performance on standardized cognitive tests or self-reported depression/anxiety. The study provides additional evidence of a disproportionate and automatic allocation of attention to facial affect in patients with DS, including both positive and negative facial expressions. Such a tendency could act as a predisposing factor for developing DS initially, or may contribute to triggering individuals' seizures on an ongoing basis. Psychological interventions such as Cognitive Behavioral Therapy (CBT) or AB modification might be suitable approaches to target this bias in clinical practice. Copyright © 2018 Elsevier Inc. All rights reserved.

  16. Allium sativum L. Improves Visual Memory and Attention in Healthy Human Volunteers

    Science.gov (United States)

    Tasnim, Sara; Haque, Parsa Sanjana; Bari, Md. Sazzadul; Hossain, Md. Monir; Islam, Sardar Mohd. Ashraful; Shahriar, Mohammad; Bhuiyan, Mohiuddin Ahmed; Bin Sayeed, Muhammad Shahdaat

    2015-01-01

    Studies have shown that Allium sativum L. (AS) protects amyloid-beta peptide-induced apoptosis, prevents oxidative insults to neurons and synapses, and thus prevent Alzheimer's disease progression in experimental animals. However, there is no experimental evidence in human regarding its putative role in memory and cognition. We have studied the effect of AS consumption by healthy human volunteers on visual memory, verbal memory, attention, and executive function in comparison to control subjects taking placebo. The study was conducted over five weeks and twenty volunteers of both genders were recruited and divided randomly into two groups: A (AS) and B (placebo). Both groups participated in the 6 computerized neuropsychological tests of the Cambridge Neuropsychological Test Automated Battery (CANTAB) twice: at the beginning and after five weeks of the study. We found statistically significant difference (p 0.05) beneficial effects on verbal memory and executive function within a short period of time among the volunteers. Study for a longer period of time with patients suffering from neurodegenerative diseases might yield more relevant results regarding the potential therapeutic role of AS. PMID:26351508

  17. Visual attention, an indicator of human-animal relationships? A study of domestic horses (Equus caballus

    Directory of Open Access Journals (Sweden)

    Céline eRochais

    2014-02-01

    Full Text Available As visual attention is an intrinsic part of social relationships, and because relationships are built on a succession of interactions, their establishment involves learning and attention. The emotional, rewarding or punishing, content can modulate selective attention. In horses, the use of positive/negative reinforcement during training determines short and long-term human-horse relationships. In a recent study in horses, where either food or withers’ grooming were used as a reward, it appeared that only the food-rewarded horses learned the task and show better relationship with humans. In the present study, we hypothesized that this differential effect of grooming/food rewards on learning performances could be due to attentional processes. Monitoring, gazes and behaviors directed towards the trainer revealed that the use of a food reward (FR as positive reinforcement increased horses’ selective attention towards their trainer. Conversely, horses trained with grooming reward (GR expressed more inattentive responses and did not show a decrease of agitated behavior. However, individual plotting of attention versus rate of learning performances revealed a complex pattern. Thus, while all FR horses showed a window of attention related to faster learning performances, GR horses’ pattern followed an almost normal curve where the extreme animals (i.e. highest and lowest attention had the slowest learning performances. On the other hand, learning was influenced by attention: at the end of training, the more attentive horses had also better learning performances. This study, based on horses, contributes to the general debates on the place of attentional processes at the interface of emotion and cognition and open new lines of thought about individual sensitivities (only individuals can tell what an appropriate reward is, attentional processes and learning.

  18. Attraction of position preference by spatial attention throughout human visual cortex.

    Science.gov (United States)

    Klein, Barrie P; Harvey, Ben M; Dumoulin, Serge O

    2014-10-01

    Voluntary spatial attention concentrates neural resources at the attended location. Here, we examined the effects of spatial attention on spatial position selectivity in humans. We measured population receptive fields (pRFs) using high-field functional MRI (fMRI) (7T) while subjects performed an attention-demanding task at different locations. We show that spatial attention attracts pRF preferred positions across the entire visual field, not just at the attended location. This global change in pRF preferred positions systematically increases up the visual hierarchy. We model these pRF preferred position changes as an interaction between two components: an attention field and a pRF without the influence of attention. This computational model suggests that increasing effects of attention up the hierarchy result primarily from differences in pRF size and that the attention field is similar across the visual hierarchy. A similar attention field suggests that spatial attention transforms different neural response selectivities throughout the visual hierarchy in a similar manner. Copyright © 2014 Elsevier Inc. All rights reserved.

  19. Consciousness isn't all-or-none: Evidence for partial awareness during the attentional blink.

    Science.gov (United States)

    Elliott, James C; Baird, Benjamin; Giesbrecht, Barry

    2016-02-01

    Alternative views of the nature of consciousness posit that awareness of an object is either an all-or-none phenomenon or that awareness can be partial, occurring independently for different levels of representation. The all-or-none hypothesis predicts that when one feature of an object is identified, all other features should be consciously accessible. The partial awareness hypothesis predicts that one feature may reach consciousness while others do not. These competing predictions were tested in two experiments that presented two targets within a central stream of letters. We used the attentional blink evoked by the first target to assess consciousness for two different features of the second target. The results provide evidence that there can be a severe impairment in conscious access to one feature even when another feature is accurately reported. This behavioral evidence supports the partial awareness hypothesis, showing that consciousness of different features of the same object can be dissociated. Copyright © 2015 Elsevier Inc. All rights reserved.

  20. Attentional modulation of neural processing of shape, color, and velocity in humans

    International Nuclear Information System (INIS)

    Corbetta, M.; Miezin, F.M.; Dobmeyer, S.; Shulman, G.L.; Petersen, S.E.

    1990-01-01

    Positron emission tomography (PET) was used to measure changes in regional cerebral blood flow of normal subjects, while they were discriminating different attributes (shape, color, and velocity) of the same set of visual stimuli. Psychophysical evidence indicated that the sensitivity for discriminating subtle stimulus changes was higher when subjects focused attention on one attribute than when they divided attention among several attributes. Correspondingly, attention enhanced the activity of different regions of extrastriate visual cortex that appear to be specialized for processing information related to the selected attribute

  1. Neural Determinants of Task Performance during Feature-Based Attention in Human Cortex

    Science.gov (United States)

    Gong, Mengyuan

    2018-01-01

    Abstract Studies of feature-based attention have associated activity in a dorsal frontoparietal network with putative attentional priority signals. Yet, how this neural activity mediates attentional selection and whether it guides behavior are fundamental questions that require investigation. We reasoned that endogenous fluctuations in the quality of attentional priority should influence task performance. Human subjects detected a speed increment while viewing clockwise (CW) or counterclockwise (CCW) motion (baseline task) or while attending to either direction amid distracters (attention task). In an fMRI experiment, direction-specific neural pattern similarity between the baseline task and the attention task revealed a higher level of similarity for correct than incorrect trials in frontoparietal regions. Using transcranial magnetic stimulation (TMS), we disrupted posterior parietal cortex (PPC) and found a selective deficit in the attention task, but not in the baseline task, demonstrating the necessity of this cortical area during feature-based attention. These results reveal that frontoparietal areas maintain attentional priority that facilitates successful behavioral selection. PMID:29497703

  2. Different Signal Enhancement Pathways of Attention and Consciousness Underlie Perception in Humans.

    Science.gov (United States)

    van Boxtel, Jeroen J A

    2017-06-14

    It is not yet known whether attention and consciousness operate through similar or largely different mechanisms. Visual processing mechanisms are routinely characterized by measuring contrast response functions (CRFs). In this report, behavioral CRFs were obtained in humans (both males and females) by measuring afterimage durations over the entire range of inducer stimulus contrasts to reveal visual mechanisms behind attention and consciousness. Deviations relative to the standard CRF, i.e., gain functions, describe the strength of signal enhancement, which were assessed for both changes due to attentional task and conscious perception. It was found that attention displayed a response-gain function, whereas consciousness displayed a contrast-gain function. Through model comparisons, which only included contrast-gain modulations, both contrast-gain and response-gain effects can be explained with a two-level normalization model, in which consciousness affects only the first level and attention affects only the second level. These results demonstrate that attention and consciousness can effectively show different gain functions because they operate through different signal enhancement mechanisms. SIGNIFICANCE STATEMENT The relationship between attention and consciousness is still debated. Mapping contrast response functions (CRFs) has allowed (neuro)scientists to gain important insights into the mechanistic underpinnings of visual processing. Here, the influence of both attention and consciousness on these functions were measured and they displayed a strong dissociation. First, attention lowered CRFs, whereas consciousness raised them. Second, attention manifests itself as a response-gain function, whereas consciousness manifests itself as a contrast-gain function. Extensive model comparisons show that these results are best explained in a two-level normalization model in which consciousness affects only the first level, whereas attention affects only the second level

  3. The human auditory brainstem response to running speech reveals a subcortical mechanism for selective attention.

    Science.gov (United States)

    Forte, Antonio Elia; Etard, Octave; Reichenbach, Tobias

    2017-10-10

    Humans excel at selectively listening to a target speaker in background noise such as competing voices. While the encoding of speech in the auditory cortex is modulated by selective attention, it remains debated whether such modulation occurs already in subcortical auditory structures. Investigating the contribution of the human brainstem to attention has, in particular, been hindered by the tiny amplitude of the brainstem response. Its measurement normally requires a large number of repetitions of the same short sound stimuli, which may lead to a loss of attention and to neural adaptation. Here we develop a mathematical method to measure the auditory brainstem response to running speech, an acoustic stimulus that does not repeat and that has a high ecological validity. We employ this method to assess the brainstem's activity when a subject listens to one of two competing speakers, and show that the brainstem response is consistently modulated by attention.

  4. Electrophysiological evidence for altered visual, but not auditory, selective attention in adolescent cochlear implant users.

    Science.gov (United States)

    Harris, Jill; Kamke, Marc R

    2014-11-01

    Selective attention fundamentally alters sensory perception, but little is known about the functioning of attention in individuals who use a cochlear implant. This study aimed to investigate visual and auditory attention in adolescent cochlear implant users. Event related potentials were used to investigate the influence of attention on visual and auditory evoked potentials in six cochlear implant users and age-matched normally-hearing children. Participants were presented with streams of alternating visual and auditory stimuli in an oddball paradigm: each modality contained frequently presented 'standard' and infrequent 'deviant' stimuli. Across different blocks attention was directed to either the visual or auditory modality. For the visual stimuli attention boosted the early N1 potential, but this effect was larger for cochlear implant users. Attention was also associated with a later P3 component for the visual deviant stimulus, but there was no difference between groups in the later attention effects. For the auditory stimuli, attention was associated with a decrease in N1 latency as well as a robust P3 for the deviant tone. Importantly, there was no difference between groups in these auditory attention effects. The results suggest that basic mechanisms of auditory attention are largely normal in children who are proficient cochlear implant users, but that visual attention may be altered. Ultimately, a better understanding of how selective attention influences sensory perception in cochlear implant users will be important for optimising habilitation strategies. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  5. All Set! Evidence of Simultaneous Attentional Control Settings for Multiple Target Colors

    Science.gov (United States)

    Irons, Jessica L.; Folk, Charles L.; Remington, Roger W.

    2012-01-01

    Although models of visual search have often assumed that attention can only be set for a single feature or property at a time, recent studies have suggested that it may be possible to maintain more than one attentional control setting. The aim of the present study was to investigate whether spatial attention could be guided by multiple attentional…

  6. Overlapping Parietal Activity in Memory and Perception: Evidence for the Attention to Memory Model

    Science.gov (United States)

    Cabeza, Roberto; Mazuz, Yonatan S.; Stokes, Jared; Kragel, James E.; Woldorff, Marty G.; Ciaramelli, Elisa; Olson, Ingrid R.; Moscovitch, Morris

    2011-01-01

    The specific role of different parietal regions to episodic retrieval is a topic of intense debate. According to the Attention to Memory (AtoM) model, dorsal parietal cortex (DPC) mediates top-down attention processes guided by retrieval goals, whereas ventral parietal cortex (VPC) mediates bottom-up attention processes captured by the retrieval…

  7. Contingent Attentional Capture by Top-Down Control Settings: Converging Evidence from Event-Related Potentials

    Science.gov (United States)

    Lien, Mei-Ching; Ruthruff, Eric; Goodin, Zachary; Remington, Roger W.

    2008-01-01

    Theories of attentional control are divided over whether the capture of spatial attention depends primarily on stimulus salience or is contingent on attentional control settings induced by task demands. The authors addressed this issue using the N2-posterior-contralateral (N2pc) effect, a component of the event-related brain potential thought to…

  8. Motivationally Significant Stimuli Show Visual Prior Entry: Evidence for Attentional Capture

    Science.gov (United States)

    West, Greg L.; Anderson, Adam A. K.; Pratt, Jay

    2009-01-01

    Previous studies that have found attentional capture effects for stimuli of motivational significance do not directly measure initial attentional deployment, leaving it unclear to what extent these items produce attentional capture. Visual prior entry, as measured by temporal order judgments (TOJs), rests on the premise that allocated attention…

  9. Asymmetric development of dorsal and ventral attention networks in the human brain

    Directory of Open Access Journals (Sweden)

    Kristafor Farrant

    2015-04-01

    Full Text Available Two neural systems for goal-directed and stimulus-driven attention have been described in the adult human brain; the dorsal attention network (DAN centered in the frontal eye fields (FEF and intraparietal sulcus (IPS, and the ventral attention network (VAN anchored in the temporoparietal junction (TPJ and ventral frontal cortex (VFC. Little is known regarding the processes governing typical development of these attention networks in the brain. Here we use resting state functional MRI data collected from thirty 7 to 12 year-old children and thirty 18 to 31 year-old adults to examine two key regions of interest from the dorsal and ventral attention networks. We found that for the DAN nodes (IPS and FEF, children showed greater functional connectivity with regions within the network compared with adults, whereas adults showed greater functional connectivity between the FEF and extra-network regions including the posterior cingulate cortex. For the VAN nodes (TPJ and VFC, adults showed greater functional connectivity with regions within the network compared with children. Children showed greater functional connectivity between VFC and nodes of the salience network. This asymmetric pattern of development of attention networks may be a neural signature of the shift from over-representation of bottom-up attention mechanisms to greater top-down attentional capacities with development.

  10. Attention-deficit hyperactivity disorder, multimodal treatment, and longitudinal outcome: evidence, paradox, and challenge.

    Science.gov (United States)

    Hinshaw, Stephen P; Arnold, L Eugene

    2015-01-01

    Given major increases in the diagnosis of attention-deficit hyperactivity disorder (ADHD) and in rates of medication for this condition, we carefully examine evidence for effects of single versus multimodal (i.e., combined medication and psychosocial/behavioral) interventions for ADHD. Our primary data source is the Multimodal Treatment Study of Children with ADHD (MTA), a 14-month, randomized clinical trial in which intensive behavioral, medication, and multimodal treatment arms were contrasted with one another and with community intervention (treatment-as-usual), regarding outcome domains of ADHD symptoms, comorbidities, and core functional impairments. Although initial reports emphasized the superiority of well-monitored medication for symptomatic improvement, reanalyses and reappraisals have highlighted (1) the superiority of combination treatment for composite outcomes and for domains of functional impairment (e.g., academic achievement, social skills, parenting practices); (2) the importance of considering moderator and mediator processes underlying differential patterns of outcome, including comorbid subgroups and improvements in family discipline style during the intervention period; (3) the emergence of side effects (e.g., mild growth suppression) in youth treated with long-term medication; and (4) the diminution of medication's initial superiority once the randomly assigned treatment phase turned into naturalistic follow-up. The key paradox is that while ADHD clearly responds to medication and behavioral treatment in the short term, evidence for long-term effectiveness remains elusive. We close with discussion of future directions and a call for greater understanding of relevant developmental processes in the attempt to promote optimal, generalized, and lasting treatments for this important and impairing neurodevelopmental disorder. © 2014 John Wiley & Sons, Ltd.

  11. Adult attention deficit hyperactivity symptoms and psychosis: Epidemiological evidence from a population survey in England.

    Science.gov (United States)

    Marwaha, Steven; Thompson, Andrew; Bebbington, Paul; Singh, Swaran P; Freeman, Daniel; Winsper, Catherine; Broome, Matthew R

    2015-09-30

    Despite both having some shared features, evidence linking psychosis and adult attention deficit hyperactivity disorder (ADHD) is sparse and inconsistent. Hypotheses tested were (1) adult ADHD symptoms are associated with auditory hallucinations, paranoid ideation and psychosis (2) links between ADHD symptoms and psychosis are mediated by prescribed ADHD medications, use of illicit drugs, and dysphoric mood. The Adult Psychiatric Morbidity Survey 2007 (N=7403) provided data for regression and multiple mediation analyses. ADHD symptoms were coded from the ADHD Self-Report Scale (ASRS). Higher ASRS total score was significantly associated with psychosis, paranoid ideation and auditory hallucinations despite controlling for socio-demographic variables, verbal IQ, autism spectrum disorder traits, childhood conduct problems, hypomanic and dysphoric mood. An ASRS score indicating probable ADHD diagnosis was also significantly associated with psychosis. The link between higher ADHD symptoms and psychosis, paranoia and auditory hallucinations was significantly mediated by dysphoric mood, but not by use of amphetamine, cocaine or cannabis. In conclusion, higher levels of adult ADHD symptoms and psychosis are linked and dysphoric mood may form part of the mechanism. Our analyses contradict the traditional clinical view that the main explanation for people with ADHD symptoms developing psychosis is illicit drugs. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  12. Evidence Report: Risk of Inadequate Human-Computer Interaction

    Science.gov (United States)

    Holden, Kritina; Ezer, Neta; Vos, Gordon

    2013-01-01

    Human-computer interaction (HCI) encompasses all the methods by which humans and computer-based systems communicate, share information, and accomplish tasks. When HCI is poorly designed, crews have difficulty entering, navigating, accessing, and understanding information. HCI has rarely been studied in an operational spaceflight context, and detailed performance data that would support evaluation of HCI have not been collected; thus, we draw much of our evidence from post-spaceflight crew comments, and from other safety-critical domains like ground-based power plants, and aviation. Additionally, there is a concern that any potential or real issues to date may have been masked by the fact that crews have near constant access to ground controllers, who monitor for errors, correct mistakes, and provide additional information needed to complete tasks. We do not know what types of HCI issues might arise without this "safety net". Exploration missions will test this concern, as crews may be operating autonomously due to communication delays and blackouts. Crew survival will be heavily dependent on available electronic information for just-in-time training, procedure execution, and vehicle or system maintenance; hence, the criticality of the Risk of Inadequate HCI. Future work must focus on identifying the most important contributing risk factors, evaluating their contribution to the overall risk, and developing appropriate mitigations. The Risk of Inadequate HCI includes eight core contributing factors based on the Human Factors Analysis and Classification System (HFACS): (1) Requirements, policies, and design processes, (2) Information resources and support, (3) Allocation of attention, (4) Cognitive overload, (5) Environmentally induced perceptual changes, (6) Misperception and misinterpretation of displayed information, (7) Spatial disorientation, and (8) Displays and controls.

  13. Dogs' (Canis familiaris) attention to human perception: Influence of breed groups and life experiences.

    Science.gov (United States)

    Heberlein, Marianne T E; Turner, Dennis C; Manser, Marta B

    2017-02-01

    Attending to the perception of others may help individuals gaining information from conspecifics, or help in competitive situations. Dogs (Canis familiaris) are attentive to humans' signals and their attentional state. We investigated whether dogs of different breed groups differ in their ability to pay attention to human's perception, first according to the genetic relatedness between dog breeds, and second according to working style differences. Once dogs had learned to leave forbidden food on the floor, they were confronted with 2 food items to which only they had unrestricted visual access. The owners saw either none or 1 food item through a transparent barrier. Our results showed that dogs pay attention to the perception of humans, whereby differences between breed groups became obvious. Within different genetic groups, ancient and hunting type dogs performed similarly, they were more attentive to their owners' perception than shepherd and the mastiff type dogs. When comparing dogs classified according to their working style, independent workers and family dogs were attentive to the owner's perception, while cooperative workers seemed not. The dogs' choice could not be explained by a general or training induced preference for eating behind an opaque screen, or by an influence of the owner's possible intention to prevent the dog from taking the food item he could see. Our study confirms that dogs are attentive/sensitive to human's perception, but genetic and working style differences among the breeds, as well as dog sport experiences explain part of the variation seen in their performance. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  14. Sensorineural hearing loss degrades behavioral and physiological measures of human spatial selective auditory attention

    Science.gov (United States)

    Dai, Lengshi; Best, Virginia; Shinn-Cunningham, Barbara G.

    2018-01-01

    Listeners with sensorineural hearing loss often have trouble understanding speech amid other voices. While poor spatial hearing is often implicated, direct evidence is weak; moreover, studies suggest that reduced audibility and degraded spectrotemporal coding may explain such problems. We hypothesized that poor spatial acuity leads to difficulty deploying selective attention, which normally filters out distracting sounds. In listeners with normal hearing, selective attention causes changes in the neural responses evoked by competing sounds, which can be used to quantify the effectiveness of attentional control. Here, we used behavior and electroencephalography to explore whether control of selective auditory attention is degraded in hearing-impaired (HI) listeners. Normal-hearing (NH) and HI listeners identified a simple melody presented simultaneously with two competing melodies, each simulated from different lateral angles. We quantified performance and attentional modulation of cortical responses evoked by these competing streams. Compared with NH listeners, HI listeners had poorer sensitivity to spatial cues, performed more poorly on the selective attention task, and showed less robust attentional modulation of cortical responses. Moreover, across NH and HI individuals, these measures were correlated. While both groups showed cortical suppression of distracting streams, this modulation was weaker in HI listeners, especially when attending to a target at midline, surrounded by competing streams. These findings suggest that hearing loss interferes with the ability to filter out sound sources based on location, contributing to communication difficulties in social situations. These findings also have implications for technologies aiming to use neural signals to guide hearing aid processing. PMID:29555752

  15. Does the Superior Colliculus Control Perceptual Sensitivity or Choice Bias during Attention? Evidence from a Multialternative Decision Framework

    Science.gov (United States)

    Steinmetz, Nicholas A.; Moore, Tirin; Knudsen, Eric I.

    2017-01-01

    Distinct networks in the forebrain and the midbrain coordinate to control spatial attention. The critical involvement of the superior colliculus (SC)—the central structure in the midbrain network—in visuospatial attention has been shown by four seminal, published studies in monkeys (Macaca mulatta) performing multialternative tasks. However, due to the lack of a mechanistic framework for interpreting behavioral data in such tasks, the nature of the SC's contribution to attention remains unclear. Here we present and validate a novel decision framework for analyzing behavioral data in multialternative attention tasks. We apply this framework to re-examine the behavioral evidence from these published studies. Our model is a multidimensional extension to signal detection theory that distinguishes between two major classes of attentional mechanisms: those that alter the quality of sensory information or “sensitivity,” and those that alter the selective gating of sensory information or “choice bias.” Model-based simulations and model-based analyses of data from these published studies revealed a converging pattern of results that indicated that choice-bias changes, rather than sensitivity changes, were the primary outcome of SC manipulation. Our results suggest that the SC contributes to attentional performance predominantly by generating a spatial choice bias for stimuli at a selected location, and that this bias operates downstream of forebrain mechanisms that enhance sensitivity. The findings lead to a testable mechanistic framework of how the midbrain and forebrain networks interact to control spatial attention. SIGNIFICANCE STATEMENT Attention involves the selection of the most relevant information for differential sensory processing and decision making. While the mechanisms by which attention alters sensory encoding (sensitivity control) are well studied, the mechanisms by which attention alters decisional weighting of sensory evidence (choice

  16. Frequency-Selective Attention in Auditory Scenes Recruits Frequency Representations Throughout Human Superior Temporal Cortex.

    Science.gov (United States)

    Riecke, Lars; Peters, Judith C; Valente, Giancarlo; Kemper, Valentin G; Formisano, Elia; Sorger, Bettina

    2017-05-01

    A sound of interest may be tracked amid other salient sounds by focusing attention on its characteristic features including its frequency. Functional magnetic resonance imaging findings have indicated that frequency representations in human primary auditory cortex (AC) contribute to this feat. However, attentional modulations were examined at relatively low spatial and spectral resolutions, and frequency-selective contributions outside the primary AC could not be established. To address these issues, we compared blood oxygenation level-dependent (BOLD) responses in the superior temporal cortex of human listeners while they identified single frequencies versus listened selectively for various frequencies within a multifrequency scene. Using best-frequency mapping, we observed that the detailed spatial layout of attention-induced BOLD response enhancements in primary AC follows the tonotopy of stimulus-driven frequency representations-analogous to the "spotlight" of attention enhancing visuospatial representations in retinotopic visual cortex. Moreover, using an algorithm trained to discriminate stimulus-driven frequency representations, we could successfully decode the focus of frequency-selective attention from listeners' BOLD response patterns in nonprimary AC. Our results indicate that the human brain facilitates selective listening to a frequency of interest in a scene by reinforcing the fine-grained activity pattern throughout the entire superior temporal cortex that would be evoked if that frequency was present alone. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  17. Working memory load can both improve and impair selective attention: evidence from the Navon paradigm.

    Science.gov (United States)

    Ahmed, Lubna; de Fockert, Jan W

    2012-10-01

    Selective attention to relevant targets has been shown to depend on the availability of working memory (WM). Under conditions of high WM load, processing of irrelevant distractors is enhanced. Here we showed that this detrimental effect of WM load on selective attention efficiency is reversed when the task requires global- rather than local-level processing. Participants were asked to attend to either the local or the global level of a hierarchical Navon stimulus while keeping either a low or a high load in WM. In line with previous findings, during attention to the local level, distractors at the global level produced more interference under high than under low WM load. By contrast, loading WM had the opposite effect of improving selective attention during attention to the global level. The findings demonstrate that the impact of WM load on selective attention is not invariant, but rather is dependent on the level of the to-be-attended information.

  18. Selective attention meets spontaneous recognition memory: Evidence for effects at retrieval.

    Science.gov (United States)

    Moen, Katherine C; Miller, Jeremy K; Lloyd, Marianne E

    2017-03-01

    Previous research on the effects of Divided Attention on recognition memory have shown consistent impairments during encoding but more variable effects at retrieval. The present study explored whether effects of Selective Attention at retrieval and subsequent testing were parallel to those of Divided Attention. Participants studied a list of pictures and then had a recognition memory test that included both full attention and selective attention (the to be responded to object was overlaid atop a blue outlined object) trials. All participants then completed a second recognition memory test. The results of 2 experiments suggest that subsequent tests consistently show impacts of the status of the ignored stimulus, and that having an initial test changes performance on a later test. The results are discussed in relation to effect of attention on memory more generally as well as spontaneous recognition memory research. Copyright © 2017 Elsevier Inc. All rights reserved.

  19. More attentional focusing through binaural beats: evidence from the global-local task.

    Science.gov (United States)

    Colzato, Lorenza S; Barone, Hayley; Sellaro, Roberta; Hommel, Bernhard

    2017-01-01

    A recent study showed that binaural beats have an impact on the efficiency of allocating attention over time. We were interested to see whether this impact affects attentional focusing or, even further, the top-down control over irrelevant information. Healthy adults listened to gamma-frequency (40 Hz) binaural beats, which are assumed to increase attentional concentration, or a constant tone of 340 Hz (control condition) for 3 min before and during a global-local task. While the size of the congruency effect (indicating the failure to suppress task-irrelevant information) was unaffected by the binaural beats, the global-precedence effect (reflecting attentional focusing) was considerably smaller after gamma-frequency binaural beats than after the control condition. Our findings suggest that high-frequency binaural beats bias the individual attentional processing style towards a reduced spotlight of attention.

  20. Modulation of human extrastriate visual processing by selective attention to colours and words.

    Science.gov (United States)

    Nobre, A C; Allison, T; McCarthy, G

    1998-07-01

    The present study investigated the effect of visual selective attention upon neural processing within functionally specialized regions of the human extrastriate visual cortex. Field potentials were recorded directly from the inferior surface of the temporal lobes in subjects with epilepsy. The experimental task required subjects to focus attention on words from one of two competing texts. Words were presented individually and foveally. Texts were interleaved randomly and were distinguishable on the basis of word colour. Focal field potentials were evoked by words in the posterior part of the fusiform gyrus. Selective attention strongly modulated long-latency potentials evoked by words. The attention effect co-localized with word-related potentials in the posterior fusiform gyrus, and was independent of stimulus colour. The results demonstrated that stimuli receive differential processing within specialized regions of the extrastriate cortex as a function of attention. The late onset of the attention effect and its co-localization with letter string-related potentials but not with colour-related potentials recorded from nearby regions of the fusiform gyrus suggest that the attention effect is due to top-down influences from downstream regions involved in word processing.

  1. Skeleton-Based Human Action Recognition With Global Context-Aware Attention LSTM Networks

    Science.gov (United States)

    Liu, Jun; Wang, Gang; Duan, Ling-Yu; Abdiyeva, Kamila; Kot, Alex C.

    2018-04-01

    Human action recognition in 3D skeleton sequences has attracted a lot of research attention. Recently, Long Short-Term Memory (LSTM) networks have shown promising performance in this task due to their strengths in modeling the dependencies and dynamics in sequential data. As not all skeletal joints are informative for action recognition, and the irrelevant joints often bring noise which can degrade the performance, we need to pay more attention to the informative ones. However, the original LSTM network does not have explicit attention ability. In this paper, we propose a new class of LSTM network, Global Context-Aware Attention LSTM (GCA-LSTM), for skeleton based action recognition. This network is capable of selectively focusing on the informative joints in each frame of each skeleton sequence by using a global context memory cell. To further improve the attention capability of our network, we also introduce a recurrent attention mechanism, with which the attention performance of the network can be enhanced progressively. Moreover, we propose a stepwise training scheme in order to train our network effectively. Our approach achieves state-of-the-art performance on five challenging benchmark datasets for skeleton based action recognition.

  2. Shifting the Spotlight of Attention: Evidence for Discrete Computations in Cognition

    OpenAIRE

    Buschman, Timothy J.; Miller, Earl K.

    2010-01-01

    Our thoughts have a limited bandwidth; we can only fully process a few items in mind simultaneously. To compensate, the brain developed attention, the ability to select information relevant to the current task, while filtering out the rest. Therefore, by understanding the neural mechanisms of attention we hope to understand a core component of cognition. Here, we review our recent investigations of the neural mechanisms underlying the control of visual attention in frontal and parietal cor...

  3. Neural evidence for a distinction between short-term memory and the focus of attention

    OpenAIRE

    Lewis-Peacock, Jarrod A; Drysdale, Andrew T; Oberauer, Klaus; Postle, Bradley R

    2012-01-01

    It is widely assumed that the short-term retention of information is accomplished via maintenance of an active neural trace. However, we demonstrate that memory can be preserved across a brief delay despite the apparent loss of sustained representations. Delay-period activity may in fact reflect the focus of attention, rather than short-term memory. We unconfounded attention and memory by causing external and internal shifts of attention away from items that were being actively retained. Mult...

  4. More attentional focusing through binaural beats: Evidence from the global-local task

    OpenAIRE

    Colzato, L.S.; Barone, H.; Sellaro, R.; Hommel, B.

    2017-01-01

    A recent study showed that binaural beats have an impact on the efficiency of allocating attention over time. We were interested to see whether this impact affects attentional focusing or, even further, the top-down control over irrelevant information. Healthy adults listened to gamma-frequency (40?Hz) binaural beats, which are assumed to increase attentional concentration, or a constant tone of 340?Hz (control condition) for 3?min before and during a global?local task. While the size of the ...

  5. Hemispheric differences in the voluntary control of spatial attention: direct evidence for a right-hemispheric dominance within frontal cortex.

    Science.gov (United States)

    Duecker, Felix; Formisano, Elia; Sack, Alexander T

    2013-08-01

    Lesion studies in neglect patients have inspired two competing models of spatial attention control, namely, Heilman's "hemispatial" theory and Kinsbourne's "opponent processor" model. Both assume a functional asymmetry between the two hemispheres but propose very different mechanisms. Neuroimaging studies have identified a bilateral dorsal frontoparietal network underlying voluntary shifts of spatial attention. However, lateralization of attentional processes within this network has not been consistently reported. In the current study, we aimed to provide direct evidence concerning the functional asymmetry of the right and left FEF during voluntary shifts of spatial attention. To this end, we applied fMRI-guided neuronavigation to disrupt individual FEF activation foci with a longer-lasting inhibitory patterned TMS protocol followed by a spatial cueing task. Our results indicate that right FEF stimulation impaired the ability of shifting spatial attention toward both hemifields, whereas the effects of left FEF stimulation were limited to the contralateral hemifield. These results provide strong direct evidence for right-hemispheric dominance in spatial attention within frontal cortex supporting Heilman's "hemispatial" theory. This complements previous TMS studies that generally conform to Kinsbourne's "opponent processor" model after disruption of parietal cortex, and we therefore propose that both theories are not mutually exclusive.

  6. Statistical Evidence Suggests that Inattention Drives Hyperactivity/Impulsivity in Attention Deficit-Hyperactivity Disorder

    Science.gov (United States)

    Sokolova, Elena; Groot, Perry; Claassen, Tom; van Hulzen, Kimm J.; Glennon, Jeffrey C.; Franke, Barbara

    2016-01-01

    Background Numerous factor analytic studies consistently support a distinction between two symptom domains of attention-deficit/hyperactivity disorder (ADHD), inattention and hyperactivity/impulsivity. Both dimensions show high internal consistency and moderate to strong correlations with each other. However, it is not clear what drives this strong correlation. The aim of this paper is to address this issue. Method We applied a sophisticated approach for causal discovery on three independent data sets of scores of the two ADHD dimensions in NeuroIMAGE (total N = 675), ADHD-200 (N = 245), and IMpACT (N = 164), assessed by different raters and instruments, and further used information on gender or a genetic risk haplotype. Results In all data sets we found strong statistical evidence for the same pattern: the clear dependence between hyperactivity/impulsivity symptom level and an established genetic factor (either gender or risk haplotype) vanishes when one conditions upon inattention symptom level. Under reasonable assumptions, e.g., that phenotypes do not cause genotypes, a causal model that is consistent with this pattern contains a causal path from inattention to hyperactivity/impulsivity. Conclusions The robust dependency cancellation observed in three different data sets suggests that inattention is a driving factor for hyperactivity/impulsivity. This causal hypothesis can be further validated in intervention studies. Our model suggests that interventions that affect inattention will also have an effect on the level of hyperactivity/impulsivity. On the other hand, interventions that affect hyperactivity/impulsivity would not change the level of inattention. This causal model may explain earlier findings on heritable factors causing ADHD reported in the study of twins with learning difficulties. PMID:27768717

  7. Effect of attentional load on audiovisual speech perception: Evidence from ERPs

    Directory of Open Access Journals (Sweden)

    Agnès eAlsius

    2014-07-01

    Full Text Available Seeing articulatory movements influences perception of auditory speech. This is often reflected in a shortened latency of auditory event-related potentials (ERPs generated in the auditory cortex. The present study addressed whether this early neural correlate of audiovisual interaction is modulated by attention. We recorded ERPs in 15 subjects while they were presented with auditory, visual and audiovisual spoken syllables. Audiovisual stimuli consisted of incongruent auditory and visual components known to elicit a McGurk effect, i.e. a visually driven alteration in the auditory speech percept. In a Dual task condition, participants were asked to identify spoken syllables whilst monitoring a rapid visual stream of pictures for targets, i.e., they had to divide their attention. In a Single task condition, participants identified the syllables without any other tasks, i.e., they were asked to ignore the pictures and focus their attention fully on the spoken syllables. The McGurk effect was weaker in the Dual task than in the Single task condition, indicating an effect of attentional load on audiovisual speech perception. Early auditory ERP components, N1 and P2, peaked earlier to audiovisual stimuli than to auditory stimuli when attention was fully focused on syllables, indicating neurophysiological audiovisual interaction. This latency decrement was reduced when attention was loaded, suggesting that attention influences early neural processing of audiovisual speech. We conclude that reduced attention weakens the interaction between vision and audition in speech.

  8. Evidence for Intact Memory-Guided Attention in School-Aged Children

    Science.gov (United States)

    Dixon, Matthew L.; Zelazo, Philip David; De Rosa, Eve

    2010-01-01

    Visual scenes contain many statistical regularities such as the likely identity and location of objects that are present; with experience, such regularities can be encoded and can ultimately facilitate the deployment of spatial attention to important locations. Memory-guided attention has been extensively examined in adults with the "contextual…

  9. Effect of attentional load on audiovisual speech perception: evidence from ERPs.

    Science.gov (United States)

    Alsius, Agnès; Möttönen, Riikka; Sams, Mikko E; Soto-Faraco, Salvador; Tiippana, Kaisa

    2014-01-01

    Seeing articulatory movements influences perception of auditory speech. This is often reflected in a shortened latency of auditory event-related potentials (ERPs) generated in the auditory cortex. The present study addressed whether this early neural correlate of audiovisual interaction is modulated by attention. We recorded ERPs in 15 subjects while they were presented with auditory, visual, and audiovisual spoken syllables. Audiovisual stimuli consisted of incongruent auditory and visual components known to elicit a McGurk effect, i.e., a visually driven alteration in the auditory speech percept. In a Dual task condition, participants were asked to identify spoken syllables whilst monitoring a rapid visual stream of pictures for targets, i.e., they had to divide their attention. In a Single task condition, participants identified the syllables without any other tasks, i.e., they were asked to ignore the pictures and focus their attention fully on the spoken syllables. The McGurk effect was weaker in the Dual task than in the Single task condition, indicating an effect of attentional load on audiovisual speech perception. Early auditory ERP components, N1 and P2, peaked earlier to audiovisual stimuli than to auditory stimuli when attention was fully focused on syllables, indicating neurophysiological audiovisual interaction. This latency decrement was reduced when attention was loaded, suggesting that attention influences early neural processing of audiovisual speech. We conclude that reduced attention weakens the interaction between vision and audition in speech.

  10. Creating Joint Attentional Frames and Pointing to Evidence in the Reading and Writing Process

    Science.gov (United States)

    Unger, John A.; Liu, Rong; Scullion, Vicki A.

    2015-01-01

    This theory-into-practice paper integrates Tomasello's concept of Joint Attentional Frames and well-known ideas related to the work of Russian psychologist, Lev Vygotsky, with more recent ideas from social semiotics. Classroom procedures for incorporating student-created Joint Attentional Frames into literacy lessons are explained by links to…

  11. Direct evidence for a role of working memory in the attentional blink

    NARCIS (Netherlands)

    Akyürek, Elkan G; Hommel, Bernhard; Jolicœur, Pierre

    Theories of selective attention often have a central memory component, which is commonly thought to be limited in some way and is thereby a potential bottleneck in the attentional process. There have been only a few attempts to validate this assertion, and they have produced mixed results. This

  12. Learned Predictiveness Influences Rapid Attentional Capture: Evidence from the Dot Probe Task

    Science.gov (United States)

    Le Pelley, Mike E.; Vadillo, Miguel; Luque, David

    2013-01-01

    Attentional theories of associative learning and categorization propose that learning about the predictiveness of a stimulus influences the amount of attention that is paid to that stimulus. Three experiments tested this idea by looking at the extent to which stimuli that had previously been experienced as predictive or nonpredictive in a…

  13. 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. Copyright © 2013 Elsevier Inc. All rights reserved.

  14. Governance and Human Development: Empirical Evidence from ...

    African Journals Online (AJOL)

    This study empirically investigates the effects of governance on human development in Nigeria. Using annual time series data covering the period 1998 to 2010, obtained from various sources, and employing the classical least squares estimation technique, the study finds that corruption, foreign aid and government ...

  15. Threat but not arousal narrows attention: Evidence from pupil dilation and saccade control

    Directory of Open Access Journals (Sweden)

    Henk eVan Steenbergen

    2011-10-01

    Full Text Available It has been shown that negative affect causes attentional narrowing. According to Easterbrook’s (1959 influential hypothesis this effect is driven by the withdrawal motivation inherent to negative emotions and might be related to increases in arousal. We investigated whether valence-unspecific increases in physiological arousal, as measured by pupil dilation, could account for attentional narrowing effects in a cognitive control task. Following the presentation of a negative, positive, or neutral picture, participants performed a saccade task with a prosaccade versus an antisaccade instruction. The reaction time difference between pro- and antisaccades was used to index attentional selectivity, and while pupil diameter was used as an index of physiological arousal. Pupil dilation was observed for both negative and positive pictures, which indicates increased physiological arousal. However, increased attentional selectivity was only observed following negative pictures. Our data show that motivational intensity effects on attentional narrowing can occur independently of physiological arousal effects.

  16. Eye movement evidence for defocused attention in dysphoria--a perceptual span analysis.

    Science.gov (United States)

    Brzezicka, Aneta; Krejtz, Izabela; von Hecker, Ulrich; Laubrock, Jochen

    2012-07-01

    The defocused attention hypothesis (von Hecker and Meiser, 2005) assumes that negative mood broadens attention, whereas the analytical rumination hypothesis (Andrews and Thompson, 2009) suggests a narrowing of the attentional focus with depression. We tested these conflicting hypotheses by directly measuring the perceptual span in groups of dysphoric and control subjects, using eye tracking. In the moving window paradigm, information outside of a variable-width gaze-contingent window was masked during reading of sentences. In measures of sentence reading time and mean fixation duration, dysphoric subjects were more pronouncedly affected than controls by a reduced window size. This difference supports the defocused attention hypothesis and seems hard to reconcile with a narrowing of attentional focus. Copyright © 2011 Elsevier B.V. All rights reserved.

  17. Underpricing, underperformance and overreaction in initial public offerings: Evidence from investor attention using online searches.

    Science.gov (United States)

    Vakrman, Tomas; Kristoufek, Ladislav

    2015-01-01

    Online activity of Internet users has proven very useful in modeling various phenomena across a wide range of scientific disciplines. In our study, we focus on two stylized facts or puzzles surrounding the initial public offerings (IPOs) - the underpricing and the long-term underperformance. Using the Internet searches on Google, we proxy the investor attention before and during the day of the offering to show that the high attention IPOs have different characteristics than the low attention ones. After controlling for various effects, we show that investor attention still remains a strong component of the high initial returns (the underpricing), primarily for the high sentiment periods. Moreover, we demonstrate that the investor attention partially explains the overoptimistic market reaction and thus also a part of the long-term underperformance.

  18. Tuning In to Sound: Frequency-Selective Attentional Filter in Human Primary Auditory Cortex

    Science.gov (United States)

    Da Costa, Sandra; van der Zwaag, Wietske; Miller, Lee M.; Clarke, Stephanie

    2013-01-01

    Cocktail parties, busy streets, and other noisy environments pose a difficult challenge to the auditory system: how to focus attention on selected sounds while ignoring others? Neurons of primary auditory cortex, many of which are sharply tuned to sound frequency, could help solve this problem by filtering selected sound information based on frequency-content. To investigate whether this occurs, we used high-resolution fMRI at 7 tesla to map the fine-scale frequency-tuning (1.5 mm isotropic resolution) of primary auditory areas A1 and R in six human participants. Then, in a selective attention experiment, participants heard low (250 Hz)- and high (4000 Hz)-frequency streams of tones presented at the same time (dual-stream) and were instructed to focus attention onto one stream versus the other, switching back and forth every 30 s. Attention to low-frequency tones enhanced neural responses within low-frequency-tuned voxels relative to high, and when attention switched the pattern quickly reversed. Thus, like a radio, human primary auditory cortex is able to tune into attended frequency channels and can switch channels on demand. PMID:23365225

  19. The Effects of Context and Attention on Spiking Activity in Human Early Visual Cortex.

    Science.gov (United States)

    Self, Matthew W; Peters, Judith C; Possel, Jessy K; Reithler, Joel; Goebel, Rainer; Ris, Peterjan; Jeurissen, Danique; Reddy, Leila; Claus, Steven; Baayen, Johannes C; Roelfsema, Pieter R

    2016-03-01

    Here we report the first quantitative analysis of spiking activity in human early visual cortex. We recorded multi-unit activity from two electrodes in area V2/V3 of a human patient implanted with depth electrodes as part of her treatment for epilepsy. We observed well-localized multi-unit receptive fields with tunings for contrast, orientation, spatial frequency, and size, similar to those reported in the macaque. We also observed pronounced gamma oscillations in the local-field potential that could be used to estimate the underlying spiking response properties. Spiking responses were modulated by visual context and attention. We observed orientation-tuned surround suppression: responses were suppressed by image regions with a uniform orientation and enhanced by orientation contrast. Additionally, responses were enhanced on regions that perceptually segregated from the background, indicating that neurons in the human visual cortex are sensitive to figure-ground structure. Spiking responses were also modulated by object-based attention. When the patient mentally traced a curve through the neurons' receptive fields, the accompanying shift of attention enhanced neuronal activity. These results demonstrate that the tuning properties of cells in the human early visual cortex are similar to those in the macaque and that responses can be modulated by both contextual factors and behavioral relevance. Our results, therefore, imply that the macaque visual system is an excellent model for the human visual cortex.

  20. The Effects of Context and Attention on Spiking Activity in Human Early Visual Cortex.

    Directory of Open Access Journals (Sweden)

    Matthew W Self

    2016-03-01

    Full Text Available Here we report the first quantitative analysis of spiking activity in human early visual cortex. We recorded multi-unit activity from two electrodes in area V2/V3 of a human patient implanted with depth electrodes as part of her treatment for epilepsy. We observed well-localized multi-unit receptive fields with tunings for contrast, orientation, spatial frequency, and size, similar to those reported in the macaque. We also observed pronounced gamma oscillations in the local-field potential that could be used to estimate the underlying spiking response properties. Spiking responses were modulated by visual context and attention. We observed orientation-tuned surround suppression: responses were suppressed by image regions with a uniform orientation and enhanced by orientation contrast. Additionally, responses were enhanced on regions that perceptually segregated from the background, indicating that neurons in the human visual cortex are sensitive to figure-ground structure. Spiking responses were also modulated by object-based attention. When the patient mentally traced a curve through the neurons' receptive fields, the accompanying shift of attention enhanced neuronal activity. These results demonstrate that the tuning properties of cells in the human early visual cortex are similar to those in the macaque and that responses can be modulated by both contextual factors and behavioral relevance. Our results, therefore, imply that the macaque visual system is an excellent model for the human visual cortex.

  1. Evidence for Cardiomyocyte Renewal in Humans

    Energy Technology Data Exchange (ETDEWEB)

    Bergmann, O; Bhardwaj, R D; Bernard, S; Zdunek, S; Barnabe-Heider, F; Walsh, S; Zupicich, J; Alkass, K; Buchholz, B A; Druid, H; Jovinge, S; Frisen, J

    2008-10-14

    It has been difficult to establish whether we are limited to the heart muscle cells we are born with or if cardiomyocytes are generated also later in life. We have taken advantage of the integration of {sup 14}C, generated by nuclear bomb tests during the Cold War, into DNA to establish the age of cardiomyocytes in humans. We report that cardiomyocytes renew, with a gradual decrease from 1% turning over annually at the age of 20 to 0.3% at the age of 75. Less than 50% of cardiomyocytes are exchanged during a normal lifespan. The capacity to generate cardiomyocytes in the adult human heart suggests that it may be rational to work towards the development of therapeutic strategies aiming to stimulate this process in cardiac pathologies.

  2. Cholinergic enhancement of visual attention and neural oscillations in the human brain.

    Science.gov (United States)

    Bauer, Markus; Kluge, Christian; Bach, Dominik; Bradbury, David; Heinze, Hans Jochen; Dolan, Raymond J; Driver, Jon

    2012-03-06

    Cognitive processes such as visual perception and selective attention induce specific patterns of brain oscillations. The neurochemical bases of these spectral changes in neural activity are largely unknown, but neuromodulators are thought to regulate processing. The cholinergic system is linked to attentional function in vivo, whereas separate in vitro studies show that cholinergic agonists induce high-frequency oscillations in slice preparations. This has led to theoretical proposals that cholinergic enhancement of visual attention might operate via gamma oscillations in visual cortex, although low-frequency alpha/beta modulation may also play a key role. Here we used MEG to record cortical oscillations in the context of administration of a cholinergic agonist (physostigmine) during a spatial visual attention task in humans. This cholinergic agonist enhanced spatial attention effects on low-frequency alpha/beta oscillations in visual cortex, an effect correlating with a drug-induced speeding of performance. By contrast, the cholinergic agonist did not alter high-frequency gamma oscillations in visual cortex. Thus, our findings show that cholinergic neuromodulation enhances attentional selection via an impact on oscillatory synchrony in visual cortex, for low rather than high frequencies. We discuss this dissociation between high- and low-frequency oscillations in relation to proposals that lower-frequency oscillations are generated by feedback pathways within visual cortex. Copyright © 2012 Elsevier Ltd. All rights reserved.

  3. Selective attention modulates human auditory brainstem responses: relative contributions of frequency and spatial cues.

    Directory of Open Access Journals (Sweden)

    Alexandre Lehmann

    Full Text Available Selective attention is the mechanism that allows focusing one's attention on a particular stimulus while filtering out a range of other stimuli, for instance, on a single conversation in a noisy room. Attending to one sound source rather than another changes activity in the human auditory cortex, but it is unclear whether attention to different acoustic features, such as voice pitch and speaker location, modulates subcortical activity. Studies using a dichotic listening paradigm indicated that auditory brainstem processing may be modulated by the direction of attention. We investigated whether endogenous selective attention to one of two speech signals affects amplitude and phase locking in auditory brainstem responses when the signals were either discriminable by frequency content alone, or by frequency content and spatial location. Frequency-following responses to the speech sounds were significantly modulated in both conditions. The modulation was specific to the task-relevant frequency band. The effect was stronger when both frequency and spatial information were available. Patterns of response were variable between participants, and were correlated with psychophysical discriminability of the stimuli, suggesting that the modulation was biologically relevant. Our results demonstrate that auditory brainstem responses are susceptible to efferent modulation related to behavioral goals. Furthermore they suggest that mechanisms of selective attention actively shape activity at early subcortical processing stages according to task relevance and based on frequency and spatial cues.

  4. An unavoidable modulation? Sensory attention and human primary motor cortex excitability.

    Science.gov (United States)

    Ruge, Diane; Muggleton, Neil; Hoad, Damon; Caronni, Antonio; Rothwell, John C

    2014-09-01

    The link between basic physiology and its modulation by cognitive states, such as attention, is poorly understood. A significant association becomes apparent when patients with movement disorders describe experiences with changing their attention focus and the fundamental effect that this has on their motor symptoms. Moreover, frequently used mental strategies for treating such patients, e.g. with task-specific dystonia, widely lack laboratory-based knowledge about physiological mechanisms. In this largely unexplored field, we looked at how the locus of attention, when it changed between internal (locus hand) and external (visual target), influenced excitability in the primary motor cortex (M1) in healthy humans. Intriguingly, both internal and external attention had the capacity to change M1 excitability. Both led to a reduced stimulation-induced GABA-related inhibition and a change in motor evoked potential size, i.e. an overall increased M1 excitability. These previously unreported findings indicated: (i) that cognitive state differentially interacted with M1 physiology, (ii) that our view of distraction (attention locus shifted towards external or distant location), which is used as a prevention or management strategy for use-dependent motor disorders, is too simple and currently unsupported for clinical application, and (iii) the physiological state reached through attention modulation represents an alternative explanation for frequently reported electrophysiology findings in neuropsychiatric disorders, such as an aberrant inhibition. © 2014 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

  5. The effect of perceptual load on tactile spatial attention: Evidence from event-related potentials.

    Science.gov (United States)

    Gherri, Elena; Berreby, Fiona

    2017-10-15

    To investigate whether tactile spatial attention is modulated by perceptual load, behavioural and electrophysiological measures were recorded during two spatial cuing tasks in which the difficulty of the target/non-target discrimination was varied (High and Low load tasks). Moreover, to study whether attentional modulations by load are sensitive to the availability of visual information, the High and Low load tasks were carried out under both illuminated and darkness conditions. ERPs to cued and uncued non-targets were compared as a function of task (High vs. Low load) and illumination condition (Light vs. Darkness). Results revealed that the locus of tactile spatial attention was determined by a complex interaction between perceptual load and illumination conditions during sensory-specific stages of processing. In the Darkness, earlier effects of attention were present in the High load than in the Low load task, while no difference between tasks emerged in the Light. By contrast, increased load was associated with stronger attention effects during later post-perceptual processing stages regardless of illumination conditions. These findings demonstrate that ERP correlates of tactile spatial attention are strongly affected by the perceptual load of the target/non-target discrimination. However, differences between illumination conditions show that the impact of load on tactile attention depends on the presence of visual information. Perceptual load is one of the many factors that contribute to determine the effects of spatial selectivity in touch. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. A resource-control account of sustained attention: evidence from mind-wandering and vigilance paradigms.

    Science.gov (United States)

    Thomson, David R; Besner, Derek; Smilek, Daniel

    2015-01-01

    Staying attentive is challenging enough when carrying out everyday tasks, such as reading or sitting through a lecture, and failures to do so can be frustrating and inconvenient. However, such lapses may even be life threatening, for example, if a pilot fails to monitor an oil-pressure gauge or if a long-haul truck driver fails to notice a car in his or her blind spot. Here, we explore two explanations of sustained-attention lapses. By one account, task monotony leads to an increasing preoccupation with internal thought (i.e., mind wandering). By another, task demands result in the depletion of information-processing resources that are needed to perform the task. A review of the sustained-attention literature suggests that neither theory, on its own, adequately explains the full range of findings. We propose a novel framework to explain why attention lapses as a function of time-on-task by combining aspects of two different theories of mind wandering: attentional resource (Smallwood & Schooler, 2006) and control failure (McVay & Kane, 2010). We then use our "resource-control" theory to explain performance decrements in sustained-attention tasks. We end by making some explicit predictions regarding mind wandering in general and sustained-attention performance in particular. © The Author(s) 2014.

  7. Contextual control over selective attention: evidence from a two-target method.

    Science.gov (United States)

    MacLellan, Ellen; Shore, David I; Milliken, Bruce

    2015-07-01

    Selective attention is generally studied with conflict tasks, using response time as the dependent measure. Here, we study the impact of selective attention to a first target, T1, presented simultaneously with a distractor, on the accuracy of subsequent encoding of a second target item, T2. This procedure produces an "attentional blink" (AB) effect much like that reported in other studies, and allowed us to study the influence of context on cognitive control with a novel method. In particular, we examined whether preparation to attend selectively to T1 had an impact on the selective encoding of T1 that would translate to report of T2. Preparation to attend selectively was manipulated by varying whether difficult selective attention T1 trials were presented in the context of other difficult selective attention T1 trials. The results revealed strong context effects of this nature, with smaller AB effects when difficult selective attention T1 trials were embedded in a context with many, rather than few, other difficult selective attention T1 trials. Further, the results suggest that both the trial-to-trial local context and the block-wide global context modulate performance in this task.

  8. Attention effects at auditory periphery derived from human scalp potentials: displacement measure of potentials.

    Science.gov (United States)

    Ikeda, Kazunari; Hayashi, Akiko; Sekiguchi, Takahiro; Era, Shukichi

    2006-10-01

    It is known in humans that electrophysiological measures such as the auditory brainstem response (ABR) are difficult to identify the attention effect at the auditory periphery, whereas the centrifugal effect has been detected by measuring otoacoustic emissions. This research developed a measure responsive to the shift of human scalp potentials within a brief post-stimulus period (13 ms), that is, displacement percentage, and applied it to an experiment to retrieve the peripheral attention effect. In the present experimental paradigm, tone pips were exposed to the left ear whereas the other ear was masked by white noise. Twelve participants each conducted two conditions of either ignoring or attending to the tone pips. Relative to averaged scalp potentials in the ignoring condition, the shift of the potentials was found within early component range during the attentive condition, and displacement percentage then revealed a significant magnitude difference between the two conditions. These results suggest that, using a measure representing the potential shift itself, the peripheral effect of attention can be detected from human scalp potentials.

  9. The effect of Nigella sativa Linn. seed on memory, attention and cognition in healthy human volunteers.

    Science.gov (United States)

    Bin Sayeed, Muhammad Shahdaat; Asaduzzaman, Md; Morshed, Helal; Hossain, Md Monir; Kadir, Mohammad Fahim; Rahman, Md Rezowanur

    2013-07-30

    Experimental evidences have demonstrated that Nigella sativa Linn. seed (NS) has positive modulation effects on aged rats with memory impairments, prevents against hippocampal pyramidal cell loss and enhances consolidation of recall capability of stored information and spatial memory in rats. NS has neuroprotective, nephroprotective, lung protective, cardioprotective, hepatoprotective activities as established by previous studies on animals. Several clinical trials with NS on human have also demonstrated beneficial effect. The present study was designed to investigate the effects of NS on memory, attention and cognition in healthy elderly volunteers. Furthermore, safety profile of NS was assessed during the nine-week study period. Forty elderly volunteers were recruited and divided randomly into group A and group B--each consisting of 20 volunteers. The treatment procedure for group A was 500 mg NS capsule twice daily for nine weeks and Group B received placebo instead of NS in the similar manner. All the volunteers were assessed for neuropsychological state and safety profile twice before treatment and after nine weeks. The neuropsychological tests were logical memory test, digit span test, Rey-Osterrieth complex figure test, letter cancellation test, trail making test and stroop test. Safety profile was assessed by measuring biochemical markers of Cardiac (total cholesterol, triglycerides and high density lipoprotein cholesterol, very low density lipoprotein, low density lipoprotein cholesterol, creatine kinase-MB); Liver (aspartate aminotransferase, alanin aminotransferase, alkaline phosphatase, total protein, albumin, bilirubin) and Kidney (creatinine and blood urea nitrogen) through using commercial kits. There was significant difference (p0.05) in any of the biochemical markers of cardiac, liver, kidney function during this nine-week study period. The current study demonstrates the role of NS in enhancing memory, attention and cognition. Therefore, whether NS

  10. Auditory Selective Attention: an introduction and evidence for distinct facilitation and inhibition mechanisms

    OpenAIRE

    Mikyska, Constanze Elisabeth Anna

    2012-01-01

    Objective Auditory selective attention is a complex brain function that is still not completely understood. The classic example is the so-called “cocktail party effect” (Cherry, 1953), which describes the impressive ability to focus one’s attention on a single voice from a multitude of voices. This means that particular stimuli in the environment are enhanced in contrast to other ones of lower priority that are ignored. To be able to understand how attention can influence the perception and p...

  11. Functional size of human visual area V1: a neural correlate of top-down attention.

    Science.gov (United States)

    Verghese, Ashika; Kolbe, Scott C; Anderson, Andrew J; Egan, Gary F; Vidyasagar, Trichur R

    2014-06-01

    Heavy demands are placed on the brain's attentional capacity when selecting a target item in a cluttered visual scene, or when reading. It is widely accepted that such attentional selection is mediated by top-down signals from higher cortical areas to early visual areas such as the primary visual cortex (V1). Further, it has also been reported that there is considerable variation in the surface area of V1. This variation may impact on either the number or specificity of attentional feedback signals and, thereby, the efficiency of attentional mechanisms. In this study, we investigated whether individual differences between humans performing attention-demanding tasks can be related to the functional area of V1. We found that those with a larger representation in V1 of the central 12° of the visual field as measured using BOLD signals from fMRI were able to perform a serial search task at a faster rate. In line with recent suggestions of the vital role of visuo-spatial attention in reading, the speed of reading showed a strong positive correlation with the speed of visual search, although it showed little correlation with the size of V1. The results support the idea that the functional size of the primary visual cortex is an important determinant of the efficiency of selective spatial attention for simple tasks, and that the attentional processing required for complex tasks like reading are to a large extent determined by other brain areas and inter-areal connections. Copyright © 2014 Elsevier Inc. All rights reserved.

  12. Oculomotor Anomalies in Attention-Deficit/Hyperactivity Disorder: Evidence for Deficits in Response Preparation and Inhibition

    Science.gov (United States)

    Mahone, E. Mark; Mostofsky, Stewart H.; Lasker, Adrian G.; Zee, David; Denckla, Martha B.

    2009-01-01

    Girls, but not boys, with attention deficit hyperactivity disorder (ADHD) have significantly longer visually guided saccades latencies. It is found that sex differences in children with ADHD extend beyond symptom presentation to the development of oculomotor control.

  13. Cultural differences in attention: Eye movement evidence from a comparative visual search task.

    Science.gov (United States)

    Alotaibi, Albandri; Underwood, Geoffrey; Smith, Alastair D

    2017-10-01

    Individual differences in visual attention have been linked to thinking style: analytic thinking (common in individualistic cultures) is thought to promote attention to detail and focus on the most important part of a scene, whereas holistic thinking (common in collectivist cultures) promotes attention to the global structure of a scene and the relationship between its parts. However, this theory is primarily based on relatively simple judgement tasks. We compared groups from Great Britain (an individualist culture) and Saudi Arabia (a collectivist culture) on a more complex comparative visual search task, using simple natural scenes. A higher overall number of fixations for Saudi participants, along with longer search times, indicated less efficient search behaviour than British participants. Furthermore, intra-group comparisons of scan-path for Saudi participants revealed less similarity than within the British group. Together, these findings suggest that there is a positive relationship between an analytic cognitive style and controlled attention. Copyright © 2017 Elsevier Inc. All rights reserved.

  14. Parietal theta burst TMS: Functional fractionation observed during bistable perception not evident in attention tasks.

    Science.gov (United States)

    Schauer, Georg; Kanai, Ryota; Brascamp, Jan W

    2016-02-01

    When visual input is ambiguous, perception spontaneously alternates between interpretations: bistable perception. Studies have identified two distinct sites near the right intraparietal sulcus where inhibitory transcranial magnetic stimulation (TMS) affects the frequency of occurrence of these alternations, but strikingly with opposite directions of effect for the two sites. Lesion and TMS studies on spatial and sustained attention have also indicated a parcellation of right parietal cortex, into areas serving distinct attentional functions. We used the exact TMS procedure previously employed to affect bistable perception, yet measured its effect on spatial and sustained attention tasks. Although there was a trend for TMS to affect performance, trends were consistently similar for both parietal sites, with no indication of opposite effects. We interpret this as signifying that the previously observed parietal fractionation of function regarding the perception of ambiguous stimuli is not due to TMS-induced modification of spatial or sustained attention. Copyright © 2016 Elsevier Inc. All rights reserved.

  15. Does apparent size capture attention in visual search? Evidence from the Muller-Lyer illusion.

    Science.gov (United States)

    Proulx, Michael J; Green, Monique

    2011-11-23

    Is perceived size a crucial factor for the bottom-up guidance of attention? Here, a visual search experiment was used to examine whether an irrelevantly longer object can capture attention when participants were to detect a vertical target item. The longer object was created by an apparent size manipulation, the Müller-Lyer illusion; however, all objects contained the same number of pixels. The vertical target was detected more efficiently when it was also perceived as the longer item that was defined by apparent size. Further analysis revealed that the longer Müller-Lyer object received a greater degree of attentional priority than published results for other features such as retinal size, luminance contrast, and the abrupt onset of a new object. The present experiment has demonstrated for the first time that apparent size can capture attention and, thus, provide bottom-up guidance on the basis of perceived salience.

  16. Attentional bias in high math-anxious individuals: evidence from an emotional Stroop task

    OpenAIRE

    Su?rez-Pellicioni, Macarena; N??ez-Pe?a, Maria Isabel; Colom?, ?ngels

    2015-01-01

    Attentional bias towards threatening or emotional information is considered a cognitive marker of anxiety, and it has been described in various clinical and subclinical populations. This study used an emotional Stroop task to investigate whether math anxiety is characterized by an attentional bias towards math-related words. Two previous studies failed to observe such an effect in math-anxious individuals, although the authors acknowledged certain methodological limitations that the present s...

  17. Newly-formed emotional memories guide selective attention processes: Evidence from event-related potentials

    OpenAIRE

    Harald T. Schupp; Ursula Kirmse; Ralf Schmälzle; Tobias Flaisch; Britta Renner

    2016-01-01

    Emotional cues can guide selective attention processes. However, emotional stimuli can both activate long-term memory representations reflecting general world knowledge and engage newly formed memory representations representing specific knowledge from the immediate past. Here, the self-completion feature of associative memory was utilized to assess the regulation of attention processes by newly-formed emotional memory. First, new memory representations were formed by presenting pictures depi...

  18. Effects of working memory load on visual selective attention: Behavioral and electrophysiological evidence

    OpenAIRE

    Nikki ePratt; Adrian eWilloughby; Diane eSwick; Diane eSwick

    2011-01-01

    Working memory and attention interact in a way that enables us to focus on relevant items and maintain current goals. The influence of working memory on attention has been noted in several studies using dual task designs. Multitasking increases the demands on working memory and reduces the amount of resources available for cognitive control functions such as resolving stimulus conflict. However, few studies have investigated the temporal activation of the cortex while multitasking. The pre...

  19. Effects of Working Memory Load on Visual Selective Attention: Behavioral and Electrophysiological Evidence

    OpenAIRE

    Pratt, Nikki; Willoughby, Adrian; Swick, Diane

    2011-01-01

    Working memory and attention interact in a way that enables us to focus on relevant items and maintain current goals. The influence of working memory on attention has been noted in several studies using dual task designs. Multitasking increases the demands on working memory and reduces the amount of resources available for cognitive control functions such as resolving stimulus conflict. However, few studies have investigated the temporal activation of the cortex while multitasking. The presen...

  20. Task-irrelevant own-race faces capture attention: eye-tracking evidence.

    Science.gov (United States)

    Cao, Rong; Wang, Shuzhen; Rao, Congquan; Fu, Jia

    2013-04-01

    To investigate attentional capture by face's race, the current study recorded saccade latencies of eye movement measurements in an inhibition of return (IOR) task. Compared to Caucasian (other-race) faces, Chinese (own-race) faces elicited longer saccade latency. This phenomenon disappeared when faces were inverted. The results indicated that own-race faces capture attention automatically with high-level configural processing. © 2013 The Authors. Scandinavian Journal of Psychology © 2013 The Scandinavian Psychological Associations.

  1. Loss of urban forest canopy and the related effects on soundscape and human directed attention

    Science.gov (United States)

    Laverne, Robert James Paul

    The specific questions addressed in this research are: Will the loss of trees in residential neighborhoods result in a change to the local soundscape? The investigation of this question leads to a related inquiry: Do the sounds of the environment in which a person is present affect their directed attention?. An invasive insect pest, the Emerald Ash Borer (Agrilus planipennis ), is killing millions of ash trees (genus Fraxinus) throughout North America. As the loss of tree canopy occurs, urban ecosystems change (including higher summer temperatures, more stormwater runoff, and poorer air quality) causing associated changes to human physical and mental health. Previous studies suggest that conditions in urban environments can result in chronic stress in humans and fatigue to directed attention, which is the ability to focus on tasks and to pay attention. Access to nature in cities can help refresh directed attention. The sights and sounds associated with parks, open spaces, and trees can serve as beneficial counterbalances to the irritating conditions associated with cities. This research examines changes to the quantity and quality of sounds in Arlington Heights, Illinois. A series of before-and-after sound recordings were gathered as trees died and were removed between 2013 and 2015. Comparison of recordings using the Raven sound analysis program revealed significant differences in some, but not all measures of sound attributes as tree canopy decreased. In general, more human-produced mechanical sounds (anthrophony) and fewer sounds associated with weather (geophony) were detected. Changes in sounds associated with animals (biophony) varied seasonally. Monitoring changes in the proportions of anthrophony, biophony and geophony can provide insight into changes in biodiversity, environmental health, and quality of life for humans. Before-tree-removal and after-tree-removal sound recordings served as the independent variable for randomly-assigned human volunteers as

  2. The legal status of evidence obtained through human rights ...

    African Journals Online (AJOL)

    The Constitution of the Republic of Uganda, 1995 is silent on the issue of dealing with evidence obtained through human rights violations. This silence dates to the earlier Constitutions of 1962, 1966 and 1967. It is only the Prohibition and Prevention of Torture Act of 2012 that renders evidence obtained through torture and ...

  3. Selective attention towards painful faces among chronic pain patients: evidence from a modified version of the dot-probe.

    Science.gov (United States)

    Khatibi, Ali; Dehghani, Mohsen; Sharpe, Louise; Asmundson, Gordon J G; Pouretemad, Hamidreza

    2009-03-01

    Evidence that patients with chronic pain selectively attend to pain-related stimuli presented in modified Stroop and dot-probe paradigms is mixed. The pain-related stimuli used in these studies have been primarily verbal in nature (i.e., words depicting themes of pain). The purpose of the present study was to determine whether patients with chronic pain, relative to healthy controls, show selective attention for pictures depicting painful faces. To do so, 170 patients with chronic pain and 40 age- and education-matched healthy control participants were tested using a dot-probe task in which painful, happy, and neutral facial expressions were presented. Selective attention was denoted using the mean reaction time and the bias index. Results indicated that, while both groups shifted attention away from happy faces (and towards neutral faces), only the control group shifted attention away from painful faces. Additional analyses were conducted on chronic pain participants after dividing them into groups on the basis of fear of pain/(re)injury. The results of these analyses revealed that while chronic pain patients with high and low levels of fear both shifted attention away from happy faces, those with low fear shifted attention away from painful faces, whereas those with high fear shifted attention towards painful faces. These results suggest that patients with chronic pain selectively attend to facial expressions of pain and, importantly, that the tendency to shift attention towards such stimuli is positively influenced by high fear of pain/(re)injury. Implications of the findings and future research directions are discussed.

  4. Retinotopy and attention to the face and house images in the human visual cortex.

    Science.gov (United States)

    Wang, Bin; Yan, Tianyi; Ohno, Seiichiro; Kanazawa, Susumu; Wu, Jinglong

    2016-06-01

    Attentional modulation of the neural activities in human visual areas has been well demonstrated. However, the retinotopic activities that are driven by face and house images and attention to face and house images remain unknown. In the present study, we used images of faces and houses to estimate the retinotopic activities that were driven by both the images and attention to the images, driven by attention to the images, and driven by the images. Generally, our results show that both face and house images produced similar retinotopic activities in visual areas, which were only observed in the attention + stimulus and the attention conditions, but not in the stimulus condition. The fusiform face area (FFA) responded to faces that were presented on the horizontal meridian, whereas parahippocampal place area (PPA) rarely responded to house at any visual field. We further analyzed the amplitudes of the neural responses to the target wedge. In V1, V2, V3, V3A, lateral occipital area 1 (LO-1), and hV4, the neural responses to the attended target wedge were significantly greater than those to the unattended target wedge. However, in LO-2, ventral occipital areas 1 and 2 (VO-1 and VO-2) and FFA and PPA, the differences were not significant. We proposed that these areas likely have large fields of attentional modulation for face and house images and exhibit responses to both the target wedge and the background stimuli. In addition, we proposed that the absence of retinotopic activity in the stimulus condition might imply no perceived difference between the target wedge and the background stimuli.

  5. Attention improves encoding of task-relevant features in the human visual cortex

    Science.gov (United States)

    Jehee, Janneke F.M.; Brady, Devin K.; Tong, Frank

    2011-01-01

    When spatial attention is directed towards a particular stimulus, increased activity is commonly observed in corresponding locations of the visual cortex. Does this attentional increase in activity indicate improved processing of all features contained within the attended stimulus, or might spatial attention selectively enhance the features relevant to the observer’s task? We used fMRI decoding methods to measure the strength of orientation-selective activity patterns in the human visual cortex while subjects performed either an orientation or contrast discrimination task, involving one of two laterally presented gratings. Greater overall BOLD activation with spatial attention was observed in areas V1-V4 for both tasks. However, multivariate pattern analysis revealed that orientation-selective responses were enhanced by attention only when orientation was the task-relevant feature, and not when the grating’s contrast had to be attended. In a second experiment, observers discriminated the orientation or color of a specific lateral grating. Here, orientation-selective responses were enhanced in both tasks but color-selective responses were enhanced only when color was task-relevant. In both experiments, task-specific enhancement of feature-selective activity was not confined to the attended stimulus location, but instead spread to other locations in the visual field, suggesting the concurrent involvement of a global feature-based attentional mechanism. These results suggest that attention can be remarkably selective in its ability to enhance particular task-relevant features, and further reveal that increases in overall BOLD amplitude are not necessarily accompanied by improved processing of stimulus information. PMID:21632942

  6. Effects of selective attention on the electrophysiological representation of concurrent sounds in the human auditory cortex.

    Science.gov (United States)

    Bidet-Caulet, Aurélie; Fischer, Catherine; Besle, Julien; Aguera, Pierre-Emmanuel; Giard, Marie-Helene; Bertrand, Olivier

    2007-08-29

    In noisy environments, we use auditory selective attention to actively ignore distracting sounds and select relevant information, as during a cocktail party to follow one particular conversation. The present electrophysiological study aims at deciphering the spatiotemporal organization of the effect of selective attention on the representation of concurrent sounds in the human auditory cortex. Sound onset asynchrony was manipulated to induce the segregation of two concurrent auditory streams. Each stream consisted of amplitude modulated tones at different carrier and modulation frequencies. Electrophysiological recordings were performed in epileptic patients with pharmacologically resistant partial epilepsy, implanted with depth electrodes in the temporal cortex. Patients were presented with the stimuli while they either performed an auditory distracting task or actively selected one of the two concurrent streams. Selective attention was found to affect steady-state responses in the primary auditory cortex, and transient and sustained evoked responses in secondary auditory areas. The results provide new insights on the neural mechanisms of auditory selective attention: stream selection during sound rivalry would be facilitated not only by enhancing the neural representation of relevant sounds, but also by reducing the representation of irrelevant information in the auditory cortex. Finally, they suggest a specialization of the left hemisphere in the attentional selection of fine-grained acoustic information.

  7. Association between Urine Phthalate Levels and Poor Attentional Performance in Children with Attention-Deficit Hyperactivity Disorder with Evidence of Dopamine Gene-Phthalate Interaction

    Directory of Open Access Journals (Sweden)

    Subin Park

    2014-06-01

    Full Text Available Although there is some evidence supporting the existence of an association between prenatal maternal or postnatal child’s urine phthalate metabolite concentrations and poor attentional performances, the interaction between urine phthalate metabolite levels and genetic variation for neuropsychological deficit of attention-deficit hyperactivity disorder (ADHD has not been examined. The aim of this study was to determine whether phthalate metabolites in urine are associated with poor neuropsychological performance in children with ADHD, and whether such association is affected by genotype-phthalate interaction. A cross-sectional examination of urine phthalate metabolite concentrations and the continuous performance test (CPT were performed in 179 Korean children with ADHD recruited from department of psychiatry of university hospital. Correlations between urine phthalate metabolite concentrations and the CPT scores were investigated, and the interaction of phthalate metabolite levels with the selected polymorphisms at major candidate genes for ADHD, namely dopamine receptor D4 (DRD4, dopamine transporter, α-2A-adrenergic receptor, and norepinephrine transporter genes. For the subjects with the DRD4 4/4 genotype, there were significant associations of the urine phthalate metabolite concentrations with the number of omission errors, the number of commission errors, and the response time variability scores on the CPT. However, for the subjects without the DRD4 4/4 genotype, no significant associations were found. The results of this study suggest a possible association between phthalate metabolite concentrations and poor attentional performances of ADHD as well as a genetic influence on this association. Further prospective and epigenetic studies are needed to investigate causality and pathophysiological mechanisms.

  8. Association between urine phthalate levels and poor attentional performance in children with attention-deficit hyperactivity disorder with evidence of dopamine gene-phthalate interaction.

    Science.gov (United States)

    Park, Subin; Kim, Bung-Nyun; Cho, Soo-Churl; Kim, Yeni; Kim, Jae-Won; Lee, Ju-Young; Hong, Soon-Beom; Shin, Min-Sup; Yoo, Hee Jeong; Im, Hosub; Cheong, Jae Hoon; Han, Doug Hyun

    2014-06-27

    Although there is some evidence supporting the existence of an association between prenatal maternal or postnatal child's urine phthalate metabolite concentrations and poor attentional performances, the interaction between urine phthalate metabolite levels and genetic variation for neuropsychological deficit of attention-deficit hyperactivity disorder (ADHD) has not been examined. The aim of this study was to determine whether phthalate metabolites in urine are associated with poor neuropsychological performance in children with ADHD, and whether such association is affected by genotype-phthalate interaction. A cross-sectional examination of urine phthalate metabolite concentrations and the continuous performance test (CPT) were performed in 179 Korean children with ADHD recruited from department of psychiatry of university hospital. Correlations between urine phthalate metabolite concentrations and the CPT scores were investigated, and the interaction of phthalate metabolite levels with the selected polymorphisms at major candidate genes for ADHD, namely dopamine receptor D4 (DRD4), dopamine transporter, α-2A-adrenergic receptor, and norepinephrine transporter genes. For the subjects with the DRD4 4/4 genotype, there were significant associations of the urine phthalate metabolite concentrations with the number of omission errors, the number of commission errors, and the response time variability scores on the CPT. However, for the subjects without the DRD4 4/4 genotype, no significant associations were found. The results of this study suggest a possible association between phthalate metabolite concentrations and poor attentional performances of ADHD as well as a genetic influence on this association. Further prospective and epigenetic studies are needed to investigate causality and pathophysiological mechanisms.

  9. Association between Urine Phthalate Levels and Poor Attentional Performance in Children with Attention-Deficit Hyperactivity Disorder with Evidence of Dopamine Gene-Phthalate Interaction

    Science.gov (United States)

    Park, Subin; Kim, Bung-Nyun; Cho, Soo-Churl; Kim, Yeni; Kim, Jae-Won; Lee, Ju-Young; Hong, Soon-Beom; Shin, Min-Sup; Yoo, Hee Jeong; Im, Hosub; Cheong, Jae Hoon; Han, Doug Hyun

    2014-01-01

    Although there is some evidence supporting the existence of an association between prenatal maternal or postnatal child’s urine phthalate metabolite concentrations and poor attentional performances, the interaction between urine phthalate metabolite levels and genetic variation for neuropsychological deficit of attention-deficit hyperactivity disorder (ADHD) has not been examined. The aim of this study was to determine whether phthalate metabolites in urine are associated with poor neuropsychological performance in children with ADHD, and whether such association is affected by genotype-phthalate interaction. A cross-sectional examination of urine phthalate metabolite concentrations and the continuous performance test (CPT) were performed in 179 Korean children with ADHD recruited from department of psychiatry of university hospital. Correlations between urine phthalate metabolite concentrations and the CPT scores were investigated, and the interaction of phthalate metabolite levels with the selected polymorphisms at major candidate genes for ADHD, namely dopamine receptor D4 (DRD4), dopamine transporter, α-2A-adrenergic receptor, and norepinephrine transporter genes. For the subjects with the DRD4 4/4 genotype, there were significant associations of the urine phthalate metabolite concentrations with the number of omission errors, the number of commission errors, and the response time variability scores on the CPT. However, for the subjects without the DRD4 4/4 genotype, no significant associations were found. The results of this study suggest a possible association between phthalate metabolite concentrations and poor attentional performances of ADHD as well as a genetic influence on this association. Further prospective and epigenetic studies are needed to investigate causality and pathophysiological mechanisms. PMID:24978879

  10. Looking on the bright side: biased attention and the human serotonin transporter gene

    OpenAIRE

    Fox, Elaine; Ridgewell, Anna; Ashwin, Chris

    2009-01-01

    Humans differ in terms of biased attention for emotional stimuli and these biases can confer differential resilience and vulnerability to emotional disorders. Selective processing of positive emotional information, for example, is associated with enhanced sociability and well-being while a bias for negative material is associated with neuroticism and anxiety. A tendency to selectively avoid negative material might also be associated with mental health and well-being. The neurobiological mecha...

  11. Evidence for deficits in the temporal attention span of poor readers.

    Science.gov (United States)

    Visser, Troy A W

    2014-01-01

    While poor reading is often associated with phonological deficits, many studies suggest that visual processing might also be impaired. In particular, recent research has indicated that poor readers show impaired spatial visual attention spans in partial and whole report tasks. Given the similarities between competition-based accounts for reduced visual attention span and similar explanations for impairments in sequential object processing, the present work examined whether poor readers show deficits in their "temporal attention span"--that is, their ability to rapidly and accurately process sequences of consecutive target items. Poor and normal readers monitored a sequential stream of visual items for two (TT condition) or three (TTT condition) consecutive target digits. Target identification was examined using both unconditional and conditional measures of accuracy in order to gauge the overall likelihood of identifying a target and the likelihood of identifying a target given successful identification of previous items. Compared to normal readers, poor readers showed small but consistent deficits in identification across targets whether unconditional or conditional accuracy was used. Additionally, in the TTT condition, final-target conditional accuracy was poorer than unconditional accuracy, particularly for poor readers, suggesting a substantial cost arising from processing the previous two targets that was not present in normal readers. Mirroring the differences found between poor and normal readers in spatial visual attention span, the present findings suggest two principal differences between the temporal attention spans of poor and normal readers. First, the consistent pattern of reduced performance across targets suggests increased competition amongst items within the same span for poor readers. Second, the steeper decline in final target performance amongst poor readers in the TTT condition suggests a reduction in the extent of their temporal attention

  12. Evidence for deficits in the temporal attention span of poor readers.

    Directory of Open Access Journals (Sweden)

    Troy A W Visser

    Full Text Available While poor reading is often associated with phonological deficits, many studies suggest that visual processing might also be impaired. In particular, recent research has indicated that poor readers show impaired spatial visual attention spans in partial and whole report tasks. Given the similarities between competition-based accounts for reduced visual attention span and similar explanations for impairments in sequential object processing, the present work examined whether poor readers show deficits in their "temporal attention span"--that is, their ability to rapidly and accurately process sequences of consecutive target items.Poor and normal readers monitored a sequential stream of visual items for two (TT condition or three (TTT condition consecutive target digits. Target identification was examined using both unconditional and conditional measures of accuracy in order to gauge the overall likelihood of identifying a target and the likelihood of identifying a target given successful identification of previous items. Compared to normal readers, poor readers showed small but consistent deficits in identification across targets whether unconditional or conditional accuracy was used. Additionally, in the TTT condition, final-target conditional accuracy was poorer than unconditional accuracy, particularly for poor readers, suggesting a substantial cost arising from processing the previous two targets that was not present in normal readers.Mirroring the differences found between poor and normal readers in spatial visual attention span, the present findings suggest two principal differences between the temporal attention spans of poor and normal readers. First, the consistent pattern of reduced performance across targets suggests increased competition amongst items within the same span for poor readers. Second, the steeper decline in final target performance amongst poor readers in the TTT condition suggests a reduction in the extent of their

  13. Explicit attention interferes with selective emotion processing in human extrastriate cortex

    Directory of Open Access Journals (Sweden)

    Junghöfer Markus

    2007-02-01

    Full Text Available Abstract Background Brain imaging and event-related potential studies provide strong evidence that emotional stimuli guide selective attention in visual processing. A reflection of the emotional attention capture is the increased Early Posterior Negativity (EPN for pleasant and unpleasant compared to neutral images (~150–300 ms poststimulus. The present study explored whether this early emotion discrimination reflects an automatic phenomenon or is subject to interference by competing processing demands. Thus, emotional processing was assessed while participants performed a concurrent feature-based attention task varying in processing demands. Results Participants successfully performed the primary visual attention task as revealed by behavioral performance and selected event-related potential components (Selection Negativity and P3b. Replicating previous results, emotional modulation of the EPN was observed in a task condition with low processing demands. In contrast, pleasant and unpleasant pictures failed to elicit increased EPN amplitudes compared to neutral images in more difficult explicit attention task conditions. Further analyses determined that even the processing of pleasant and unpleasant pictures high in emotional arousal is subject to interference in experimental conditions with high task demand. Taken together, performing demanding feature-based counting tasks interfered with differential emotion processing indexed by the EPN. Conclusion The present findings demonstrate that taxing processing resources by a competing primary visual attention task markedly attenuated the early discrimination of emotional from neutral picture contents. Thus, these results provide further empirical support for an interference account of the emotion-attention interaction under conditions of competition. Previous studies revealed the interference of selective emotion processing when attentional resources were directed to locations of explicitly task

  14. Explicit attention interferes with selective emotion processing in human extrastriate cortex.

    Science.gov (United States)

    Schupp, Harald T; Stockburger, Jessica; Bublatzky, Florian; Junghöfer, Markus; Weike, Almut I; Hamm, Alfons O

    2007-02-22

    Brain imaging and event-related potential studies provide strong evidence that emotional stimuli guide selective attention in visual processing. A reflection of the emotional attention capture is the increased Early Posterior Negativity (EPN) for pleasant and unpleasant compared to neutral images (approximately 150-300 ms poststimulus). The present study explored whether this early emotion discrimination reflects an automatic phenomenon or is subject to interference by competing processing demands. Thus, emotional processing was assessed while participants performed a concurrent feature-based attention task varying in processing demands. Participants successfully performed the primary visual attention task as revealed by behavioral performance and selected event-related potential components (Selection Negativity and P3b). Replicating previous results, emotional modulation of the EPN was observed in a task condition with low processing demands. In contrast, pleasant and unpleasant pictures failed to elicit increased EPN amplitudes compared to neutral images in more difficult explicit attention task conditions. Further analyses determined that even the processing of pleasant and unpleasant pictures high in emotional arousal is subject to interference in experimental conditions with high task demand. Taken together, performing demanding feature-based counting tasks interfered with differential emotion processing indexed by the EPN. The present findings demonstrate that taxing processing resources by a competing primary visual attention task markedly attenuated the early discrimination of emotional from neutral picture contents. Thus, these results provide further empirical support for an interference account of the emotion-attention interaction under conditions of competition. Previous studies revealed the interference of selective emotion processing when attentional resources were directed to locations of explicitly task-relevant stimuli. The present data suggest

  15. Living with symptoms of attention deficit hyperactivity disorder in adulthood: a systematic review of qualitative evidence.

    Science.gov (United States)

    Bjerrum, Merete B; Pedersen, Preben U; Larsen, Palle

    2017-04-01

    Attention deficit hyperactivity disorder (ADHD) relates to four dimensions of behavior: inattentiveness, restlessness, impulsiveness and hyperactivity. Symptoms affect multiple areas of daily life such as academic performance and social functioning. Despite the negative effects of ADHD, people diagnosed with ADHD do not necessarily regard themselves as being impaired. However, it is unclear how adults with ADHD experience and manage their symptoms. To identify and synthesize the best available evidence on how adults experience living with ADHD. Adults with confirmed ADHD diagnosis. How adults with ADHD experience and manage the symptoms of ADHD and links between protective factors provided by relatives, friends, fellow students, mentors and colleagues. Studies based on qualitative data, including, but not limited to, designs within phenomenology, grounded theory, content analysis or ethnography. A three-step search strategy identified published and unpublished qualitative studies from 1990 to July 2015. Studies meeting the inclusion criteria were independently assessed by two reviewers using the standardized critical appraisal instrument from the Joanna Briggs Institute Qualitative Assessment and Review Instrument (JBI-QARI). Data were extracted from 10 included studies using the JBI-QARI. Qualitative research findings were synthesized using the JBI-QARI. A total of 103 findings from 10 studies were aggregated into 16 categories that were meta-synthesized into four synthesized findings: "Adults are aware of being different from others and strive to be an integrated, accepted part of the community;" "Adults with ADHD are creative and inventive;" "Adults with ADHD develop coping strategies in striving for a healthy balance in life" and "For adults with ADHD, accomplishing and organizing tasks in everyday life is a challenge but it can also be rewarding." Adults with ADHD have problems stemming from ADHD symptoms in relation to interacting in social relationships

  16. Newly-formed emotional memories guide selective attention processes: Evidence from event-related potentials

    Science.gov (United States)

    Schupp, Harald T.; Kirmse, Ursula; Schmälzle, Ralf; Flaisch, Tobias; Renner, Britta

    2016-01-01

    Emotional cues can guide selective attention processes. However, emotional stimuli can both activate long-term memory representations reflecting general world knowledge and engage newly formed memory representations representing specific knowledge from the immediate past. Here, the self-completion feature of associative memory was utilized to assess the regulation of attention processes by newly-formed emotional memory. First, new memory representations were formed by presenting pictures depicting a person either in an erotic pose or as a portrait. Afterwards, to activate newly-built memory traces, edited pictures were presented showing only the head region of the person. ERP recordings revealed the emotional regulation of attention by newly-formed memories. Specifically, edited pictures from the erotic compared to the portrait category elicited an early posterior negativity and late positive potential, similar to the findings observed for the original pictures. A control condition showed that the effect was dependent on newly-formed memory traces. Given the large number of new memories formed each day, they presumably make an important contribution to the regulation of attention in everyday life. PMID:27321471

  17. Comparing Perception of Stroop Stimuli in Focused versus Divided Attention Paradigms: Evidence for Dramatic Processing Differences

    Science.gov (United States)

    Eidels, Ami; Townsend, James T.; Algom, Daniel

    2010-01-01

    A huge set of focused attention experiments show that when presented with color words printed in color, observers report the ink color faster if the carrier word is the name of the color rather than the name of an alternative color, the Stroop effect. There is also a large number (although not so numerous as the Stroop task) of so-called…

  18. Speech Perception Engages a General Timer: Evidence from a Divided Attention Word Identification Task

    Science.gov (United States)

    Casini, Laurence; Burle, Boris; Nguyen, Noel

    2009-01-01

    Time is essential to speech. The duration of speech segments plays a critical role in the perceptual identification of these segments, and therefore in that of spoken words. Here, using a French word identification task, we show that vowels are perceived as shorter when attention is divided between two tasks, as compared to a single task control…

  19. Newly-formed emotional memories guide selective attention processes: Evidence from event-related potentials.

    Science.gov (United States)

    Schupp, Harald T; Kirmse, Ursula; Schmälzle, Ralf; Flaisch, Tobias; Renner, Britta

    2016-06-20

    Emotional cues can guide selective attention processes. However, emotional stimuli can both activate long-term memory representations reflecting general world knowledge and engage newly formed memory representations representing specific knowledge from the immediate past. Here, the self-completion feature of associative memory was utilized to assess the regulation of attention processes by newly-formed emotional memory. First, new memory representations were formed by presenting pictures depicting a person either in an erotic pose or as a portrait. Afterwards, to activate newly-built memory traces, edited pictures were presented showing only the head region of the person. ERP recordings revealed the emotional regulation of attention by newly-formed memories. Specifically, edited pictures from the erotic compared to the portrait category elicited an early posterior negativity and late positive potential, similar to the findings observed for the original pictures. A control condition showed that the effect was dependent on newly-formed memory traces. Given the large number of new memories formed each day, they presumably make an important contribution to the regulation of attention in everyday life.

  20. A Split-Attention Effect in Multimedia Learning: Evidence for Dual Processing Systems in Working Memory.

    Science.gov (United States)

    Mayer, Richard E.; Moreno, Roxana

    1998-01-01

    Multimedia learners (n=146 college students) were able to integrate words and computer-presented pictures more easily when the words were presented aurally rather than visually. This split-attention effect is consistent with a dual-processing model of working memory. (SLD)

  1. Feature-selective attention: evidence for a decline in old age.

    Science.gov (United States)

    Quigley, Cliodhna; Andersen, Søren K; Schulze, Lars; Grunwald, Martin; Müller, Matthias M

    2010-04-19

    Although attention in older adults is an active research area, feature-selective aspects have not yet been explicitly studied. Here we report the results of an exploratory study involving directed changes in feature-selective attention. The stimuli used were two random dot kinematograms (RDKs) of different colours, superimposed and centrally presented. A colour cue with random onset after the beginning of each trial instructed young and older subjects to attend to one of the RDKs and detect short intervals of coherent motion while ignoring analogous motion events in the non-cued RDK. Behavioural data show that older adults could detect motion, but discriminated target from distracter motion less reliably than young adults. The method of frequency tagging allowed us to separate the EEG responses to the attended and ignored stimuli and directly compare steady-state visual evoked potential (SSVEP) amplitudes elicited by each stimulus before and after cue onset. We found that younger adults show a clear attentional enhancement of SSVEP amplitude in the post-cue interval, while older adults' SSVEP responses to attended and ignored stimuli do not differ. Thus, in situations where attentional selection cannot be spatially resolved, older adults show a deficit in selection that is not shared by young adults. Copyright 2010 Elsevier Ireland Ltd. All rights reserved.

  2. Nonspatial intermodal selective attention is mediated by sensory brain areas: Evidence from event-related potential.

    NARCIS (Netherlands)

    Talsma, D.; Kok, A.

    2001-01-01

    Focuses on the question of whether inter-and intramodal forms of attention are reflected in activation of the same or different brain areas. ERPs were recorded while Ss (aged 18-41 yrs) were presented a random sequence of visual and auditory stimuli. They were instructed to attend to nonspatial

  3. Nonspatial intermodal selective attention is mediated by sensory brain areas: Evidence from event-related potentials

    NARCIS (Netherlands)

    Talsma, D.; Kok, Albert

    2001-01-01

    The present study focuses on the question of whether inter- and intramodal forms of attention are reflected in activation of the same or different brain areas. ERPs were recorded while subjects were presented a random sequence of visual and auditory stimuli. They were instructed to attend to

  4. ’What’ and ’Where’ in Visual Attention: Evidence from the Neglect Syndrome

    Science.gov (United States)

    1992-01-01

    representations of the visual world, visual attention, and object representations. 24 Bauer, R. M., & Rubens, A. B. (1985). Agnosia . In K. M. Heilman, & E...visual information. Journal of Experimental Psychology: General, 1-1, 501-517. Farah, M. J. (1990). Visual Agnosia : Disorders of Object Recognition and

  5. Electrophysiological Evidence for Endogenous Control of Attention in Switching between Languages in Overt Picture Naming

    Science.gov (United States)

    Verhoef, Kim M. W.; Roelofs, Ardi; Chwilla, Dorothee J.

    2010-01-01

    Language switching in bilingual speakers requires attentional control to select the appropriate language, for example, in picture naming. Previous language-switch studies used the color of pictures to indicate the required language thereby confounding endogenous and exogenous control. To investigate endogenous language control, our language cues…

  6. Impaired Conflict Resolution and Alerting in Children with ADHD: Evidence from the Attention Network Task (ANT)

    Science.gov (United States)

    Johnson, Katherine A.; Robertson, Ian H.; Barry, Edwina; Mulligan, Aisling; Daibhis, Aoife; Daly, Michael; Watchorn, Amy; Gill, Michael; Bellgrove, Mark A.

    2008-01-01

    Background: An important theory of attention suggests that there are three separate networks that execute discrete cognitive functions. The "alerting" network acquires and maintains an alert state, the "orienting" network selects information from sensory input and the "conflict" network resolves conflict that arises between potential responses.…

  7. Musical experience shapes top-down auditory mechanisms: evidence from masking and auditory attention performance.

    Science.gov (United States)

    Strait, Dana L; Kraus, Nina; Parbery-Clark, Alexandra; Ashley, Richard

    2010-03-01

    A growing body of research suggests that cognitive functions, such as attention and memory, drive perception by tuning sensory mechanisms to relevant acoustic features. Long-term musical experience also modulates lower-level auditory function, although the mechanisms by which this occurs remain uncertain. In order to tease apart the mechanisms that drive perceptual enhancements in musicians, we posed the question: do well-developed cognitive abilities fine-tune auditory perception in a top-down fashion? We administered a standardized battery of perceptual and cognitive tests to adult musicians and non-musicians, including tasks either more or less susceptible to cognitive control (e.g., backward versus simultaneous masking) and more or less dependent on auditory or visual processing (e.g., auditory versus visual attention). Outcomes indicate lower perceptual thresholds in musicians specifically for auditory tasks that relate with cognitive abilities, such as backward masking and auditory attention. These enhancements were observed in the absence of group differences for the simultaneous masking and visual attention tasks. Our results suggest that long-term musical practice strengthens cognitive functions and that these functions benefit auditory skills. Musical training bolsters higher-level mechanisms that, when impaired, relate to language and literacy deficits. Thus, musical training may serve to lessen the impact of these deficits by strengthening the corticofugal system for hearing. 2009 Elsevier B.V. All rights reserved.

  8. Attentional bias in high math-anxious individuals: evidence from an emotional Stroop task

    Science.gov (United States)

    Suárez-Pellicioni, Macarena; Núñez-Peña, Maria Isabel; Colomé, Àngels

    2015-01-01

    Attentional bias toward threatening or emotional information is considered a cognitive marker of anxiety, and it has been described in various clinical and subclinical populations. This study used an emotional Stroop task to investigate whether math anxiety is characterized by an attentional bias toward math-related words. Two previous studies failed to observe such an effect in math-anxious individuals, although the authors acknowledged certain methodological limitations that the present study seeks to avoid. Twenty high math-anxious (HMA) and 20 low math-anxious (LMA) individuals were presented with an emotional Stroop task including math-related and neutral words. Participants in the two groups did not differ in trait anxiety or depression. We found that the HMA group showed slower response times to math-related words than to neutral words, as well as a greater attentional bias (math-related – neutral difference score) than the LMA one, which constitutes the first demonstration of an attentional bias toward math-related words in HMA individuals. PMID:26539137

  9. Attentional bias in high math-anxious individuals: evidence from an emotional Stroop task

    Directory of Open Access Journals (Sweden)

    MACARENA eSUÁREZ PELLICIONI

    2015-10-01

    Full Text Available Attentional bias towards threatening or emotional information is considered a cognitive marker of anxiety, and it has been described in various clinical and subclinical populations. This study used an emotional Stroop task to investigate whether math anxiety is characterized by an attentional bias towards math-related words. Two previous studies failed to observe such an effect in math-anxious individuals, although the authors acknowledged certain methodological limitations that the present study seeks to avoid. Twenty high math-anxious (HMA and 20 low math-anxious (LMA individuals were presented with an emotional Stroop task including math-related and neutral words. Participants in the two groups did not differ in trait anxiety or depression. We found that the HMA group showed slower response times to math-related words than to neutral words, as well as a greater attentional bias (math-related – neutral difference score than the LMA one, which constitutes the first demonstration of an attentional bias towards math-related words in HMA individuals.

  10. Neural Evidence for a Distinction between Short-Term Memory and the Focus of Attention

    Science.gov (United States)

    Lewis-Peacock, Jarrod A.; Drysdale, Andrew T.; Oberauer, Klaus; Postle, Bradley R.

    2012-01-01

    It is widely assumed that the short-term retention of information is accomplished via maintenance of an active neural trace. However, we demonstrate that memory can be preserved across a brief delay despite the apparent loss of sustained representations. Delay period activity may, in fact, reflect the focus of attention, rather than STM. We…

  11. Pupil dilation indicates the coding of past prediction errors: Evidence for attentional learning theory.

    Science.gov (United States)

    Koenig, Stephan; Uengoer, Metin; Lachnit, Harald

    2018-04-01

    The attentional learning theory of Pearce and Hall () predicts more attention to uncertain cues that have caused a high prediction error in the past. We examined how the cue-elicited pupil dilation during associative learning was linked to such error-driven attentional processes. In three experiments, participants were trained to acquire associations between different cues and their appetitive (Experiment 1), motor (Experiment 2), or aversive (Experiment 3) outcomes. All experiments were designed to examine differences in the processing of continuously reinforced cues (consistently followed by the outcome) versus partially reinforced, uncertain cues (randomly followed by the outcome). We measured the pupil dilation elicited by the cues in anticipation of the outcome and analyzed how this conditioned pupil response changed over the course of learning. In all experiments, changes in pupil size complied with the same basic pattern: During early learning, consistently reinforced cues elicited greater pupil dilation than uncertain, randomly reinforced cues, but this effect gradually reversed to yield a greater pupil dilation for uncertain cues toward the end of learning. The pattern of data accords with the changes in prediction error and error-driven attention formalized by the Pearce-Hall theory. © 2017 The Authors. Psychophysiology published by Wiley Periodicals, Inc. on behalf of Society for Psychophysiological Research.

  12. Focus of spatial attention during spatial working memory maintenance : Evidence from pupillary light response

    NARCIS (Netherlands)

    Fabius, J. H.; Mathôt, Sebastiaan; Schut, M. J.; Nijboer, T. C.W.; Van der Stigchel, S.

    2017-01-01

    In this experiment, we demonstrate modulation of the pupillary light response by spatial working memory (SWM). The pupillary light response has previously been shown to reflect the focus of covert attention, as demonstrated by smaller pupil sizes when a subject covertly attends a location on a

  13. A bottom-up model of spatial attention predicts human error patterns in rapid scene recognition.

    Science.gov (United States)

    Einhäuser, Wolfgang; Mundhenk, T Nathan; Baldi, Pierre; Koch, Christof; Itti, Laurent

    2007-07-20

    Humans demonstrate a peculiar ability to detect complex targets in rapidly presented natural scenes. Recent studies suggest that (nearly) no focal attention is required for overall performance in such tasks. Little is known, however, of how detection performance varies from trial to trial and which stages in the processing hierarchy limit performance: bottom-up visual processing (attentional selection and/or recognition) or top-down factors (e.g., decision-making, memory, or alertness fluctuations)? To investigate the relative contribution of these factors, eight human observers performed an animal detection task in natural scenes presented at 20 Hz. Trial-by-trial performance was highly consistent across observers, far exceeding the prediction of independent errors. This consistency demonstrates that performance is not primarily limited by idiosyncratic factors but by visual processing. Two statistical stimulus properties, contrast variation in the target image and the information-theoretical measure of "surprise" in adjacent images, predict performance on a trial-by-trial basis. These measures are tightly related to spatial attention, demonstrating that spatial attention and rapid target detection share common mechanisms. To isolate the causal contribution of the surprise measure, eight additional observers performed the animal detection task in sequences that were reordered versions of those all subjects had correctly recognized in the first experiment. Reordering increased surprise before and/or after the target while keeping the target and distractors themselves unchanged. Surprise enhancement impaired target detection in all observers. Consequently, and contrary to several previously published findings, our results demonstrate that attentional limitations, rather than target recognition alone, affect the detection of targets in rapidly presented visual sequences.

  14. Evidence for a Priori Existence of Attentional Bias Subgroups in Emotional Processing of Aversive Stimuli

    Directory of Open Access Journals (Sweden)

    Casper H. van Heck

    2017-05-01

    Full Text Available Little is known regarding inter-individual differences in attentional biases for pain-related information; more knowledge is crucial, since these biases have been associated with differences in pain processing as well as in predicting the risk of postoperative pain. The present study investigated EEG correlates of attentional bias patterns for pain-related information, with specific focus on avoidance- and vigilance-like behavior. Forty-one participants performed a dot-probe task, where neutral and pain-related words were used to create neutral, congruent, incongruent, and double (two pain-related words trials. EEG was recorded, which was used to generate ERP's of the word-processing phase and the post-dot phase. Participants were placed in two subgroups based on the direction of their attentional bias (either positive; toward the pain-related words, or negative; away from pain-related words. Using t-profiles, four latency windows were identified on which the two subgroups differed significantly. These latency windows yield areas which correspond with the P1-N1 domain and the P3b for the word-processing phase, while the post-dot phase latency windows cover the areas of the P200 and the P3b. The two subgroups show differences on congruent, incongruent, and the double trials, but interestingly also on the neutral trials. Most notably, the area in the word-phase associated with the P3b is diminished in the subgroup showing a negative bias. The deflections associated with both early and late attentional components, including the P3B, as well as a positive deflection in the timeframe of proposed response evaluation processes differ significantly between subgroups. In this study we demonstrated that different attentional biases exist in the healthy population, by showing differences in ERP's. We also show differences in processing neutral trials, which suggests there are fundamental differences between these groups in processing words in general.

  15. Effects of working memory load on visual selective attention: Behavioral and electrophysiological evidence

    Directory of Open Access Journals (Sweden)

    Nikki ePratt

    2011-06-01

    Full Text Available Working memory and attention interact in a way that enables us to focus on relevant items and maintain current goals. The influence of working memory on attention has been noted in several studies using dual task designs. Multitasking increases the demands on working memory and reduces the amount of resources available for cognitive control functions such as resolving stimulus conflict. However, few studies have investigated the temporal activation of the cortex while multitasking. The present study addresses the extent to which working memory load influences early (P1 and late (P300 attention-sensitive event-related potential (ERP components using a dual task paradigm. Participants performed an arrow flanker task alone (single task condition or concurrently with a Sternberg memory task (dual task condition. In the flanker task, participants responded to the direction of a central arrow surrounded by congruent or incongruent arrows. In the dual task condition, participants were presented with a Sternberg task that consisted of either 4 or 7 consonants to remember prior to a short block of flanker trials. Participants were slower and less accurate on incongruent versus congruent trials. Furthermore, accuracy on incongruent trials was reduced in both dual task conditions. Likewise, P300 amplitude to incongruent flanker stimuli decreased when working memory load increased. These findings suggest that interference from incongruent flankers was more difficult to suppress when working memory was taxed. In addition, P1 amplitude was diminished on all flanker trials in the dual task condition. This result indicates that top-down attentional control over early visual processing is diminished by increasing demands on working memory. Both the behavioral and electrophysiological results suggest that working memory is critical in maintaining attentional focus and resolving conflict.

  16. Modulatory Effects of Attention on Lateral Inhibition in the Human Auditory Cortex.

    Directory of Open Access Journals (Sweden)

    Alva Engell

    Full Text Available Reduced neural processing of a tone is observed when it is presented after a sound whose spectral range closely frames the frequency of the tone. This observation might be explained by the mechanism of lateral inhibition (LI due to inhibitory interneurons in the auditory system. So far, several characteristics of bottom up influences on LI have been identified, while the influence of top-down processes such as directed attention on LI has not been investigated. Hence, the study at hand aims at investigating the modulatory effects of focused attention on LI in the human auditory cortex. In the magnetoencephalograph, we present two types of masking sounds (white noise vs. withe noise passing through a notch filter centered at a specific frequency, followed by a test tone with a frequency corresponding to the center-frequency of the notch filter. Simultaneously, subjects were presented with visual input on a screen. To modulate the focus of attention, subjects were instructed to concentrate either on the auditory input or the visual stimuli. More specific, on one half of the trials, subjects were instructed to detect small deviations in loudness in the masking sounds while on the other half of the trials subjects were asked to detect target stimuli on the screen. The results revealed a reduction in neural activation due to LI, which was larger during auditory compared to visual focused attention. Attentional modulations of LI were observed in two post-N1m time intervals. These findings underline the robustness of reduced neural activation due to LI in the auditory cortex and point towards the important role of attention on the modulation of this mechanism in more evaluative processing stages.

  17. Modulatory Effects of Attention on Lateral Inhibition in the Human Auditory Cortex.

    Science.gov (United States)

    Engell, Alva; Junghöfer, Markus; Stein, Alwina; Lau, Pia; Wunderlich, Robert; Wollbrink, Andreas; Pantev, Christo

    2016-01-01

    Reduced neural processing of a tone is observed when it is presented after a sound whose spectral range closely frames the frequency of the tone. This observation might be explained by the mechanism of lateral inhibition (LI) due to inhibitory interneurons in the auditory system. So far, several characteristics of bottom up influences on LI have been identified, while the influence of top-down processes such as directed attention on LI has not been investigated. Hence, the study at hand aims at investigating the modulatory effects of focused attention on LI in the human auditory cortex. In the magnetoencephalograph, we present two types of masking sounds (white noise vs. withe noise passing through a notch filter centered at a specific frequency), followed by a test tone with a frequency corresponding to the center-frequency of the notch filter. Simultaneously, subjects were presented with visual input on a screen. To modulate the focus of attention, subjects were instructed to concentrate either on the auditory input or the visual stimuli. More specific, on one half of the trials, subjects were instructed to detect small deviations in loudness in the masking sounds while on the other half of the trials subjects were asked to detect target stimuli on the screen. The results revealed a reduction in neural activation due to LI, which was larger during auditory compared to visual focused attention. Attentional modulations of LI were observed in two post-N1m time intervals. These findings underline the robustness of reduced neural activation due to LI in the auditory cortex and point towards the important role of attention on the modulation of this mechanism in more evaluative processing stages.

  18. Short-term retention of visual information: Evidence in support of feature-based attention as an underlying mechanism.

    Science.gov (United States)

    Sneve, Markus H; Sreenivasan, Kartik K; Alnæs, Dag; Endestad, Tor; Magnussen, Svein

    2015-01-01

    Retention of features in visual short-term memory (VSTM) involves maintenance of sensory traces in early visual cortex. However, the mechanism through which this is accomplished is not known. Here, we formulate specific hypotheses derived from studies on feature-based attention to test the prediction that visual cortex is recruited by attentional mechanisms during VSTM of low-level features. Functional magnetic resonance imaging (fMRI) of human visual areas revealed that neural populations coding for task-irrelevant feature information are suppressed during maintenance of detailed spatial frequency memory representations. The narrow spectral extent of this suppression agrees well with known effects of feature-based attention. Additionally, analyses of effective connectivity during maintenance between retinotopic areas in visual cortex show that the observed highlighting of task-relevant parts of the feature spectrum originates in V4, a visual area strongly connected with higher-level control regions and known to convey top-down influence to earlier visual areas during attentional tasks. In line with this property of V4 during attentional operations, we demonstrate that modulations of earlier visual areas during memory maintenance have behavioral consequences, and that these modulations are a result of influences from V4. Copyright © 2014 Elsevier Ltd. All rights reserved.

  19. Attention to Color Sharpens Neural Population Tuning via Feedback Processing in the Human Visual Cortex Hierarchy.

    Science.gov (United States)

    Bartsch, Mandy V; Loewe, Kristian; Merkel, Christian; Heinze, Hans-Jochen; Schoenfeld, Mircea A; Tsotsos, John K; Hopf, Jens-Max

    2017-10-25

    Attention can facilitate the selection of elementary object features such as color, orientation, or motion. This is referred to as feature-based attention and it is commonly attributed to a modulation of the gain and tuning of feature-selective units in visual cortex. Although gain mechanisms are well characterized, little is known about the cortical processes underlying the sharpening of feature selectivity. Here, we show with high-resolution magnetoencephalography in human observers (men and women) that sharpened selectivity for a particular color arises from feedback processing in the human visual cortex hierarchy. To assess color selectivity, we analyze the response to a color probe that varies in color distance from an attended color target. We find that attention causes an initial gain enhancement in anterior ventral extrastriate cortex that is coarsely selective for the target color and transitions within ∼100 ms into a sharper tuned profile in more posterior ventral occipital cortex. We conclude that attention sharpens selectivity over time by attenuating the response at lower levels of the cortical hierarchy to color values neighboring the target in color space. These observations support computational models proposing that attention tunes feature selectivity in visual cortex through backward-propagating attenuation of units less tuned to the target. SIGNIFICANCE STATEMENT Whether searching for your car, a particular item of clothing, or just obeying traffic lights, in everyday life, we must select items based on color. But how does attention allow us to select a specific color? Here, we use high spatiotemporal resolution neuromagnetic recordings to examine how color selectivity emerges in the human brain. We find that color selectivity evolves as a coarse to fine process from higher to lower levels within the visual cortex hierarchy. Our observations support computational models proposing that feature selectivity increases over time by attenuating the

  20. Object formation in visual working memory: Evidence from object-based attention.

    Science.gov (United States)

    Zhou, Jifan; Zhang, Haihang; Ding, Xiaowei; Shui, Rende; Shen, Mowei

    2016-09-01

    We report on how visual working memory (VWM) forms intact perceptual representations of visual objects using sub-object elements. Specifically, when objects were divided into fragments and sequentially encoded into VWM, the fragments were involuntarily integrated into objects in VWM, as evidenced by the occurrence of both positive and negative object-based attention effects: In Experiment 1, when subjects' attention was cued to a location occupied by the VWM object, the target presented at the location of that object was perceived as occurring earlier than that presented at the location of a different object. In Experiment 2, responses to a target were significantly slower when a distractor was presented at the same location as the cued object (Experiment 2). These results suggest that object fragments can be integrated into objects within VWM in a manner similar to that of visual perception. Copyright © 2016 Elsevier B.V. All rights reserved.

  1. Time to learn: evidence for two types of attentional guidance in contextual cueing.

    Science.gov (United States)

    Ogawa, Hirokazu; Watanabe, Katsumi

    2010-01-01

    Repetition of the same spatial configurations of a search display implicitly facilitates performance of a visual-search task when the target location in the display is fixed. The improvement of performance is referred to as contextual cueing. We examined whether the association process between target location and surrounding configuration of distractors occurs during active search or at the instant the target is found. To dissociate these two processes, we changed the surrounding configuration of the distractors at the instant of target detection so that the layout where the participants had searched for the target and the layout presented at the instant of target detection differed. The results demonstrated that both processes are responsible for the contextual-cueing effect, but they differ in the accuracies of attentional guidance and their time courses, suggesting that two different types of attentional-guidance processes may be involved in contextual cueing.

  2. The relationship between bilingualism and selective attention in young adults: Evidence from an ambiguous figures task.

    Science.gov (United States)

    Chung-Fat-Yim, Ashley; Sorge, Geoff B; Bialystok, Ellen

    2017-03-01

    Previous research has shown that bilinguals outperform monolinguals on a variety of tasks that have been described as involving executive functioning, but the precise mechanism for those effects or a clear definition for "executive function" is unknown. This uncertainty has led to a number of studies for which no performance difference between monolingual and bilingual adults has been detected. One approach to clarifying these issues comes from research with children showing that bilinguals were more able than their monolingual peers to perceive both interpretations of an ambiguous figure, an ability that is more tied to a conception of selective attention than to specific components of executive function. The present study extends this notion to adults by assessing their ability to see the alternative image in an ambiguous figure. Bilinguals performed this task more efficiently than monolinguals by requiring fewer cues to identify the second image. This finding has implications for the role of selective attention in performance differences between monolinguals and bilinguals.

  3. Attention Determines Contextual Enhancement versus Suppression in Human Primary Visual Cortex.

    Science.gov (United States)

    Flevaris, Anastasia V; Murray, Scott O

    2015-09-02

    Neural responses in primary visual cortex (V1) depend on stimulus context in seemingly complex ways. For example, responses to an oriented stimulus can be suppressed when it is flanked by iso-oriented versus orthogonally oriented stimuli but can also be enhanced when attention is directed to iso-oriented versus orthogonal flanking stimuli. Thus the exact same contextual stimulus arrangement can have completely opposite effects on neural responses-in some cases leading to orientation-tuned suppression and in other cases leading to orientation-tuned enhancement. Here we show that stimulus-based suppression and enhancement of fMRI responses in humans depends on small changes in the focus of attention and can be explained by a model that combines feature-based attention with response normalization. Neurons in the primary visual cortex (V1) respond to stimuli within a restricted portion of the visual field, termed their "receptive field." However, neuronal responses can also be influenced by stimuli that surround a receptive field, although the nature of these contextual interactions and underlying neural mechanisms are debated. Here we show that the response in V1 to a stimulus in the same context can either be suppressed or enhanced depending on the focus of attention. We are able to explain the results using a simple computational model that combines two well established properties of visual cortical responses: response normalization and feature-based enhancement. Copyright © 2015 the authors 0270-6474/15/3512273-08$15.00/0.

  4. Pupil size directly modulates the feedforward response in human primary visual cortex independently of attention.

    Science.gov (United States)

    Bombeke, Klaas; Duthoo, Wout; Mueller, Sven C; Hopf, Jens-Max; Boehler, C Nico

    2016-02-15

    Controversy revolves around the question of whether psychological factors like attention and emotion can influence the initial feedforward response in primary visual cortex (V1). Although traditionally, the electrophysiological correlate of this response in humans (the C1 component) has been found to be unaltered by psychological influences, a number of recent studies have described attentional and emotional modulations. Yet, research into psychological effects on the feedforward V1 response has neglected possible direct contributions of concomitant pupil-size modulations, which are known to also occur under various conditions of attentional load and emotional state. Here we tested the hypothesis that such pupil-size differences themselves directly affect the feedforward V1 response. We report data from two complementary experiments, in which we used procedures that modulate pupil size without differences in attentional load or emotion while simultaneously recording pupil-size and EEG data. Our results confirm that pupil size indeed directly influences the feedforward V1 response, showing an inverse relationship between pupil size and early V1 activity. While it is unclear in how far this effect represents a functionally-relevant adaptation, it identifies pupil-size differences as an important modulating factor of the feedforward response of V1 and could hence represent a confounding variable in research investigating the neural influence of psychological factors on early visual processing. Copyright © 2015 Elsevier Inc. All rights reserved.

  5. Embodied niche construction in the hominin lineage: semiotic structure and sustained attention in human embodied cognition

    Science.gov (United States)

    Stutz, Aaron J.

    2014-01-01

    Human evolution unfolded through a rather distinctive, dynamically constructed ecological niche. The human niche is not only generally terrestrial in habitat, while being flexibly and extensively heterotrophic in food-web connections. It is also defined by semiotically structured and structuring embodied cognitive interfaces, connecting the individual organism with the wider environment. The embodied dimensions of niche-population co-evolution have long involved semiotic system construction, which I hypothesize to be an evolutionarily primitive aspect of learning and higher-level cognitive integration and attention in the great apes and humans alike. A clearly pre-linguistic form of semiotic cognitive structuration is suggested to involve recursively learned and constructed object icons. Higher-level cognitive iconic representation of visually, auditorily, or haptically perceived extrasomatic objects would be learned and evoked through indexical connections to proprioceptive and affective somatic states. Thus, private cognitive signs would be defined, not only by their learned and perceived extrasomatic referents, but also by their associations to iconically represented somatic states. This evolutionary modification of animal associative learning is suggested to be adaptive in ecological niches occupied by long-lived, large-bodied ape species, facilitating memory construction and recall in highly varied foraging and social contexts, while sustaining selective attention during goal-directed behavioral sequences. The embodied niche construction (ENC) hypothesis of human evolution posits that in the early hominin lineage, natural selection further modified the ancestral ape semiotic adaptations, favoring the recursive structuration of concise iconic narratives of embodied interaction with the environment. PMID:25136323

  6. Priming of pop-out modulates attentional target selection in visual search: Behavioural and electrophysiological evidence

    OpenAIRE

    Eimer, Martin; Kiss, Monika; Cheung, Theodore

    2009-01-01

    Previous behavioural studies have shown that the repetition of target or distractor features across trials speeds pop-out visual search. We obtained behavioural and event-related brain potential (ERP) measures in two experiments where participants searched for a colour singleton target among homogeneously coloured distractors. An ERP marker of spatially selective attention (N2pc component) was delayed when either target or distractor colours were swapped across successive trials, demonstratin...

  7. To beg, or not to beg? That is the question: mangabeys modify their production of requesting gestures in response to human's attentional states.

    Directory of Open Access Journals (Sweden)

    Audrey Maille

    Full Text Available BACKGROUND: Although gestural communication is widespread in primates, few studies focused on the cognitive processes underlying gestures produced by monkeys. METHODOLOGY/PRINCIPAL FINDINGS: The present study asked whether red-capped mangabeys (Cercocebus torquatus trained to produce visually based requesting gestures modify their gestural behavior in response to human's attentional states. The experimenter held a food item and displayed five different attentional states that differed on the basis of body, head and gaze orientation; mangabeys had to request food by extending an arm toward the food item (begging gesture. Mangabeys were sensitive, at least to some extent, to the human's attentional state. They reacted to some postural cues of a human recipient: they gestured more and faster when both the body and the head of the experimenter were oriented toward them than when they were oriented away. However, they did not seem to use gaze cues to recognize an attentive human: monkeys begged at similar levels regardless of the experimenter's eyes state. CONCLUSIONS/SIGNIFICANCE: These results indicate that mangabeys lowered their production of begging gestures when these could not be perceived by the human who had to respond to it. This finding provides important evidence that acquired begging gestures of monkeys might be used intentionally.

  8. Social exclusion leads to attentional bias to emotional social information: Evidence from eye movement.

    Science.gov (United States)

    Chen, Zhuohao; Du, Jinchen; Xiang, Min; Zhang, Yan; Zhang, Shuyue

    2017-01-01

    Social exclusion has many effects on individuals, including the increased need to belong and elevated sensitivity to social information. Using a self-reporting method, and an eye-tracking technique, this study explored people's need to belong and attentional bias towards the socio-emotional information (pictures of positive and negative facial expressions compared to those of emotionally-neutral expressions) after experiencing a brief episode of social exclusion. We found that: (1) socially-excluded individuals reported higher negative emotions, lower positive emotions, and stronger need to belong than those who were not socially excluded; (2) compared to a control condition, social exclusion caused a longer response time to probe dots after viewing positive or negative face images; (3) social exclusion resulted in a higher frequency ratio of first attentional fixation on both positive and negative emotional facial pictures (but not on the neutral pictures) than the control condition; (4) in the social exclusion condition, participants showed shorter first fixation latency and longer first fixation duration to positive pictures than neutral ones but this effect was not observed for negative pictures; (5) participants who experienced social exclusion also showed longer gazing duration on the positive pictures than those who did not; although group differences also existed for the negative pictures, the gaze duration bias from both groups showed no difference from chance. This study demonstrated the emotional response to social exclusion as well as characterising multiple eye-movement indicators of attentional bias after experiencing social exclusion.

  9. L1 and L2 Spoken Word Processing: Evidence from Divided Attention Paradigm.

    Science.gov (United States)

    Shafiee Nahrkhalaji, Saeedeh; Lotfi, Ahmad Reza; Koosha, Mansour

    2016-10-01

    The present study aims to reveal some facts concerning first language (L 1 ) and second language (L 2 ) spoken-word processing in unbalanced proficient bilinguals using behavioral measures. The intention here is to examine the effects of auditory repetition word priming and semantic priming in first and second languages of these bilinguals. The other goal is to explore the effects of attention manipulation on implicit retrieval of perceptual and conceptual properties of spoken L 1 and L 2 words. In so doing, the participants performed auditory word priming and semantic priming as memory tests in their L 1 and L 2 . In a half of the trials of each experiment, they carried out the memory test while simultaneously performing a secondary task in visual modality. The results revealed that effects of auditory word priming and semantic priming were present when participants processed L 1 and L 2 words in full attention condition. Attention manipulation could reduce priming magnitude in both experiments in L 2 . Moreover, L 2 word retrieval increases the reaction times and reduces accuracy on the simultaneous secondary task to protect its own accuracy and speed.

  10. Allostatic dysregulation of natural reward processing in prescription opioid misuse: autonomic and attentional evidence.

    Science.gov (United States)

    Garland, Eric L; Froeliger, Brett; Howard, Matthew O

    2015-02-01

    Chronic pain patients who misuse prescription opioids may suffer from allostatic dysregulation of natural reward processing. Hence, this study examined whether prescription opioid misusers with chronic pain (n=72) evidenced decreased natural reward responsiveness relative to non-misusers with chronic pain (n=26). Subjects completed a dot probe task containing pain-related, opioid-related, and natural reward stimuli while attentional bias (AB) scores and heart rate variability (HRV) responses were assessed. Compared to non-misusers, misusers evidenced significantly more attenuated HRV responses to opioid, pain, and natural reward cues presented during the dot probe task. These significant between-groups differences in HRV were largest during attention to natural reward cues, but became non-significant in a sensitivity analysis controlling for opioid dosing. In addition, non-misusers evidenced an AB toward natural reward cues, whereas misusers did not. Findings suggest that opioid misusers exhibit attentional and autonomic deficits during reward processing. Copyright © 2015 Elsevier B.V. All rights reserved.

  11. Conjunction of color and form without attention: evidence from an orientation-contingent color aftereffect.

    Science.gov (United States)

    Houck, M R; Hoffman, J E

    1986-05-01

    According to feature-integration theory (Treisman & Gelade, 1980), separable features such as color and shape exist in separate maps in preattentive vision and can be integrated only through the use of spatial attention. Many perceptual aftereffects, however, which are also assumed to reflect the features available in preattentive vision, are sensitive to conjunctions of features. One possible resolution of these views holds that adaptation to conjunctions depends on spatial attention. We tested this proposition by presenting observers with gratings varying in color and orientation. The resulting McCollough aftereffects were independent of whether the adaptation stimuli were presented inside or outside of the focus of spatial attention. Therefore, color and shape appear to be conjoined preattentively, when perceptual aftereffects are used as the measure. These same stimuli, however, appeared to be separable in two additional experiments that required observers to search for gratings of a specified color and orientation. These results show that different experimental procedures may be tapping into different stages of preattentive vision.

  12. Attachment and children's biased attentional processing: evidence for the exclusion of attachment-related information.

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    Eva Vandevivere

    Full Text Available Research in both infants and adults demonstrated that attachment expectations are associated with the attentional processing of attachment-related information. However, this research suffered from methodological issues and has not been validated across ages. Employing a more ecologically valid paradigm to measure attentional processes by virtue of eye tracking, the current study tested the defensive exclusion hypothesis in late childhood. According to this hypothesis, insecurely attached children are assumed to defensively exclude attachment-related information. We hypothesized that securely attached children process attachment- related neutral and emotional information in a more open manner compared to insecurely attached children. Sixty-two children (59.7% girls, 8-12 years completed two different tasks, while eye movements were recorded: task one presented an array of neutral faces including mother and unfamiliar women and task two presented the same with happy and angry faces. Results indicated that more securely attached children looked longer at mother's face regardless of the emotional expression. Also, they tend to have more maintained attention to mother's neutral face. Furthermore, more attachment avoidance was related to a reduced total viewing time of mother's neutral, happy, and angry face. Attachment anxiety was not consistently related to the processing of mother's face. Findings support the theoretical assumption that securely attached children have an open manner of processing all attachment-related information.

  13. Attentional selection of relative SF mediates global versus local processing: evidence from EEG.

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    Flevaris, Anastasia V; Bentin, Shlomo; Robertson, Lynn C

    2011-06-13

    Previous research on functional hemispheric differences in visual processing has associated global perception with low spatial frequency (LSF) processing biases of the right hemisphere (RH) and local perception with high spatial frequency (HSF) processing biases of the left hemisphere (LH). The Double Filtering by Frequency (DFF) theory expanded this hypothesis by proposing that visual attention selects and is directed to relatively LSFs by the RH and relatively HSFs by the LH, suggesting a direct causal relationship between SF selection and global versus local perception. We tested this idea in the current experiment by comparing activity in the EEG recorded at posterior right and posterior left hemisphere sites while participants' attention was directed to global or local levels of processing after selection of relatively LSFs versus HSFs in a previous stimulus. Hemispheric asymmetry in the alpha band (8-12 Hz) during preparation for global versus local processing was modulated by the selected SF. In contrast, preparatory activity associated with selection of SF was not modulated by the previously attended level (global/local). These results support the DFF theory that top-down attentional selection of SF mediates global and local processing.

  14. An investigation into the temporal dimension of the Mozart effect: evidence from the attentional blink task.

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    Ho, Cristy; Mason, Oliver; Spence, Charles

    2007-05-01

    In the present study, we examined whether the 'Mozart effect' would influence participants' temporal attention using a visual attentional blink (AB) task that provides a reliable measure of the temporal dynamics of visual attention. The 'Mozart effect' refers to the specific claim that listening to Mozart's Sonata for Two Pianos in D Major, K.448 can improve the performance in spatio-temporal tasks. Participants had to try and identify two target digits (in their correct order of presentation) presented amongst a stream of distractor letters in three different conditions (presented in separate blocks of trials): while listening to the Mozart sonata played normally, while listening to the same Mozart sonata played in reverse, and while in silence. The results showed that the participants were able to detect the second target (T2) significantly more accurately (given the correct detection of the first target, T1) in the AB stream when the Mozart sonata was played normally than in either of the other two conditions. Possible explanations for the differential effects of Mozart's music being played normally and in reverse and potential confounds in previous studies reporting a facilitatory 'Mozart effect' are discussed. Our results therefore provide the first empirical demonstration supporting the existence of a purely temporal component to the 'Mozart effect' using a non-spatial visual AB task.

  15. Modulation of induced gamma band activity in the human EEG by attention and visual information processing.

    Science.gov (United States)

    Müller, M M; Gruber, T; Keil, A

    2000-12-01

    Here we present a series of four studies aimed to investigate the link between induced gamma band activity in the human EEG and visual information processing. We demonstrated and validated the modulation of spectral gamma band power by spatial selective visual attention. When subjects attended to a certain stimulus, spectral power was increased as compared to when the same stimulus was ignored. In addition, we showed a shift in spectral gamma band power increase to the contralateral hemisphere when subjects shifted their attention to one visual hemifield. The following study investigated induced gamma band activity and the perception of a Gestalt. Ambiguous rotating figures were used to operationalize the law of good figure (gute Gestalt). We found increased gamma band power at posterior electrode sites when subjects perceived an object. In the last experiment we demonstrated a differential hemispheric gamma band activation when subjects were confronted with emotional pictures. Results of the present experiments in combination with other studies presented in this volume are supportive for the notion that induced gamma band activity in the human EEG is closely related to visual information processing and attentional perceptual mechanisms.

  16. Natural Tendency towards Beauty in Humans: Evidence from Binocular Rivalry.

    Science.gov (United States)

    Mo, Ce; Xia, Tiansheng; Qin, Kaixin; Mo, Lei

    2016-01-01

    Although human preference for beauty is common and compelling in daily life, it remains unknown whether such preference is essentially subserved by social cognitive demands or natural tendency towards beauty encoded in the human mind intrinsically. Here we demonstrate experimentally that humans automatically exhibit preference for visual and moral beauty without explicit cognitive efforts. Using a binocular rivalry paradigm, we identified enhanced gender-independent perceptual dominance for physically attractive persons, and the results suggested universal preference for visual beauty based on perceivable forms. Moreover, we also identified perceptual dominance enhancement for characters associated with virtuous descriptions after controlling for facial attractiveness and vigilance-related attention effects, which suggested a similar implicit preference for moral beauty conveyed in prosocial behaviours. Our findings show that behavioural preference for beauty is driven by an inherent natural tendency towards beauty in humans rather than explicit social cognitive processes.

  17. Lines of evidence for environmentally driven human migration

    Science.gov (United States)

    Davis, K. F.; D'Odorico, P.

    2012-12-01

    International human migration is an important mechanism that affects, and is affected by, various human and natural systems. With the number of people living outside their countries of origin currently estimated at 214 million people and projected to potentially reach more than 400 million people by mid-century, the topic of international human movements presents possible advantages and pitfalls for both sending and receiving countries on multiple fronts (e.g. economic, environmental, political and cultural). Understanding how human migration interacts with human and natural systems is therefore essential in realizing a sustainable and balanced future. While the study of international migration has historically been motivated largely by economic and political interests, the issue of environmentally induced migration has become increasingly important in light of a rapidly changing climate in conjunction with increasing population pressure on many important resources. Particularly in terms of theoretical and conceptual discussions, environmentally induced human migration has been receiving increased attention in the literature. To date, few studies - many of which focus on internal (intra-national) or regional migration - have attempted to quantify the interactions of human migration and the environment, with little attention paid to the global scale as a result of varying regional factors and lack of sufficient data. Recently available global bilateral migration datasets have been developed that allow for a more comprehensive understanding of human movements between all countries. With these datasets, we seek to elucidate environmental drivers of human migration over the past half-century using a multi-pronged approach. First, using a recently developed universal radiation model, we examine human movements based solely on global population distribution. Next, by comparison of migration movements with selected economic, environmental and human welfare indicators, we

  18. Cortical Dynamics of Contextually Cued Attentive Visual Learning and Search: Spatial and Object Evidence Accumulation

    Science.gov (United States)

    Huang, Tsung-Ren; Grossberg, Stephen

    2010-01-01

    How do humans use target-predictive contextual information to facilitate visual search? How are consistently paired scenic objects and positions learned and used to more efficiently guide search in familiar scenes? For example, humans can learn that a certain combination of objects may define a context for a kitchen and trigger a more efficient…

  19. Evidence of directional and stabilizing selection in contemporary humans.

    Science.gov (United States)

    Sanjak, Jaleal S; Sidorenko, Julia; Robinson, Matthew R; Thornton, Kevin R; Visscher, Peter M

    2018-01-02

    Modern molecular genetic datasets, primarily collected to study the biology of human health and disease, can be used to directly measure the action of natural selection and reveal important features of contemporary human evolution. Here we leverage the UK Biobank data to test for the presence of linear and nonlinear natural selection in a contemporary population of the United Kingdom. We obtain phenotypic and genetic evidence consistent with the action of linear/directional selection. Phenotypic evidence suggests that stabilizing selection, which acts to reduce variance in the population without necessarily modifying the population mean, is widespread and relatively weak in comparison with estimates from other species.

  20. Primate social attention: Species differences and effects of individual experience in humans, great apes, and macaques.

    Directory of Open Access Journals (Sweden)

    Fumihiro Kano

    Full Text Available When viewing social scenes, humans and nonhuman primates focus on particular features, such as the models' eyes, mouth, and action targets. Previous studies reported that such viewing patterns vary significantly across individuals in humans, and also across closely-related primate species. However, the nature of these individual and species differences remains unclear, particularly among nonhuman primates. In large samples of human and nonhuman primates, we examined species differences and the effects of experience on patterns of gaze toward social movies. Experiment 1 examined the species differences across rhesus macaques, nonhuman apes (bonobos, chimpanzees, and orangutans, and humans while they viewed movies of various animals' species-typical behaviors. We found that each species had distinct viewing patterns of the models' faces, eyes, mouths, and action targets. Experiment 2 tested the effect of individuals' experience on chimpanzee and human viewing patterns. We presented movies depicting natural behaviors of chimpanzees to three groups of chimpanzees (individuals from a zoo, a sanctuary, and a research institute differing in their early social and physical experiences. We also presented the same movies to human adults and children differing in their expertise with chimpanzees (experts vs. novices or movie-viewing generally (adults vs. preschoolers. Individuals varied within each species in their patterns of gaze toward models' faces, eyes, mouths, and action targets depending on their unique individual experiences. We thus found that the viewing patterns for social stimuli are both individual- and species-specific in these closely-related primates. Such individual/species-specificities are likely related to both individual experience and species-typical temperament, suggesting that primate individuals acquire their unique attentional biases through both ontogeny and evolution. Such unique attentional biases may help them learn

  1. Primate social attention: Species differences and effects of individual experience in humans, great apes, and macaques.

    Science.gov (United States)

    Kano, Fumihiro; Shepherd, Stephen V; Hirata, Satoshi; Call, Josep

    2018-01-01

    When viewing social scenes, humans and nonhuman primates focus on particular features, such as the models' eyes, mouth, and action targets. Previous studies reported that such viewing patterns vary significantly across individuals in humans, and also across closely-related primate species. However, the nature of these individual and species differences remains unclear, particularly among nonhuman primates. In large samples of human and nonhuman primates, we examined species differences and the effects of experience on patterns of gaze toward social movies. Experiment 1 examined the species differences across rhesus macaques, nonhuman apes (bonobos, chimpanzees, and orangutans), and humans while they viewed movies of various animals' species-typical behaviors. We found that each species had distinct viewing patterns of the models' faces, eyes, mouths, and action targets. Experiment 2 tested the effect of individuals' experience on chimpanzee and human viewing patterns. We presented movies depicting natural behaviors of chimpanzees to three groups of chimpanzees (individuals from a zoo, a sanctuary, and a research institute) differing in their early social and physical experiences. We also presented the same movies to human adults and children differing in their expertise with chimpanzees (experts vs. novices) or movie-viewing generally (adults vs. preschoolers). Individuals varied within each species in their patterns of gaze toward models' faces, eyes, mouths, and action targets depending on their unique individual experiences. We thus found that the viewing patterns for social stimuli are both individual- and species-specific in these closely-related primates. Such individual/species-specificities are likely related to both individual experience and species-typical temperament, suggesting that primate individuals acquire their unique attentional biases through both ontogeny and evolution. Such unique attentional biases may help them learn efficiently about their

  2. Human pupillary dilation response to deviant auditory stimuli: Effects of stimulus properties and voluntary attention

    Directory of Open Access Journals (Sweden)

    Hsin-I eLiao

    2016-02-01

    Full Text Available A unique sound that deviates from a repetitive background sound induces signature neural responses, such as mismatch negativity and novelty P3 response in electro-encephalography studies. Here we show that a deviant auditory stimulus induces a human pupillary dilation response (PDR that is sensitive to the stimulus properties and irrespective whether attention is directed to the sounds or not. In an auditory oddball sequence, we used white noise and 2000-Hz tones as oddballs against repeated 1000-Hz tones. Participants’ pupillary responses were recorded while they listened to the auditory oddball sequence. In Experiment 1, they were not involved in any task. Results show that pupils dilated to the noise oddballs for approximately 4 s, but no such PDR was found for the 2000-Hz tone oddballs. In Experiments 2, two types of visual oddballs were presented synchronously with the auditory oddballs. Participants discriminated the auditory or visual oddballs while trying to ignore stimuli from the other modality. The purpose of this manipulation was to direct attention to or away from the auditory sequence. In Experiment 3, the visual oddballs and the auditory oddballs were always presented asynchronously to prevent residuals of attention on to-be-ignored oddballs due to the concurrence with the attended oddballs. Results show that pupils dilated to both the noise and 2000-Hz tone oddballs in all conditions. Most importantly, PDRs to noise were larger than those to the 2000-Hz tone oddballs regardless of the attention condition in both experiments. The overall results suggest that the stimulus-dependent factor of the PDR appears to be independent of attention.

  3. Human Pupillary Dilation Response to Deviant Auditory Stimuli: Effects of Stimulus Properties and Voluntary Attention.

    Science.gov (United States)

    Liao, Hsin-I; Yoneya, Makoto; Kidani, Shunsuke; Kashino, Makio; Furukawa, Shigeto

    2016-01-01

    A unique sound that deviates from a repetitive background sound induces signature neural responses, such as mismatch negativity and novelty P3 response in electro-encephalography studies. Here we show that a deviant auditory stimulus induces a human pupillary dilation response (PDR) that is sensitive to the stimulus properties and irrespective whether attention is directed to the sounds or not. In an auditory oddball sequence, we used white noise and 2000-Hz tones as oddballs against repeated 1000-Hz tones. Participants' pupillary responses were recorded while they listened to the auditory oddball sequence. In Experiment 1, they were not involved in any task. Results show that pupils dilated to the noise oddballs for approximately 4 s, but no such PDR was found for the 2000-Hz tone oddballs. In Experiments 2, two types of visual oddballs were presented synchronously with the auditory oddballs. Participants discriminated the auditory or visual oddballs while trying to ignore stimuli from the other modality. The purpose of this manipulation was to direct attention to or away from the auditory sequence. In Experiment 3, the visual oddballs and the auditory oddballs were always presented asynchronously to prevent residuals of attention on to-be-ignored oddballs due to the concurrence with the attended oddballs. Results show that pupils dilated to both the noise and 2000-Hz tone oddballs in all conditions. Most importantly, PDRs to noise were larger than those to the 2000-Hz tone oddballs regardless of the attention condition in both experiments. The overall results suggest that the stimulus-dependent factor of the PDR appears to be independent of attention.

  4. Influence of auditory spatial attention on cross-modal semantic priming effect: evidence from N400 effect.

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    Wang, Hongyan; Zhang, Gaoyan; Liu, Baolin

    2017-01-01

    Semantic priming is an important research topic in the field of cognitive neuroscience. Previous studies have shown that the uni-modal semantic priming effect can be modulated by attention. However, the influence of attention on cross-modal semantic priming is unclear. To investigate this issue, the present study combined a cross-modal semantic priming paradigm with an auditory spatial attention paradigm, presenting the visual pictures as the prime stimuli and the semantically related or unrelated sounds as the target stimuli. Event-related potentials results showed that when the target sound was attended to, the N400 effect was evoked. The N400 effect was also observed when the target sound was not attended to, demonstrating that the cross-modal semantic priming effect persists even though the target stimulus is not focused on. Further analyses revealed that the N400 effect evoked by the unattended sound was significantly lower than the effect evoked by the attended sound. This contrast provides new evidence that the cross-modal semantic priming effect can be modulated by attention.

  5. Cross-Modal Decoding of Neural Patterns Associated with Working Memory: Evidence for Attention-Based Accounts of Working Memory.

    Science.gov (United States)

    Majerus, Steve; Cowan, Nelson; Péters, Frédéric; Van Calster, Laurens; Phillips, Christophe; Schrouff, Jessica

    2016-01-01

    Recent studies suggest common neural substrates involved in verbal and visual working memory (WM), interpreted as reflecting shared attention-based, short-term retention mechanisms. We used a machine-learning approach to determine more directly the extent to which common neural patterns characterize retention in verbal WM and visual WM. Verbal WM was assessed via a standard delayed probe recognition task for letter sequences of variable length. Visual WM was assessed via a visual array WM task involving the maintenance of variable amounts of visual information in the focus of attention. We trained a classifier to distinguish neural activation patterns associated with high- and low-visual WM load and tested the ability of this classifier to predict verbal WM load (high-low) from their associated neural activation patterns, and vice versa. We observed significant between-task prediction of load effects during WM maintenance, in posterior parietal and superior frontal regions of the dorsal attention network; in contrast, between-task prediction in sensory processing cortices was restricted to the encoding stage. Furthermore, between-task prediction of load effects was strongest in those participants presenting the highest capacity for the visual WM task. This study provides novel evidence for common, attention-based neural patterns supporting verbal and visual WM. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  6. Drooling in Parkinson's Disease: Evidence of a Role for Divided Attention.

    Science.gov (United States)

    Reynolds, Hannah; Miller, Nick; Walker, Richard

    2018-05-21

    Drooling is a frequently reported symptom in Parkinson's Disease (PD) with significant psychosocial impact and negative health consequences including silent aspiration of saliva with the associated risk of respiratory infections. It is suggested that in PD drooling is associated with inefficient oropharyngeal swallowing which reduces the effective clearance of saliva rather than hyper-salivation. This is compounded by unintended mouth opening and flexed posture increasing anterior loss of saliva. It is reported to occur most frequently during cognitively distracting concurrent tasks suggesting an impact from divided attention in a dual-task situation. However, this supposition has not been systematically examined. This study assessed whether frequency of saliva swallows reduced, and drooling severity and frequency increased, when people with PD engaged in a cognitively distracting task. 18 patients with idiopathic PD reporting daytime drooling on the Unified Parkinson's Disease Rating Scale (UPDRS) were recruited. They completed the Radboud Oral Motor Inventory for PD saliva questionnaire and the Montreal Cognitive Assessment. UPDRS drooling score, disease stage, duration, gender, and age were recorded. Swallow frequency and drooling severity and frequency were measured at rest and during a distracting computer-based language task. There was no significant difference between drooling severity at rest and during distraction (Wilcoxon signed rank test z = - 1.724, p = 0.085). There was a significant difference between at rest and distraction conditions for both drooling frequency (Wilcoxon signed rank test z = - 2.041, p = 0.041) and swallow frequency (Wilcoxon signed rank test z = - 3.054, p = 0.002). Participants swallowed less frequently and drooled more often during the distraction task. The frequency of saliva swallows and drooling are affected by divided attention in a dual-task paradigm. Further studies are needed to explore the

  7. Attentional Bias in Patients with Decompensated Tinnitus: Prima Facie Evidence from Event-Related Potentials.

    Science.gov (United States)

    Li, Zhicheng; Gu, Ruolei; Zeng, Xiangli; Zhong, Weifang; Qi, Min; Cen, Jintian

    2016-01-01

    Tinnitus refers to the auditory perception of sound in the absence of external sound or electric stimuli. The influence of tinnitus on cognitive processing is at the cutting edge of ongoing tinnitus research. In this study, we adopted an objective indicator of attentional processing, i.e. the mismatch negativity (MMN), to assess the attentional bias in patients with decompensated tinnitus. Three kinds of pure tones, D1 (8,000 Hz), S (8,500 Hz) and D2 (9,000 Hz), were used to induce event-related potentials (ERPs) in the normal ear. Employing the oddball paradigm, the task was divided into two blocks in which D1 and D2 were set as deviation stimuli, respectively. Only D2 induced a significant MMN in the tinnitus group, while neither D1 nor D2 was able to induce MMN in the control group. In addition, the ERPs in the left hemisphere, which were recorded within the time window of 90-150 ms (ERP 90-150 ms), were significantly higher than those in the right hemisphere in the tinnitus group, while no significant difference was observed in the control group. Lastly, the amplitude of ERP 90-150 ms in the tinnitus group was significantly higher than that in the control group. These findings suggest that patients with decompensated tinnitus showed automatic processing of acoustic stimuli, thereby indicating that these patients allocated more cognitive resources to acoustic stimulus processing. We suggest that the difficulty in disengaging or facilitated attention of patients might underlie this phenomenon. The limitations of the current study are discussed. © 2016 S. Karger AG, Basel.

  8. Ventromedial Frontal Cortex Is Critical for Guiding Attention to Reward-Predictive Visual Features in Humans.

    Science.gov (United States)

    Vaidya, Avinash R; Fellows, Lesley K

    2015-09-16

    Adaptively interacting with our environment requires extracting information that will allow us to successfully predict reward. This can be a challenge, particularly when there are many candidate cues, and when rewards are probabilistic. Recent work has demonstrated that visual attention is allocated to stimulus features that have been associated with reward on previous trials. The ventromedial frontal lobe (VMF) has been implicated in learning in dynamic environments of this kind, but the mechanism by which this region influences this process is not clear. Here, we hypothesized that the VMF plays a critical role in guiding attention to reward-predictive stimulus features based on feedback. We tested the effects of VMF damage in human subjects on a visual search task in which subjects were primed to attend to task-irrelevant colors associated with different levels of reward, incidental to the search task. Consistent with previous work, we found that distractors had a greater influence on reaction time when they appeared in colors associated with high reward in the previous trial compared with colors associated with low reward in healthy control subjects and patients with prefrontal damage sparing the VMF. However, this reward modulation of attentional priming was absent in patients with VMF damage. Thus, an intact VMF is necessary for directing attention based on experience with cue-reward associations. We suggest that this region plays a role in selecting reward-predictive cues to facilitate future learning. There has been a swell of interest recently in the ventromedial frontal cortex (VMF), a brain region critical to associative learning. However, the underlying mechanism by which this region guides learning is not well understood. Here, we tested the effects of damage to this region in humans on a task in which rewards were linked incidentally to visual features, resulting in trial-by-trial attentional priming. Controls and subjects with prefrontal damage

  9. Attachment Avoidance Is Significantly Related to Attentional Preference for Infant Faces: Evidence from Eye Movement Data.

    Science.gov (United States)

    Jia, Yuncheng; Cheng, Gang; Zhang, Dajun; Ta, Na; Xia, Mu; Ding, Fangyuan

    2017-01-01

    Objective: To determine the influence of adult attachment orientations on infant preference. Methods: We adopted eye-tracking technology to monitor childless college women's eye movements when looking at pairs of faces, including one adult face (man or woman) and one infant face, with three different expressions (happy, sadness, and neutral). The participants ( N = 150; 84% Han ethnicity) were aged 18-29 years ( M = 19.22, SD = 1.72). A random intercepts multilevel linear regression analysis was used to assess the unique contribution of attachment avoidance, determined using the Experiences in Close Relationships scale, to preference for infant faces. Results: Women with higher attachment avoidance showed less infant preference, as shown by less sustained overt attentional bias to the infant face than the adult face based on fixation time and count. Conclusion: Adult attachment might be related to infant preference according to eye movement indices. Women with higher attachment avoidance may lack attentional preference for infant faces. The findings may aid the treatment and remediation of the interactions between children and mothers with insecure attachment.

  10. Evidence inhibition responds reactively to the salience of distracting information during focused attention.

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    Natalie Wyatt

    Full Text Available Along with target amplification, distractor inhibition is regarded as a major contributor to selective attention. Some theories suggest that the strength of inhibitory processing is proportional to the salience of the distractor (i.e., inhibition reacts to the distractor intensity. Other theories suggest that the strength of inhibitory processing does not depend on the salience of the distractor (i.e., inhibition does not react to the distractor intensity. The present study aimed to elucidate the relationship between the intensity of a distractor and its subsequent inhibition during focused attention. A flanker task with a variable distractor-target stimulus-onset asynchrony (SOA was used to measure both distractor interference and distractor inhibition. We manipulated the intensity of the distractor in two separate ways, by varying its distance from the target (Experiment 1 and by varying its brightness (Experiment 2. The results indicate that more intense distractors were associated with both increased interference and stronger distractor inhibition. The latter outcome provides novel support for the reactive inhibition hypothesis, which posits that inhibition reacts to the strength of distractor input, such that more salient distractors elicit stronger inhibition.

  11. Collective attention and stock prices: evidence from Google Trends data on Standard and Poor's 100.

    Directory of Open Access Journals (Sweden)

    Raphael H Heiberger

    Full Text Available Today´s connected world allows people to gather information in shorter intervals than ever before, widely monitored by massive online data sources. As a dramatic economic event, recent financial crisis increased public interest for large companies considerably. In this paper, we exploit this change in information gathering behavior by utilizing Google query volumes as a "bad news" indicator for each corporation listed in the Standard and Poor´s 100 index. Our results provide not only an investment strategy that gains particularly in times of financial turmoil and extensive losses by other market participants, but reveal new sectoral patterns between mass online behavior and (bearish stock market movements. Based on collective attention shifts in search queries for individual companies, hence, these findings can help to identify early warning signs of financial systemic risk. However, our disaggregated data also illustrate the need for further efforts to understand the influence of collective attention shifts on financial behavior in times of regular market activities with less tremendous changes in search volumes.

  12. Collective attention and stock prices: evidence from Google Trends data on Standard and Poor's 100.

    Science.gov (United States)

    Heiberger, Raphael H

    2015-01-01

    Today´s connected world allows people to gather information in shorter intervals than ever before, widely monitored by massive online data sources. As a dramatic economic event, recent financial crisis increased public interest for large companies considerably. In this paper, we exploit this change in information gathering behavior by utilizing Google query volumes as a "bad news" indicator for each corporation listed in the Standard and Poor´s 100 index. Our results provide not only an investment strategy that gains particularly in times of financial turmoil and extensive losses by other market participants, but reveal new sectoral patterns between mass online behavior and (bearish) stock market movements. Based on collective attention shifts in search queries for individual companies, hence, these findings can help to identify early warning signs of financial systemic risk. However, our disaggregated data also illustrate the need for further efforts to understand the influence of collective attention shifts on financial behavior in times of regular market activities with less tremendous changes in search volumes.

  13. Electrophysiological Evidence for Adult Age-Related Sparing and Decrements in Emotion Perception and Attention

    Directory of Open Access Journals (Sweden)

    Joshua W. Pollock

    2012-08-01

    Full Text Available The present study examined adult age differences in processing emotional faces using a psychological refractory period (PRP paradigm. We used both behavioral and event-related potential (P1 component measures. Task 1 was tone discrimination (fuzzy vs. pure tones and Task 2 was emotional facial discrimination (happy vs. angry faces. The stimulus onset asynchrony (SOA between the two tasks was 100 ms, 300 ms, and 900 ms. Earlier research observed age deficits in emotional facial discrimination for negative (angry than for positive (happy faces (Baena et al., 2010. Thus, we predicted that older adults would show decreased attentional efficiency in carrying out dual-task processing on the P1 (a component linked to amygdalar modulation of visual perception; Rotshtein et al., 2010. Both younger and older groups showed significantly higher P1 amplitudes at 100- and 300-ms SOAs than at the 900-ms SOA, and this suggests that both age groups could process Task 2 emotions without central attention. Also, younger adults showed significantly higher P1 activations for angry than for happy faces, but older adults showed no difference. These results are consistent with the idea that younger adults exhibited amygdalar modulation of visual perception, but that older adults did not.

  14. Collective Attention and Stock Prices: Evidence from Google Trends Data on Standard and Poor's 100

    Science.gov (United States)

    Heiberger, Raphael H.

    2015-01-01

    Today´s connected world allows people to gather information in shorter intervals than ever before, widely monitored by massive online data sources. As a dramatic economic event, recent financial crisis increased public interest for large companies considerably. In this paper, we exploit this change in information gathering behavior by utilizing Google query volumes as a "bad news" indicator for each corporation listed in the Standard and Poor´s 100 index. Our results provide not only an investment strategy that gains particularly in times of financial turmoil and extensive losses by other market participants, but reveal new sectoral patterns between mass online behavior and (bearish) stock market movements. Based on collective attention shifts in search queries for individual companies, hence, these findings can help to identify early warning signs of financial systemic risk. However, our disaggregated data also illustrate the need for further efforts to understand the influence of collective attention shifts on financial behavior in times of regular market activities with less tremendous changes in search volumes. PMID:26258498

  15. Gestalt perceptual organization of visual stimuli captures attention automatically: Electrophysiological evidence

    Directory of Open Access Journals (Sweden)

    Francesco Marini

    2016-08-01

    Full Text Available The visual system leverages organizational regularities of perceptual elements to create meaningful representations of the world. One clear example of such function, which has been formalized in the Gestalt psychology principles, is the perceptual grouping of simple visual elements (e.g., lines and arcs into unitary objects (e.g., forms and shapes. The present study sought to characterize automatic attentional capture and related cognitive processing of Gestalt-like visual stimuli at the psychophysiological level by using event-related potentials (ERPs. We measured ERPs during a simple visual reaction time task with bilateral presentations of physically matched elements with or without a Gestalt organization. Results showed that Gestalt (vs. non-Gestalt stimuli are characterized by a larger N2pc together with enhanced ERP amplitudes of non-lateralized components (N1, N2, P3 starting around 150ms post-stimulus onset. Thus, we conclude that Gestalt stimuli capture attention automatically and entail characteristic psychophysiological signatures at both early and late processing stages.

  16. Shifts in attention during mental fatigue: Evidence from subjective, behavioral, physiological, and eye-tracking data

    NARCIS (Netherlands)

    Hopstaken, J.; Linden, D. van der; Bakker, A.B.; Kompier, M.A.J.; Leung, Y.K.

    2016-01-01

    There is an increasing amount of evidence that during mental fatigue, shifts in motivation drive performance rather than reductions in finite mental energy. So far, studies that investigated such an approach have mainly focused on cognitive indicators of task engagement that were measured during

  17. Evidence that humans metabolize benzene via two pathways.

    NARCIS (Netherlands)

    Rappaport, S.M.; Kim, S.; Lan, Q.; Vermeulen, R.C.H.; Waidyanatha, S.; Zhang, L.; Li, G.; Yin, S.; Hayes, R.B.; Rothman, N.; Smith, M.T.

    2009-01-01

    BACKGROUND: Recent evidence has shown that humans metabolize benzene more efficiently at environmental air concentrations than at concentrations > 1 ppm. This led us to speculate that an unidentified metabolic pathway was mainly responsible for benzene metabolism at ambient levels. OBJECTIVE: We

  18. Recognition and attention guidance during contextual cueing in real-world scenes: evidence from eye movements.

    Science.gov (United States)

    Brockmole, James R; Henderson, John M

    2006-07-01

    When confronted with a previously encountered scene, what information is used to guide search to a known target? We contrasted the role of a scene's basic-level category membership with its specific arrangement of visual properties. Observers were repeatedly shown photographs of scenes that contained consistently but arbitrarily located targets, allowing target positions to be associated with scene content. Learned scenes were then unexpectedly mirror reversed, spatially translating visual features as well as the target across the display while preserving the scene's identity and concept. Mirror reversals produced a cost as the eyes initially moved toward the position in the display in which the target had previously appeared. The cost was not complete, however; when initial search failed, the eyes were quickly directed to the target's new position. These results suggest that in real-world scenes, shifts of attention are initially based on scene identity, and subsequent shifts are guided by more detailed information regarding scene and object layout.

  19. Moral concerns increase attention and response monitoring during IAT performance: ERP evidence

    Science.gov (United States)

    Ellemers, Naomi; Derks, Belle; Nieuwenhuis, Sander

    2014-01-01

    Previous research has revealed that people value morality as a more important person characteristic than competence. In this study, we tested whether people adjust their less explicit behavior more to moral than competence values. Participants performed an Implicit Association Test (IAT) that was either framed as a test of their morality or as a test of their competence. The behavioral results revealed a smaller IAT effect (i.e. a weaker negative implicit bias toward Muslims) in the morality condition than in the competence condition. Moreover, event-related potentials indicated increased social categorization of faces (as indexed by the N1 and P150) and enhanced conflict- and error monitoring (N450 and error-related negativity) in the morality condition compared to the competence condition. These findings indicate that an emphasis on morality can increase attentional and motivational processes that help to improve people’s task performance. PMID:23175679

  20. Obese adults have visual attention bias for food cue images: evidence for altered reward system function.

    Science.gov (United States)

    Castellanos, E H; Charboneau, E; Dietrich, M S; Park, S; Bradley, B P; Mogg, K; Cowan, R L

    2009-09-01

    The major aim of this study was to investigate whether the motivational salience of food cues (as reflected by their attention-grabbing properties) differs between obese and normal-weight subjects in a manner consistent with altered reward system function in obesity. A total of 18 obese and 18 normal-weight, otherwise healthy, adult women between the ages of 18 and 35 participated in an eye-tracking paradigm in combination with a visual probe task. Eye movements and reaction time to food and non-food images were recorded during both fasted and fed conditions in a counterbalanced design. Eating behavior and hunger level were assessed by self-report measures. Obese individuals had higher scores than normal-weight individuals on self-report measures of responsiveness to external food cues and vulnerability to disruptions in control of eating behavior. Both obese and normal-weight individuals demonstrated increased gaze duration for food compared to non-food images in the fasted condition. In the fed condition, however, despite reduced hunger in both groups, obese individuals maintained the increased attention to food images, whereas normal-weight individuals had similar gaze duration for food and non-food images. Additionally, obese individuals had preferential orienting toward food images at the onset of each image. Obese and normal-weight individuals did not differ in reaction time measures in the fasted or fed condition. Food cue incentive salience is elevated equally in normal-weight and obese individuals during fasting. Obese individuals retain incentive salience for food cues despite feeding and decreased self-report of hunger. Sensitization to food cues in the environment and their dysregulation in obese individuals may play a role in the development and/or maintenance of obesity.

  1. Functional ADA polymorphism increases sleep depth and reduces vigilant attention in humans.

    Science.gov (United States)

    Bachmann, Valérie; Klaus, Federica; Bodenmann, Sereina; Schäfer, Nikolaus; Brugger, Peter; Huber, Susanne; Berger, Wolfgang; Landolt, Hans-Peter

    2012-04-01

    Homeostatically regulated slow-wave oscillations in non-rapid eye movement (REM) sleep may reflect synaptic changes across the sleep-wake continuum and the restorative function of sleep. The nonsynonymous c.22G>A polymorphism (rs73598374) of adenosine deaminase (ADA) reduces the conversion of adenosine to inosine and predicts baseline differences in sleep slow-wave oscillations. We hypothesized that this polymorphism affects cognitive functions, and investigated whether it modulates electroencephalogram (EEG), behavioral, subjective, and biochemical responses to sleep deprivation. Attention, learning, memory, and executive functioning were quantified in healthy adults. Right-handed carriers of the variant allele (G/A genotype, n = 29) performed worse on the d2 attention task than G/G homozygotes (n = 191). To test whether this difference reflects elevated homeostatic sleep pressure, sleep and sleep EEG before and after sleep deprivation were studied in 2 prospectively matched groups of G/A and G/G genotype subjects. Deep sleep and EEG 0.75- to 1.5-Hz oscillations in non-REM sleep were significantly higher in G/A than in G/G genotype. Moreover, attention and vigor were reduced, whereas waking EEG alpha activity (8.5-12 Hz), sleepiness, fatigue, and α-amylase in saliva were enhanced. These convergent data demonstrate that genetic reduction of ADA activity elevates sleep pressure and plays a key role in sleep and waking quality in humans.

  2. Understanding of visual attention by adult humans (Homo sapiens): a partial replication of Povinelli, Bierschwale, and Cech (1999).

    Science.gov (United States)

    Thomas, Emily; Murphy, Mary; Pitt, Rebecca; Rivers, Angela; Leavens, David A

    2008-11-01

    Povinelli, Bierschwale, and Cech (1999) reported that when tested on a visual attention task, the behavior of juvenile chimpanzees did not support a high-level understanding of visual attention. This study replicates their research using adult humans and aims to investigate the validity of their experimental design. Participants were trained to respond to pointing cues given by an experimenter, and then tested on their ability to locate hidden objects from visual cues. Povinelli et al.'s assertion that the generalization of pointing to gaze is indicative of a high-level framework was not supported by our findings: Training improved performance only on initial probe trials when the experimenter's gaze was not directed at the baited cup. Furthermore, participants performed above chance on such trials, the same result exhibited by chimpanzees and used as evidence by Povinelli et al. to support a low-level framework. These findings, together with the high performance of participants in an incongruent condition, in which the experimenter pointed to or gazed at an unbaited container, challenge the validity of their experimental design. (PsycINFO Database Record (c) 2008 APA, all rights reserved).

  3. Active glass-type human augmented cognition system considering attention and intention

    Science.gov (United States)

    Kim, Bumhwi; Ojha, Amitash; Lee, Minho

    2015-10-01

    Human cognition is the result of an interaction of several complex cognitive processes with limited capabilities. Therefore, the primary objective of human cognitive augmentation is to assist and expand these limited human cognitive capabilities independently or together. In this study, we propose a glass-type human augmented cognition system, which attempts to actively assist human memory functions by providing relevant, necessary and intended information by constantly assessing intention of the user. To achieve this, we exploit selective attention and intention processes. Although the system can be used in various real-life scenarios, we test the performance of the system in a person identity scenario. To detect the intended face, the system analyses the gaze points and change in pupil size to determine the intention of the user. An assessment of the gaze points and change in pupil size together indicates that the user intends to know the identity and information about the person in question. Then, the system retrieves several clues through speech recognition system and retrieves relevant information about the face, which is finally displayed through head-mounted display. We present the performance of several components of the system. Our results show that the active and relevant assistance based on users' intention significantly helps the enhancement of memory functions.

  4. The mind-writing pupil : A human-computer interface based on decoding of covert attention through pupillometry

    NARCIS (Netherlands)

    Mathôt, Sebastiaan; Melmi, Jean Baptiste; Van Der Linden, Lotje; Van Der Stigchel, Stefan

    2016-01-01

    We present a new human-computer interface that is based on decoding of attention through pupillometry. Our method builds on the recent finding that covert visual attention affects the pupillary light response: Your pupil constricts when you covertly (without looking at it) attend to a bright,

  5. Influences of Long-Term Memory-Guided Attention and Stimulus-Guided Attention on Visuospatial Representations within Human Intraparietal Sulcus.

    Science.gov (United States)

    Rosen, Maya L; Stern, Chantal E; Michalka, Samantha W; Devaney, Kathryn J; Somers, David C

    2015-08-12

    Human parietal cortex plays a central role in encoding visuospatial information and multiple visual maps exist within the intraparietal sulcus (IPS), with each hemisphere symmetrically representing contralateral visual space. Two forms of hemispheric asymmetries have been identified in parietal cortex ventrolateral to visuotopic IPS. Key attentional processes are localized to right lateral parietal cortex in the temporoparietal junction and long-term memory (LTM) retrieval processes are localized to the left lateral parietal cortex in the angular gyrus. Here, using fMRI, we investigate how spatial representations of visuotopic IPS are influenced by stimulus-guided visuospatial attention and by LTM-guided visuospatial attention. We replicate prior findings that a hemispheric asymmetry emerges under stimulus-guided attention: in the right hemisphere (RH), visual maps IPS0, IPS1, and IPS2 code attentional targets across the visual field; in the left hemisphere (LH), IPS0-2 codes primarily contralateral targets. We report the novel finding that, under LTM-guided attention, both RH and LH IPS0-2 exhibit bilateral responses and hemispheric symmetry re-emerges. Therefore, we demonstrate that both hemispheres of IPS0-2 are independently capable of dynamically changing spatial coding properties as attentional task demands change. These findings have important implications for understanding visuospatial and memory-retrieval deficits in patients with parietal lobe damage. The human parietal lobe contains multiple maps of the external world that spatially guide perception, action, and cognition. Maps in each cerebral hemisphere code information from the opposite side of space, not from the same side, and the two hemispheres are symmetric. Paradoxically, damage to specific parietal regions that lack spatial maps can cause patients to ignore half of space (hemispatial neglect syndrome), but only for right (not left) hemisphere damage. Conversely, the left parietal cortex has

  6. Embodied Niche Construction in the Hominin Lineage: Semiotic Structure and Sustained Attention in Human Embodied Cognition

    Directory of Open Access Journals (Sweden)

    Aaron Jonas Stutz

    2014-08-01

    Full Text Available Human evolution unfolded through a rather distinctive, dynamically constructed ecological niche. The human niche is not only generally terrestrial in habitat, while being flexibly and extensively heterotrophic in food-web connections. It is also defined by semiotically structured and structuring embodied cognitive interfaces, connecting the individual organism with the wider environment. The embodied dimensions of niche-population co-evolution have long involved semiotic system construction, which I hypothesize to be an evolutionarily primitive aspect of learning and higher-level cognitive integration and attention in the great apes and humans alike. A clearly pre-linguistic form of semiotic cognitive structuration is suggested to involve recursively learned and constructed object icons. Higher-level cognitive iconic representation of visually, auditorily, or haptically perceived extrasomatic objects would be learned and evoked through indexical connections to proprioceptive and affective somatic states. Thus, private cognitive signs would be defined, not only by their learned and perceived extrasomatic referents, but also by their associations to iconically represented somatic states. This evolutionary modification of animal associative learning is suggested to be adaptive in ecological niches occupied by long-lived, large-bodied ape species, facilitating memory construction and recall in highly varied foraging and social contexts, while sustaining selective attention during goal-directed behavioral sequences. The embodied niche construction (ENC hypothesis of human evolution posits that in the early hominin lineage, natural selection further modified the ancestral ape semiotic adaptations, favoring the recursive structuration of concise iconic narratives of embodied interaction with the environment.

  7. Worry or craving? A selective review of evidence for food-related attention biases in obese individuals, eating-disorder patients, restrained eaters and healthy samples.

    Science.gov (United States)

    Werthmann, Jessica; Jansen, Anita; Roefs, Anne

    2015-05-01

    Living in an 'obesogenic' environment poses a serious challenge for weight maintenance. However, many people are able to maintain a healthy weight indicating that not everybody is equally susceptible to the temptations of this food environment. The way in which someone perceives and reacts to food cues, that is, cognitive processes, could underlie differences in susceptibility. An attention bias for food could be such a cognitive factor that contributes to overeating. However, an attention bias for food has also been implicated with restrained eating and eating-disorder symptomatology. The primary aim of the present review was to determine whether an attention bias for food is specifically related to obesity while also reviewing evidence for attention biases in eating-disorder patients, restrained eaters and healthy-weight individuals. Another aim was to systematically examine how selective attention for food relates (causally) to eating behaviour. Current empirical evidence on attention bias for food within obese samples, eating-disorder patients, and, even though to a lesser extent, in restrained eaters is contradictory. However, present experimental studies provide relatively consistent evidence that an attention bias for food contributes to subsequent food intake. This review highlights the need to distinguish not only between different (temporal) attention bias components, but also to take different motivations (craving v. worry) and their impact on attentional processing into account. Overall, the current state of research suggests that biased attention could be one important cognitive mechanism by which the food environment tempts us into overeating.

  8. Evidence for distinct mechanisms underlying attentional priming and sensory memory for bistable perception.

    Science.gov (United States)

    Brinkhuis, M A B; Kristjánsson, Á; Brascamp, J W

    2015-08-01

    Attentional selection in visual search paradigms and perceptual selection in bistable perception paradigms show functional similarities. For example, both are sensitive to trial history: They are biased toward previously selected targets or interpretations. We investigated whether priming by target selection in visual search and sensory memory for bistable perception are related. We did this by presenting two trial types to observers. We presented either ambiguous spheres that rotated over a central axis and could be perceived as rotating in one of two directions, or search displays in which the unambiguously rotating target and distractor spheres closely resembled the two possible interpretations of the ambiguous stimulus. We interleaved both trial types within experiments, to see whether priming by target selection during search trials would affect the perceptual outcome of bistable perception and, conversely, whether sensory memory during bistable perception would affect target selection times during search. Whereas we found intertrial repetition effects among consecutive search trials and among consecutive bistable trials, we did not find cross-paradigm effects. Thus, even though we could ascertain that our experiments robustly elicited processes of both search priming and sensory memory for bistable perception, these same experiments revealed no interaction between the two.

  9. Conscious access is linked to ongoing brain state: electrophysiological evidence from the attentional blink.

    Science.gov (United States)

    Pincham, Hannah L; Szucs, Dénes

    2012-10-01

    Neuroscience explanations of conscious access focus on neural events elicited by stimuli. In contrast, here, we used the attentional blink paradigm in combination with event-related brain potentials to examine whether the ongoing state of the brain before a stimulus can determine both conscious access and the poststimulus neural events associated with consciousness. Participants were required to detect 2 target letters from digit distractors while their brain activity was being recorded. Trials were classified based on whether the secondcritical target (T2) was detected. We found that T2-detection was predetermined by brain activity prior to the onset of the stimulation stream. Specifically, T2-detected trials were predicated by a frontocentral positive going deflection that started more than 200 ms before the stream began. Accurate T2 detection was also accompanied by enhanced poststimulus neural activity, as reflected by a larger P3b component. Furthermore, prestimulus and poststimulus markers of T2-detection were highly correlated with one another. We therefore argue that conscious experiences are shaped by potentially random fluctuations in neural activity. Overall, the results reveal that conscious access is underpinned by an important relationship involving predictive prestimulus neural activity and responsive poststimulus brain activity.

  10. Object-based Encoding in Visual Working Memory: Evidence from Memory-driven Attentional Capture.

    Science.gov (United States)

    Gao, Zaifeng; Yu, Shixian; Zhu, Chengfeng; Shui, Rende; Weng, Xuchu; Li, Peng; Shen, Mowei

    2016-03-09

    Visual working memory (VWM) adopts a specific manner of object-based encoding (OBE) to extract perceptual information: Whenever one feature-dimension is selected for entry into VWM, the others are also extracted. Currently most studies revealing OBE probed an 'irrelevant-change distracting effect', where changes of irrelevant-features dramatically affected the performance of the target feature. However, the existence of irrelevant-feature change may affect participants' processing manner, leading to a false-positive result. The current study conducted a strict examination of OBE in VWM, by probing whether irrelevant-features guided the deployment of attention in visual search. The participants memorized an object's colour yet ignored shape and concurrently performed a visual-search task. They searched for a target line among distractor lines, each embedded within a different object. One object in the search display could match the shape, colour, or both dimensions of the memory item, but this object never contained the target line. Relative to a neutral baseline, where there was no match between the memory and search displays, search time was significantly prolonged in all match conditions, regardless of whether the memory item was displayed for 100 or 1000 ms. These results suggest that task-irrelevant shape was extracted into VWM, supporting OBE in VWM.

  11. Irritable bowel syndrome and symptom severity: evidence of negative attention bias, diminished vigour, and autonomic dysregulation.

    Science.gov (United States)

    Phillips, Kristy; Wright, Bradley J; Kent, Stephen

    2014-07-01

    To determine if cognitive processing, and subjective and physiological responses to stress and relaxation differed between an irritable bowel syndrome (IBS) group and control group. How these variables relate to the severity of IBS symptoms was also determined. Twenty-one IBS participants and 20 controls provided cognitive (attention and processing), subjective (perceived stress and vigour), and physiological (heart rate, blood pressure, and skin conductance) data during a relaxation and stress phase. Logistic regression analyses determined which variables are related to the IBS group and hierarchical linear regression assessed how the variables are related to the severity of IBS symptoms. Subjective and cognitive factors (drowsiness at baseline, total vigour, and reduced Stroop colour-naming accuracy for negative words) are significantly related to IBS, χ2 (3, N=41)=23.67, pself-schema, as well as perceived low vigour were important in categorising IBS. Low subjective vigour and reduced physiological reactivity to both relaxation and stress conditions were associated with IBS severity, suggestive of illness-related allostatic load. Copyright © 2014 Elsevier Inc. All rights reserved.

  12. Robust memory of where from way back when: evidence from behaviour and visual attention.

    Science.gov (United States)

    Bauer, Patricia J; Stewart, Rebekah; Sirkin, Ruth E; Larkina, Marina

    2017-09-01

    Retention of events typically exhibits a sharp initial decrease followed by levelling off of forgetting. In an apparent exception to this general rule, college students have robust memory for their own locations in obscured versions of photographs of their entering classes taken during orientation-related activities, whether tested 2 months or 42 months after the event. Experiment 1 of the present research was a test for conceptual replication of this finding in photographs depicting more than twice the number of students (and thus potential distracters). There was no difference in memory accuracy for personal spatial location across retention intervals of 6-30 months. Experiment 2 featured 40-h and 2-month retention intervals, thereby providing a more fine-grained test of the forgetting function. The findings replicated Experiment 1. In Experiment 3, eye-tracking measures of visual attention revealed that participants rapidly fixated their own spatial locations within the photographs, even in the absence of explicit awareness. In all three experiments, memory for temporal features of the orientation activities (e.g., day and time the photograph was taken) followed the typical forgetting function. The findings suggest differential preservation of episodic memory for where relative to other aspects of events and experiences, such as when.

  13. Direct evidence of milk consumption from ancient human dental calculus.

    Science.gov (United States)

    Warinner, C; Hendy, J; Speller, C; Cappellini, E; Fischer, R; Trachsel, C; Arneborg, J; Lynnerup, N; Craig, O E; Swallow, D M; Fotakis, A; Christensen, R J; Olsen, J V; Liebert, A; Montalva, N; Fiddyment, S; Charlton, S; Mackie, M; Canci, A; Bouwman, A; Rühli, F; Gilbert, M T P; Collins, M J

    2014-11-27

    Milk is a major food of global economic importance, and its consumption is regarded as a classic example of gene-culture evolution. Humans have exploited animal milk as a food resource for at least 8500 years, but the origins, spread, and scale of dairying remain poorly understood. Indirect lines of evidence, such as lipid isotopic ratios of pottery residues, faunal mortality profiles, and lactase persistence allele frequencies, provide a partial picture of this process; however, in order to understand how, where, and when humans consumed milk products, it is necessary to link evidence of consumption directly to individuals and their dairy livestock. Here we report the first direct evidence of milk consumption, the whey protein β-lactoglobulin (BLG), preserved in human dental calculus from the Bronze Age (ca. 3000 BCE) to the present day. Using protein tandem mass spectrometry, we demonstrate that BLG is a species-specific biomarker of dairy consumption, and we identify individuals consuming cattle, sheep, and goat milk products in the archaeological record. We then apply this method to human dental calculus from Greenland's medieval Norse colonies, and report a decline of this biomarker leading up to the abandonment of the Norse Greenland colonies in the 15(th) century CE.

  14. Written threat: Electrophysiological evidence for an attention bias to affective words in social anxiety disorder.

    Science.gov (United States)

    Wabnitz, Pascal; Martens, Ulla; Neuner, Frank

    2016-01-01

    Social anxiety disorder (SAD) is associated with heightened sensitivity to threat cues, typically represented by emotional facial expressions. To examine if this bias can be transferred to a general hypersensitivity or whether it is specific to disorder relevant cues, we investigated electrophysiological correlates of emotional word processing (alpha activity and event-related potentials) in 20 healthy participants and 20 participants with SAD. The experimental task was a silent reading of neutral, positive, physically threatening and socially threatening words (the latter were abusive swear words) while responding to a randomly presented dot. Subsequently, all participants were asked to recall as many words as possible during an unexpected recall test. Participants with SAD showed blunted sensory processing followed by a rapid processing of emotional words during early stages (early posterior negativity - EPN). At later stages, all participants showed enhanced processing of negative (physically and socially threatening) compared to neutral and positive words (N400). Moreover, at later processing stages alpha activity was increased specifically for negative words in participants with SAD but not in healthy controls. Recall of emotional words for all subjects was best for socially threatening words, followed by negative and positive words irrespective of social anxiety. The present findings indicate that SAD is associated with abnormalities in emotional word processing characterised by early hypervigilance to emotional cues followed by cognitive avoidance at later processing stages. Most importantly, the specificity of these attentional biases seems to change as a function of time with a general emotional bias at early and a more specific bias at later processing stages.

  15. The right planum temporale is involved in stimulus-driven, auditory attention--evidence from transcranial magnetic stimulation.

    Directory of Open Access Journals (Sweden)

    Marco Hirnstein

    Full Text Available It is well known that the planum temporale (PT area in the posterior temporal lobe carries out spectro-temporal analysis of auditory stimuli, which is crucial for speech, for example. There are suggestions that the PT is also involved in auditory attention, specifically in the discrimination and selection of stimuli from the left and right ear. However, direct evidence is missing so far. To examine the role of the PT in auditory attention we asked fourteen participants to complete the Bergen Dichotic Listening Test. In this test two different consonant-vowel syllables (e.g., "ba" and "da" are presented simultaneously, one to each ear, and participants are asked to verbally report the syllable they heard best or most clearly. Thus attentional selection of a syllable is stimulus-driven. Each participant completed the test three times: after their left and right PT (located with anatomical brain scans had been stimulated with repetitive transcranial magnetic stimulation (rTMS, which transiently interferes with normal brain functioning in the stimulated sites, and after sham stimulation, where participants were led to believe they had been stimulated but no rTMS was applied (control. After sham stimulation the typical right ear advantage emerged, that is, participants reported relatively more right than left ear syllables, reflecting a left-hemispheric dominance for language. rTMS over the right but not left PT significantly reduced the right ear advantage. This was the result of participants reporting more left and fewer right ear syllables after right PT stimulation, suggesting there was a leftward shift in stimulus selection. Taken together, our findings point to a new function of the PT in addition to auditory perception: particularly the right PT is involved in stimulus selection and (stimulus-driven, auditory attention.

  16. Exploring the Cognitive Foundations of the Shared Attention Mechanism: Evidence for a Relationship between Self-Categorization and Shared Attention across the Autism Spectrum

    Science.gov (United States)

    Skorich, Daniel P.; Gash, Tahlia B.; Stalker, Katie L.; Zheng, Lidan; Haslam, S. Alexander

    2017-01-01

    The social difficulties of autism spectrum disorder (ASD) are typically explained as a disruption in the Shared Attention Mechanism (SAM) sub-component of the theory of mind (ToM) system. In the current paper, we explore the hypothesis that SAM's capacity to construct the self-other-object relations necessary for shared-attention arises from a…

  17. Characterization of Evidence for Human System Risk Assessment

    Science.gov (United States)

    Steinberg, S. L.; Van Baalen, M.; Rossi, M.; Riccio, G.; Romero, E.; Francisco, D.

    2016-01-01

    Understanding the kinds of evidence available and using the best evidence to answer a question is critical to evidenced-based decision-making, and it requires synthesis of evidence from a variety of sources. Categorization of human system risks in spaceflight, in particular, focuses on how well the integration and interpretation of all available evidence informs the risk statement that describes the relationship between spaceflight hazards and an outcome of interest. A mature understanding and categorization of these risks requires: 1) sufficient characterization of risk, 2) sufficient knowledge to determine an acceptable level of risk (i.e., a standard), 3) development of mitigations to meet the acceptable level of risk, and 4) identification of factors affecting generalizability of the evidence to different design reference missions. In the medical research community, evidence is often ranked by increasing confidence in findings gleaned from observational and experimental research (e.g., "levels of evidence"). However, an approach based solely on aspects of experimental design is problematic in assessing human system risks for spaceflight. For spaceflight, the unique challenges and opportunities include: (1) The independent variables in most evidence are the hazards of spaceflight, such as space radiation or low gravity, which cannot be entirely duplicated in terrestrial (Earth-based) analogs, (2) Evidence is drawn from multiple sources including medical and mission operations, Lifetime Surveillance of Astronaut Health (LSAH), spaceflight research (LSDA), and relevant environmental & terrestrial databases, (3) Risk metrics based primarily on LSAH data are typically derived from available prevalence or incidence data, which may limit rigorous interpretation, (4) The timeframe for obtaining adequate spaceflight sample size (n) is very long, given the small population, (5) Randomized controlled trials are unattainable in spaceflight, (6) Collection of personal and

  18. Direct evidence of milk consumption from ancient human dental calculus

    DEFF Research Database (Denmark)

    Warinner, C.; Hendy, J.; Speller, C.

    2014-01-01

    directly to individuals and their dairy livestock. Here we report the first direct evidence of milk consumption, the whey protein β-lactoglobulin (BLG), preserved in human dental calculus from the Bronze Age (ca. 3000 BCE) to the present day. Using protein tandem mass spectrometry, we demonstrate that BLG...... is a species-specific biomarker of dairy consumption, and we identify individuals consuming cattle, sheep, and goat milk products in the archaeological record. We then apply this method to human dental calculus from Greenland's medieval Norse colonies, and report a decline of this biomarker leading up...

  19. Associative learning in baboons (Papio papio) and humans (Homo sapiens): species differences in learned attention to visual features.

    Science.gov (United States)

    Fagot, J; Kruschke, J K; Dépy, D; Vauclair, J

    1998-10-01

    We examined attention shifting in baboons and humans during the learning of visual categories. Within a conditional matching-to-sample task, participants of the two species sequentially learned two two-feature categories which shared a common feature. Results showed that humans encoded both features of the initially learned category, but predominantly only the distinctive feature of the subsequently learned category. Although baboons initially encoded both features of the first category, they ultimately retained only the distinctive features of each category. Empirical data from the two species were analyzed with the 1996 ADIT connectionist model of Kruschke. ADIT fits the baboon data when the attentional shift rate is zero, and the human data when the attentional shift rate is not zero. These empirical and modeling results suggest species differences in learned attention to visual features.

  20. Glucose administration prior to a divided attention task improves tracking performance but not word recognition: evidence against differential memory enhancement?

    Science.gov (United States)

    Scholey, Andrew B; Sünram-Lea, Sandra I; Greer, Joanna; Elliott, Jade; Kennedy, David O

    2009-01-01

    The cognition-enhancing effects of glucose administration to humans have been well-documented; however, it remains unclear whether this effect preferentially targets episodic memory or other cognitive domains. The effect of glucose on the allocation of attentional resources during memory encoding was assessed using a sensitive dual-attention paradigm. One hundred and twenty volunteers (mean age 21.60, SD 4.89, 77 females) took part in this randomised, double-blind, placebo-controlled, parallel groups study where each consumed a 25-g glucose drink or a placebo. Half of the participants in each drink condition attempted to track a moving on-screen target during auditory word presentation. The distance between the cursor and the tracking target was used as an index of attentional cost during encoding. Effects of drink and tracking on recognition memory and drink on tracking performance were assessed. Self-rated appetite and mood were co-monitored. Co-performing the tracking task significantly impaired memory performance irrespective of drink condition. In the placebo-tracking condition, there was a cost to tracking manifest as greater deviation from target during and immediately following word presentation. Compared with placebo, the glucose drink significantly improved tracking performance during encoding. There were significant time-related changes in thirst and alertness ratings but these were not differentially affected by drink or tracking conditions. Tracking but not memory was enhanced by glucose. This finding suggests that, under certain task conditions, glucose administrations does not preferentially enhance memory performance. One mechanism through which glucose acts as a cognition enhancer is through allowing greater allocation of attentional resources.

  1. Nasal Oxytocin Treatment Biases Dogs’ Visual Attention and Emotional Response toward Positive Human Facial Expressions

    Directory of Open Access Journals (Sweden)

    Sanni Somppi

    2017-10-01

    Full Text Available The neuropeptide oxytocin plays a critical role in social behavior and emotion regulation in mammals. The aim of this study was to explore how nasal oxytocin administration affects gazing behavior during emotional perception in domestic dogs. Looking patterns of dogs, as a measure of voluntary attention, were recorded during the viewing of human facial expression photographs. The pupil diameters of dogs were also measured as a physiological index of emotional arousal. In a placebo-controlled within-subjects experimental design, 43 dogs, after having received either oxytocin or placebo (saline nasal spray treatment, were presented with pictures of unfamiliar male human faces displaying either a happy or an angry expression. We found that, depending on the facial expression, the dogs’ gaze patterns were affected selectively by oxytocin treatment. After receiving oxytocin, dogs fixated less often on the eye regions of angry faces and revisited (glanced back at more often the eye regions of smiling (happy faces than after the placebo treatment. Furthermore, following the oxytocin treatment dogs fixated and revisited the eyes of happy faces significantly more often than the eyes of angry faces. The analysis of dogs’ pupil diameters during viewing of human facial expressions indicated that oxytocin may also have a modulatory effect on dogs’ emotional arousal. While subjects’ pupil sizes were significantly larger when viewing angry faces than happy faces in the control (placebo treatment condition, oxytocin treatment not only eliminated this effect but caused an opposite pupil response. Overall, these findings suggest that nasal oxytocin administration selectively changes the allocation of attention and emotional arousal in domestic dogs. Oxytocin has the potential to decrease vigilance toward threatening social stimuli and increase the salience of positive social stimuli thus making eye gaze of friendly human faces more salient for dogs. Our

  2. The earliest evidence for anatomically modern humans in northwestern Europe.

    Science.gov (United States)

    Higham, Tom; Compton, Tim; Stringer, Chris; Jacobi, Roger; Shapiro, Beth; Trinkaus, Erik; Chandler, Barry; Gröning, Flora; Collins, Chris; Hillson, Simon; O'Higgins, Paul; FitzGerald, Charles; Fagan, Michael

    2011-11-02

    The earliest anatomically modern humans in Europe are thought to have appeared around 43,000-42,000 calendar years before present (43-42 kyr cal BP), by association with Aurignacian sites and lithic assemblages assumed to have been made by modern humans rather than by Neanderthals. However, the actual physical evidence for modern humans is extremely rare, and direct dates reach no farther back than about 41-39 kyr cal BP, leaving a gap. Here we show, using stratigraphic, chronological and archaeological data, that a fragment of human maxilla from the Kent's Cavern site, UK, dates to the earlier period. The maxilla (KC4), which was excavated in 1927, was initially diagnosed as Upper Palaeolithic modern human. In 1989, it was directly radiocarbon dated by accelerator mass spectrometry to 36.4-34.7 kyr cal BP. Using a Bayesian analysis of new ultrafiltered bone collagen dates in an ordered stratigraphic sequence at the site, we show that this date is a considerable underestimate. Instead, KC4 dates to 44.2-41.5 kyr cal BP. This makes it older than any other equivalently dated modern human specimen and directly contemporary with the latest European Neanderthals, thus making its taxonomic attribution crucial. We also show that in 13 dental traits KC4 possesses modern human rather than Neanderthal characteristics; three other traits show Neanderthal affinities and a further seven are ambiguous. KC4 therefore represents the oldest known anatomically modern human fossil in northwestern Europe, fills a key gap between the earliest dated Aurignacian remains and the earliest human skeletal remains, and demonstrates the wide and rapid dispersal of early modern humans across Europe more than 40 kyr ago. ©2011 Macmillan Publishers Limited. All rights reserved

  3. An Evidence Base for Human Spaceflight Risks in Wikipedia

    Science.gov (United States)

    Kundrot, Craig; Steil, Jennifer; Lumpkins, Sarah; Pellis, Neal

    2013-01-01

    NASA's Human Research Program (HRP) is focused on understanding and mitigating thirty two risks to crew health and performance in exploration missions beyond low Earth orbit. The HRP has developed an evidence report for each of the risks. Most evidence reports are a brief review article describing the evidence related to a specified risk, written at a level appropriate for the scientifically educated, non-specialist reader. Each evidence report captured the current state of knowledge from both research and operations. Two limitations of the evidence reports have become apparent: 1) they are updated infrequently and 2) they do not take full advantage of the expertise available in other space agencies and in related fields of terrestrial research. Therefore, the HRP is experimenting with the use of Wikipedia articles as a repository for evidence. Wikipedia's accessibility to the international space flight community and researchers in related terrestrial fields creates the opportunity to generate a more timely and comprehensive evidence base. Initial Wikipedia articles were populated for seven risks using a subset of the information in the HRP-approved evidence reports: Fatigue and Sleep Loss, Treating An Ill or Injured Crew Member, Radiation Carcinogenesis, Visual Impairment and Intracranial Pressure, Renal Stone Formation, Team Cohesion, and Intervertebral Disc Damage. Since the initial articles were created, there have been additions to these Wikipedia articles, including content from sources outside the HRP, and editorial changes to the pages. We will report on the nature of the contributions made after the initial articles were created, the comprehensiveness of the resulting Wikipedia articles, and the effort required to maintain quality control of the content. The Wikipedia approach will also be compared to wiki efforts that exert more traditional editorial control of content prior to posting.

  4. What kind of evidence is it that Evidence-Based Medicine advocates want health care providers and consumers to pay attention to?

    Directory of Open Access Journals (Sweden)

    Haynes R Brian

    2002-03-01

    Full Text Available Abstract Background In 1992, Evidence-Based Medicine advocates proclaimed a "new paradigm", in which evidence from health care research is the best basis for decisions for individual patients and health systems. Hailed in New York Times Magazine in 2001 as one of the most influential ideas of the year, this approach was initially and provocatively pitted against the traditional teaching of medicine, in which the key elements of knowing for clinical purposes are understanding of basic pathophysiologic mechanisms of disease coupled with clinical experience. This paper reviews the origins, aspirations, philosophical limitations, and practical challenges of evidence-based medicine. Discussion EBM has long since evolved beyond its initial (misconception, that EBM might replace traditional medicine. EBM is now attempting to augment rather than replace individual clinical experience and understanding of basic disease mechanisms. EBM must continue to evolve, however, to address a number of issues including scientific underpinnings, moral stance and consequences, and practical matters of dissemination and application. For example, accelerating the transfer of research findings into clinical practice is often based on incomplete evidence from selected groups of people, who experience a marginal benefit from an expensive technology, raising issues of the generalizability of the findings, and increasing problems with how many and who can afford the new innovations in care. Summary Advocates of evidence-based medicine want clinicians and consumers to pay attention to the best findings from health care research that are both valid and ready for clinical application. Much remains to be done to reach this goal.

  5. The brain's silent messenger: using selective attention to decode human thought for brain-based communication.

    Science.gov (United States)

    Naci, Lorina; Cusack, Rhodri; Jia, Vivian Z; Owen, Adrian M

    2013-05-29

    The interpretation of human thought from brain activity, without recourse to speech or action, is one of the most provoking and challenging frontiers of modern neuroscience. In particular, patients who are fully conscious and awake, yet, due to brain damage, are unable to show any behavioral responsivity, expose the limits of the neuromuscular system and the necessity for alternate forms of communication. Although it is well established that selective attention can significantly enhance the neural representation of attended sounds, it remains, thus far, untested as a response modality for brain-based communication. We asked whether its effect could be reliably used to decode answers to binary (yes/no) questions. Fifteen healthy volunteers answered questions (e.g., "Do you have brothers or sisters?") in the fMRI scanner, by selectively attending to the appropriate word ("yes" or "no"). Ninety percent of the answers were decoded correctly based on activity changes within the attention network. The majority of volunteers conveyed their answers with less than 3 min of scanning, suggesting that this technique is suited for communication in a reasonable amount of time. Formal comparison with the current best-established fMRI technique for binary communication revealed improved individual success rates and scanning times required to detect responses. This novel fMRI technique is intuitive, easy to use in untrained participants, and reliably robust within brief scanning times. Possible applications include communication with behaviorally nonresponsive patients.

  6. Human-computer interaction for alert warning and attention allocation systems of the multimodal watchstation

    Science.gov (United States)

    Obermayer, Richard W.; Nugent, William A.

    2000-11-01

    The SPAWAR Systems Center San Diego is currently developing an advanced Multi-Modal Watchstation (MMWS); design concepts and software from this effort are intended for transition to future United States Navy surface combatants. The MMWS features multiple flat panel displays and several modes of user interaction, including voice input and output, natural language recognition, 3D audio, stylus and gestural inputs. In 1999, an extensive literature review was conducted on basic and applied research concerned with alerting and warning systems. After summarizing that literature, a human computer interaction (HCI) designer's guide was prepared to support the design of an attention allocation subsystem (AAS) for the MMWS. The resultant HCI guidelines are being applied in the design of a fully interactive AAS prototype. An overview of key findings from the literature review, a proposed design methodology with illustrative examples, and an assessment of progress made in implementing the HCI designers guide are presented.

  7. The human figure drawing as related to attention-deficit hyperactivity disorder (ADHD).

    Science.gov (United States)

    Perets-Dubrovsky, Sharon; Kaveh, Michelle; Deutsh-Castel, Tsofia; Cohen, Ayala; Tirosh, Emanuel

    2010-06-01

    To assess the reliability and validity of the human figure drawing test among children with attention-deficit hyperactivity disorder (ADHD) and/or learning disability, boys (n = 136) between the ages of 8 and 10 years, with either or both ADHD and learning disability, were included. Two drawings were used: person and house, tree and person. The drawings were analyzed using the Koppitz emotional and developmental scales. Conners teacher and parent rating scales and the Matching Familiar Figure Test were administered. High intertest reliability for the emotional scale and a significant negative correlation between the 2 scales were found. The reported anxiety and learning were significantly correlated with the cognitive score. A combination of cognitive and emotional items resulted in 67% correct classification of ADHD and learning disability. This test can be used as part of the assessment of ADHD/learning disability.

  8. The Processing of Human Emotional Faces by Pet and Lab Dogs: Evidence for Lateralization and Experience Effects

    Science.gov (United States)

    Barber, Anjuli L. A.; Randi, Dania; Müller, Corsin A.; Huber, Ludwig

    2016-01-01

    From all non-human animals dogs are very likely the best decoders of human behavior. In addition to a high sensitivity to human attentive status and to ostensive cues, they are able to distinguish between individual human faces and even between human facial expressions. However, so far little is known about how they process human faces and to what extent this is influenced by experience. Here we present an eye-tracking study with dogs emanating from two different living environments and varying experience with humans: pet and lab dogs. The dogs were shown pictures of familiar and unfamiliar human faces expressing four different emotions. The results, extracted from several different eye-tracking measurements, revealed pronounced differences in the face processing of pet and lab dogs, thus indicating an influence of the amount of exposure to humans. In addition, there was some evidence for the influences of both, the familiarity and the emotional expression of the face, and strong evidence for a left gaze bias. These findings, together with recent evidence for the dog's ability to discriminate human facial expressions, indicate that dogs are sensitive to some emotions expressed in human faces. PMID:27074009

  9. Genetic evidence for a Paleolithic human population expansion in Africa

    Science.gov (United States)

    Reich, David E.; Goldstein, David B.

    1998-01-01

    Human populations have undergone dramatic expansions in size, but other than the growth associated with agriculture, the dates and magnitudes of those expansions have never been resolved. Here, we introduce two new statistical tests for population expansion, which use variation at a number of unlinked genetic markers to study the demographic histories of natural populations. By analyzing genetic variation in various aboriginal populations from throughout the world, we show highly significant evidence for a major human population expansion in Africa, but no evidence of expansion outside of Africa. The inferred African expansion is estimated to have occurred between 49,000 and 640,000 years ago, certainly before the Neolithic expansions, and probably before the splitting of African and non-African populations. In showing a significant difference between African and non-African populations, our analysis supports the unique role of Africa in human evolutionary history, as has been suggested by most other genetic work. In addition, the missing signal in non-African populations may be the result of a population bottleneck associated with the emergence of these populations from Africa, as postulated in the “Out of Africa” model of modern human origins. PMID:9653150

  10. Evidence for expansion of the precuneus in human evolution.

    Science.gov (United States)

    Bruner, Emiliano; Preuss, Todd M; Chen, Xu; Rilling, James K

    2017-03-01

    The evolution of neurocranial morphology in Homo sapiens is characterized by bulging of the parietal region, a feature unique to our species. In modern humans, expansion of the parietal surface occurs during the first year of life, in a morphogenetic stage which is absent in chimpanzees and Neandertals. A similar variation in brain shape among living adult humans is associated with expansion of the precuneus. Using MRI-derived structural brain templates, we compare medial brain morphology between humans and chimpanzees through shape analysis and geometrical modeling. We find that the main spatial difference is a prominent expansion of the precuneus in our species, providing further evidence of evolutionary changes associated with this area. The precuneus is a major hub of brain organization, a central node of the default-mode network, and plays an essential role in visuospatial integration. Together, the comparative neuroanatomical and paleontological evidence suggest that precuneus expansion is a neurological specialization of H. sapiens that evolved in the last 150,000 years that may be associated with recent human cognitive specializations.

  11. Exploring the Cognitive Foundations of the Shared Attention Mechanism: Evidence for a Relationship Between Self-Categorization and Shared Attention Across the Autism Spectrum.

    Science.gov (United States)

    Skorich, Daniel P; Gash, Tahlia B; Stalker, Katie L; Zheng, Lidan; Haslam, S Alexander

    2017-05-01

    The social difficulties of autism spectrum disorder (ASD) are typically explained as a disruption in the Shared Attention Mechanism (SAM) sub-component of the theory of mind (ToM) system. In the current paper, we explore the hypothesis that SAM's capacity to construct the self-other-object relations necessary for shared-attention arises from a self-categorization process, which is weaker among those with more autistic-like traits. We present participants with self-categorization and shared-attention tasks, and measure their autism-spectrum quotient (AQ). Results reveal a negative relationship between AQ and shared-attention, via self-categorization, suggesting a role for self-categorization in the disruption in SAM seen in ASD. Implications for intervention, and for a ToM model in which weak central coherence plays a role are discussed.

  12. Serologic Evidence of Human Monocytic and Granulocytic Ehrlichiosis in Israel

    Science.gov (United States)

    Keysary, Avi; Amram, Lili; Keren, Gershon; Sthoeger, Zev; Potasman, Israel; Jacob, Amir; Strenger, Carmella; Dawson, Jacqueline E.

    1999-01-01

    We conducted a retrospective serosurvey of 1,000 persons in Israel who had fever of undetermined cause to look for Ehrlichia chaffeensis antibodies. Four of five cases with antibodies reactive to E. chaffeensis were diagnosed in the summer, when ticks are more active. All patients had influenzalike symptoms with high fever. None of the cases was fatal. Three serum samples were also seroreactive for antibodies to E. canis, and one was also reactive to the human granulocytic ehrlichiosis (HGE) agent. The titer to the HGE agent in this patient was higher than the serum titer to E. chaffeensis, and the Western blot analysis also indicated that the HGE agent was the primary cause of infection. We present the first serologic evidence that the agents of human monocytic ehrlichiosis (HME) and HGE are present in Israel. Therefore, human ehrlichiosis should be included in the differential diagnoses for persons in Israel who have been exposed to ticks and have influenzalike symptoms. PMID:10603210

  13. Behavioral and neural evidence of increased attention to the bottom half of the face in deaf signers

    Science.gov (United States)

    Mitchell, Teresa V.; Letourneau, Susan M.; Maslin, Melissa T.

    2013-01-01

    Purpose This study examined the effects of deafness and sign language use on the distribution of attention across the top and bottom halves of faces. Methods In a composite face task, congenitally deaf signers and typically hearing controls made same/different judgments of the top or bottom halves of faces presented with the halves aligned or spatially misaligned, while event-related potentials (ERPs) were recorded. Results Both groups were more accurate when judging misaligned than aligned faces, which indicates holistic face processing. Misalignment affected all ERP components examined, with effects on the N170 resembling those of face inversion. Hearing adults were similarly accurate when judging the top and bottom halves of the faces, but deaf signers were more accurate when attending to the bottom than the top. Attending to the top elicited faster P1 and N170 latencies for both groups; within the deaf group, this effect was greatest for individuals who produced the highest accuracies when attending to the top. Conclusions These findings dovetail with previous research by providing behavioral and neural evidence of increased attention to the bottom half of the face in deaf signers, and by documenting that these effects generalize to a speeded task, in the absence of gaze shifts, with neutral facial expressions. PMID:23142816

  14. A computer vision system for rapid search inspired by surface-based attention mechanisms from human perception.

    Science.gov (United States)

    Mohr, Johannes; Park, Jong-Han; Obermayer, Klaus

    2014-12-01

    Humans are highly efficient at visual search tasks by focusing selective attention on a small but relevant region of a visual scene. Recent results from biological vision suggest that surfaces of distinct physical objects form the basic units of this attentional process. The aim of this paper is to demonstrate how such surface-based attention mechanisms can speed up a computer vision system for visual search. The system uses fast perceptual grouping of depth cues to represent the visual world at the level of surfaces. This representation is stored in short-term memory and updated over time. A top-down guided attention mechanism sequentially selects one of the surfaces for detailed inspection by a recognition module. We show that the proposed attention framework requires little computational overhead (about 11 ms), but enables the system to operate in real-time and leads to a substantial increase in search efficiency. Copyright © 2014 Elsevier Ltd. All rights reserved.

  15. Evidence for a bimodal distribution in human communication.

    Science.gov (United States)

    Wu, Ye; Zhou, Changsong; Xiao, Jinghua; Kurths, Jürgen; Schellnhuber, Hans Joachim

    2010-11-02

    Interacting human activities underlie the patterns of many social, technological, and economic phenomena. Here we present clear empirical evidence from Short Message correspondence that observed human actions are the result of the interplay of three basic ingredients: Poisson initiation of tasks and decision making for task execution in individual humans as well as interaction among individuals. This interplay leads to new types of interevent time distribution, neither completely Poisson nor power-law, but a bimodal combination of them. We show that the events can be separated into independent bursts which are generated by frequent mutual interactions in short times following random initiations of communications in longer times by the individuals. We introduce a minimal model of two interacting priority queues incorporating the three basic ingredients which fits well the distributions using the parameters extracted from the empirical data. The model can also embrace a range of realistic social interacting systems such as e-mail and letter communications when taking the time scale of processing into account. Our findings provide insight into various human activities both at the individual and network level. Our analysis and modeling of bimodal activity in human communication from the viewpoint of the interplay between processes of different time scales is likely to shed light on bimodal phenomena in other complex systems, such as interevent times in earthquakes, rainfall, forest fire, and economic systems, etc.

  16. Review of current evidence on the impact of pesticides, polychlorinated biphenyls and selected metals on attention deficit / hyperactivity disorder in children

    Directory of Open Access Journals (Sweden)

    Kinga Polańska

    2013-02-01

    Full Text Available The aim of this review was to investigate the association between attention defi cit / hyperactivity disorder (ADHD or ADHD- related symptoms and industrial chemicals, such as organophosphates and organochlorine pesticides, polychlorinated biphenyls (PCBs, lead, mercury and manganese. Medline, PubMed and EBSCO searches were performed to identify the studies that analyzed the association of prenatal and postnatal child exposure to such toxicants and ADHD or ADHD-related symptoms. The review is restricted to human studies published in English in peer-reviewed journals since 2000. Most of the presented studies focused on pesticides, PCB and lead. The impact of mercury and manganese was investigated less frequently. The fi ndings indicate that children’s exposure to organophosphate pesticides may cause symptoms consistent with pervasive developmental disorder, ADHD or attention problems. Exposures to organochlorine pesticides and PCBs were associated with ADHD-like behaviors such as alertness, quality of alert response, and cost of attention. The studies provided evidence that blood lead level below 10 μg/dl was associated with ADHD or ADHD-related symptoms. Information on the association between exposure to mercury and neurotoxicity is limited, and requires further confi rmation in future research. Two studies indicated that exposure to manganese is related to ADHD; such exposure and its impact on children neurodevelopment need to be further investigated. Future studies should use a prospective design with multiple biological samples collected over time for better assessment of exposure and its critical windows. Additionally, inclusion of potential confounding factors and co-exposures is crucial.

  17. Frequency-specific attentional modulation in human primary auditory cortex and midbrain

    NARCIS (Netherlands)

    Riecke, Lars; Peters, Judith C; Valente, Giancarlo; Poser, Benedikt A; Kemper, Valentin G; Formisano, Elia; Sorger, Bettina

    2018-01-01

    Paying selective attention to an audio frequency selectively enhances activity within primary auditory cortex (PAC) at the tonotopic site (frequency channel) representing that frequency. Animal PAC neurons achieve this 'frequency-specific attentional spotlight' by adapting their frequency tuning,

  18. Cortical depth dependent population receptive field attraction by spatial attention in human V1

    NARCIS (Netherlands)

    Klein, Barrie P.; Fracasso, Alessio; van Dijk, Jelle A.; Paffen, Chris L.E.; te Pas, Susan F.; Dumoulin, Serge O.

    2018-01-01

    Visual spatial attention concentrates neural resources at the attended location. Recently, we demonstrated that voluntary spatial attention attracts population receptive fields (pRFs) toward its location throughout the visual hierarchy. Theoretically, both a feed forward or feedback mechanism could

  19. Acute stress alters auditory selective attention in humans independent of HPA: a study of evoked potentials.

    Directory of Open Access Journals (Sweden)

    Ludger Elling

    Full Text Available BACKGROUND: Acute stress is a stereotypical, but multimodal response to a present or imminent challenge overcharging an organism. Among the different branches of this multimodal response, the consequences of glucocorticoid secretion have been extensively investigated, mostly in connection with long-term memory (LTM. However, stress responses comprise other endocrine signaling and altered neuronal activity wholly independent of pituitary regulation. To date, knowledge of the impact of such "paracorticoidal" stress responses on higher cognitive functions is scarce. We investigated the impact of an ecological stressor on the ability to direct selective attention using event-related potentials in humans. Based on research in rodents, we assumed that a stress-induced imbalance of catecholaminergic transmission would impair this ability. METHODOLOGY/PRINCIPAL FINDINGS: The stressor consisted of a single cold pressor test. Auditory negative difference (Nd and mismatch negativity (MMN were recorded in a tonal dichotic listening task. A time series of such tasks confirmed an increased distractibility occurring 4-7 minutes after onset of the stressor as reflected by an attenuated Nd. Salivary cortisol began to rise 8-11 minutes after onset when no further modulations in the event-related potentials (ERP occurred, thus precluding a causal relationship. This effect may be attributed to a stress-induced activation of mesofrontal dopaminergic projections. It may also be attributed to an activation of noradrenergic projections. Known characteristics of the modulation of ERP by different stress-related ligands were used for further disambiguation of causality. The conjuncture of an attenuated Nd and an increased MMN might be interpreted as indicating a dopaminergic influence. The selective effect on the late portion of the Nd provides another tentative clue for this. CONCLUSIONS/SIGNIFICANCE: Prior studies have deliberately tracked the adrenocortical influence

  20. Psychopharmacological and Other Treatments in Preschool Children with Attention-Deficit/Hyperactivity Disorder: Current Evidence and Practice

    Science.gov (United States)

    Arnold, L. Eugene; Anthony, Bruno J.

    2008-01-01

    Abstract Objective This article reviews rational approaches to treating attention-deficit/hyperactivity disorder (ADHD) in preschool children, including pharmacological and nonpharmacological treatments. Implications for clinical practice are discussed. Data Sources We searched MEDLINE, PsychINFO, Cumulative Index to Nursing & Allied Health, Educational Resources Information Center, Cochrane Database of Systematic Reviews and Database of Abstracts of Reviews of Effects for relevant literature published in English from 1967 to 2007 on preschool ADHD. We also reviewed the references cited in identified reports. Study Selection Studies were reviewed if the sample included at least some children younger than 6 years of age or attending kindergarten, the study participants had a diagnosis of ADHD or equivalent symptoms, received intervention aimed at ADHD symptoms, and included a relevant outcome measure. Data Extraction Studies were reviewed for type of intervention and outcome relevant to ADHD and were rated for the level of evidence for adequacy of the data to inform clinical practice. Conclusions The current level of evidence for adequacy of empirical data to inform clinical practice for short-term treatment of ADHD in preschool children is Level A for methylphenidate and Level B for parent behavior training, child training, and additive-free elimination diet. PMID:18844482

  1. ERP evidence for selective drop in attentional costs in uncertain environments: challenging a purely premotor account of covert orienting of attention.

    Science.gov (United States)

    Lasaponara, Stefano; Chica, Ana B; Lecce, Francesca; Lupianez, Juan; Doricchi, Fabrizio

    2011-07-01

    Several studies have proved that the reliability of endogenous spatial cues linearly modulates the reaction time advantage in the processing of targets at validly cued vs. invalidly cued locations, i.e. the "validity effect". This would imply that with non-predictive cues, no "validity effect" should be observed. However, contrary to this prediction, one could hypothesize that attentional benefits by valid cuing (i.e. the RT advantage for validly vs. neutrally cued targets) can still be maintained with non-predictive cues, if the brain were endowed with mechanisms allowing the selective reduction in costs of reorienting from invalidly cued locations (i.e. the reduction of the RT disadvantage for invalidly vs. neutrally cued targets). This separated modulation of attentional benefits and costs would be adaptive in uncertain contexts where cues predict at chance level the location of targets. Through the joint recording of manual reaction times and event-related cerebral potentials (ERPs), we have found that this is the case and that relying on non-predictive endogenous cues results in abatement of attentional costs and the difference in the amplitude of the P1 brain responses evoked by invalidly vs. neutrally cued targets. In contrast, the use of non-predictive cues leaves unaffected attentional benefits and the difference in the amplitude of the N1 responses evoked by validly vs. neutrally cued targets. At the individual level, the drop in costs with non-predictive cues was matched with equivalent lateral biases in RTs to neutrally and invalidly cued targets presented in the left and right visual field. During the cue period, the drop in costs with non-predictive cues was preceded by reduction of the Early Directing Attention Negativity (EDAN) on posterior occipital sites and by enhancement of the frontal Anterior Directing Attention Negativity (ADAN) correlated to preparatory voluntary orienting. These findings demonstrate, for the first time, that the segregation

  2. Behavioral and genetic evidence for a novel animal model of Attention-Deficit/Hyperactivity Disorder Predominantly Inattentive Subtype

    Directory of Open Access Journals (Sweden)

    Zhang-James Y

    2008-12-01

    genomic differences between the WKY/NCrl and WKY/NHsd rats for eight short tandem repeat loci and 2625 SNPs. About 33.5 percent of the genome differs between the two WKY rat substrains, with large stretches of divergence on each chromosome. Discussion These data provide solid behavioral and genetic evidence that the WKY/NCrl and WKY/NHsd rats should be considered as separate substrains. Moreover, the behavioral features of the WKY/NCrl rat indicate that it should be a useful model for ADHD-PI, the primarily inattentive subtype of ADHD. The SD/NTac and the WH/HanTac rats show significant genetic and/or behavioral differences from WKY/NHsd rats and appear not to be appropriate controls in studies using the SHR/NCrl. The present results support the conclusion that SHR/NCrl is the best validated animal model of ADHD-C. The overactivity, impulsiveness and deficient sustained attention of the SHR/NCrl strain are independent behaviors. Thus, overactivity does not account for this strain's impulsiveness and deficient sustained attention. Finally, the present study shows that great care has to be exercised to select the model and comparison groups.

  3. Looking on the bright side: biased attention and the human serotonin transporter gene.

    Science.gov (United States)

    Fox, Elaine; Ridgewell, Anna; Ashwin, Chris

    2009-05-22

    Humans differ in terms of biased attention for emotional stimuli and these biases can confer differential resilience and vulnerability to emotional disorders. Selective processing of positive emotional information, for example, is associated with enhanced sociability and well-being while a bias for negative material is associated with neuroticism and anxiety. A tendency to selectively avoid negative material might also be associated with mental health and well-being. The neurobiological mechanisms underlying these cognitive phenotypes are currently unknown. Here we show for the first time that allelic variation in the promotor region of the serotonin transporter gene (5-HTTLPR) is associated with differential biases for positive and negative affective pictures. Individuals homozygous for the long allele (LL) showed a marked bias to selectively process positive affective material alongside selective avoidance of negative affective material. This potentially protective pattern was absent among individuals carrying the short allele (S or SL). Thus, allelic variation on a common genetic polymorphism was associated with the tendency to selectively process positive or negative information. The current study is important in demonstrating a genotype-related alteration in a well-established processing bias, which is a known risk factor in determining both resilience and vulnerability to emotional disorders.

  4. Psilocybin links binocular rivalry switch rate to attention and subjective arousal levels in humans.

    Science.gov (United States)

    Carter, Olivia L; Hasler, Felix; Pettigrew, John D; Wallis, Guy M; Liu, Guang B; Vollenweider, Franz X

    2007-12-01

    Binocular rivalry occurs when different images are simultaneously presented to each eye. During continual viewing of this stimulus, the observer will experience repeated switches between visual awareness of the two images. Previous studies have suggested that a slow rate of perceptual switching may be associated with clinical and drug-induced psychosis. The objective of the study was to explore the proposed relationship between binocular rivalry switch rate and subjective changes in psychological state associated with 5-HT2A receptor activation. This study used psilocybin, the hallucinogen found naturally in Psilocybe mushrooms that had previously been found to induce psychosis-like symptoms via the 5-HT2A receptor. The effects of psilocybin (215 microg/kg) were considered alone and after pretreatment with the selective 5-HT2A antagonist ketanserin (50 mg) in ten healthy human subjects. Psilocybin significantly reduced the rate of binocular rivalry switching and increased the proportion of transitional/mixed percept experience. Pretreatment with ketanserin blocked the majority of psilocybin's "positive" psychosis-like hallucinogenic symptoms. However, ketanserin had no influence on either the psilocybin-induced slowing of binocular rivalry or the drug's "negative-type symptoms" associated with reduced arousal and vigilance. Together, these findings link changes in binocular rivalry switching rate to subjective levels of arousal and attention. In addition, it suggests that psilocybin's effect on binocular rivalry is unlikely to be mediated by the 5-HT2A receptor.

  5. A human visual model-based approach of the visual attention and performance evaluation

    Science.gov (United States)

    Le Meur, Olivier; Barba, Dominique; Le Callet, Patrick; Thoreau, Dominique

    2005-03-01

    In this paper, a coherent computational model of visual selective attention for color pictures is described and its performances are precisely evaluated. The model based on some important behaviours of the human visual system is composed of four parts: visibility, perception, perceptual grouping and saliency map construction. This paper focuses mainly on its performances assessment by achieving extended subjective and objective comparisons with real fixation points captured by an eye-tracking system used by the observers in a task-free viewing mode. From the knowledge of the ground truth, qualitatively and quantitatively comparisons have been made in terms of the measurement of the linear correlation coefficient (CC) and of the Kulback Liebler divergence (KL). On a set of 10 natural color images, the results show that the linear correlation coefficient and the Kullback Leibler divergence are of about 0.71 and 0.46, respectively. CC and Kl measures with this model are respectively improved by about 4% and 7% compared to the best model proposed by L.Itti. Moreover, by comparing the ability of our model to predict eye movements produced by an average observer, we can conclude that our model succeeds quite well in predicting the spatial locations of the most important areas of the image content.

  6. Attention and prediction in human audition: a lesson from cognitive psychophysiology

    Science.gov (United States)

    Schröger, Erich; Marzecová, Anna; SanMiguel, Iria

    2015-01-01

    Attention is a hypothetical mechanism in the service of perception that facilitates the processing of relevant information and inhibits the processing of irrelevant information. Prediction is a hypothetical mechanism in the service of perception that considers prior information when interpreting the sensorial input. Although both (attention and prediction) aid perception, they are rarely considered together. Auditory attention typically yields enhanced brain activity, whereas auditory prediction often results in attenuated brain responses. However, when strongly predicted sounds are omitted, brain responses to silence resemble those elicited by sounds. Studies jointly investigating attention and prediction revealed that these different mechanisms may interact, e.g. attention may magnify the processing differences between predicted and unpredicted sounds. Following the predictive coding theory, we suggest that prediction relates to predictions sent down from predictive models housed in higher levels of the processing hierarchy to lower levels and attention refers to gain modulation of the prediction error signal sent up to the higher level. As predictions encode contents and confidence in the sensory data, and as gain can be modulated by the intention of the listener and by the predictability of the input, various possibilities for interactions between attention and prediction can be unfolded. From this perspective, the traditional distinction between bottom-up/exogenous and top-down/endogenous driven attention can be revisited and the classic concepts of attentional gain and attentional trace can be integrated. PMID:25728182

  7. Evidence for Alpha Receptors in the Human Ureter

    Science.gov (United States)

    Madeb, Ralph; Knopf, Joy; Golijanin, Dragan; Bourne, Patricia; Erturk, Erdal

    2007-04-01

    An immunohistochemical and western blot expression analysis of human ureters was performed in order to characterize the alpha-1-adrenergic receptor distribution along the length of the human ureteral wall. Mapping the distribution will assist in understanding the potential role alpha -1-adrenergic receptors and their subtype density might have in the pathophysiology of ureteral colic and stone passage. Patients diagnosed with renal cancer or bladder cancer undergoing nephrectomy, nephroureterectomy, or cystectomy had ureteral specimens taken from the proximal, mid, distal and tunneled ureter. Tissues were processed for fresh frozen examination and fixed in formalin. None of the ureteral specimens were involved with cancer. Serial histologic sections and immunohistochemical studies were performed using antibodies specific for alpha-1-adrenergic receptor subtypes (alpha 1a, alpha 1b, alpha 1d). The sections were examined under a light microscope and scored as positive or negative. In order to validate and quantify the alpha receptor subtypes along the human ureter. Western blotting techniques were applied. Human ureter stained positively for alpha -1-adrenergic receptors. Immunostaining appeared red, with intense reaction in the smooth muscle of the ureter and endothelium of the neighboring blood vessels. There was differential expression between all the receptors with the highest staining for alpha-1D subtype. The highest protein expression for all three subtypes was in the renal pelvis and decreased with advancement along the ureter to the distal ureter. At the distal ureter, there was marked increase in expression as one progressed towards the ureteral orifice. The same pattern of protein expression was exhibited for all three alpha -1-adrenergic receptor subtypes. We provide preliminary evidence for the ability to detect and quantify the alpha-1-receptor subtypes along the human ureter which to the best of our knowledge has never been done with

  8. Family-genetic study of executive functioning in attention-deficit/hyperactivity disorder: Evidence for an endophenotype?

    NARCIS (Netherlands)

    Slaats-Willemse, D.I.E.; Swaab-Barneveld, H.J.; Sonneville, L.M. de; Buitelaar, J.K.

    2007-01-01

    This study examined familiality of attentional control and mental flexibility in multiplex attention-deficit/hyperactivity disorder (ADHD) families. The authors hypothesized that siblings of ADHD probands, although not behaviorally expressing ADHD, have deficits in these executive functions and that

  9. Attention and Emotion-Enhanced Memory: A Systematic Review and Meta-Analysis of Behavioural and Neuroimaging Evidence

    OpenAIRE

    Kohler, Mark; Cross, Zachariah; Santamaria, Amanda

    2018-01-01

    The interaction between attention and emotion is posited to influence long-term memory consolidation. We systematically reviewed experiments investigating the influence of attention on emotional memory to determine: (i) the reported effect of attention on memory for emotional stimuli, and (ii) whether there is homogeneity between behavioural and neuroimaging based effects. Over half of the 47 included experiments found a moderate-to-large effect of attention on emotional memory as measured be...

  10. Object-Based Visual Attention in 8-Month-Old Infants: Evidence from an Eye-Tracking Study

    Science.gov (United States)

    Bulf, Hermann; Valenza, Eloisa

    2013-01-01

    Visual attention is one of the infant's primary tools for gathering relevant information from the environment for further processing and learning. The space-based component of visual attention in infants has been widely investigated; however, the object-based component of visual attention has received scarce interest. This scarcity is…

  11. Are there age differences in attention to emotional images following a sad mood induction? Evidence from a free-viewing eye-tracking paradigm.

    Science.gov (United States)

    Speirs, Calandra; Belchev, Zorry; Fernandez, Amanda; Korol, Stephanie; Sears, Christopher

    2017-10-30

    Two experiments examined age differences in the effect of a sad mood induction (MI) on attention to emotional images. Younger and older adults viewed sets of four images while their eye gaze was tracked throughout an 8-s presentation. Images were viewed before and after a sad MI to assess the effect of a sad mood on attention to positive and negative scenes. Younger and older adults exhibited positively biased attention after the sad MI, significantly increasing their attention to positive images, with no evidence of an age difference in either experiment. A test of participants' recognition memory for the images indicated that the sad MI reduced memory accuracy for sad images for younger and older adults. The results suggest that heightened attention to positive images following a sad MI reflects an affect regulation strategy related to mood repair. The implications for theories of the positivity effect are discussed.

  12. Modafinil improves attentional performance in healthy, non-sleep deprived humans at doses not inducing hyperarousal across species

    NARCIS (Netherlands)

    Cope, Zackary A; Minassian, Arpi; Kreitner, Dustin; MacQueen, David A; Milienne-Petiot, Morgane; Geyer, Mark A; Perry, William; Young, Jared W

    2017-01-01

    The wake-promoting drug modafinil is frequently used off-label to improve cognition in psychiatric and academic populations alike. The domain-specific attentional benefits of modafinil have yet to be quantified objectively in healthy human volunteers using tasks validated for comparison across

  13. Competitive interactions of attentional resources in early visual cortex during sustained visuospatial attention within or between visual hemifields: evidence for the different-hemifield advantage.

    Science.gov (United States)

    Walter, Sabrina; Quigley, Cliodhna; Mueller, Matthias M

    2014-05-01

    Performing a task across the left and right visual hemifields results in better performance than in a within-hemifield version of the task, termed the different-hemifield advantage. Although recent studies used transient stimuli that were presented with long ISIs, here we used a continuous objective electrophysiological (EEG) measure of competitive interactions for attentional processing resources in early visual cortex, the steady-state visual evoked potential (SSVEP). We frequency-tagged locations in each visual quadrant and at central fixation by flickering light-emitting diodes (LEDs) at different frequencies to elicit distinguishable SSVEPs. Stimuli were presented for several seconds, and participants were cued to attend to two LEDs either in one (Within) or distributed across left and right visual hemifields (Across). In addition, we introduced two reference measures: one for suppressive interactions between the peripheral LEDs by using a task at fixation where attention was withdrawn from the periphery and another estimating the upper bound of SSVEP amplitude by cueing participants to attend to only one of the peripheral LEDs. We found significantly greater SSVEP amplitude modulations in Across compared with Within hemifield conditions. No differences were found between SSVEP amplitudes elicited by the peripheral LEDs when participants attended to the centrally located LEDs compared with when peripheral LEDs had to be ignored in Across and Within trials. Attending to only one LED elicited the same SSVEP amplitude as Across conditions. Although behavioral data displayed a more complex pattern, SSVEP amplitudes were well in line with the predictions of the different-hemifield advantage account during sustained visuospatial attention.

  14. Dynamic reorganization of human resting-state networks during visuospatial attention.

    Science.gov (United States)

    Spadone, Sara; Della Penna, Stefania; Sestieri, Carlo; Betti, Viviana; Tosoni, Annalisa; Perrucci, Mauro Gianni; Romani, Gian Luca; Corbetta, Maurizio

    2015-06-30

    Fundamental problems in neuroscience today are understanding how patterns of ongoing spontaneous activity are modified by task performance and whether/how these intrinsic patterns influence task-evoked activation and behavior. We examined these questions by comparing instantaneous functional connectivity (IFC) and directed functional connectivity (DFC) changes in two networks that are strongly correlated and segregated at rest: the visual (VIS) network and the dorsal attention network (DAN). We measured how IFC and DFC during a visuospatial attention task, which requires dynamic selective rerouting of visual information across hemispheres, changed with respect to rest. During the attention task, the two networks remained relatively segregated, and their general pattern of within-network correlation was maintained. However, attention induced a decrease of correlation in the VIS network and an increase of the DAN→VIS IFC and DFC, especially in a top-down direction. In contrast, within the DAN, IFC was not modified by attention, whereas DFC was enhanced. Importantly, IFC modulations were behaviorally relevant. We conclude that a stable backbone of within-network functional connectivity topography remains in place when transitioning between resting wakefulness and attention selection. However, relative decrease of correlation of ongoing "idling" activity in visual cortex and synchronization between frontoparietal and visual cortex were behaviorally relevant, indicating that modulations of resting activity patterns are important for task performance. Higher order resting connectivity in the DAN was relatively unaffected during attention, potentially indicating a role for simultaneous ongoing activity as a "prior" for attention selection.

  15. Right Hemispheric Dominance in Gaze-Triggered Reflexive Shift of Attention in Humans

    Science.gov (United States)

    Okada, Takashi; Sato, Wataru; Toichi, Motomi

    2006-01-01

    Recent findings suggest a right hemispheric dominance in gaze-triggered shifts of attention. The aim of this study was to clarify the dominant hemisphere in the gaze processing that mediates attentional shift. A target localization task, with preceding non-predicative gaze cues presented to each visual field, was undertaken by 44 healthy subjects,…

  16. Human Abilities and Modes of Attention: The Issue of Stylistic Consistencies in Cognition.

    Science.gov (United States)

    Messick, Samuel

    Spearman's notions of mental energy and mental span presage modern conceptions of attentional resources and working memory as fundamental to intelligence. Viewing attention as the conative directing of the intellect, as "the application of intellectual energy," Spearman's quantitative law of mental span deals with limits on the…

  17. Evidence from intrinsic activity that asymmetry of the human brain is controlled by multiple factors.

    Science.gov (United States)

    Liu, Hesheng; Stufflebeam, Steven M; Sepulcre, Jorge; Hedden, Trey; Buckner, Randy L

    2009-12-01

    Cerebral lateralization is a fundamental property of the human brain and a marker of successful development. Here we provide evidence that multiple mechanisms control asymmetry for distinct brain systems. Using intrinsic activity to measure asymmetry in 300 adults, we mapped the most strongly lateralized brain regions. Both men and women showed strong asymmetries with a significant, but small, group difference. Factor analysis on the asymmetric regions revealed 4 separate factors that each accounted for significant variation across subjects. The factors were associated with brain systems involved in vision, internal thought (the default network), attention, and language. An independent sample of right- and left-handed individuals showed that hand dominance affects brain asymmetry but differentially across the 4 factors supporting their independence. These findings show the feasibility of measuring brain asymmetry using intrinsic activity fluctuations and suggest that multiple genetic or environmental mechanisms control cerebral lateralization.

  18. Benefits of donor human milk for preterm infants: current evidence.

    Science.gov (United States)

    Bertino, Enrico; Giuliani, Francesca; Occhi, Luciana; Coscia, Alessandra; Tonetto, Paola; Marchino, Federica; Fabris, Claudio

    2009-10-01

    It's undoubted that optimum nutrition for term infants is breastfeeding, exclusive for the first six months, then followed by a complementary diet and carried on, if possible, for the first year of life or even more. During the last decades several data confirmed the great advantages of fresh mother's milk use also for feeding very low and extremely low birthweight preterm infants. When mother's milk is unavailable or in short supply, pasteurized donor breast milk is widely used in neonatal intensive care units. Pasteurization partially affects nutritional and immunological properties of breast milk, however it is known that pasteurized milk maintains some biological properties and clinical benefits. The substantial benefits of mother's own milk feeding of preterm infants are supported by strong evidence. However, there is increasing evidence also on specific benefits of donor breast milk. Future research is needed to compare formula vs. nutrient fortified donor breast milk, to compare formula and DM as supplements to maternal milk rather than as sole diet and to compare effects of different methods of heat treatments on donor human milk quality.

  19. Double attention bias for positive and negative emotional faces in clinical depression: evidence from an eye-tracking study.

    Science.gov (United States)

    Duque, Almudena; Vázquez, Carmelo

    2015-03-01

    According to cognitive models, attentional biases in depression play key roles in the onset and subsequent maintenance of the disorder. The present study examines the processing of emotional facial expressions (happy, angry, and sad) in depressed and non-depressed adults. Sixteen unmedicated patients with Major Depressive Disorder (MDD) and 34 never-depressed controls (ND) completed an eye-tracking task to assess different components of visual attention (orienting attention and maintenance of attention) in the processing of emotional faces. Compared to ND, participants with MDD showed a negative attentional bias in attentional maintenance indices (i.e. first fixation duration and total fixation time) for sad faces. This attentional bias was positively associated with the severity of depressive symptoms. Furthermore, the MDD group spent a marginally less amount of time viewing happy faces compared with the ND group. No differences were found between the groups with respect to angry faces and orienting attention indices. The current study is limited by its cross-sectional design. These results support the notion that attentional biases in depression are specific to depression-related information and that they operate in later stages in the deployment of attention. Copyright © 2014 Elsevier Ltd. All rights reserved.

  20. Human endogenous retroviruses and cancer prevention: evidence and prospects

    Directory of Open Access Journals (Sweden)

    Cegolon Luca

    2013-01-01

    as other tumors like sarcoma, lymphoma, bladder and breast cancer. An amino acid sequence similar to HERV-K-MEL, recognized to cause a significant protective effect against melanoma, is shared by the antigenic determinants expressed by some vaccines such as BCG, vaccinia virus and the yellow fever virus. HERV-K are also reactivated in the majority of human breast cancers. Monoclonal and single-chain antibodies against the HERV-K Env protein recently proved capable of blocking the proliferation of human breast cancer cells in vitro, inhibiting tumor growth in mice bearing xenograft tumors. Summary A recent epidemiological study provided provisional evidence of how melanoma risk could possibly be reduced if the yellow fever virus vaccine (YFV were received at least 10 years before, possibly preventing tumor initiation rather than culling melanoma cells already compromised. Further research is recommended to confirm the temporal pattern of this protection and eliminate/attenuate the potential role of relevant confounders as socio-economic status and other vaccinations. It appears also appropriate to examine the potential protective effect of YFV against other malignancies expressing high levels of HERV-K antigens, namely breast cancer, sarcoma, lymphoma and bladder cancer. Tumor immune-therapy, as described for the monoclonal antibodies against breast cancer, is indeed considered more complex and less advantageous than immune-prevention. Cellular immunity possibly triggered by vaccines as for YFV might also be involved in anti-cancer response, in addition to humoral immunity.

  1. Human endogenous retroviruses and cancer prevention: evidence and prospects.

    Science.gov (United States)

    Cegolon, Luca; Salata, Cristiano; Weiderpass, Elisabete; Vineis, Paolo; Palù, Giorgio; Mastrangelo, Giuseppe

    2013-01-03

    breast cancer. An amino acid sequence similar to HERV-K-MEL, recognized to cause a significant protective effect against melanoma, is shared by the antigenic determinants expressed by some vaccines such as BCG, vaccinia virus and the yellow fever virus.HERV-K are also reactivated in the majority of human breast cancers. Monoclonal and single-chain antibodies against the HERV-K Env protein recently proved capable of blocking the proliferation of human breast cancer cells in vitro, inhibiting tumor growth in mice bearing xenograft tumors. A recent epidemiological study provided provisional evidence of how melanoma risk could possibly be reduced if the yellow fever virus vaccine (YFV) were received at least 10 years before, possibly preventing tumor initiation rather than culling melanoma cells already compromised. Further research is recommended to confirm the temporal pattern of this protection and eliminate/attenuate the potential role of relevant confounders as socio-economic status and other vaccinations.It appears also appropriate to examine the potential protective effect of YFV against other malignancies expressing high levels of HERV-K antigens, namely breast cancer, sarcoma, lymphoma and bladder cancer.Tumor immune-therapy, as described for the monoclonal antibodies against breast cancer, is indeed considered more complex and less advantageous than immune-prevention. Cellular immunity possibly triggered by vaccines as for YFV might also be involved in anti-cancer response, in addition to humoral immunity.

  2. Human endogenous retroviruses and cancer prevention: evidence and prospects

    International Nuclear Information System (INIS)

    Cegolon, Luca; Salata, Cristiano; Weiderpass, Elisabete; Vineis, Paolo; Palù, Giorgio; Mastrangelo, Giuseppe

    2013-01-01

    and breast cancer. An amino acid sequence similar to HERV-K-MEL, recognized to cause a significant protective effect against melanoma, is shared by the antigenic determinants expressed by some vaccines such as BCG, vaccinia virus and the yellow fever virus. HERV-K are also reactivated in the majority of human breast cancers. Monoclonal and single-chain antibodies against the HERV-K Env protein recently proved capable of blocking the proliferation of human breast cancer cells in vitro, inhibiting tumor growth in mice bearing xenograft tumors. A recent epidemiological study provided provisional evidence of how melanoma risk could possibly be reduced if the yellow fever virus vaccine (YFV) were received at least 10 years before, possibly preventing tumor initiation rather than culling melanoma cells already compromised. Further research is recommended to confirm the temporal pattern of this protection and eliminate/attenuate the potential role of relevant confounders as socio-economic status and other vaccinations. It appears also appropriate to examine the potential protective effect of YFV against other malignancies expressing high levels of HERV-K antigens, namely breast cancer, sarcoma, lymphoma and bladder cancer. Tumor immune-therapy, as described for the monoclonal antibodies against breast cancer, is indeed considered more complex and less advantageous than immune-prevention. Cellular immunity possibly triggered by vaccines as for YFV might also be involved in anti-cancer response, in addition to humoral immunity

  3. Recognizing the degree of human attention using EEG signals from mobile sensors.

    Science.gov (United States)

    Liu, Ning-Han; Chiang, Cheng-Yu; Chu, Hsuan-Chin

    2013-08-09

    During the learning process, whether students remain attentive throughout instruction generally influences their learning efficacy. If teachers can instantly identify whether students are attentive they can be suitably reminded to remain focused, thereby improving their learning effects. Traditional teaching methods generally require that teachers observe students' expressions to determine whether they are attentively learning. However, this method is often inaccurate and increases the burden on teachers. With the development of electroencephalography (EEG) detection tools, mobile brainwave sensors have become mature and affordable equipment. Therefore, in this study, whether students are attentive or inattentive during instruction is determined by observing their EEG signals. Because distinguishing between attentiveness and inattentiveness is challenging, two scenarios were developed for this study to measure the subjects' EEG signals when attentive and inattentive. After collecting EEG data using mobile sensors, various common features were extracted from the raw data. A support vector machine (SVM) classifier was used to calculate and analyze these features to identify the combination of features that best indicates whether students are attentive. Based on the experiment results, the method proposed in this study provides a classification accuracy of up to 76.82%. The study results can be used as a reference for learning system designs in the future.

  4. Sustained selective attention to competing amplitude-modulations in human auditory cortex.

    Science.gov (United States)

    Riecke, Lars; Scharke, Wolfgang; Valente, Giancarlo; Gutschalk, Alexander

    2014-01-01

    Auditory selective attention plays an essential role for identifying sounds of interest in a scene, but the neural underpinnings are still incompletely understood. Recent findings demonstrate that neural activity that is time-locked to a particular amplitude-modulation (AM) is enhanced in the auditory cortex when the modulated stream of sounds is selectively attended to under sensory competition with other streams. However, the target sounds used in the previous studies differed not only in their AM, but also in other sound features, such as carrier frequency or location. Thus, it remains uncertain whether the observed enhancements reflect AM-selective attention. The present study aims at dissociating the effect of AM frequency on response enhancement in auditory cortex by using an ongoing auditory stimulus that contains two competing targets differing exclusively in their AM frequency. Electroencephalography results showed a sustained response enhancement for auditory attention compared to visual attention, but not for AM-selective attention (attended AM frequency vs. ignored AM frequency). In contrast, the response to the ignored AM frequency was enhanced, although a brief trend toward response enhancement occurred during the initial 15 s. Together with the previous findings, these observations indicate that selective enhancement of attended AMs in auditory cortex is adaptive under sustained AM-selective attention. This finding has implications for our understanding of cortical mechanisms for feature-based attentional gain control.

  5. Sustained Selective Attention to Competing Amplitude-Modulations in Human Auditory Cortex

    Science.gov (United States)

    Riecke, Lars; Scharke, Wolfgang; Valente, Giancarlo; Gutschalk, Alexander

    2014-01-01

    Auditory selective attention plays an essential role for identifying sounds of interest in a scene, but the neural underpinnings are still incompletely understood. Recent findings demonstrate that neural activity that is time-locked to a particular amplitude-modulation (AM) is enhanced in the auditory cortex when the modulated stream of sounds is selectively attended to under sensory competition with other streams. However, the target sounds used in the previous studies differed not only in their AM, but also in other sound features, such as carrier frequency or location. Thus, it remains uncertain whether the observed enhancements reflect AM-selective attention. The present study aims at dissociating the effect of AM frequency on response enhancement in auditory cortex by using an ongoing auditory stimulus that contains two competing targets differing exclusively in their AM frequency. Electroencephalography results showed a sustained response enhancement for auditory attention compared to visual attention, but not for AM-selective attention (attended AM frequency vs. ignored AM frequency). In contrast, the response to the ignored AM frequency was enhanced, although a brief trend toward response enhancement occurred during the initial 15 s. Together with the previous findings, these observations indicate that selective enhancement of attended AMs in auditory cortex is adaptive under sustained AM-selective attention. This finding has implications for our understanding of cortical mechanisms for feature-based attentional gain control. PMID:25259525

  6. Adrenocorticotropin widens the focus of attention in humans. A nonliner electroencephalographic analysis.

    Science.gov (United States)

    Mölle, M; Albrecht, C; Marshall, L; Fehm, H L; Born, J

    1997-01-01

    This study examined the effects of ACTH 4-10, a fragment of adrenocorticotropin (ACTH) with known central nervous system (CNS) activity, on the dimensional complexity of the ongoing electroencephalographic (EEG) activity. Stressful stimuli cause ACTH to be released from the pituitary, and as a neuropeptide ACTH may concurrently exert adaptive influences on the brain's processing of these stimuli. Previous studies have indicated an impairing influence of ACTH on selective attention. Dimensional complexity of the EEG, which indexes the brain's way of stimulus processing, was evaluated while subjects performed tasks with different attention demands. Sixteen healthy men (23 to 33 years) were tested once after placebo and another time after administration of ACTH 4-10 (1.25 mg intravenously (i.v.), 30 minutes before testing). The EEG was recorded while subjects were presented with a dichotic listening task (consisting of the concurrent presentation of tone pips to the left and right ear). Subjects either a) listened to pips in both ears (divided attention), or b) listened selectively to pips in one ear (selective attention), or c) ignored all pips. Dimensional complexity of the EEG was higher during divided than selective attention. ACTH significantly increased the EEG complexity during selective attention, in particular over the midfrontal cortex (Fz, Cz). The effects support the view of a de-focusing action of ACTH during selective attention that could serve to improve the organism's adaptation to stress stimuli.

  7. Focused and divided attention in a simulated cocktail-party situation: ERP evidence from younger and older adults.

    Science.gov (United States)

    Getzmann, Stephan; Golob, Edward J; Wascher, Edmund

    2016-05-01

    Speech perception under complex listening conditions usually decreases in aging. This is especially true for listening conditions requiring divided attention among 2 and more relevant speakers. Using a speech perception task and event-related potential measures, we studied the ability of younger and older adults to attend to speech information from a single-target speaker (focused attention) or from 2 different (alternative) target speakers (divided attention). The focused and divided attention conditions were presented either in silence or in the presence of 3 concurrent speakers. In the presence of concurrent speakers, older participants showed worse performance with divided versus focused attention. In contrast, there was no effect of attention condition for the younger adults. Relative to the young, event-related potential analysis in older subjects indicated a decline in preparatory activity for the critical speech information (a delayed and smaller contingent negative variation), and delayed attentional control (indicated by a longer P2 latency). Standardized low-resolution brain electromagnetic tomography revealed that the age-related decline in preparatory activity was associated with reduced activation of medial and superior frontal gyrus and anterior cingulate gyrus. The results suggest that age-related differences in these prefrontal brain areas reflect declines in preparatory attention and gating of subsequent task-related speech information, especially under conditions of divided attention. These findings may reflect mechanisms relating to impaired speech perception by older people in "cocktail-party" listening situations. Copyright © 2016 Elsevier Inc. All rights reserved.

  8. Impact of climate change on human infectious diseases: Empirical evidence and human adaptation.

    Science.gov (United States)

    Wu, Xiaoxu; Lu, Yongmei; Zhou, Sen; Chen, Lifan; Xu, Bing

    2016-01-01

    Climate change refers to long-term shifts in weather conditions and patterns of extreme weather events. It may lead to changes in health threat to human beings, multiplying existing health problems. This review examines the scientific evidences on the impact of climate change on human infectious diseases. It identifies research progress and gaps on how human society may respond to, adapt to, and prepare for the related changes. Based on a survey of related publications between 1990 and 2015, the terms used for literature selection reflect three aspects--the components of infectious diseases, climate variables, and selected infectious diseases. Humans' vulnerability to the potential health impacts by climate change is evident in literature. As an active agent, human beings may control the related health effects that may be effectively controlled through adopting proactive measures, including better understanding of the climate change patterns and of the compound disease-specific health effects, and effective allocation of technologies and resources to promote healthy lifestyles and public awareness. The following adaptation measures are recommended: 1) to go beyond empirical observations of the association between climate change and infectious diseases and develop more scientific explanations, 2) to improve the prediction of spatial-temporal process of climate change and the associated shifts in infectious diseases at various spatial and temporal scales, and 3) to establish locally effective early warning systems for the health effects of predicated climate change. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

  9. An Evaluation of a Human Machine Interface based on Attentional-resources Effectiveness

    International Nuclear Information System (INIS)

    Ha, Jun Su; Seong, Poong Hyun

    2008-01-01

    Measures of attentional-resource effectiveness during monitoring and detection tasks in nuclear power plants (NPPs) have been developed based on cost-benefit principle and validated with experimental studies. The underlying principle of the measures is that information sources should be selectively attended according to their informational importance. One of two measures is Fixation to Importance Ratio (FIR) which represents attentional-resources (eye fixations) spent on an information source compared to importance of the information source

  10. The own-age bias in face memory is unrelated to differences in attention--evidence from event-related potentials.

    Science.gov (United States)

    Neumann, Markus F; End, Albert; Luttmann, Stefanie; Schweinberger, Stefan R; Wiese, Holger

    2015-03-01

    Participants are more accurate at remembering faces from their own relative to a different age group (the own-age bias, or OAB). A recent socio-cognitive account has suggested that differential allocation of attention to old versus young faces underlies this phenomenon. Critically, empirical evidence for a direct relationship between attention to own- versus other-age faces and the OAB in memory is lacking. To fill this gap, we tested the roles of attention in three different experimental paradigms, and additionally analyzed event-related brain potentials (ERPs). In Experiment 1, we compared the learning of old and young faces during focused versus divided attention, but revealed similar OABs in subsequent memory for both attention conditions. Similarly, manipulating attention during learning did not differentially affect the ERPs elicited by young versus old faces. In Experiment 2, we examined the repetition effects from task-irrelevant old and young faces presented under varying attentional loads on the N250r ERP component as an index of face recognition. Independent of load, the N250r effects were comparable for both age categories. Finally, in Experiment 3 we measured the N2pc as an index of attentional selection of old versus young target faces in a visual search task. The N2pc was not significantly different for the young versus the old target search conditions, suggesting similar orientations of attention to either face age group. Overall, we propose that the OAB in memory is largely unrelated to early attentional processes. Our findings therefore contrast with the predictions from socio-cognitive accounts on own-group biases in recognition memory, and are more easily reconciled with expertise-based models.

  11. Influence of attention focus on neural activity in the human spinal cord during thermal sensory stimulation.

    Science.gov (United States)

    Stroman, Patrick W; Coe, Brian C; Munoz, Doug P

    2011-01-01

    Perceptions of sensation and pain in healthy people are believed to be the net result of sensory input and descending modulation from brainstem and cortical regions depending on emotional and cognitive factors. Here, the influence of attention on neural activity in the spinal cord during thermal sensory stimulation of the hand was investigated with functional magnetic resonance imaging by systematically varying the participants' attention focus across and within repeated studies. Attention states included (1) attention to the stimulus by rating the sensation and (2) attention away from the stimulus by performing various mental tasks of watching a movie and identifying characters, detecting the direction of coherently moving dots within a randomly moving visual field and answering mentally-challenging questions. Functional MRI results spanning the cervical spinal cord and brainstem consistently demonstrated that the attention state had a significant influence on the activity detected in the cervical spinal cord, as well as in brainstem regions involved with the descending analgesia system. These findings have important implications for the detection and study of pain, and improved characterization of the effects of injury or disease. Copyright © 2011 Elsevier Inc. All rights reserved.

  12. Serological evidence for human cystic echinococcosis in Slovenia

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    Kotar Tadeja

    2008-05-01

    Full Text Available Abstract Background Cystic echinococcosis (CE is caused by the larva of tapeworm Echinococcus granulosus. Dogs and other canids are the primary definitive hosts for this parasite. CE may develop after accidental ingestion of tapeworm eggs, excreted with the feces of these animals. In the intestine, the larvae released from the eggs are nested in the liver, lungs or other organs of livestock as intermediate hosts and humans as aberrant hosts. The aim of this study was to examine serologically whether some of the patients in Slovenia, suspected of CE by imaging findings in the liver or lungs had been infected with the larva of Echinococcus granulosus. Methods Between January 1, 2002 and the end of December 2006, 1323 patients suspected of having echinococcosis were screened serologically by indirect haemagglutination assay (IHA. For confirmation and differentiation of Echinococcus spp. infection, the sera of IHA-positive patients were then retested by western blot (WB. Results Out of 127 IHA-positive sera, 34 sera were confirmed by WB and considered specific for CE. Of 34 sera of CE-positive patients sera, 32 corresponded to the characteristic imaging findings of a liver cysts and 2 to those of lung cysts. The mean age of CE-positive patients was 58.3 years. No significant differences were found between the CE-positive patients in regard to their sex. Conclusion In the study, it was found out that CE was mostly spread in the same area of Slovenia as in the past, but its prevalence decreased from 4.8 per 105 inhabitants in the period 1956–1968 to 1.7 per 105 inhabitants in the period 2002–2006. In spite of the decreased prevalence of CE in the last years, it is suggested that clinicians and public health authorities, especially in the eastern parts of Slovenia where the most CE patients come from, should pay greater attention to this disease in the future.

  13. Electrophysiological evidence of the time course of attentional bias in nonpatients reporting symptoms of depression with and without co-occurring anxiety

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    Sarah M. Sass

    2014-04-01

    Full Text Available Anxiety is characterized by attentional biases to threat, but findings are inconsistent for depression. To address this inconsistency, the present study systematically assessed the role of co-occurring anxiety in attentional bias in depression. In addition, the role of emotional valence, arousal, and gender was explored. Ninety-two nonpatients completed the Penn State Worry Questionnaire (PSWQ; Meyer et al., 1990; Molina & Borkovec, 1994 and portions of the Mood and Anxiety Symptom Questionnaire (MASQ; Watson, Clark, et al., 1995; Watson, Weber, et al., 1995. Individuals reporting high levels of depression and low levels of anxiety (depression only, high levels of depression and anxiety (combined, or low levels of both (control completed an emotion-word Stroop task during event-related brain potential (ERP recording. Pleasant and unpleasant words were matched on emotional arousal level. An attentional bias was not evident in the depression-only group. Women in the combined group had larger N200 amplitude for pleasant than unpleasant stimuli, and the combined group as a whole had larger right-lateralized P300 amplitude for pleasant than unpleasant stimuli, consistent with an early and later attentional bias that is specific to unpleasant valence in the combined group. Men in the control group had larger N200 amplitude for pleasant than unpleasant stimuli, consistent with an early attentional bias that is specific to pleasant valence. The present study indicates that the nature and time course of attention prompted by emotional valence and not arousal differentiates depression with and without anxiety, with some evidence of gender moderating early effects. Overall, results suggest that co-occurring anxiety is more important than previously acknowledged in demonstrating evidence of attentional biases in depression.

  14. AD/HD and the Capture of Attention by Briefly Exposed Delay-Related Cues: Evidence from a Conditioning Paradigm

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    Sonuga-Barke, Edmund J. S.; De Houwer, Jan; De Ruiter, Karen; Ajzenstzen, Michal; Holland, Sarah

    2004-01-01

    Background: The selective attention of children with attention deficit/hyperactivity disorder (AD/HD) to briefly exposed delay-related cues was examined in two experiments using a dot-probe conditioning paradigm. Method: Colour cues were paired with negatively (i.e., imposition of delay) and positively valenced cues (i.e., escape from or avoidance…

  15. Eye-movement evidence of the time-course of attentional bias for threatening pictures in test-anxious students

    NARCIS (Netherlands)

    Dong, Y.; Beuckelaer, A. de; Yu, L.; Zhou, R

    2017-01-01

    Protocols for measuring attentional bias to threat in test-anxiety, a special form of trait-anxiety, are rarely found in the literature. In our eye-tracking study, we introduced a new protocol, and studied the time-course of attention to test-related pictures with varying threat levels in 22 high

  16. You see what you have learned. Evidence for an interrelation of associative learning and visual selective attention.

    Science.gov (United States)

    Feldmann-Wüstefeld, Tobias; Uengoer, Metin; Schubö, Anna

    2015-11-01

    Besides visual salience and observers' current intention, prior learning experience may influence deployment of visual attention. Associative learning models postulate that observers pay more attention to stimuli previously experienced as reliable predictors of specific outcomes. To investigate the impact of learning experience on deployment of attention, we combined an associative learning task with a visual search task and measured event-related potentials of the EEG as neural markers of attention deployment. In the learning task, participants categorized stimuli varying in color/shape with only one dimension being predictive of category membership. In the search task, participants searched a shape target while disregarding irrelevant color distractors. Behavioral results showed that color distractors impaired performance to a greater degree when color rather than shape was predictive in the learning task. Neurophysiological results show that the amplified distraction was due to differential attention deployment (N2pc). Experiment 2 showed that when color was predictive for learning, color distractors captured more attention in the search task (ND component) and more suppression of color distractor was required (PD component). The present results thus demonstrate that priority in visual attention is biased toward predictive stimuli, which allows learning experience to shape selection. We also show that learning experience can overrule strong top-down control (blocked tasks, Experiment 3) and that learning experience has a longer-term effect on attention deployment (tasks on two successive days, Experiment 4). © 2015 Society for Psychophysiological Research.

  17. Abrupt onsets capture attention independent of top-down control settings 11: Additivity is no evidence for filtering

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    Schreij, D.; Theeuwes, J.; Olivers, C.N.L.

    2010-01-01

    Is attentional capture contingent on top-down control settings or involuntarily driven by salient stimuli? Supporting the stimulus-driven attentional capture view, Schreij, Owens, and Theeuwes (2008) found that an onset distractor caused a response delay, in spite of participants' having adopted an

  18. Sensitive periods in human development: evidence from musical training.

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    Penhune, Virginia B

    2011-10-01

    One of the primary goals of cognitive neuroscience is to understand the interaction between genes, development and specific experience. A particularly fascinating example of this interaction is a sensitive period - a time during development when experience has a differential effect on behavior and the brain. Behavioral and brain imaging studies in musicians have provided suggestive evidence for a possible sensitive period for musical training; showing that musicians who began training early show better task performance and greater changes in auditory and motor regions of the brain. However, these studies have not controlled for likely differences between early- (ET) and late-trained (LT) musicians in the number of years of musical experience. This review presents behavioral work from our laboratory comparing the performance of ET (before age seven) and LT musicians who were matched for years of experience on the ability to tap in synchrony with auditory and visual rhythms. The results demonstrate the existence of a possible sensitive period for musical training that has its greatest impact on measures of sensorimotor integration. Work on motor learning in children and how this might relate to the observed sensitive period effect is also reviewed. These studies are described in the context of what is currently known about sensitive periods in animals and humans; drawing on evidence from anatomy and physiology, studies of deafness, as well as structural and functional neuroimaging studies in trained musicians. The possible mechanisms underlying sensitive periods for musical training are discussed based on current theories describing the influence of both low-level features of sensory experience and higher-level cognitive processing. Copyright © 2011 Elsevier Srl. All rights reserved.

  19. Contributions of emotional state and attention to the processing of syntactic agreement errors: evidence from P600

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    Martine Wilhelmina Francina Teresia Verhees

    2015-04-01

    Full Text Available The classic account of language is that language processing occurs in isolation from other cognitive systems, like perception, motor action and emotion. The theme of this paper is the relationship between a participant’s emotional state and language comprehension. Does emotional context affect how we process neutral words? Recent studies showed that processing of word meaning –traditionally conceived as an automatic process– is affected by emotional state. The influence of emotional state on syntactic processing is less clear. One study reported a mood-related P600 modulation, while another study did not observe an effect of mood on syntactic processing. The goals of this study were: First, to clarify whether and if so how mood affects syntactic processing. Second, to shed light on the underlying mechanisms by separating possible effects of mood from those of attention on syntactic processing.ERPs were recorded while participants read syntactically correct or incorrect sentences. Mood (happy vs. sad was manipulated by presenting film clips. Attention was manipulated by directing attention to syntactic features vs. physical features. The mood induction was effective. Interactions between mood, attention and syntactic correctness were obtained, showing that mood and attention modulated P600. The mood manipulation led to a reduction in P600 for sad as compared to happy mood when attention was directed at syntactic features. The attention manipulation led to a reduction in P600 when attention was directed at physical features compared to syntactic features for happy mood. From this we draw two conclusions: First, emotional state does affect syntactic processing. We propose mood-related differences in the reliance on heuristics as the underlying mechanism. Second, attention can contribute to emotion-related ERP effects in syntactic language processing. Therefore, future studies on the relation between language and emotion will have to control

  20. Contributions of emotional state and attention to the processing of syntactic agreement errors: evidence from P600.

    Science.gov (United States)

    Verhees, Martine W F T; Chwilla, Dorothee J; Tromp, Johanne; Vissers, Constance T W M

    2015-01-01

    The classic account of language is that language processing occurs in isolation from other cognitive systems, like perception, motor action, and emotion. The central theme of this paper is the relationship between a participant's emotional state and language comprehension. Does emotional context affect how we process neutral words? Recent studies showed that processing of word meaning - traditionally conceived as an automatic process - is affected by emotional state. The influence of emotional state on syntactic processing is less clear. One study reported a mood-related P600 modulation, while another study did not observe an effect of mood on syntactic processing. The goals of this study were: First, to clarify whether and if so how mood affects syntactic processing. Second, to shed light on the underlying mechanisms by separating possible effects of mood from those of attention on syntactic processing. Event-related potentials (ERPs) were recorded while participants read syntactically correct or incorrect sentences. Mood (happy vs. sad) was manipulated by presenting film clips. Attention was manipulated by directing attention to syntactic features vs. physical features. The mood induction was effective. Interactions between mood, attention and syntactic correctness were obtained, showing that mood and attention modulated P600. The mood manipulation led to a reduction in P600 for sad as compared to happy mood when attention was directed at syntactic features. The attention manipulation led to a reduction in P600 when attention was directed at physical features compared to syntactic features for happy mood. From this we draw two conclusions: First, emotional state does affect syntactic processing. We propose mood-related differences in the reliance on heuristics as the underlying mechanism. Second, attention can contribute to emotion-related ERP effects in syntactic language processing. Therefore, future studies on the relation between language and emotion will

  1. Functional Imaging of Audio-Visual Selective Attention in Monkeys and Humans: How do Lapses in Monkey Performance Affect Cross-Species Correspondences?

    Science.gov (United States)

    Rinne, Teemu; Muers, Ross S; Salo, Emma; Slater, Heather; Petkov, Christopher I

    2017-06-01

    The cross-species correspondences and differences in how attention modulates brain responses in humans and animal models are poorly understood. We trained 2 monkeys to perform an audio-visual selective attention task during functional magnetic resonance imaging (fMRI), rewarding them to attend to stimuli in one modality while ignoring those in the other. Monkey fMRI identified regions strongly modulated by auditory or visual attention. Surprisingly, auditory attention-related modulations were much more restricted in monkeys than humans performing the same tasks during fMRI. Further analyses ruled out trivial explanations, suggesting that labile selective-attention performance was associated with inhomogeneous modulations in wide cortical regions in the monkeys. The findings provide initial insights into how audio-visual selective attention modulates the primate brain, identify sources for "lost" attention effects in monkeys, and carry implications for modeling the neurobiology of human cognition with nonhuman animals. © The Author 2017. Published by Oxford University Press.

  2. Functional Imaging of Audio–Visual Selective Attention in Monkeys and Humans: How do Lapses in Monkey Performance Affect Cross-Species Correspondences?

    Science.gov (United States)

    Muers, Ross S.; Salo, Emma; Slater, Heather; Petkov, Christopher I.

    2017-01-01

    Abstract The cross-species correspondences and differences in how attention modulates brain responses in humans and animal models are poorly understood. We trained 2 monkeys to perform an audio–visual selective attention task during functional magnetic resonance imaging (fMRI), rewarding them to attend to stimuli in one modality while ignoring those in the other. Monkey fMRI identified regions strongly modulated by auditory or visual attention. Surprisingly, auditory attention-related modulations were much more restricted in monkeys than humans performing the same tasks during fMRI. Further analyses ruled out trivial explanations, suggesting that labile selective-attention performance was associated with inhomogeneous modulations in wide cortical regions in the monkeys. The findings provide initial insights into how audio–visual selective attention modulates the primate brain, identify sources for “lost” attention effects in monkeys, and carry implications for modeling the neurobiology of human cognition with nonhuman animals. PMID:28419201

  3. The influence of banner advertisements on attention and memory: human faces with averted gaze can enhance advertising effectiveness.

    Science.gov (United States)

    Sajjacholapunt, Pitch; Ball, Linden J

    2014-01-01

    Research suggests that banner advertisements used in online marketing are often overlooked, especially when positioned horizontally on webpages. Such inattention invariably gives rise to an inability to remember advertising brands and messages, undermining the effectiveness of this marketing method. Recent interest has focused on whether human faces within banner advertisements can increase attention to the information they contain, since the gaze cues conveyed by faces can influence where observers look. We report an experiment that investigated the efficacy of faces located in banner advertisements to enhance the attentional processing and memorability of banner contents. We tracked participants' eye movements when they examined webpages containing either bottom-right vertical banners or bottom-center horizontal banners. We also manipulated facial information such that banners either contained no face, a face with mutual gaze or a face with averted gaze. We additionally assessed people's memories for brands and advertising messages. Results indicated that relative to other conditions, the condition involving faces with averted gaze increased attention to the banner overall, as well as to the advertising text and product. Memorability of the brand and advertising message was also enhanced. Conversely, in the condition involving faces with mutual gaze, the focus of attention was localized more on the face region rather than on the text or product, weakening any memory benefits for the brand and advertising message. This detrimental impact of mutual gaze on attention to advertised products was especially marked for vertical banners. These results demonstrate that the inclusion of human faces with averted gaze in banner advertisements provides a promising means for marketers to increase the attention paid to such adverts, thereby enhancing memory for advertising information.

  4. The influence of banner advertisements on attention and memory: Human faces with averted gaze can enhance advertising effectiveness

    Directory of Open Access Journals (Sweden)

    Pitch eSajjacholapunt

    2014-03-01

    Full Text Available Research suggests that banner advertisements used in online marketing are often overlooked, especially when positioned horizontally on webpages. Such inattention invariably gives rise to an inability to remember advertising brands and messages, undermining the effectiveness of this marketing method. Recent interest has focused on whether human faces within banner advertisements can increase attention to the information they contain, since the gaze cues conveyed by faces can influence where observers look. We report an experiment that investigated the efficacy of faces located in banner advertisements to enhance the attentional processing and memorability of banner contents. We tracked participants’ eye movements when they examined webpages containing either bottom-right vertical banners or bottom-centre horizontal banners. We also manipulated facial information such that banners either contained no face, a face with mutual gaze or a face with averted gaze. We additionally assessed people’s memories for brands and advertising messages. Results indicated that relative to other conditions, the condition involving faces with averted gaze increased attention to the banner overall, as well as to the advertising text and product. Memorability of the brand and advertising message was also enhanced. Conversely, in the condition involving faces with mutual gaze, the focus of attention was localised more on the face region rather than on the text or product, weakening any memory benefits for the brand and advertising message. This detrimental impact of mutual gaze on attention to advertised products was especially marked for vertical banners. These results demonstrate that the inclusion of human faces with averted gaze in banner advertisements provides a promising means for marketers to increase the attention paid to such adverts, thereby enhancing memory for advertising information.

  5. Evidence of Recent Intricate Adaptation in Human Populations.

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    Leeyoung Park

    Full Text Available Recent human adaptations have shaped population differentiation in genomic regions containing putative functional variants, mostly located in predicted regulatory elements. However, their actual functionalities and the underlying mechanism of recent adaptation remain poorly understood. In the current study, regions of genes and repeats were investigated for functionality depending on the degree of population differentiation, FST or ΔDAF (a difference in derived allele frequency. The high FST in the 5´ or 3´ untranslated regions (UTRs, in particular, confirmed that population differences arose mainly from differences in regulation. Expression quantitative trait loci (eQTL analyses using lymphoblastoid cell lines indicated that the majority of the highly population-specific regions represented cis- and/or trans-eQTL. However, groups having the highest ΔDAFs did not necessarily have higher proportions of eQTL variants; in these groups, the patterns were complex, indicating recent intricate adaptations. The results indicated that East Asian (EAS and European populations (EUR experienced mutual selection pressures. The mean derived allele frequency of the high ΔDAF groups suggested that EAS and EUR underwent strong adaptation; however, the African population in Africa (AFR experienced slight, yet broad, adaptation. The DAF distributions of variants in the gene regions showed clear selective pressure in each population, which implies the existence of more recent regulatory adaptations in cells other than lymphoblastoid cell lines. In-depth analysis of population-differentiated regions indicated that the coding gene, RNF135, represented a trans-regulation hotspot via cis-regulation by the population-specific variants in the region of selective sweep. Together, the results provide strong evidence of actual intricate adaptation of human populations via regulatory manipulation.

  6. Additive effects of affective arousal and top-down attention on the event-related brain responses to human bodies.

    Science.gov (United States)

    Hietanen, Jari K; Kirjavainen, Ilkka; Nummenmaa, Lauri

    2014-12-01

    The early visual event-related 'N170 response' is sensitive to human body configuration and it is enhanced to nude versus clothed bodies. We tested whether the N170 response as well as later EPN and P3/LPP responses to nude bodies reflect the effect of increased arousal elicited by these stimuli, or top-down allocation of object-based attention to the nude bodies. Participants saw pictures of clothed and nude bodies and faces. In each block, participants were asked to direct their attention towards stimuli from a specified target category while ignoring others. Object-based attention did not modulate the N170 amplitudes towards attended stimuli; instead N170 response was larger to nude bodies compared to stimuli from other categories. Top-down attention and affective arousal had additive effects on the EPN and P3/LPP responses reflecting later processing stages. We conclude that nude human bodies have a privileged status in the visual processing system due to the affective arousal they trigger. Copyright © 2014 Elsevier B.V. All rights reserved.

  7. Attention to emotion modulates fMRI activity in human right superior temporal sulcus.

    Science.gov (United States)

    Narumoto, J; Okada, T; Sadato, N; Fukui, K; Yonekura, Y

    2001-10-01

    A parallel neural network has been proposed for processing various types of information conveyed by faces including emotion. Using functional magnetic resonance imaging (fMRI), we tested the effect of the explicit attention to the emotional expression of the faces on the neuronal activity of the face-responsive regions. Delayed match to sample procedure was adopted. Subjects were required to match the visually presented pictures with regard to the contour of the face pictures, facial identity, and emotional expressions by valence (happy and fearful expressions) and arousal (fearful and sad expressions). Contour matching of the non-face scrambled pictures was used as a control condition. The face-responsive regions that responded more to faces than to non-face stimuli were the bilateral lateral fusiform gyrus (LFG), the right superior temporal sulcus (STS), and the bilateral intraparietal sulcus (IPS). In these regions, general attention to the face enhanced the activities of the bilateral LFG, the right STS, and the left IPS compared with attention to the contour of the facial image. Selective attention to facial emotion specifically enhanced the activity of the right STS compared with attention to the face per se. The results suggest that the right STS region plays a special role in facial emotion recognition within distributed face-processing systems. This finding may support the notion that the STS is involved in social perception.

  8. Spatial attention improves the quality of population codes in human visual cortex.

    Science.gov (United States)

    Saproo, Sameer; Serences, John T

    2010-08-01

    Selective attention enables sensory input from behaviorally relevant stimuli to be processed in greater detail, so that these stimuli can more accurately influence thoughts, actions, and future goals. Attention has been shown to modulate the spiking activity of single feature-selective neurons that encode basic stimulus properties (color, orientation, etc.). However, the combined output from many such neurons is required to form stable representations of relevant objects and little empirical work has formally investigated the relationship between attentional modulations on population responses and improvements in encoding precision. Here, we used functional MRI and voxel-based feature tuning functions to show that spatial attention induces a multiplicative scaling in orientation-selective population response profiles in early visual cortex. In turn, this multiplicative scaling correlates with an improvement in encoding precision, as evidenced by a concurrent increase in the mutual information between population responses and the orientation of attended stimuli. These data therefore demonstrate how multiplicative scaling of neural responses provides at least one mechanism by which spatial attention may improve the encoding precision of population codes. Increased encoding precision in early visual areas may then enhance the speed and accuracy of perceptual decisions computed by higher-order neural mechanisms.

  9. Concurrent deployment of visual attention and response selection bottleneck in a dual-task: Electrophysiological and behavioural evidence.

    Science.gov (United States)

    Reimer, Christina B; Strobach, Tilo; Schubert, Torsten

    2017-12-01

    Visual attention and response selection are limited in capacity. Here, we investigated whether visual attention requires the same bottleneck mechanism as response selection in a dual-task of the psychological refractory period (PRP) paradigm. The dual-task consisted of an auditory two-choice discrimination Task 1 and a conjunction search Task 2, which were presented at variable temporal intervals (stimulus onset asynchrony, SOA). In conjunction search, visual attention is required to select items and to bind their features resulting in a serial search process around the items in the search display (i.e., set size). We measured the reaction time of the visual search task (RT2) and the N2pc, an event-related potential (ERP), which reflects lateralized visual attention processes. If the response selection processes in Task 1 influence the visual attention processes in Task 2, N2pc latency and amplitude would be delayed and attenuated at short SOA compared to long SOA. The results, however, showed that latency and amplitude were independent of SOA, indicating that visual attention was concurrently deployed to response selection. Moreover, the RT2 analysis revealed an underadditive interaction of SOA and set size. We concluded that visual attention does not require the same bottleneck mechanism as response selection in dual-tasks.

  10. Eye-movement evidence of the time-course of attentional bias for threatening pictures in test-anxious students.

    Science.gov (United States)

    Dong, Yunying; De Beuckelaer, Alain; Yu, Liang; Zhou, Renlai

    2017-06-01

    Protocols for measuring attentional bias to threat in test-anxiety, a special form of trait-anxiety, are rarely found in the literature. In our eye-tracking study, we introduced a new protocol, and studied the time-course of attention to test-related pictures with varying threat levels in 22 high test-anxious (HTA) and 22 low test-anxious (LTA) subjects. To determine whether attentional bias to test-related pictures is due to test-anxiety and not to state-anxiety, we also included a third group of 22 subjects with high state-anxiety but low test-anxiety (HSA). The subjects completed a free viewing task (FVT) in which high threat-neutral (HT-N) and low threat-neutral (LT-N) picture pairs were presented for 3 s. The results demonstrated that: (1) HTA subjects showed initial orienting to LT pictures, early attentional engagement with HT pictures later on and avoidance of HT pictures at the very end; (2) LTA subjects showed initial orienting to HT pictures and maintenance of attention on them later on; while (3) HSA subjects showed an initial orientation towards LT pictures and maintenance of attention on LT and HT pictures later on. These results suggest that, (high) test-anxiety is also prone to attentional bias towards test-related threat stimuli. Implications for future research are discussed.

  11. When memory is not enough: Electrophysiological evidence for goal-dependent use of working memory representations in guiding visual attention

    Science.gov (United States)

    Carlisle, Nancy B.; Woodman, Geoffrey F.

    2014-01-01

    Biased competition theory proposes that representations in working memory drive visual attention to select similar inputs. However, behavioral tests of this hypothesis have led to mixed results. These inconsistent findings could be due to the inability of behavioral measures to reliably detect the early, automatic effects on attentional deployment that the memory representations exert. Alternatively, executive mechanisms may govern how working memory representations influence attention based on higher-level goals. In the present study, we tested these hypotheses using the N2pc component of participants’ event-related potentials (ERPs) to directly measure the early deployments of covert attention. Participants searched for a target in an array that sometimes contained a memory-matching distractor. In Experiments 1–3, we manipulated the difficulty of the target discrimination and the proximity of distractors, but consistently observed that covert attention was deployed to the search targets and not the memory-matching distractors. In Experiment 4, we showed that when participants’ goal involved attending to memory-matching items that these items elicited a large and early N2pc. Our findings demonstrate that working memory representations alone are not sufficient to guide early deployments of visual attention to matching inputs and that goal-dependent executive control mediates the interactions between working memory representations and visual attention. PMID:21254796

  12. Face scanning in autism spectrum disorder (ASD and attention deficit/hyperactivity disorder (ADHD: human versus dog face scanning

    Directory of Open Access Journals (Sweden)

    Mauro eMuszkat

    2015-10-01

    Full Text Available This study used eye-tracking to explore attention allocation to human and dog faces in children and adolescents with autism spectrum disorder (ASD, attention deficit/hyperactivity disorder (ADHD, and typical development (TD. Significant differences were found among the three groups. TD participants looked longer at the eyes than ASD and ADHD ones, irrespective of the faces presented. In spite of this difference, groups were similar in that they looked more to the eyes than to the mouth areas of interest. The ADHD group gazed longer at the mouth region than the other groups. Furthermore, groups were also similar in that they looked more to the dog than to the human faces. The eye tracking technology proved to be useful for behavioral investigation in different neurodevelopmental disorders.

  13. Attention is allocated closely ahead of the target during smooth pursuit eye movements: Evidence from EEG frequency tagging.

    Science.gov (United States)

    Chen, Jing; Valsecchi, Matteo; Gegenfurtner, Karl R

    2017-07-28

    It is under debate whether attention during smooth pursuit is centered right on the pursuit target or allocated preferentially ahead of it. Attentional deployment was previously probed using a secondary task, which might have altered attention allocation and led to inconsistent findings. We measured frequency-tagged steady-state visual evoked potentials (SSVEP) to measure attention allocation in the absence of any secondary probing task. The observers pursued a moving dot while stimuli flickering at different frequencies were presented at various locations ahead or behind the pursuit target. We observed a significant increase in EEG power at the flicker frequency of the stimulus in front of the pursuit target, compared to the frequency of the stimulus behind. When testing many different locations, we found that the enhancement was detectable up to about 1.5° ahead during pursuit, but vanished by 3.5°. In a control condition using attentional cueing during fixation, we did observe an enhanced EEG response to stimuli at this eccentricity, indicating that the focus of attention during pursuit is narrower than allowed for by the resolution of the attentional system. In a third experiment, we ruled out the possibility that the SSVEP enhancement was a byproduct of the catch-up saccades occurring during pursuit. Overall, we showed that attention is on average allocated ahead of the pursuit target during smooth pursuit. EEG frequency tagging seems to be a powerful technique that allows for the investigation of attention/perception implicitly when an overt task would be confounding. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Bear phalanx traumatically introduced into a living human: Prehistoric evidence.

    Science.gov (United States)

    Richards, Gary D; Ojeda, Hillary M; Jabbour, Rebecca S; Ibarra, Caitlin L; Horton, Caroline F

    2013-03-01

    Traumatically induced skeletal injuries are common and can be ascribed to a normal range of events occurring in an individual's lifetime. A subset of these trauma-induced injuries provides enhanced insight into cultural history. Such cases might include those referable to medico-surgical and religious/ritualistic practices. We describe prehistoric evidence and cultural implications of the traumatic insertion of an Ursus manual phalanx into the elbow of a living human. The injury healed and the phalanx remained in situ until death. The individual derives from the Ellis Landing shellmound and dates to a subphase of the Middle Period (≈500BC-300AD) in the California cultural sequence. The remains are of a 30-40 year-old female. Comparative data on arm morphology and pathological conditions present were collected (n=159). Three Ursus subspecies (n=15) were examined to identify the taxon represented by the phalanx. The described individual was probably wearing bear paw ornaments at the time she was crushed by a heavy object. During this event, a bear claw was driven into her cubital fossa, the basal phalangeal tubercle being impressed into the humerus. The wound healed completely. The presence of Ursus body parts indicates an elevated societal role for this female; most likely she was a shaman or healer. Copyright © 2013 Elsevier Inc. All rights reserved.

  15. Distinct representations for shifts of spatial attention and changes of reward contingencies in the human brain.

    Science.gov (United States)

    Tosoni, Annalisa; Shulman, Gordon L; Pope, Anna L W; McAvoy, Mark P; Corbetta, Maurizio

    2013-06-01

    Success in a dynamically changing world requires both rapid shifts of attention to the location of important objects and the detection of changes in motivational contingencies that may alter future behavior. Here we addressed the relationship between these two processes by measuring the blood-oxygenation-level-dependent (BOLD) signal during a visual search task in which the location and the color of a salient cue respectively indicated where a rewarded target would appear and the monetary gain (large or small) associated with its detection. While cues that either shifted or maintained attention were presented every 4 to 8 sec, the reward magnitude indicated by the cue changed roughly every 30 sec, allowing us to distinguish a change in expected reward magnitude from a maintained state of expected reward magnitude. Posterior cingulate cortex was modulated by cues signaling an increase in expected reward magnitude, but not by cues for shifting versus maintaining spatial attention. Dorsal fronto-parietal regions in precuneus and frontal eye field (FEF) also showed increased BOLD activity for changes in expected reward magnitude from low to high, but in addition showed large independent modulations for shifting versus maintaining attention. In particular, the differential activation for shifting versus maintaining attention was not affected by expected reward magnitude. These results indicate that BOLD activations for shifts of attention and increases in expected reward magnitude are largely separate. Finally, visual cortex showed sustained spatially selective signals that were significantly enhanced when greater reward magnitude was expected, but this reward-related modulation was not observed in spatially selective regions of dorsal fronto-parietal cortex. Copyright © 2012 Elsevier Ltd. All rights reserved.

  16. Discriminative stimuli that control instrumental tobacco-seeking by human smokers also command selective attention.

    Science.gov (United States)

    Hogarth, Lee; Dickinson, Anthony; Duka, Theodora

    2003-08-01

    Incentive salience theory states that acquired bias in selective attention for stimuli associated with tobacco-smoke reinforcement controls the selective performance of tobacco-seeking and tobacco-taking behaviour. To support this theory, we assessed whether a stimulus that had acquired control of a tobacco-seeking response in a discrimination procedure would command the focus of visual attention in a subsequent test phase. Smokers received discrimination training in which an instrumental key-press response was followed by tobacco-smoke reinforcement when one visual discriminative stimulus (S+) was present, but not when another stimulus (S-) was present. The skin conductance response to the S+ and S- assessed whether Pavlovian conditioning to the S+ had taken place. In a subsequent test phase, the S+ and S- were presented in the dot-probe task and the allocation of the focus of visual attention to these stimuli was measured. Participants learned to perform the instrumental tobacco-seeking response selectively in the presence of the S+ relative to the S-, and showed a greater skin conductance response to the S+ than the S-. In the subsequent test phase, participants allocated the focus of visual attention to the S+ in preference to the S-. Correlation analysis revealed that the visual attentional bias for the S+ was positively associated with the number of times the S+ had been paired with tobacco-smoke in training, the skin conductance response to the S+ and with subjective craving to smoke. Furthermore, increased exposure to tobacco-smoke in the natural environment was associated with reduced discrimination learning. These data demonstrate that discriminative stimuli that signal that tobacco-smoke reinforcement is available acquire the capacity to command selective attentional and elicit instrumental tobacco-seeking behaviour.

  17. The effect of human engagement depicted in contextual photographs on the visual attention patterns of adults with traumatic brain injury.

    Science.gov (United States)

    Thiessen, Amber; Brown, Jessica; Beukelman, David; Hux, Karen

    2017-09-01

    Photographs are a frequently employed tool for the rehabilitation of adults with traumatic brain injury (TBI). Speech-language pathologists (SLPs) working with these individuals must select photos that are easily identifiable and meaningful to their clients. In this investigation, we examined the visual attention response to camera- (i.e., depicted human figure looking toward camera) and task-engaged (i.e., depicted human figure looking at and touching an object) contextual photographs for a group of adults with TBI and a group of adults without neurological conditions. Eye-tracking technology served to accurately and objectively measure visual fixations. Although differences were hypothesized given the cognitive deficits associated with TBI, study results revealed little difference in the visual fixation patterns of adults with and without TBI. Specifically, both groups of participants tended to fixate rapidly on the depicted human figure and fixate more on objects in which a human figure was task-engaged than when a human figure was camera-engaged. These results indicate that strategic placement of human figures in a contextual photograph may modify the way in which individuals with TBI visually attend to and interpret photographs. In addition, task-engagement appears to have a guiding effect on visual attention that may be of benefit to SLPs hoping to select more effective contextual photographs for their clients with TBI. Finally, the limited differences in visual attention patterns between individuals with TBI and their age and gender matched peers without neurological impairments indicates that these two groups find similar photograph regions to be worthy of visual fixation. Readers will gain knowledge regarding the photograph selection process for individuals with TBI. In addition, readers will be able to identify camera- and task-engaged photographs and to explain why task-engagement may be a beneficial component of contextual photographs. Copyright © 2017

  18. Fluctuations of Attentional Networks and Default Mode Network during the Resting State Reflect Variations in Cognitive States: Evidence from a Novel Resting-state Experience Sampling Method.

    Science.gov (United States)

    Van Calster, Laurens; D'Argembeau, Arnaud; Salmon, Eric; Peters, Frédéric; Majerus, Steve

    2017-01-01

    Neuroimaging studies have revealed the recruitment of a range of neural networks during the resting state, which might reflect a variety of cognitive experiences and processes occurring in an individual's mind. In this study, we focused on the default mode network (DMN) and attentional networks and investigated their association with distinct mental states when participants are not performing an explicit task. To investigate the range of possible cognitive experiences more directly, this study proposes a novel method of resting-state fMRI experience sampling, informed by a phenomenological investigation of the fluctuation of mental states during the resting state. We hypothesized that DMN activity would increase as a function of internal mentation and that the activity of dorsal and ventral networks would indicate states of top-down versus bottom-up attention at rest. Results showed that dorsal attention network activity fluctuated as a function of subjective reports of attentional control, providing evidence that activity of this network reflects the perceived recruitment of controlled attentional processes during spontaneous cognition. Activity of the DMN increased when participants reported to be in a subjective state of internal mentation, but not when they reported to be in a state of perception. This study provides direct evidence for a link between fluctuations of resting-state neural activity and fluctuations in specific cognitive processes.

  19. Eye Movement Evidence of Attentional Bias for Substance-Related Cues in Heroin Dependents on Methadone Maintenance Therapy.

    Science.gov (United States)

    Zhao, Hui; Yang, Bo; Zhu, Qian; Zhang, Guangqun; Xiao, Yuqin; Guo, Xiao; Huang, Xiu; Zhang, Zhuo

    2017-03-21

    Attentional biases toward substance-related stimuli might play a contributing role in addictive behaviors. This study investigated the selective attention to substance-related stimuli in heroin dependents receiving methadone maintenance therapy. Thirty outpatients receiving methadone maintenance treatment for heroin dependence and 38 healthy controls completed a visual probe task with concurrent eye movement monitoring. The results showed that the heroin group reacted faster to probes associated with substance-related pictures than neutral pictures, and they directed more initial fixations and maintained longer initial fixation durations toward substance-related pictures than neutral pictures. However, attentional bias was not correlated with addiction severity in the heroin group. These findings suggest that attentional bias towards substance-related cues occurs in heroin dependents, although this bias might not be associated with the severity of drug-using behavior.

  20. A Polygenic Risk Score of glutamatergic SNPs associated with schizophrenia predicts attentional behavior and related brain activity in healthy humans.

    Science.gov (United States)

    Rampino, Antonio; Taurisano, Paolo; Fanelli, Giuseppe; Attrotto, Mariateresa; Torretta, Silvia; Antonucci, Linda Antonella; Miccolis, Grazia; Pergola, Giulio; Ursini, Gianluca; Maddalena, Giancarlo; Romano, Raffaella; Masellis, Rita; Di Carlo, Pasquale; Pignataro, Patrizia; Blasi, Giuseppe; Bertolino, Alessandro

    2017-09-01

    Multiple genetic variations impact on risk for schizophrenia. Recent analyses by the Psychiatric Genomics Consortium (PGC2) identified 128 SNPs genome-wide associated with the disorder. Furthermore, attention and working memory deficits are core features of schizophrenia, are heritable and have been associated with variation in glutamatergic neurotransmission. Based on this evidence, in a sample of healthy volunteers, we used SNPs associated with schizophrenia in PGC2 to construct a Polygenic-Risk-Score (PRS) reflecting the cumulative risk for schizophrenia, along with a Polygenic-Risk-Score including only SNPs related to genes implicated in glutamatergic signaling (Glu-PRS). We performed Factor Analysis for dimension reduction of indices of cognitive performance. Furthermore, both PRS and Glu-PRS were used as predictors of cognitive functioning in the domains of Attention, Speed of Processing and Working Memory. The association of the Glu-PRS on brain activity during the Variable Attention Control (VAC) task was also explored. Finally, in a second independent sample of healthy volunteers we sought to confirm the association between the Glu-PRS and both performance in the domain of Attention and brain activity during the VAC.We found that performance in Speed of Processing and Working Memory was not associated with any of the Polygenic-Risk-Scores. The Glu-PRS, but not the PRS was associated with Attention and brain activity during the VAC. The specific effects of Glu-PRS on Attention and brain activity during the VAC were also confirmed in the replication sample.Our results suggest a pathway specificity in the relationship between genetic risk for schizophrenia, the associated cognitive dysfunction and related brain processing. Copyright © 2017 Elsevier B.V. and ECNP. All rights reserved.

  1. The wandering mind of men: ERP evidence for gender differences in attention bias towards attractive opposite sex faces

    OpenAIRE

    van Hooff, Johanna C.; Crawford, Helen; van Vugt, Mark

    2010-01-01

    To examine the time course and automaticity of our attention bias towards attractive opposite sex faces, event-related potentials (ERPs) were recorded from 20 males and 20 females while they carried out a covert orienting task. Faces that were high, low or average in attractiveness, were presented in focus of attention, but were unrelated to task goals. Across the entire sample larger P2 amplitudes were found in response to both attractive and unattractive opposite sex faces, presumably refle...

  2. Self-esteem modulates automatic attentional responses to self-relevant stimuli: evidence from event-related brain potentials

    OpenAIRE

    Chen, Jie; Shui, Qing; Zhong, Yiping

    2015-01-01

    Previous studies have widely shown that self-esteem modulates the attention bias towards social rejection or emotion-related information. However, little is known about the influences of self-esteem on attention bias towards self-relevant stimuli. We aimed to investigate neural correlates that underlie the modulation effect of self-esteem on self-relevant processing. Event-related potentials (ERP) were recorded for subjects’ own names and close others’ names (the names of their friends) while...

  3. The wandering mind of men: ERP evidence for gender differences in attention bias towards attractive opposite sex faces.

    Science.gov (United States)

    van Hooff, Johanna C; Crawford, Helen; van Vugt, Mark

    2011-09-01

    To examine the time course and automaticity of our attention bias towards attractive opposite sex faces, event-related potentials (ERPs) were recorded from 20 males and 20 females while they carried out a covert orienting task. Faces that were high, low or average in attractiveness, were presented in focus of attention, but were unrelated to task goals. Across the entire sample larger P2 amplitudes were found in response to both attractive and unattractive opposite sex faces, presumably reflecting early implicit selective attention to distinctive faces. In male but not female participants this was followed by an increased late slow wave for the attractive faces, signifying heightened processing linked to motivated attention. This latter finding is consistent with sexual strategy theory, which suggests that men and women have evolved to pursue different mating strategies with men being more attentive to cues such as facial beauty. In general, our ERP results suggest that, in addition to threat-related stimuli, other evolutionary-relevant information is also prioritized by our attention systems.

  4. Can attentional control settings be maintained for two color-location conjunctions? Evidence from an RSVP task.

    Science.gov (United States)

    Irons, Jessica L; Remington, Roger W

    2013-07-01

    Previous investigations of the ability to maintain separate attentional control settings for different spatial locations have relied principally on a go/no-go spatial-cueing paradigm. The results have suggested that control of attention is accomplished only late in processing. However, the go/no-go task does not provide strong incentives to withhold attention from irrelevant color-location conjunctions. We used a modified version of the task in which failing to adopt multiple control settings would be detrimental to performance. Two RSVP streams of colored letters appeared to the left and right of fixation. Participants searched for targets that were a conjunction of color and location, so that the target color for one stream acted as a distractor when presented in the opposite stream. Distractors that did not match the target conjunctions nevertheless captured attention and interfered with performance. This was the case even when the target conjunctions were previewed early in the trial prior to the target (Exp. 2). However, distractor interference was reduced when the upcoming distractor was previewed early on in the trial (Exp. 3). Attentional selection of targets by color-location conjunctions may be effective if facilitative attentional sets are accompanied by the top-down inhibition of irrelevant items.

  5. Mapping the timecourse of goal-directed attention to location and colour in human vision.

    Science.gov (United States)

    Adams, Rachel C; Chambers, Christopher D

    2012-03-01

    Goal-directed attention prioritises perception of task-relevant stimuli according to location, features, or onset time. In this study we compared the behavioural timecourse of goal-directed selection to locations and colours by varying the stimulus-onset asynchrony (SOA) between cue and target in a strategic cueing paradigm. Participants reported the presence or absence of a target following prior information regarding its location or colour. Results revealed that preparatory selection by colour is more effective at enhancing perceptual sensitivity than selection by location, even though both types of cue provided equivalent overall information. More detailed analysis revealed that this advantage arose due a limitation of spatial attention in maintaining a sufficiently broad focus (>2°) for target detection across multiple stimuli. In contrast, when target stimuli fell within 2° of the spatial attention spotlight, the strategic advantages and speed of spatial and colour attention were equated. Our findings are consistent with the conclusion that, under spatially optimal conditions, prior spatial and colour information are equally proficient at guiding top-down selection. When spatial locations are ambiguous, however, colour-based selection is the more efficient mechanism. Copyright © 2012 Elsevier B.V. All rights reserved.

  6. The impact of top-down spatial attention on laterality and hemispheric asymmetry in the human parietal cortex.

    Science.gov (United States)

    Jeong, Su Keun; Xu, Yaoda

    2016-08-01

    The human parietal cortex exhibits a preference to contralaterally presented visual stimuli (i.e., laterality) as well as an asymmetry between the two hemispheres with the left parietal cortex showing greater laterality than the right. Using visual short-term memory and perceptual tasks and varying target location predictability, this study examined whether hemispheric laterality and asymmetry are fixed characteristics of the human parietal cortex or whether they are dynamic and modulated by the deployment of top-down attention to the target present hemifield. Two parietal regions were examined here that have previously been shown to be involved in visual object individuation and identification and are located in the inferior and superior intraparietal sulcus (IPS), respectively. Across three experiments, significant laterality was found in both parietal regions regardless of attentional modulation with laterality being greater in the inferior than superior IPS, consistent with their roles in object individuation and identification, respectively. Although the deployment of top-down attention had no effect on the superior IPS, it significantly increased laterality in the inferior IPS. The deployment of top-down spatial attention can thus amplify the strength of laterality in the inferior IPS. Hemispheric asymmetry, on the other hand, was absent in both brain regions and only emerged in the inferior but not the superior IPS with the deployment of top-down attention. Interestingly, the strength of hemispheric asymmetry significantly correlated with the strength of laterality in the inferior IPS. Hemispheric asymmetry thus seems to only emerge when there is a sufficient amount of laterality present in a brain region.

  7. Holistic processing of human body postures: Evidence from the composite effect

    Directory of Open Access Journals (Sweden)

    Sam eWillems

    2014-06-01

    Full Text Available The perception of socially relevant stimuli (e.g., faces and bodies has received considerable attention in the vision science community. It is now widely accepted that human faces are processed holistically and not only analytically. One observation that has been taken as evidence for holistic face processing is the face composite effect: Two identical top halves of a face tend to be perceived as being different when combined with different bottom halves. This supports the hypothesis that face processing proceeds holistically. Indeed, the interference effect disappears when the two face parts are misaligned (blocking holistic perception. In the present study, we investigated whether there is also a composite effect for the perception of body postures: Are two identical body halves perceived as being in different poses when the irrelevant body halves differ from each other? Both a horizontal (i.e., top-bottom body halves; Experiment 1 and a vertical composite effect (i.e., left-right body halves; Experiment 2 were examined by means of a delayed matching-to-sample task. Results of both experiments indicate the existence of a body posture composite effect. This provides evidence for the hypothesis that body postures, as faces, are processed holistically.

  8. Holistic processing of human body postures: evidence from the composite effect.

    Science.gov (United States)

    Willems, Sam; Vrancken, Leia; Germeys, Filip; Verfaillie, Karl

    2014-01-01

    The perception of socially relevant stimuli (e.g., faces and bodies) has received considerable attention in the vision science community. It is now widely accepted that human faces are processed holistically and not only analytically. One observation that has been taken as evidence for holistic face processing is the face composite effect: two identical top halves of a face tend to be perceived as being different when combined with different bottom halves. This supports the hypothesis that face processing proceeds holistically. Indeed, the interference effect disappears when the two face parts are misaligned (blocking holistic perception). In the present study, we investigated whether there is also a composite effect for the perception of body postures: are two identical body halves perceived as being in different poses when the irrelevant body halves differ from each other? Both a horizontal (i.e., top-bottom body halves; Experiment 1) and a vertical composite effect (i.e., left-right body halves; Experiment 2) were examined by means of a delayed matching-to-sample task. Results of both experiments indicate the existence of a body posture composite effect. This provides evidence for the hypothesis that body postures, as faces, are processed holistically.

  9. Modafinil improves attentional performance in healthy, non-sleep deprived humans at doses not inducing hyperarousal across species.

    Science.gov (United States)

    Cope, Zackary A; Minassian, Arpi; Kreitner, Dustin; MacQueen, David A; Milienne-Petiot, Morgane; Geyer, Mark A; Perry, William; Young, Jared W

    2017-10-01

    The wake-promoting drug modafinil is frequently used off-label to improve cognition in psychiatric and academic populations alike. The domain-specific attentional benefits of modafinil have yet to be quantified objectively in healthy human volunteers using tasks validated for comparison across species. Further, given that modafinil is a low-affinity inhibitor for the dopamine and norepinephrine transporters (DAT/NET respectively) it is unclear if any effects are attributable to a non-specific increase in arousal, a feature of many catecholamine reuptake inhibitors (e.g., cocaine, amphetamine). These experiments were designed to test for domain-specific enhancement of attention and cognitive control by modafinil (200 and 400 mg) in healthy volunteers using the 5-choice continuous performance task (5C-CPT) and Wisconsin Card Sort Task (WCST). An additional cross-species assessment of arousal and hyperactivity was performed in this group and in mice (3.2, 10, or 32 mg/kg) using species-specific versions of the behavioral pattern monitor (BPM). Modafinil significantly enhanced attention (d prime) in humans performing the 5C-CPT at doses that did not affect WCST performance or induce hyperactivity in the BPM. In mice, only the highest dose elicited increased activity in the BPM. These results indicate that modafinil produces domain-specific enhancement of attention in humans not driven by hyperarousal, unlike other drugs in this class, and higher equivalent doses were required for hyperarousal in mice. Further, these data support the utility of using the 5C-CPT across species to more precisely determine the mechanism(s) underlying the pro-cognitive effects of modafinil and potentially other pharmacological treatments. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Low level perceptual, not attentional, processes modulate distractor interference in high perceptual load displays: evidence from neglect/extinction.

    Science.gov (United States)

    Mevorach, Carmel; Tsal, Yehoshua; Humphreys, Glyn W

    2014-01-10

    According to perceptual load theory (Lavie, 2005) distractor interference is determined by the availability of attentional resources. If target processing does not exhaust resources (with low perceptual load) distractor processing will take place resulting in interference with a primary task; however, when target processing uses-up attentional capacity (with high perceptual load) interference can be avoided. An alternative account (Tsal and Benoni, 2010a) suggests that perceptual load effects can be based on distractor dilution by the mere presence of additional neutral items in high-load displays so that the effect is not driven by the amount of attention resources required for target processing. Here we tested whether patients with unilateral neglect or extinction would show dilution effects from neutral items in their contralesional (neglected/extinguished) field, even though these items do not impose increased perceptual load on the target and at the same time attract reduced attentional resources compared to stimuli in the ipsilesional field. Thus, such items do not affect the amount of attention resources available for distractor processing. We found that contralesional neutral elements can eliminate distractor interference as strongly as centrally presented ones in neglect/extinction patients, despite contralesional items being less well attended. The data are consistent with an account in terms of perceptual dilution of distracters rather than available resources for distractor processing. We conclude that distractor dilution can underlie the elimination of distractor interference in visual displays.

  11. Low level perceptual, not attentional, processes modulate distractor interference in high perceptual Load displays: evidence from neglect/extinction

    Directory of Open Access Journals (Sweden)

    Carmel eMevorach

    2014-01-01

    Full Text Available According to perceptual load theory (Lavie, 2005 distractor interference is determined by the availability of attentional resources. If target processing does not exhaust resources (with low perceptual load distractor processing will take place resulting in interference with a primary task; however when target processing uses-up attentional capacity (with high perceptual load interference can be avoided. An alternative account (Tsal & Benoni, 2010 suggests that perceptual load effects can be based on distractor dilution by the mere presence of additional neutral items in high load displays so that the effect is not driven by the amount of attention resources required for target processing. Here we tested whether patients with unilateral neglect or extinction would show dilution effects from neutral items in their contralesional (neglected/extinguished field, even though these items do not impose increased perceptual load on the target and at the same time attract reduced attentional resources compared to stimuli in the ipsilesional field. Thus, such items do not affect the amount of attention resources available for distractor processing. We found that contralesional neutral elements can eliminate distractor interference as strongly as centrally presented ones in neglect/extinction patients, despite contralesional items being less well attended. The data are consistent with an account in terms of perceptual dilution of distracters rather than available resources for distractor processing. We conclude that distractor dilution can underlie the elimination of distractor interference in visual displays.

  12. Primate social attention: Species differences and effects of individual experience in humans, great apes, and macaques

    OpenAIRE

    Kano, Fumihiro; Shepherd, Stephen V.; Hirata, Satoshi; Call, Josep

    2018-01-01

    When viewing social scenes, humans and nonhuman primates focus on particular features, such as the models’ eyes, mouth, and action targets. Previous studies reported that such viewing patterns vary significantly across individuals in humans, and also across closely-related primate species. However, the nature of these individual and species differences remains unclear, particularly among nonhuman primates. In large samples of human and nonhuman primates, we examined species differences and th...

  13. A single bout of meditation biases cognitive control but not attentional focusing: Evidence from the global-local task.

    Science.gov (United States)

    Colzato, Lorenza S; van der Wel, Pauline; Sellaro, Roberta; Hommel, Bernhard

    2016-01-01

    Recent studies show that a single bout of meditation can impact information processing. We were interested to see whether this impact extends to attentional focusing and the top-down control over irrelevant information. Healthy adults underwent brief single bouts of either focused attention meditation (FAM), which is assumed to increase top-down control, or open monitoring meditation (OMM), which is assumed to weaken top-down control, before performing a global-local task. While the size of the global-precedence effect (reflecting attentional focusing) was unaffected by type of meditation, the congruency effect (indicating the failure to suppress task-irrelevant information) was considerably larger after OMM than after FAM. Our findings suggest that engaging in particular kinds of meditation creates particular cognitive-control states that bias the individual processing style toward either goal-persistence or cognitive flexibility. Copyright © 2015 Elsevier Inc. All rights reserved.

  14. Top-down attention affects sequential regularity representation in the human visual system.

    Science.gov (United States)

    Kimura, Motohiro; Widmann, Andreas; Schröger, Erich

    2010-08-01

    Recent neuroscience studies using visual mismatch negativity (visual MMN), an event-related brain potential (ERP) index of memory-mismatch processes in the visual sensory system, have shown that although sequential regularities embedded in successive visual stimuli can be automatically represented in the visual sensory system, an existence of sequential regularity itself does not guarantee that the sequential regularity will be automatically represented. In the present study, we investigated the effects of top-down attention on sequential regularity representation in the visual sensory system. Our results showed that a sequential regularity (SSSSD) embedded in a modified oddball sequence where infrequent deviant (D) and frequent standard stimuli (S) differing in luminance were regularly presented (SSSSDSSSSDSSSSD...) was represented in the visual sensory system only when participants attended the sequential regularity in luminance, but not when participants ignored the stimuli or simply attended the dimension of luminance per se. This suggests that top-down attention affects sequential regularity representation in the visual sensory system and that top-down attention is a prerequisite for particular sequential regularities to be represented. Copyright 2010 Elsevier B.V. All rights reserved.

  15. Cortical depth dependent population receptive field attraction by spatial attention in human V1.

    Science.gov (United States)

    Klein, Barrie P; Fracasso, Alessio; van Dijk, Jelle A; Paffen, Chris L E; Te Pas, Susan F; Dumoulin, Serge O

    2018-04-27

    Visual spatial attention concentrates neural resources at the attended location. Recently, we demonstrated that voluntary spatial attention attracts population receptive fields (pRFs) toward its location throughout the visual hierarchy. Theoretically, both a feed forward or feedback mechanism could underlie pRF attraction in a given cortical area. Here, we use sub-millimeter ultra-high field functional MRI to measure pRF attraction across cortical depth and assess the contribution of feed forward and feedback signals to pRF attraction. In line with previous findings, we find consistent attraction of pRFs with voluntary spatial attention in V1. When assessed as a function of cortical depth, we find pRF attraction in every cortical portion (deep, center and superficial), although the attraction is strongest in deep cortical portions (near the gray-white matter boundary). Following the organization of feed forward and feedback processing across V1, we speculate that a mixture of feed forward and feedback processing underlies pRF attraction in V1. Specifically, we propose that feedback processing contributes to the pRF attraction in deep cortical portions. Copyright © 2018. Published by Elsevier Inc.

  16. The Effects of Context and Attention on Spiking Activity in Human Early Visual Cortex

    NARCIS (Netherlands)

    Self, Matthew W.; Peters, Judith C.; Possel, Jessy K.; Reithler, Joel; Goebel, Rainer; Ris, Peterjan; Jeurissen, Danique; Reddy, Leila; Claus, Steven; Baayen, Johannes C.; Roelfsema, Pieter R.

    2016-01-01

    Here we report the first quantitative analysis of spiking activity in human early visual cortex. We recorded multi-unit activity from two electrodes in area V2/V3 of a human patient implanted with depth electrodes as part of her treatment for epilepsy. We observed well-localized multi-unit receptive

  17. The Effects of Context and Attention on Spiking Activity in Human Early Visual Cortex

    NARCIS (Netherlands)

    Self, Matthew W; Peters, Judith C; Possel, Jessy K; Reithler, Joel; Goebel, Rainer; Ris, Peterjan; Jeurissen, Danique; Reddy, Leila; Claus, Steven; Baayen, Johannes C; Roelfsema, Pieter R

    Here we report the first quantitative analysis of spiking activity in human early visual cortex. We recorded multi-unit activity from two electrodes in area V2/V3 of a human patient implanted with depth electrodes as part of her treatment for epilepsy. We observed well-localized multi-unit receptive

  18. Seroepidemiology of Human Brucellosis Among Blood Donors in Southern Ethiopia: Calling Attention to a Neglected Zoonotic Disease.

    Science.gov (United States)

    Workalemahu, Bereket; Sewunet, Tsegaye; Astatkie, Ayalew

    2017-01-11

    Human brucellosis is neglected in southern Ethiopia. Although traditional food processing practices and animal husbandry which increase the risk of brucellosis are common, it has not been properly studied yet. This study was conducted to determine the seroepidemiology of brucellosis among apparently healthy individuals in southern Ethiopia. In the study, blood samples were collected to screen for serum agglutinins reactive to stained antigen of Brucella abortus Standard tube titration was performed for reactive serum to determine the titer of the agglutinin. A structured questionnaire was used to collect data on possible risk factors for brucellosis. The seroprevalence of human brucellosis in this study was found to be 10.6% (95% confidence interval = 7.0, 14.0). Possession of domestic ruminant animals, contact with ruminant animals, and husbandry practices at home were associated with seropositivity. The higher seroprevalence of human brucellosis in the study area needs attention and additional confirmatory investigation. © The American Society of Tropical Medicine and Hygiene.

  19. Resveratrol and Clinical Trials: The Crossroad from In Vitro Studies to Human Evidence

    Science.gov (United States)

    Tomé-Carneiro, Joao; Larrosa, Mar; González-Sarrías, Antonio; Tomás-Barberán, Francisco A.; García-Conesa, María Teresa; Espín, Juan Carlos

    2013-01-01

    Resveratrol (3,5,4’-trihydroxy-trans-stilbene) is a non-flavonoid polyphenol that may be present in a limited number of food-stuffs such as grapes and red wine. Resveratrol has been reported to exert a plethora of health benefits through many different mechanisms of action. This versatility and presence in the human diet have drawn the worldwide attention of many research groups over the past twenty years, which has resulted in a huge output of in vitro and animal (preclinical) studies. In line with this expectation, many resveratrol-based nutraceuticals are consumed all over the world with questionable clinical/scientific support. In fact, the confirmation of these benefits in humans through randomized clinical trials is still very limited. The vast majority of preclinical studies have been performed using assay conditions with a questionable extrapolation to humans, i.e. too high concentrations with potential safety concerns (adverse effects and drug interactions), short-term exposures, in vitro tests carried out with non-physiological metabolites and/or concentrations, etc. Unfortunately, all these hypothesis-generating studies have contributed to increased the number of ‘potential’ benefits and mechanisms of resveratrol but confirmation in humans is very limited. Therefore, there are many issues that should be addressed to avoid an apparent endless loop in resveratrol research. The so-called ‘Resveratrol Paradox’, i.e., low bioavailability but high bioactivity, is a conundrum not yet solved in which the final responsible actor (if any) for the exerted effects has not yet been unequivocally identified. It is becoming evident that resveratrol exerts cardioprotective benefits through the improvement of inflammatory markers, atherogenic profile, glucose metabolism and endothelial function. However, safety concerns remain unsolved regarding chronic consumption of high RES doses, specially in medicated people. This review will focus on the currently

  20. FCJ-201 Visual Evidence from Above: Assessing the Value of Earth Observation Satellites for Supporting Human Rights

    Directory of Open Access Journals (Sweden)

    Tanya Notley

    2016-03-01

    Full Text Available Public access to data collected by remote sensing Earth Observation Satellites has, until recently, been very limited. Now, citizens and rights advocacy groups are increasingly utilising satellite-collected images to interrogate justice issues; to document, prevent and verify rights abuses; and to imagine and propose social change. Yet while other communication technologies have received substantial critical analysis regarding their value as tools of social justice, activism and resistance, satellites have received comparatively scant attention. This article examines the uses of satellite-collected images in human rights contexts including the opportunities, challenges and risks they pose. We conclude this examination by arguing that if satellites are to be used effectively to collect evidence from above by rights advocates, greater attention to and capacity for ensuring accountability from below is required.

  1. Complementary medicines (herbal and nutritional products) in the treatment of Attention Deficit Hyperactivity Disorder (ADHD): a systematic review of the evidence.

    Science.gov (United States)

    Sarris, Jerome; Kean, James; Schweitzer, Isaac; Lake, James

    2011-08-01

    Complementary and Alternative Medicines (CAMs) are frequently given to children and adolescents for reputed benefits in the treatment of hyperkinetic and concentration disorders such as Attention Deficit Hyperactivity Disorder (ADHD). In such vulnerable populations high quality evidence is required to support such claims. The aim of the paper is to assess the current evidence of herbal and nutritional interventions for ADHD using a systematic search of clinical trials meeting an acceptable standard of evidence. PubMed, PsycINFO, Cochrane Library and CINAHL were searched up to May 26th, 2011 for randomised, controlled clinical trials using CAM products as interventions to treat ADHD. A quality analysis using a purpose-designed scale, and an estimation of effect sizes (Cohen's d) where data were available, were also calculated. The review revealed that 16 studies met inclusion criteria, with predominant evidentiary support found for zinc, iron, Pinus marinus (French maritime pine bark), and a Chinese herbal formula (Ningdong); and mixed (mainly inconclusive) evidence for omega-3, and l-acetyl carnitine. Current data suggest that Ginkgo biloba (ginkgo), and Hypercium perforatum (St. John's wort) are ineffective in treating ADHD. The research suggests only some CAMs may be beneficial in ADHD, thus clinicians need to be aware of the current evidence. Promising candidates for future research include Bacopa monniera (brahmi) and Piper methysticum (kava), providing potential efficacy in improving attentional and hyperkinetic disorders via a combination of cognitive enhancing and sedative effects. Copyright © 2011 Elsevier Ltd. All rights reserved.

  2. Are Children's Memory Illusions Created Differently from Those of Adults? Evidence from Levels-of-Processing and Divided Attention Paradigms

    Science.gov (United States)

    Wimmer, Marina C.; Howe, Mark L.

    2010-01-01

    In two experiments, we investigated the robustness and automaticity of adults' and children's generation of false memories by using a levels-of-processing paradigm (Experiment 1) and a divided attention paradigm (Experiment 2). The first experiment revealed that when information was encoded at a shallow level, true recognition rates decreased for…

  3. Effects of mood state on divided attention in patients with bipolar disorder: evidence for beneficial effects of subclinical manic symptoms.

    Science.gov (United States)

    Koenders, Manja A; Spijker, Annet T; Hoencamp, Erik; Haffmans, Judith P M; Zitman, Frans G; Giltay, Erik J

    2014-12-15

    A relatively small number of studies have been dedicated to the differential effects of the current mood state on cognition in patients with a bipolar disorder (BD). The aim of the current study was to investigate the effect of current mood state on divided attention (DA) performance, and specifically examine possible beneficial effects of the (hypo-) manic state. Over a maximum period of 24 months, medication use, divided attention test (a subtest of the Test for Attentional Performance (TAP)) was assessed every 6 months in 189 outpatients with BD. Data were analyzed with multilevel regression analysis (i.e. linear mixed models). DA performance varied considerable over time within patients. Corrected for psychotropic medication a significant quadratic relationship between manic symptoms and DA performance was found, with mild hypomanic symptoms having a positive influence on divided attention scores and moderate to severe manic symptoms having a negative influence. No association between depressive symptoms and DA performance was found. In future research on mania and cognition as well as in the clinical practice both the beneficial and negative effects of mania should be taken into account. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  4. Chronic Pain and Selective Attention to Pain Arousing Daily Activity Pictures: Evidence From an Eye Tracking Study

    Directory of Open Access Journals (Sweden)

    Masoumeh Mahmoodi-Aghdam

    2017-11-01

    Conclusion: Although these results did not provide unequivocal support for the vigilance-avoidance hypothesis, they are generally consistent with the results of studies using eye tracking technology. Furthermore, our findings put a question over characterization of attentional biases in patients with chronic pain by simply relating that to difficulty in disengaging from pain-related stimuli.

  5. Do Faces Capture the Attention of Individuals with Williams Syndrome or Autism? Evidence from Tracking Eye Movements

    Science.gov (United States)

    Riby, Deborah M.; Hancock, Peter J. B.

    2009-01-01

    The neuro-developmental disorders of Williams syndrome (WS) and autism can reveal key components of social cognition. Eye-tracking techniques were applied in two tasks exploring attention to pictures containing faces. Images were (i) scrambled pictures containing faces or (ii) pictures of scenes with embedded faces. Compared to individuals who…

  6. Neural Dissociation of Phonological and Visual Attention Span Disorders in Developmental Dyslexia: fMRI Evidence from Two Case Reports

    Science.gov (United States)

    Peyrin, C.; Lallier, M.; Demonet, J. F.; Pernet, C.; Baciu, M.; Le Bas, J. F.; Valdois, S.

    2012-01-01

    A dissociation between phonological and visual attention (VA) span disorders has been reported in dyslexic children. This study investigates whether this cognitively-based dissociation has a neurobiological counterpart through the investigation of two cases of developmental dyslexia. LL showed a phonological disorder but preserved VA span whereas…

  7. Attention mediates the effect of nutrition label information on consumers’ choice. Evidence from a choice experiment involving eye-tracking

    NARCIS (Netherlands)

    Bialkova, Svetlana; Bialkova, Svetlana; Grunert, Klaus G.; Juhl, Hans Jørn; Wasowicz-Kirylo, Grazyna; Stysko-Kunkowska, Malgorzata; van Trijp, Hans C.M.

    2014-01-01

    In two eye-tracking studies, we explored whether and how attention to nutrition information mediates consumers’ choice. Consumers had to select either the healthiest option or a product of their preference within an assortment. On each product a particular label (Choices logo, monochrome GDA label,

  8. Nonspatial intermodal selective attention is mediated by sensory brain brain areas: Evidence from event-related potential.

    NARCIS (Netherlands)

    Talsma, D.; Kok, A.

    2001-01-01

    Focuses on the question of whether inter-and intramodal forms of attention are reflected in activation of the same or different brain areas. ERPs were recorded while Ss (aged 18-41 yrs) were presented a random sequence of visual and auditory stimuli. They were instructed to attend to nonspatial

  9. Reading Difficulties and Attention-Deficit/Hyperactivity Behaviours: Evidence of an Early Association in a Nonclinical Sample

    Science.gov (United States)

    Luoni, Chiara; Balottin, Umberto; Zaccagnino, Maria; Brembilla, Laura; Livetti, Giulia; Termine, Cristiano

    2015-01-01

    Attention-deficit/hyperactivity disorder (ADHD) often co-occurs with reading disability. A cross-sectional study in an Italian-speaking, nonclinical sample was conducted in an attempt to document the existence of an early association between reading difficulties (RD) and ADHD behaviours. We recruited a sample of 369 children in their first year at…

  10. The Effect of Retrieval Cues on Visual Preferences and Memory in Infancy: Evidence for a Four-Phase Attention Function.

    Science.gov (United States)

    Bahrick, Lorraine E.; Hernandez-Reif, Maria; Pickens, Jeffrey N.

    1997-01-01

    Tested hypothesis from Bahrick and Pickens' infant attention model that retrieval cues increase memory accessibility and shift visual preferences toward greater novelty to resemble recent memories. Found that after retention intervals associated with remote or intermediate memory, previous familiarity preferences shifted to null or novelty…

  11. Neurofeedback as a Treatment for Attention-Deficit/Hyperactivity Disorder: A Systematic Review of Evidence for Practice

    Science.gov (United States)

    Willis, W. Grant; Weyandt, Lisa L.; Lubiner, Anna G.; Schubart, Chelsea D.

    2011-01-01

    Neurofeedback training is being offered with increasing frequency as a treatment for Attention-Deficit/Hyperactivity Disorder (ADHD). School psychologists are in a unique position to educate teachers, parents, students, and others about a variety of disorders including ADHD, and it is important for them to be properly informed about the validity…

  12. Attention mediates the effect of nutrition label information on consumers' choice. Evidence from a choice experiment involving eye-tracking

    NARCIS (Netherlands)

    Bialkova, S.; Grunert, K.G.; Juhl, H.J.; Wasowicz-Kirylo, G.; Stysko-Kunkowska, M.; Trijp, van J.C.M.

    2014-01-01

    In two eye-tracking studies, we explored whether and how attention to nutrition information mediates consumers' choice. Consumers had to select either the healthiest option or a product of their preference within an assortment. On each product a particular label (Choices logo, monochrome GDA label,

  13. Assessing Selective Sustained Attention in 3- to 5-Year-Old Children: Evidence from a New Paradigm

    Science.gov (United States)

    Fisher, Anna; Thiessen, Erik; Godwin, Karrie; Kloos, Heidi; Dickerson, John

    2013-01-01

    Selective sustained attention (SSA) is crucial for higher order cognition. Factors promoting SSA are described as exogenous or endogenous. However, there is little research specifying how these factors interact during development, due largely to the paucity of developmentally appropriate paradigms. We report findings from a novel paradigm designed…

  14. The wandering mind of men: ERP evidence for gender differences in attention bias towards attractive opposite sex faces

    NARCIS (Netherlands)

    van Hooff, J.C.; Crawford, H.; van Vugt, M.

    2011-01-01

    To examine the time course and automaticity of our attention bias towards attractive opposite sex faces, event-related potentials (ERPs) were recorded from 20 males and 20 females while they carried out a covert orienting task. Faces that were high, low or average in attractiveness, were presented

  15. Attentional control underlies the perceptual load effect: Evidence from voxel-wise degree centrality and resting-state functional connectivity.

    Science.gov (United States)

    Yin, Shouhang; Liu, Lu; Tan, Jinfeng; Ding, Cody; Yao, Dezhong; Chen, Antao

    2017-10-24

    The fact that interference from peripheral distracting information can be reduced in high perceptual load tasks has been widely demonstrated in previous research. The modulation from the perceptual load is known as perceptual load effect (PLE). Previous functional magnetic resonance imaging (fMRI) studies on perceptual load have reported the brain areas implicated in attentional control. To date, the contribution of attentional control to PLE and the relationship between the organization of functional connectivity and PLE are still poorly understood. In the present study, we used resting-state fMRI to explore the association between the voxel-wise degree centrality (DC) and PLE in an individual differences design and further investigated the potential resting-state functional connectivity (RSFC) contributing to individual's PLE. DC-PLE correlation analysis revealed that PLE was positively associated with the right middle temporal visual area (MT)-one of dorsal attention network (DAN) nodes. Furthermore, the right MT functionally connected to the conventional DAN and the RSFCs between right MT and DAN nodes were also positively associated with individual difference in PLE. The results suggest an important role of attentional control in perceptual load tasks and provide novel insights into the understanding of the neural correlates underlying PLE. Copyright © 2017 IBRO. Published by Elsevier Ltd. All rights reserved.

  16. Habituation of the Irrelevant Sound Effect: Evidence for an Attentional Theory of Short-Term Memory Disruption

    Science.gov (United States)

    Bell, Raoul; Roer, Jan P.; Dentale, Sandra; Buchner, Axel

    2012-01-01

    Immediate serial recall is seriously disrupted by to-be-ignored sound. According to the embedded-processes model, auditory distractors elicit attentional orienting that draws processing resources away from the recall task. The model predicts that interference should be attenuated after repeated exposure to the auditory distractors. Previous…

  17. The Ebb and Flow of Infant Attentional Preferences: Evidence for Long-Term Recognition Memory in 3-Month-Olds.

    Science.gov (United States)

    Courage, Mary L.; Howe, Mark L.

    1998-01-01

    Two experiments used paired-comparisons to investigate 3-month olds' recognition of dynamic visual events after various retention intervals. Results indicated a changing pattern of attentional preferences over time consistent with models of infant recognition memory in which novelty, familiarity, and null preferences are considered conjointly and…

  18. Exogenous Attentional Capture by Subliminal Abrupt-Onset Cues: Evidence from Contrast-Polarity Independent Cueing Effects

    NARCIS (Netherlands)

    Fuchs, I.; Theeuwes, J.; Ansorge, U.

    2013-01-01

    In the present study, we tested whether subliminal abrupt-onset cues capture attention in a bottom-up or top-down controlled manner. For our tests, we varied the searched-for target-contrast polarity (i.e., dark or light targets against a gray background) over four experiments. In line with the

  19. Colour-specific differences in attentional deployment for equiluminant pop-out colours: evidence from lateralised potentials.

    Science.gov (United States)

    Pomerleau, Vincent Jetté; Fortier-Gauthier, Ulysse; Corriveau, Isabelle; Dell'Acqua, Roberto; Jolicœur, Pierre

    2014-03-01

    We investigated how target colour affected behavioural and electrophysiological results in a visual search task. Perceptual and attentional mechanisms were tracked using the N2pc component of the event-related potential and other lateralised components. Four colours (red, green, blue, or yellow) were calibrated for each participant for luminance through heterochromatic flicker photometry and equated to the luminance of grey distracters. Each visual display contained 10 circles, 1 colored and 9 grey, each of which contained an oriented line segment. The task required deploying attention to the colored circle, which was either in the left or right visual hemifield. Three lateralised ERP components relative to the side of the lateral coloured circle were examined: a posterior contralateral positivity (Ppc) prior to N2pc, the N2pc, reflecting the deployment of visual spatial attention, and a temporal and contralateral positivity (Ptc) following N2pc. Red or blue stimuli, as compared to green or yellow, had an earlier N2pc. Both the Ppc and Ptc had higher amplitudes to red stimuli, suggesting particular selectivity for red. The results suggest that attention may be deployed to red and blue more quickly than to other colours and suggests special caution when designing ERP experiments involving stimuli in different colours, even when all colours are equiluminant. Copyright © 2013 Elsevier B.V. All rights reserved.

  20. Chronological overlap between humans and megafauna in Sahul (Pleistocene Australia New Guinea): A review of the evidence

    Science.gov (United States)

    Field, Judith; Fillios, Melanie; Wroe, Stephen

    2008-08-01

    Over 60 faunal species disappeared from the Australian continent during the Middle-Late Pleistocene. Most of these animals were large to gigantic marsupials, birds and reptiles. A terminal extinction date of 46.4 kyr has been proposed for the megafauna, with all sites containing younger fossil megafauna dismissed by some researchers because of questions over stratigraphic integrity or chronologies. The timing of the extinctions is argued to be broadly coincident with estimates of first colonization of the continent by modern humans, and explanatory extinction models involving humans have subsequently gained currency. However there is considerable evidence to suggest that in some parts of the continent, people and some species of megafauna may have co-existed well beyond 46.4 kyr. In other places, such as Tasmania and the north of the continent, there is no known record of a human-megafauna temporal overlap. A review of the available evidence indicates that only 13 species of megafauna were extant on human arrival in Australia. The archaeology of this period indicates that rather than a focus on big game hunting or 'firestick farming', it was characterized by regional variability in subsistence strategies consistent with the range of environmental zones. At the present time there is no substantive argument for a terminal extinction date of 46.4 kyr, the current evidence indicating that there is no specific time period that correlates to any single mass extinction event. On the basis of available evidence arguments for either human or climatic causation are entirely circumstantial and implicitly require acceptance of many unproven assumptions. Claims to have eliminated climate as a primary driver are premature and the recent focus on delivering 'proof' of human causation in Pleistocene faunal extinctions diverts attention from achieving a better understanding of the differential impacts of climate change and short term climatic flux in a land of environmental

  1. Corporate philanthropic responses to emergent human needs: the role of organizational attention focus

    NARCIS (Netherlands)

    Muller, A.; Whiteman, G.

    2015-01-01

    Research on corporate philanthropy typically focuses on organization-external pressures and aggregated donation behavior. Hence, our understanding of the organization-internal structures that determine whether a given organization will respond philanthropically to a specific human need remains

  2. Law, Economic Growth and Human Development: Evidence from Africa

    OpenAIRE

    Asongu Simplice

    2011-01-01

    This paper cuts adrift the mainstream approach to the legal-origins debate on the law-growth nexus by integrating both overall economic and human components in our understanding of how regulation quality and the rule of law lie at the heart of economic and inequality adjusted human developments. Findings summarily reveal that legal-origin does not explain economic growth and human development beyond the mechanisms of law. Our results support the current consensus that, English common-law coun...

  3. 基于记忆的注意捕获和注意抑制效应:ERP证据%Electrophysiological evidence for memory-based attentional capture and memory-based attentional rejection effects

    Institute of Scientific and Technical Information of China (English)

    胡艳梅; 张明

    2016-01-01

    %/50%/80%), suggesting the memory-based attentional capture effects. Furthermore, N2pc amplitudes were reduced when the proportion of matching trials increased from 50% to 80%. N2pc latencies were speeded with higher proportion of matching trials. Secondly, the positive difference waves corresponding to the inhibition of the memory-matching item were then observed after N2pc (since approximately 300 ms post-stimulus) in 50% and 80% conditions, suggesting the memory-based attentional rejection effects. Such positive difference waves were enhanced when the proportion of matching trials increased. In sum, our results indicate the guidance effect of visual working memory on attention has two phases, i.e., the memory-based attentional capture on the early phase and the memory-based attentional rejection on the later phase. The early memory-based attentional capture effect is involuntary, though the effect-size and time course of it can be varied by the level of cognitive control incentive. The later memory-based attentional rejection effect is voluntary and more in evidence with higher cognitive control incentive.%采用工作记忆与视觉搜索双任务范式,通过操作匹配试次出现概率来诱发不同水平的认知控制动机,考察了基于记忆的注意引导过程的时程特点。结果:记忆匹配刺激首先诱发了 N2pc 成分,随后诱发了与抑制过程相关的差异正波。并且,认知控制动机水平越高, N2pc波幅越小、潜伏期越短;抑制性差异正波波幅越大。结论:基于记忆的注意引导过程包括早期的注意捕获和后期的注意抑制两个阶段;其效应量和时程受到认知控制动机水平的调节。

  4. Functional MRI studies of the neural mechanisms of human brain attentional networks

    International Nuclear Information System (INIS)

    Hao Jing; Li Kuncheng; Chen Qi; Wang Yan; Peng Xiaozhe; Zhou Xiaolin

    2005-01-01

    Objective: To identify the neural mechanisms of the anterior attention network (AAN) and posterior attention network (PAN) , investigate the possible interaction between them with event-related functional MRI(ER-fMRI). Methods: Eight right-handed healthy volunteers participated in the experiment designed with inhibition of return in visual orienting and Stroop color-word interference effect. The fMRI data were collected on Siemens 1.5 T Sonata MRI systems and analyzed by AFNI to generate the activation map. Results: The data sets from 6 of 8 subjects were used in the study. The functional localizations of the Stroop and IOR, which manifest the function of the AAN and PAN respectively, were consistent with previous imaging researches. On cued locations, left inferior parietal lobule (IPL), area MT/V5, right dorsolateral prefrontal cortex (DLPFC) and left anterior cingulated cortex (ACC) were significantly activated. On uncued locations, right superior parietal lobule (SPL) and bilateral area MT/V5 were significantly activated. Conclusion: The AAN exerts control over the PAN, while its function can be in turn modulated by the PAN. There are interaction between the AAN and PAN. In addition, it is also proved that ER-fMRI is a feasible method to revise preexisting cognitive model and theory. (authors)

  5. Music Recommendation System for Human Attention Modulation by Facial Recognition on a driving task: A Proof of Concept

    Directory of Open Access Journals (Sweden)

    Avila-Vázquez Roberto

    2017-01-01

    Full Text Available The role of music on driving process had been discussed in the context of driver assistance as an element of security and comfort. Throughout this document, we present the development of an audio recommender system for the use by drivers, based on facial expression analysis. This recommendation system has the objective of increasing the attention of the driver by the election of specific music pieces. For this pilot study, we start presenting an introduction to audio recommender systems and a brief explanation of the function of our facial expression analysis system. During the driving course the subjects (seven participants between 19 and 25 years old are stimulated with a chosen group of audio compositions and their facial expressions are captured via a camera mounted in the car's dashboard. Once the videos were captured and recollected, we proceeded to analyse them using the FACET™ module of the biometric capture platform iMotions™. This software provides us with the expression analysis of the subjects. Analysed data is postprocessed and the data obtained were modelled on a quadratic surface that was optimized based on the known cestrum and tempo of the songs and the average evidence of emotion. The results showed very different optimal points for each subject, that indicates different type of music for optimizing driving attention. This work is a first step for obtaining a music recommendation system capable to modulate subject attention while driving.

  6. News coverage of controversial emerging technologies. Evidence for the issue attention cycle in print and online media.

    Science.gov (United States)

    Anderson, Ashley A; Brossard, Dominique; Scheufele, Dietram A

    2012-01-01

    This study analyzes the issue attention cycle for print and online media coverage of a scientific publication examining the deaths of Chinese factory workers due to lung damage from chronic exposure to nanoparticles. The results of the nanoparticle study, published in 2009, embody news values that would make the study a prime candidate for press coverage, namely, novelty, negativity, controversy, and potential widespread impact. Nevertheless, mentions of the event in traditional English-language print media were nearly nonexistent. Online media, on the other hand, gave the story greater coverage. This case study exemplifies why online media may not be bound to the same issue attention cycle that print media are for controversial scientific events.

  7. Stroop color-word interference and electroencephalogram activation: evidence for age-related decline of the anterior attention system.

    Science.gov (United States)

    West, R; Bell, M A

    1997-07-01

    Groups of healthy, community-dwelling younger and older adults performed a Stroop task in which color and word could be congruent or incongruent and spatially integrated or separated. During the task, continuous electroencephalogram (EEG) was recorded from frontal, parietal, and occipital regions. The magnitude of the Stroop interference effect and task-related EEG activation was greater for older than younger adults when stimuli were integrated. This effect was significant over medial and lateral frontal and parietal, but not occipital, regions. In comparison, interference and EEG activation did not differ for younger and older adults when stimuli were separated. These findings support the hypothesis that the anterior attention system is more sensitive to the effects of increasing age than the posterior attention system.

  8. The Navigation Guide - evidence-based medicine meets environmental health: integration of animal and human evidence for PFOA effects on fetal growth.

    Science.gov (United States)

    Lam, Juleen; Koustas, Erica; Sutton, Patrice; Johnson, Paula I; Atchley, Dylan S; Sen, Saunak; Robinson, Karen A; Axelrad, Daniel A; Woodruff, Tracey J

    2014-10-01

    The Navigation Guide is a novel systematic review method to synthesize scientific evidence and reach strength of evidence conclusions for environmental health decision making. Our aim was to integrate scientific findings from human and nonhuman studies to determine the overall strength of evidence for the question "Does developmental exposure to perfluorooctanoic acid (PFOA) affect fetal growth in humans?" We developed and applied prespecified criteria to systematically and transparently a) rate the quality of the scientific evidence as "high," "moderate," or "low"; b) rate the strength of the human and nonhuman evidence separately as "sufficient," "limited," "moderate," or "evidence of lack of toxicity"; and c) integrate the strength of the human and nonhuman evidence ratings into a strength of the evidence conclusion. We identified 18 epidemiology studies and 21 animal toxicology studies relevant to our study question. We rated both the human and nonhuman mammalian evidence as "moderate" quality and "sufficient" strength. Integration of these evidence ratings produced a final strength of evidence rating in which review authors concluded that PFOA is "known to be toxic" to human reproduction and development based on sufficient evidence of decreased fetal growth in both human and nonhuman mammalian species. We concluded that developmental exposure to PFOA adversely affects human health based on sufficient evidence of decreased fetal growth in both human and nonhuman mammalian species. The results of this case study demonstrate the application of a systematic and transparent methodology, via the Navigation Guide, for reaching strength of evidence conclusions in environmental health.

  9. The Effect of Medical Treatment of Attention Deficit Hyperactivity Disorder (ADHD) on Foster Care Caseloads: Evidence from Danish Registry Data

    DEFF Research Database (Denmark)

    Fallesen, Peter; Wildeman, Christopher

    Since the early 2000s, foster care caseloads have decreased in many wealthy democracies, yet the causes of these declines remain, for the most part, a mystery. This paper uses administrative data from one country that experienced a sharp decline in foster care caseloads, Denmark, to show that inc...... rate all shape foster care caseloads, future research should be attentive to how medical treatment aimed at addressing children’s acute behavioral problems could also have a powerful effect on foster care caseloads....

  10. Arousal and attention re-orienting in autism spectrum disorders: evidence from auditory event-related potentials

    Directory of Open Access Journals (Sweden)

    Elena V Orekhova

    2014-02-01

    Full Text Available The extended phenotype of autism spectrum disorders (ASD includes a combination of arousal regulation problems, sensory modulation difficulties, and attention re-orienting deficit. A slow and inefficient re-orienting to stimuli that appear outside of the attended sensory stream is thought to be especially detrimental for social functioning. Event-related potentials (ERPs and magnetic fields (ERFs may help to reveal which processing stages underlying brain response to unattended but salient sensory event are affected in individuals with ASD. Previous research focusing on two sequential stages of the brain response - automatic detection of physical changes in auditory stream, indexed by mismatch negativity (MMN, and evaluation of stimulus novelty, indexed by P3a component, - found in individuals with ASD either increased, decreased or normal processing of deviance and novelty. The review examines these apparently conflicting results, notes gaps in previous findings, and suggests a potentially unifying hypothesis relating the dampened responses to unattended sensory events to the deficit in rapid arousal process. Specifically, ‘sensory gating’ studies focused on pre-attentive arousal consistently demonstrated that brain response to unattended and temporally novel sound in ASD is already affected at around 100 ms after stimulus onset. We hypothesize that abnormalities in nicotinic cholinergic arousal pathways, previously reported in individuals with ASD, may contribute to these ERP/ERF aberrations and result in attention re-orienting deficit. Such cholinergic dysfunction may be present in individuals with ASD early in life and can influence both sensory processing and attention re-orienting behavior. Identification of early neurophysiological biomarkers for cholinergic deficit would help to detect infants at risk who can potentially benefit from particular types of therapies or interventions.

  11. Implicit theories of online trolling: evidence that attention-seeking conceptions are associated with\\ud increased psychological resilience.

    OpenAIRE

    Maltby, John; Day, Liza; Hatcher, Ruth; Tazzyman, Sarah; Flowe, Heather D; Palmer, Emma J; Frosch, Caren A; O'Reilly, Michelle; Jones, Ceri; Buckley, Chloe; Knieps, Melanie; Cutts, Katie J

    2016-01-01

    Three studies were conducted to investigate people’s conceptions of online trolls, particularly conceptions associated with psychological resilience to trolling. In Study 1, factor analytic analysis of participants’ ratings of characteristics of online trolls found a replicable bifactor model of conceptions of online trolls, with both a general factor of general conceptions towards online trolls being identified, but five group factors (attention-conflict seeking, low selfconfidence,\\ud vicio...

  12. Birth order and human capital development: evidence from Ecuador

    NARCIS (Netherlands)

    de Haan, M.; Plug, E.; Rosero, J.

    2012-01-01

    In this paper we examine the effect of birth order on human capital development in Ecuador using a large national database together with self-collected survey data. Using family fixed effects models we find significant positive birth order effects; earlier born children stay behind in their human

  13. Birth order and human capital development: evidence from Ecuador

    NARCIS (Netherlands)

    de Haan, M.; Plug, E.; Rosero, J.

    2014-01-01

    In this paper we examine the effect of birth order on human capital development in Ecuador. Using family fixed effects models we find positive and persistent birth order effects; earlier-born children stay behind in their human capital development from infancy to adolescence. Turning to potential

  14. Time course of affective bias in visual attention: convergent evidence from steady-state visual evoked potentials and behavioral data.

    Science.gov (United States)

    Hindi Attar, Catherine; Andersen, Søren K; Müller, Matthias M

    2010-12-01

    Selective attention to a primary task can be biased by the occurrence of emotional distractors that involuntary attract attention due to their intrinsic stimulus significance. What is largely unknown is the time course and magnitude of competitive interactions between a to-be-attended foreground task and emotional distractors. We used pleasant, unpleasant and neutral pictures from the International Affective Picture System (IAPS) that were either presented in intact or phase-scrambled form. Pictures were superimposed by a flickering display of moving random dots, which constituted the primary task and enabled us to record steady-state visual evoked potentials (SSVEPs) as a continuous measure of attentional resource allocation directed to the task. Subjects were required to attend to the dots and to detect short intervals of coherent motion while ignoring the background pictures. We found that pleasant and unpleasant relative to neutral pictures more strongly influenced task-related processing as reflected in a significant decrease in SSVEP amplitudes and target detection rates, both covering a time window of several hundred milliseconds. Strikingly, the effect of semantic relative to phase-scrambled pictures on task-related activity was much larger, emerged earlier and lasted longer in time compared to the specific effect of emotion. The observed differences in size and duration of time courses of semantic and emotional picture processing strengthen the assumption of separate functional mechanisms for both processes rather than a general boosting of neural activity in favor of emotional stimulus processing. Copyright © 2010 Elsevier Inc. All rights reserved.

  15. Implicit theories of online trolling: Evidence that attention-seeking conceptions are associated with increased psychological resilience.

    Science.gov (United States)

    Maltby, John; Day, Liz; Hatcher, Ruth M; Tazzyman, Sarah; Flowe, Heather D; Palmer, Emma J; Frosch, Caren A; O'Reilly, Michelle; Jones, Ceri; Buckley, Chloe; Knieps, Melanie; Cutts, Katie

    2016-08-01

    Three studies were conducted to investigate people's conceptions of online trolls, particularly conceptions associated with psychological resilience to trolling. In Study 1, a factor analysis of participants' ratings of characteristics of online trolls found a replicable bifactor model of conceptions of online trolls, with a general factor of general conceptions towards online trolls being identified, but five group factors (attention-conflict seeking, low self-confidence, viciousness, uneducated, amusement) as most salient. In Study 2, participants evaluated hypothetical profiles of online trolling messages to establish the validity of the five factors. Three constructs (attention-conflict seeking, viciousness, and uneducated) were actively employed when people considered profiles of online trolling scenarios. Study 3 introduced a 20-item 'Conceptions of Online Trolls scale' to examine the extent to which the five group factors were associated with resilience to trolling. Results indicated that viewing online trolls as seeking conflict or attention was associated with a decrease in individuals' negative affect around previous trolling incidents. Overall, the findings suggest that adopting an implicit theories approach can further our understanding and measurement of conceptions towards trolling through the identification of five salient factors, of which at least one factor may act as a resilience strategy. © 2015 The British Psychological Society.

  16. Exploratory analysis of diffusion tensor imaging in children with attention deficit hyperactivity disorder: evidence of abnormal white matter structure.

    Science.gov (United States)

    Pastura, Giuseppe; Doering, Thomas; Gasparetto, Emerson Leandro; Mattos, Paulo; Araújo, Alexandra Prüfer

    2016-06-01

    Abnormalities in the white matter microstructure of the attentional system have been implicated in the aetiology of attention deficit hyperactivity disorder (ADHD). Diffusion tensor imaging (DTI) is a promising magnetic resonance imaging (MRI) technology that has increasingly been used in studies of white matter microstructure in the brain. The main objective of this work was to perform an exploratory analysis of white matter tracts in a sample of children with ADHD versus typically developing children (TDC). For this purpose, 13 drug-naive children with ADHD of both genders underwent MRI using DTI acquisition methodology and tract-based spatial statistics. The results were compared to those of a sample of 14 age- and gender-matched TDC. Lower fractional anisotropy was observed in the splenium of the corpus callosum, right superior longitudinal fasciculus, bilateral retrolenticular part of the internal capsule, bilateral inferior fronto-occipital fasciculus, left external capsule and posterior thalamic radiation (including right optic radiation). We conclude that white matter tracts in attentional and motor control systems exhibited signs of abnormal microstructure in this sample of drug-naive children with ADHD.

  17. Self-esteem modulates automatic attentional responses to self-relevant stimuli: Evidence from event-related brain potentials

    Directory of Open Access Journals (Sweden)

    Jie eChen

    2015-06-01

    Full Text Available Previous studies have widely shown that self-esteem modulates the attention bias towards social rejection or emotion-related information. However, little is known about the influences of self-esteem on attention bias towards self-relevant stimuli. We aimed to investigate neural correlates that underlie the modulation effect of self-esteem on self-relevant processing. Event-related potentials were recorded for subjects’ own names and close others’ names (the names of their friends while subjects performed a three-stimulus oddball task. The results showed larger P2 amplitudes for one’s own name than for close-other’s name in the low self-esteem group, whereas this P2 effect were not observed in the high self-esteem group. In addition, one’s own name elicited equivalent N250 amplitudes and larger P3 amplitudes compared with close-other’s name in both high and low self-esteem groups. However, no interaction effects were observed between self-esteem and self-relevant processing in the N250 and P3 components. Thus, we found that the modulation effects of self-esteem on self-relevant processing occurred at the early P2 stage, but not at the later N250 and P3 stages. These findings reflect that individuals with low self-esteem demonstrate automatic attention towards their own names.

  18. P2-23: Deficits on Preference but Not Attention in Patients with Depression: Evidence from Gaze Cue

    Directory of Open Access Journals (Sweden)

    Jingling Li

    2012-10-01

    Full Text Available Gaze is an important social cue and can easily capture attention. Our preference judgment is biased by others' gaze; that is, we prefer objects gazed by happy or neutral faces and dislike objects gazed by disgust faces. Since patients with depression have a negative bias in emotional perception, we hypothesized that they may have different preference judgment on the gazed objects than healthy controls. Twenty-one patients with major depressive disorder and 21 healthy age-matched controls completed an object categorization task and then rated their preference on those objects. In the categorization task, a schematic face either gazed toward or away from the to-be-categorized object. The results showed that both groups categorized faster for gazed objects than non-gazed objects, suggesting that patients did not have deficits on their attention to gaze cues. Nevertheless, healthy controls preferred gazed objects more than non-gazed objects, while patients did not have significant preference. Our result indicated that patients with depression have deficits on their social cognition rather than basic attentional mechanism.

  19. You Can Leave Your Head On: Attention Management and Turn-Taking in Multi-party Interaction with a Virtual Human/Robot Duo

    NARCIS (Netherlands)

    Linssen, Jeroen; Berkhoff, Meike; Bode, Max; Rens, Eduard; Theune, Mariet; Wiltenburg, Daan; Beskow, Jonas; Peters, Christopher; Castellano, Ginevra; O'Sullivan, Carol; Leite, Iolanda; Kopp, Stefan

    In two small studies, we investigated how a virtual human/ robot duo can complement each other in joint interaction with one or more users. The robot takes care of turn management while the virtual human draws attention to the robot. Our results show that having the virtual human address the robot,

  20. Genetic Evidence of Human Adaptation to a Cooked Diet.

    Science.gov (United States)

    Carmody, Rachel N; Dannemann, Michael; Briggs, Adrian W; Nickel, Birgit; Groopman, Emily E; Wrangham, Richard W; Kelso, Janet

    2016-04-13

    Humans have been argued to be biologically adapted to a cooked diet, but this hypothesis has not been tested at the molecular level. Here, we combine controlled feeding experiments in mice with comparative primate genomics to show that consumption of a cooked diet influences gene expression and that affected genes bear signals of positive selection in the human lineage. Liver gene expression profiles in mice fed standardized diets of meat or tuber were affected by food type and cooking, but not by caloric intake or consumer energy balance. Genes affected by cooking were highly correlated with genes known to be differentially expressed in liver between humans and other primates, and more genes in this overlap set show signals of positive selection in humans than would be expected by chance. Sequence changes in the genes under selection appear before the split between modern humans and two archaic human groups, Neandertals and Denisovans, supporting the idea that human adaptation to a cooked diet had begun by at least 275,000 years ago. © The Author 2016. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

  1. Age-Dependent Effects of Methylphenidate on the Human Dopaminergic System in Young vs Adult Patients With Attention-Deficit/Hyperactivity Disorder: A Randomized Clincal Trial

    NARCIS (Netherlands)

    Schrantee, A.; Tamminga, H.G.H.; Bouziane, C.; Bottelier, M.A.; Bron, E.E.; Mutsaerts, H.-J.M.M.; Zwinderman, A.H.; Groote, I.R.; Rombouts, S.A.R.B.; Lindauer, R.J.L.; Klein, S.; Niessen, W.J.; Opmeer, B.C.; Boer, F.; Lucassen, P.J.; Andersen, S.L.; Geurts, H.M.; Reneman, L.

    2016-01-01

    Importance: Although numerous children receive methylphenidate hydrochloride for the treatment of attention-deficit/hyperactivity disorder (ADHD), little is known about age-dependent and possibly lasting effects of methylphenidate on the human dopaminergic system. Objectives: To determine whether

  2. Age-dependent effects of methylphenidate on the human dopaminergic system in young vs adult patients with attention-deficit/hyperactivity disorder: A randomized clinical trial

    NARCIS (Netherlands)

    Schrantee, A. (Anouk); Tamminga, H.G.H. (Hyke G. H.); C. Bouziane (Cheima); Bottelier, M.A. (Marco A.); E.E. Bron (Esther); H.J.M.M. Mutsaerts (Henri J. M.); A.H. Zwinderman (Ailko); Groote, I.R. (Inge R.); S.A.R.B. Rombouts (Serge); Lindauer, R.J.L. (Ramon J. L.); S. Klein (Stefan); W.J. Niessen (Wiro); B.C. Opmeer (Brent); Boer, F. (Frits); P.J. Lucassen; Andersen, S.L. (Susan L.); H.M. Geurts (Hilde ); L. Reneman (Liesbeth)

    2016-01-01

    textabstractIMPORTANCE Although numerous children receivemethylphenidate hydrochloride for the treatment of attention-deficit/hyperactivity disorder (ADHD), little is known about age-dependent and possibly lasting effects of methylphenidate on the human dopaminergic system. OBJECTIVES To determine

  3. Age-Dependent Effects of Methylphenidate on the Human Dopaminergic System in Young vs Adult Patients With Attention-Deficit/Hyperactivity Disorder: A Randomized Clinical Trial

    NARCIS (Netherlands)

    Schrantee, Anouk; Tamminga, Hyke G. H.; Bouziane, Cheima; Bottelier, Marco A.; Bron, Esther E.; Mutsaerts, Henk-Jan M. M.; Zwinderman, Aeilko H.; Groote, Inge R.; Rombouts, Serge A. R. B.; Lindauer, Ramon J. L.; Klein, Stefan; Niessen, Wiro J.; Opmeer, Brent C.; Boer, Frits; Lucassen, Paul J.; Andersen, Susan L.; Geurts, Hilde M.; Reneman, Liesbeth

    2016-01-01

    Although numerous children receive methylphenidate hydrochloride for the treatment of attention-deficit/hyperactivity disorder (ADHD), little is known about age-dependent and possibly lasting effects of methylphenidate on the human dopaminergic system. To determine whether the effects of

  4. Are numbers, size and brightness equally efficient in orienting visual attention? Evidence from an eye-tracking study.

    Directory of Open Access Journals (Sweden)

    Hermann Bulf

    Full Text Available A number of studies have shown strong relations between numbers and oriented spatial codes. For example, perceiving numbers causes spatial shifts of attention depending upon numbers' magnitude, in a way suggestive of a spatially oriented, mental representation of numbers. Here, we investigated whether this phenomenon extends to non-symbolic numbers, as well as to the processing of the continuous dimensions of size and brightness, exploring whether different quantitative dimensions are equally mapped onto space. After a numerical (symbolic Arabic digits or non-symbolic arrays of dots; Experiment 1 or a non-numerical cue (shapes of different size or brightness level; Experiment 2 was presented, participants' saccadic response to a target that could appear either on the left or the right side of the screen was registered using an automated eye-tracker system. Experiment 1 showed that, both in the case of Arabic digits and dot arrays, right targets were detected faster when preceded by large numbers, and left targets were detected faster when preceded by small numbers. Participants in Experiment 2 were faster at detecting right targets when cued by large-sized shapes and left targets when cued by small-sized shapes, whereas brightness cues did not modulate the detection of peripheral targets. These findings indicate that looking at a symbolic or a non-symbolic number induces attentional shifts to a peripheral region of space that is congruent with the numbers' relative position on a mental number line, and that a similar shift in visual attention is induced by looking at shapes of different size. More specifically, results suggest that, while the dimensions of number and size spontaneously map onto an oriented space, the dimension of brightness seems to be independent at a certain level of magnitude elaboration from the dimensions of spatial extent and number, indicating that not all continuous dimensions are equally mapped onto space.

  5. Are numbers, size and brightness equally efficient in orienting visual attention? Evidence from an eye-tracking study.

    Science.gov (United States)

    Bulf, Hermann; Macchi Cassia, Viola; de Hevia, Maria Dolores

    2014-01-01

    A number of studies have shown strong relations between numbers and oriented spatial codes. For example, perceiving numbers causes spatial shifts of attention depending upon numbers' magnitude, in a way suggestive of a spatially oriented, mental representation of numbers. Here, we investigated whether this phenomenon extends to non-symbolic numbers, as well as to the processing of the continuous dimensions of size and brightness, exploring whether different quantitative dimensions are equally mapped onto space. After a numerical (symbolic Arabic digits or non-symbolic arrays of dots; Experiment 1) or a non-numerical cue (shapes of different size or brightness level; Experiment 2) was presented, participants' saccadic response to a target that could appear either on the left or the right side of the screen was registered using an automated eye-tracker system. Experiment 1 showed that, both in the case of Arabic digits and dot arrays, right targets were detected faster when preceded by large numbers, and left targets were detected faster when preceded by small numbers. Participants in Experiment 2 were faster at detecting right targets when cued by large-sized shapes and left targets when cued by small-sized shapes, whereas brightness cues did not modulate the detection of peripheral targets. These findings indicate that looking at a symbolic or a non-symbolic number induces attentional shifts to a peripheral region of space that is congruent with the numbers' relative position on a mental number line, and that a similar shift in visual attention is induced by looking at shapes of different size. More specifically, results suggest that, while the dimensions of number and size spontaneously map onto an oriented space, the dimension of brightness seems to be independent at a certain level of magnitude elaboration from the dimensions of spatial extent and number, indicating that not all continuous dimensions are equally mapped onto space.

  6. Weighing serological evidence of human exposure to animal influenza viruses − A literature review

    NARCIS (Netherlands)

    Sikkema, R.S. (Reina S.); G.S. Freidl (Gudrun); E.I. de Bruin (Esther); M.P.G. Koopmans D.V.M. (Marion)

    2016-01-01

    textabstractAssessing influenza A virus strains circulating in animals and their potential to cross the species barrier and cause human infections is important to improve human influenza surveillance and preparedness. We reviewed studies describing serological evidence of human exposure to animal

  7. Primate social attention : species differences and effects of individual experience in humans, great apes, and macaques

    OpenAIRE

    Kano, Fumihiro; Shepherd, Stephen V.; Hirata, Satoshi; Call, Josep

    2018-01-01

    Financial support came from Japan Society for Promotion of Science (JSPS) [grant numbers: KAKENHI 26885040, 16K21108 to FK, KAKENHI 26245069, 16H06301, 16H06283, JSPS-LGP-U04 to SH] and Ministry of Education, Culture, Sports, Science and Technology (MEXT) [K-CONNEX to FK], and the European Research Council [SOMICS 609819 to JC]. When viewing social scenes, humans and nonhuman primates focus on particular features, such as the models’ eyes, mouth, and action targets. Previous studies report...

  8. Executive and perceptual attention play different roles in visual working memory: evidence from suffix and strategy effects.

    Science.gov (United States)

    Hu, Yanmei; Hitch, Graham J; Baddeley, Alan D; Zhang, Ming; Allen, Richard J

    2014-08-01

    Four experiments studied the interfering effects of a to-be-ignored "stimulus suffix" on cued recall of feature bindings for a series of objects. When each object was given equal weight (Experiment 1) or rewards favored recent items (Experiments 2 and 4), a recency effect emerged that was selectively reduced by a suffix. The reduction was greater for a "plausible" suffix with features drawn from the same set as the memory items, in which case a feature of the suffix was frequently recalled as an intrusion error. Changing payoffs to reward recall of early items led to a primacy effect alongside recency (Experiments 3 and 4). Primacy, like recency, was reduced by a suffix and the reduction was greater for a suffix with plausible features, such features often being recalled as intrusion errors. Experiment 4 revealed a tradeoff such that increased primacy came at the cost of a reduction in recency. These observations show that priority instructions and recency combine to determine a limited number of items that are the most accessible for immediate recall and yet at the same time the most vulnerable to interference. We interpret this outcome in terms of a labile, limited capacity "privileged state" controlled by both central executive processes and perceptual attention. We suggest further that this privileged state can be usefully interpreted as the focus of attention in the episodic buffer.

  9. Common region wins the competition between extrinsic grouping cues: Evidence from a task without explicit attention to grouping.

    Science.gov (United States)

    Montoro, Pedro R; Villalba-García, Cristina; Luna, Dolores; Hinojosa, José A

    2017-12-01

    The competition between perceptual grouping factors is a relatively ignored topic, especially in the case of extrinsic grouping cues (e.g., common region or connectedness). Recent studies have examined the integration of extrinsic cues using tasks that induce selective attention to groups based on different grouping cues. However, this procedure could generate alternative strategies for task performance, which are non-related to the perceptual grouping operations. In the current work, we used an indirect task, i.e. repetition discrimination task, without explicit attention to grouping cues to further examine the rules that govern dominance between competing extrinsic grouping factors. This procedure allowed us to obtain an unbiased measure of the competition between common region and connectedness cues acting within the same display. The results corroborate previous data showing that grouping by common region dominated the perceived organization of the display, even though the phenomenological strength of the grouping cues was equated for each participant by means of a preliminary scaling task. Our results highlight the relevance of using indirect tasks as an essential tool for the systematic study of the integration of extrinsic grouping cues.

  10. Attention to Attention

    DEFF Research Database (Denmark)

    Tække, Jesper; Paulsen, Michael Eric

    In these years digital media and wireless networks are introduced in upper secondary schools in Denmark. This implies new “attentional objects” like updates on Facebook or tweets on Twitter within instant reach of the pupils and teachers. Also it implies new kinds of attention (awareness) like when...... pupils try to listen to the teacher and simultaneously participate in online games. To this new social setting the teachers has reacted with either prohibition or unconcern. What has not been realised is that the introduction of new media profoundly challenges the way attention hitherto has functioned...... as a psychic prerequisite for the social interaction between pupils and teachers. New kinds of “split attention” arise and new kinds of social mediation (regulation and “use”) of psychic attention become necessary if teaching in the new digital medium milieu shall be beneficial. In this paper we qualify...

  11. HUMAN CAPITAL GROWTH AND POVERTY: EVIDENCE FROM ETHIOPIA AND PERU.

    Science.gov (United States)

    Attanasio, Orazio; Meghir, Costas; Nix, Emily; Salvati, Francesca

    2017-04-01

    In this paper we use high quality data from two developing countries, Ethiopia and Peru, to estimate the production functions of human capital from age 1 to age 15. We characterize the nature of persistence and dynamic complementarities between two components of human capital: health and cognition. We also explore the implications of different functional form assumptions for the production functions. We find that more able and higher income parents invest more, particularly at younger ages when investments have the greatest impacts. These differences in investments by parental income lead to large gaps in inequality by age 8 that persist through age 15.

  12. Chinese Public Attention to the Outbreak of Ebola in West Africa: Evidence from the Online Big Data Platform.

    Science.gov (United States)

    Liu, Kui; Li, Li; Jiang, Tao; Chen, Bin; Jiang, Zhenggang; Wang, Zhengting; Chen, Yongdi; Jiang, Jianmin; Gu, Hua

    2016-08-04

    The outbreak of the Ebola epidemic in West Africa in 2014 exerted enormous global public reaction via the Internet and social media. This study aimed to investigate and evaluate the public reaction to Ebola in China and identify the primitive correlation between possible influence factors caused by the outbreak of Ebola in West Africa and Chinese public attention via Internet surveillance. Baidu Index (BDI) and Sina Micro Index (SMI) were collected from their official websites, and the disease-related data were recorded from the websites of the World Health Organization (WHO), U.S. Centers for Disease Control and Prevention (CDC), and U.S. National Ministries of Health. The average BDI of Internet users in different regions were calculated to identify the public reaction to the Ebola outbreak. Spearman's rank correlation was used to check the relationship of epidemic trends with BDI and SMI. Additionally, spatio-temporal analysis and autocorrelation analysis were performed to detect the clustered areas with the high attention to the topic of "Ebola". The related news reports were collected from authoritative websites to identify potential patterns. The BDI and the SMI for "Ebola" showed a similar fluctuating trend with a correlation coefficient = 0.9 (p < 0.05). The average BDI in Beijing, Tibet, and Shanghai was higher than other cities. However, the disease-related indicators did not identify potential correlation with both indices above. A hotspot area was detected in Tibet by local autocorrelation analysis. The most likely cluster identified by spatiotemporal cluster analysis was in the northeast regions of China with the relative risk (RR) of 2.26 (p ≤ 0.01) from 30 July to 14 August in 2014. Qualitative analysis indicated that negative news could lead to a continuous increase of the public's attention until the appearance of a positive news report. Confronted with the risk of cross-border transmission of the infectious disease, online surveillance might be

  13. Environmental heat stress enhances mental fatigue during sustained attention task performing: evidence from an ASL perfusion study.

    Science.gov (United States)

    Qian, Shaowen; Li, Min; Li, Guoying; Liu, Kai; Li, Bo; Jiang, Qingjun; Li, Li; Yang, Zhen; Sun, Gang

    2015-03-01

    This study was to investigate the potential enhancing effect of heat stress on mental fatigue progression during sustained attention task using arterial spin labeling (ASL) imaging. Twenty participants underwent two thermal exposures in an environmental chamber: normothermic (NT) condition (25°C, 1h) and hyperthermic (HT) condition (50°C, 1h). After thermal exposure, they performed a twenty-minute psychomotor vigilance test (PVT) in the scanner. Behavioral analysis revealed progressively increasing subjective fatigue ratings and reaction time as PVT progressed. Moreover, heat stress caused worse performance. Perfusion imaging analyses showed significant resting-state cerebral blood flow (CBF) alterations after heat exposure. Specifically, increased CBF mainly gathered in thalamic-brainstem area while decreased CBF predominantly located in fronto-parietal areas, anterior cingulate cortex, posterior cingulate cortex, and medial frontal cortex. More importantly, diverse CBF distributions and trend of changes between both conditions were observed as the fatigue level progressed during subsequent PVT task. Specifically, higher CBF and enhanced rising trend were presented in superior parietal lobe, precuneus, posterior cingulate cortex and anterior cingulate cortex, while lower CBF or inhibited rising trend was found in dorsolateral frontal cortex, medial frontal cortex, inferior parietal lobe and thalamic-brainstem areas. Furthermore, the decrease of post-heat resting-state CBF in fronto-parietal cortex was correlated with subsequent slower reaction time, suggesting prior disturbed resting-state CBF might be indicator of performance potential and fatigue level in following task. These findings may provide proof for such a view: heat stress has a potential fatigue-enhancing effect when individual is performing highly cognition-demanding attention task. Copyright © 2014 Elsevier B.V. All rights reserved.

  14. Losing the left side of the world: rightward shift in human spatial attention with sleep onset.

    Science.gov (United States)

    Bareham, Corinne A; Manly, Tom; Pustovaya, Olga V; Scott, Sophie K; Bekinschtein, Tristan A

    2014-05-28

    Unilateral brain damage can lead to a striking deficit in awareness of stimuli on one side of space called Spatial Neglect. Patient studies show that neglect of the left is markedly more persistent than of the right and that its severity increases under states of low alertness. There have been suggestions that this alertness-spatial awareness link may be detectable in the general population. Here, healthy human volunteers performed an auditory spatial localisation task whilst transitioning in and out of sleep. We show, using independent electroencephalographic measures, that normal drowsiness is linked with a remarkable unidirectional tendency to mislocate left-sided stimuli to the right. The effect may form a useful healthy model of neglect and help in understanding why leftward inattention is disproportionately persistent after brain injury. The results also cast light on marked changes in conscious experience before full sleep onset.

  15. What's next? New evidence for prediction in human vision.

    Science.gov (United States)

    Enns, James T; Lleras, Alejandro

    2008-09-01

    Everyday visual experience involves making implicit predictions, as revealed by our surprise when something disturbs our expectations. Many theories of vision have been premised on the central role played by prediction. Yet, implicit prediction in human vision has been difficult to assess in the laboratory, and many results have not distinguished between the indisputably important role of memory and the future-oriented aspect of prediction. Now, a new and unexpected finding - that humans can resume an interrupted visual search much faster than they can start a new search - offers new hope, because the rapid resumption of a search seems to depend on participants forming an implicit prediction of what they will see after the interruption. These findings combined with results of recent neurophysiology studies provide a framework for studying implicit prediction in perception.

  16. The treatment of sex offenders: evidence, ethics, and human rights.

    Science.gov (United States)

    Birgden, Astrid; Cucolo, Heather

    2011-09-01

    Public policy is necessarily a political process with the law and order issue high on the political agenda. Consequently, working with sex offenders is fraught with legal and ethical minefields, including the mandate that community protection automatically outweighs offender rights. In addressing community protection, contemporary sex offender treatment is based on management rather than rehabilitation. We argue that treatment-as-management violates offender rights because it is ineffective and unethical. The suggested alternative is to deliver treatment-as-rehabilitation underpinned by international human rights law and universal professional ethics. An effective and ethical community-offender balance is more likely when sex offenders are treated with respect and dignity that, as human beings, they have a right to claim.

  17. Pesticides and human chronic diseases: Evidences, mechanisms, and perspectives

    International Nuclear Information System (INIS)

    Mostafalou, Sara; Abdollahi, Mohammad

    2013-01-01

    Along with the wide use of pesticides in the world, the concerns over their health impacts are rapidly growing. There is a huge body of evidence on the relation between exposure to pesticides and elevated rate of chronic diseases such as different types of cancers, diabetes, neurodegenerative disorders like Parkinson, Alzheimer, and amyotrophic lateral sclerosis (ALS), birth defects, and reproductive disorders. There is also circumstantial evidence on the association of exposure to pesticides with some other chronic diseases like respiratory problems, particularly asthma and chronic obstructive pulmonary disease (COPD), cardiovascular disease such as atherosclerosis and coronary artery disease, chronic nephropathies, autoimmune diseases like systemic lupus erythematous and rheumatoid arthritis, chronic fatigue syndrome, and aging. The common feature of chronic disorders is a disturbance in cellular homeostasis, which can be induced via pesticides' primary action like perturbation of ion channels, enzymes, receptors, etc., or can as well be mediated via pathways other than the main mechanism. In this review, we present the highlighted evidence on the association of pesticide's exposure with the incidence of chronic diseases and introduce genetic damages, epigenetic modifications, endocrine disruption, mitochondrial dysfunction, oxidative stress, endoplasmic reticulum stress and unfolded protein response (UPR), impairment of ubiquitin proteasome system, and defective autophagy as the effective mechanisms of action. - Highlights: ► There is a link between exposure to pesticides and incidence of chronic diseases. ► Genotoxicity and proteotoxicity are two main involved mechanisms. ► Epigenetic knowledge may help diagnose the relationships. ► Efficient policies on safe use of pesticides should be set up

  18. Pesticides and human chronic diseases: Evidences, mechanisms, and perspectives

    Energy Technology Data Exchange (ETDEWEB)

    Mostafalou, Sara; Abdollahi, Mohammad, E-mail: Mohammad.Abdollahi@UToronto.Ca

    2013-04-15

    Along with the wide use of pesticides in the world, the concerns over their health impacts are rapidly growing. There is a huge body of evidence on the relation between exposure to pesticides and elevated rate of chronic diseases such as different types of cancers, diabetes, neurodegenerative disorders like Parkinson, Alzheimer, and amyotrophic lateral sclerosis (ALS), birth defects, and reproductive disorders. There is also circumstantial evidence on the association of exposure to pesticides with some other chronic diseases like respiratory problems, particularly asthma and chronic obstructive pulmonary disease (COPD), cardiovascular disease such as atherosclerosis and coronary artery disease, chronic nephropathies, autoimmune diseases like systemic lupus erythematous and rheumatoid arthritis, chronic fatigue syndrome, and aging. The common feature of chronic disorders is a disturbance in cellular homeostasis, which can be induced via pesticides' primary action like perturbation of ion channels, enzymes, receptors, etc., or can as well be mediated via pathways other than the main mechanism. In this review, we present the highlighted evidence on the association of pesticide's exposure with the incidence of chronic diseases and introduce genetic damages, epigenetic modifications, endocrine disruption, mitochondrial dysfunction, oxidative stress, endoplasmic reticulum stress and unfolded protein response (UPR), impairment of ubiquitin proteasome system, and defective autophagy as the effective mechanisms of action. - Highlights: ► There is a link between exposure to pesticides and incidence of chronic diseases. ► Genotoxicity and proteotoxicity are two main involved mechanisms. ► Epigenetic knowledge may help diagnose the relationships. ► Efficient policies on safe use of pesticides should be set up.

  19. Education on human rights and healthcare: evidence from Serbia.

    Science.gov (United States)

    Vranes, Aleksandra Jovic; Mikanovic, Vesna Bjegovic; Vukovic, Dejana; Djikanovic, Bosiljka; Babic, Momcilo

    2015-03-01

    Ensuring and enforcing human rights in patient care are important to promote health and to provide quality and appropriate healthcare services. Therefore, continued medical education (CME) is essential for healthcare professionals to utilize their sphere of influence to affect change in healthcare practice. A total of 123 participants attended three CME courses. Course topics covered: (i) the areas of human rights and healthcare, (ii) rights, obligations and responsibilities of healthcare professionals in relation to human rights and the rights of patients, (iii) healthcare of vulnerable groups and (iv) access to essential medical services. Evaluation of the CME courses involved two components: evaluation of participants' performance and the participants' evaluation of the teaching process. The participants were assessed at the beginning and end of each course. Each of the courses was evaluated by the participants through a questionnaire distributed at the end of each course. Descriptive statistics was used for data interpretation. Knowledge of the healthcare professionals improved at the end of all the three courses. The participants assessed several aspects of the courses, including the course topics, educational methods, the course methods, organization, duration and dynamics as well as the physical environment and the technical facilities of the course, and rated each very highly. Our results corroborate the importance and necessity of courses to heighten awareness of the state of current healthcare and human rights issues to increase the involvement of healthcare professionals both locally and globally. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  20. Longitudinal evidence that fatherhood decreases testosterone in human males.

    Science.gov (United States)

    Gettler, Lee T; McDade, Thomas W; Feranil, Alan B; Kuzawa, Christopher W

    2011-09-27

    In species in which males care for young, testosterone (T) is often high during mating periods but then declines to allow for caregiving of resulting offspring. This model may apply to human males, but past human studies of T and fatherhood have been cross-sectional, making it unclear whether fatherhood suppresses T or if men with lower T are more likely to become fathers. Here, we use a large representative study in the Philippines (n = 624) to show that among single nonfathers at baseline (2005) (21.5 ± 0.3 y), men with high waking T were more likely to become partnered fathers by the time of follow-up 4.5 y later (P < 0.05). Men who became partnered fathers then experienced large declines in waking (median: -26%) and evening (median: -34%) T, which were significantly greater than declines in single nonfathers (P < 0.001). Consistent with the hypothesis that child interaction suppresses T, fathers reporting 3 h or more of daily childcare had lower T at follow-up compared with fathers not involved in care (P < 0.05). Using longitudinal data, these findings show that T and reproductive strategy have bidirectional relationships in human males, with high T predicting subsequent mating success but then declining rapidly after men become fathers. Our findings suggest that T mediates tradeoffs between mating and parenting in humans, as seen in other species in which fathers care for young. They also highlight one likely explanation for previously observed health disparities between partnered fathers and single men.

  1. Statistical evidence about human influence on the climate system

    OpenAIRE

    Pierre Perron; Francisco Estrada; Benjamín Martínez-López

    2012-01-01

    We use recent methods for the analysis of time series data, in particular related to breaks in trends, to establish that human factors are the main contributors to the secular movements in observed global and hemispheric temperatures series. The most important feature documented is a marked increase in the growth rates of temperatures (purged from the Atlantic Multidecadal Oscillation) and anthropogenic greenhouse gases occurring for all series around 1955, which marks the start of sustained ...

  2. How to support action prediction: Evidence from human coordination tasks

    DEFF Research Database (Denmark)

    Vesper, Cordula

    2014-01-01

    When two or more people perform actions together such as shaking hands, playing ensemble music or carrying an object together, they often naturally adjust the spatial and temporal parameters of their movements to facilitate smooth task performance. This paper reviews recent findings from experime......”) might be a useful approach also for robotic systems to assist human users, thereby reducing cognitive load and flexibly supporting the acquisition of new skills....

  3. In Silico Evidence for Gluconeogenesis from Fatty Acids in Humans

    Science.gov (United States)

    Kaleta, Christoph; de Figueiredo, Luís F.; Werner, Sarah; Guthke, Reinhard; Ristow, Michael; Schuster, Stefan

    2011-01-01

    The question whether fatty acids can be converted into glucose in humans has a long standing tradition in biochemistry, and the expected answer is “No”. Using recent advances in Systems Biology in the form of large-scale metabolic reconstructions, we reassessed this question by performing a global investigation of a genome-scale human metabolic network, which had been reconstructed on the basis of experimental results. By elementary flux pattern analysis, we found numerous pathways on which gluconeogenesis from fatty acids is feasible in humans. On these pathways, four moles of acetyl-CoA are converted into one mole of glucose and two moles of CO2. Analyzing the detected pathways in detail we found that their energetic requirements potentially limit their capacity. This study has many other biochemical implications: effect of starvation, sports physiology, practically carbohydrate-free diets of inuit, as well as survival of hibernating animals and embryos of egg-laying animals. Moreover, the energetic loss associated to the usage of gluconeogenesis from fatty acids can help explain the efficiency of carbohydrate reduced and ketogenic diets such as the Atkins diet. PMID:21814506

  4. In silico evidence for gluconeogenesis from fatty acids in humans.

    Directory of Open Access Journals (Sweden)

    Christoph Kaleta

    2011-07-01

    Full Text Available The question whether fatty acids can be converted into glucose in humans has a long standing tradition in biochemistry, and the expected answer is "No". Using recent advances in Systems Biology in the form of large-scale metabolic reconstructions, we reassessed this question by performing a global investigation of a genome-scale human metabolic network, which had been reconstructed on the basis of experimental results. By elementary flux pattern analysis, we found numerous pathways on which gluconeogenesis from fatty acids is feasible in humans. On these pathways, four moles of acetyl-CoA are converted into one mole of glucose and two moles of CO₂. Analyzing the detected pathways in detail we found that their energetic requirements potentially limit their capacity. This study has many other biochemical implications: effect of starvation, sports physiology, practically carbohydrate-free diets of inuit, as well as survival of hibernating animals and embryos of egg-laying animals. Moreover, the energetic loss associated to the usage of gluconeogenesis from fatty acids can help explain the efficiency of carbohydrate reduced and ketogenic diets such as the Atkins diet.

  5. Evidence for radical-oxidation of plasma proteins in humans

    International Nuclear Information System (INIS)

    Wang, D.; Davies, M.; Dean, R.; Fu, S.; Taurins, A.; Sullivans, D.

    1998-01-01

    Oxidation of proteins by radicals has been implicated in many pathological processes. The hydroxyl radical is known to generate protein-bound hydroxylated derivatives of amino acids, for example hydroxyvaline (from Val), hydroxyleucine (from Leu), o-tyrosine (from Phe), and DOPA (from Tyr). In this study, we have investigated the occurrence of these oxidised amino acids in human plasma proteins from both normal subjects and dialysis patients. By employing previously established HPLC methods [Fu et al. Biochemical Journal, 330, 233-239, 1998], we have found that oxidised amino acids exist in normal human plasma proteins (n=32). The level of these oxidised amino acids is not correlated to age. Similar levels of oxidised amino acids are found in the plasma proteins of the dialysis patients (n=6), but a more detailed survey is underway. The relative abundance of the oxidised amino acids is similar to that resulting from oxidation of BSA by hydroxy radicals or Fenton systems [Fu et al. Biochemical Journal, 333, 519-525, 1998]. The results suggest that metal-ion catalysed oxyl-radical chemistry may be a key contributor to the oxidative damage in plasma proteins in vivo in humans

  6. Testing a cue outside the training context increases attention to the contexts and impairs performance in human predictive learning.

    Science.gov (United States)

    Aristizabal, José A; Ramos-Álvarez, Manuel M; Callejas-Aguilera, José E; Rosas, Juan M

    2017-12-01

    One experiment in human predictive learning explored the impact of a context change on attention to contexts and predictive ratings controlled by the cue. In Context A: cue X was paired with an outcome four times, while cue Y was presented without an outcome four times in Context B:. In both contexts filler cues were presented without the outcome. During the test, target cues X and Y were presented either in the context where they were trained, or in the alternative context. With the context change expectation of the outcome X, expressed as predictive ratings, decreased in the presence of X and increased in the presence of Y. Looking at the contexts, expressed as a percentage of the overall gaze dwell time on a trial, was high across the four training trials, and increased with the context change. Results suggest that the presentation of unexpected information leads to increases in attention to contextual cues. Implications for contextual control of behavior are discussed. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Human performance across decision making, selective attention, and working memory tasks: Experimental data and computer simulations

    Directory of Open Access Journals (Sweden)

    Andrea Stocco

    2018-04-01

    Full Text Available This article describes the data analyzed in the paper “Individual differences in the Simon effect are underpinned by differences in the competitive dynamics in the basal ganglia: An experimental verification and a computational model” (Stocco et al., 2017 [1]. The data includes behavioral results from participants performing three cognitive tasks (Probabilistic Stimulus Selection (Frank et al., 2004 [2], Simon task (Craft and Simon, 1970 [3], and Automated Operation Span (Unsworth et al., 2005 [4], as well as simulationed traces generated by a computational neurocognitive model that accounts for individual variations in human performance across the tasks. The experimental data encompasses individual data files (in both preprocessed and native output format as well as group-level summary files. The simulation data includes the entire model code, the results of a full-grid search of the model's parameter space, and the code used to partition the model space and parallelize the simulations. Finally, the repository includes the R scripts used to carry out the statistical analyses reported in the original paper.

  8. Human performance across decision making, selective attention, and working memory tasks: Experimental data and computer simulations.

    Science.gov (United States)

    Stocco, Andrea; Yamasaki, Brianna L; Prat, Chantel S

    2018-04-01

    This article describes the data analyzed in the paper "Individual differences in the Simon effect are underpinned by differences in the competitive dynamics in the basal ganglia: An experimental verification and a computational model" (Stocco et al., 2017) [1]. The data includes behavioral results from participants performing three cognitive tasks (Probabilistic Stimulus Selection (Frank et al., 2004) [2], Simon task (Craft and Simon, 1970) [3], and Automated Operation Span (Unsworth et al., 2005) [4]), as well as simulationed traces generated by a computational neurocognitive model that accounts for individual variations in human performance across the tasks. The experimental data encompasses individual data files (in both preprocessed and native output format) as well as group-level summary files. The simulation data includes the entire model code, the results of a full-grid search of the model's parameter space, and the code used to partition the model space and parallelize the simulations. Finally, the repository includes the R scripts used to carry out the statistical analyses reported in the original paper.

  9. Evidence of Ice Age humans in Beringia: new insights on the peopling of the Americas

    Science.gov (United States)

    Vachula, R. S.; Longo, W. M.; Daniels, W.; Dee, S.; Russell, J. M.; Huang, Y.

    2017-12-01

    The American continents were the final frontier of the global proliferation of Homo sapiens. The Bering Land Bridge that once connected Eurasia and North America, is widely accepted as the corridor for this human migration. However, the timeline, pathway, and environmental impact of human arrival to these previously unpeopled lands remain contentious in part due to a sparsity of physical archaeological or paleoenvironmental evidence. Recent conflicting genetic evidence suggests that humans lived in Beringia for an extended period of time (ca. 15,000 years) and did not diverge from Asian populations prior to 23,000 years before present (BP). The genetic evidence lacks supporting physical data, is prone to uncertainties inherent to molecular clocks, and thus further occludes our understanding of this segment of human history. Using a multi-disciplinary approach incorporating paleoecological and organic geochemical analyses of a lacustrine sediment record, and climate modelling methodologies, we present evidence of prolonged human-caused environmental disturbance in modern-day northern Alaska and show that humans were present in this area as early as 32,000 years ago. We measured fecal biomarkers preserved in the Lake E5 sediment archive to confirm prolonged human presence in the watershed, and find evidence of contemporaneous burning, as inferred from macroscopic charcoal and polycyclic aromatic hydrocarbons. Climate simulations show that natural lightning ignitions were suppressed during the period of greatest fire frequency, and so we infer that humans likely played an important role in fire ignitions. We thus present new physical evidence of sustained human presence in eastern Beringia throughout the last Glacial, which reorients our understanding of the human migration to the Americas. Furthermore, our research offers new insight into the ecology of the mammoth steppe and the role of humans in the extinction of the Pleistocene megafauna.

  10. [Evaluation and treatment of sleep problems in children diagnosed with attention deficit hyperactivity disorder: an update of the evidence].

    Science.gov (United States)

    Chamorro, M; Lara, J P; Insa, I; Espadas, M; Alda-Diez, J A

    2017-05-01

    Attention deficit hyperactivity disorder (ADHD) affects approximately 5% of all children and adolescents, and these patients frequently suffer from sleep problems. The association between sleep disorders and ADHD, however, is multifaceted and complex. To explore the relationship between sleep disorders and ADHD. Sleep problems in children with ADHD include altered sleep and specific disorders per se or that may be due to comorbid psychiatric disorders or to the stimulants they receive as treatment for their ADHD. Today, an evaluation of the sleep conditions in children with ADHD is recommended before starting pharmacological treatment. The first step in managing their sleep problems is good sleep hygiene and cognitive-behavioural psychotherapy. Another option is to consider modifying the dosage and formulation of the stimulants. Atomoxetine and melatonin are therapeutic alternatives for children with ADHD and more severe sleep problems. Specific treatments exist for respiratory and movement disorders during sleep. It is important to evaluate sleep in children who present symptoms suggestive of ADHD, since problems during sleep can play a causal role or exacerbate the clinical features of ADHD. Correct evaluation and treatment of sleep disorders increase the family's and the child's quality of life and can lessen the severity of the symptoms of ADHD.

  11. Leading, but not trailing, primes influence temporal order perception: further evidence for an attentional account of perceptual latency priming.

    Science.gov (United States)

    Scharlau, Ingrid

    2002-11-01

    Presenting a masked prime leading a target influences the perceived onset of the masking target (perceptual latency priming; Scharlau & Neumann, in press). This priming effect is explained by the asynchronous updating model (Neumann, 1982; Scharlau & Neumann, in press): The prime initiates attentional allocation toward its location, which renders a trailing target at the same place consciously available earlier. In three experiments, this perceptual latency priming by leading primes was examined jointly with the effects of trailing primes in order to compare the explanation of the asynchronous updating model with the onset-averaging and the P-center hypotheses. Experiment 1 showed that an attended, as well as an unattended, prime leads to perceptual latency priming. In addition, a large effect of trailing primes on the onset of a target was found. As Experiment 2 demonstrated, this effect is quite robust, although smaller than that of a leading prime. In Experiment 3, masked primes were used. Under these conditions, no influence of trailing primes could be found, whereas perceptual latency priming persisted. Thus, a nonattentional explanation for the effect of trailing primes seems likely.

  12. Neurobiological evidence for attention bias to food, emotional dysregulation, disinhibition and deficient somatosensory awareness in obesity with binge eating disorder.

    Science.gov (United States)

    Aviram-Friedman, Roni; Astbury, Nerys; Ochner, Christopher N; Contento, Isobel; Geliebter, Allan

    2018-02-01

    To refine the biobehavioral markers of binge eating disorder (BED). We conducted fMRI brain scans using images of high energy processed food (HEPF), low energy unprocessed food (LEUF), or non-foods (NF) in 42 adults (obese with BED [obese -BED; n=13] and obese with no BED [obese non-BED; n=29]) selected via ads. Two blood oxygenated level dependent (BOLD) signal contrast maps were examined: food versus nonfood, and HEPF versus LEUF. In addition, score differences on the disinhibition scale were correlated with BOLD signals. food versus nonfood showed greater BOLD activity for BED in emotional, motivational and somatosensory brain areas: insula, anterior cingulate cortex (ACC), Brodmann areas (BA) 19 & 32, inferior parietal lobule (IPL), posterior cingulate cortex (PCC), and lingual, postcentral, middle temporal and cuneate gyri (p≤0.005; k≥88). HEPF versus LEUF showed greater BOLD activity for BED in inhibitory brain regions: BA 6, middle and superior frontal gyri (pFood images elicited neural activity indicating attention bias (cuneate & PCG), emotion dysregulation (BA 19 & 32), and disinhibition (MFG, BA6 & SFG) in obese with BED. These may help tailor a treatment for the obesity with BED phenotype. Copyright © 2017. Published by Elsevier Inc.

  13. Preliminary evidence of altered neural response during intertemporal choice of losses in adult attention-deficit hyperactivity disorder.

    Science.gov (United States)

    Tanaka, Saori C; Yahata, Noriaki; Todokoro, Ayako; Kawakubo, Yuki; Kano, Yukiko; Nishimura, Yukika; Ishii-Takahashi, Ayaka; Ohtake, Fumio; Kasai, Kiyoto

    2018-04-30

    Impulsive behaviours are common symptoms of attention-deficit hyperactivity disorder (ADHD). Although previous studies have suggested functional models of impulsive behaviour, a full explanation of impulsivity in ADHD remains elusive. To investigate the detailed mechanisms behind impulsive behaviour in ADHD, we applied an economic intertemporal choice task involving gains and losses to adults with ADHD and healthy controls and measured brain activity by functional magnetic resonance imaging. In the intertemporal choice of future gains, we observed no behavioural or neural difference between the two groups. In the intertemporal choice of future losses, adults with ADHD exhibited higher discount rates than the control participants. Furthermore, a comparison of brain activity representing the sensitivity of future loss in the two groups revealed significantly lower activity in the striatum and higher activity in the amygdala in adults with ADHD than in controls. Our preliminary findings suggest that an altered size sensitivity to future loss is involved in apparent impulsive choice behaviour in adults with ADHD and shed light on the multifaceted impulsivity underlying ADHD.

  14. Visual selective attention is equally functional for individuals with low and high working memory capacity: evidence from accuracy and eye movements.

    Science.gov (United States)

    Mall, Jonathan T; Morey, Candice C; Wolff, Michael J; Lehnert, Franziska

    2014-10-01

    Selective attention and working memory capacity (WMC) are related constructs, but debate about the manner in which they are related remains active. One elegant explanation of variance in WMC is that the efficiency of filtering irrelevant information is the crucial determining factor, rather than differences in capacity per se. We examined this hypothesis by relating WMC (as measured by complex span tasks) to accuracy and eye movements during visual change detection tasks with different degrees of attentional filtering and allocation requirements. Our results did not indicate strong filtering differences between high- and low-WMC groups, and where differences were observed, they were counter to those predicted by the strongest attentional filtering hypothesis. Bayes factors indicated evidence favoring positive or null relationships between WMC and correct responses to unemphasized information, as well as between WMC and the time spent looking at unemphasized information. These findings are consistent with the hypothesis that individual differences in storage capacity, not only filtering efficiency, underlie individual differences in working memory.

  15. Insulin action in the human brain: evidence from neuroimaging studies.

    Science.gov (United States)

    Kullmann, S; Heni, M; Fritsche, A; Preissl, H

    2015-06-01

    Thus far, little is known about the action of insulin in the human brain. Nonetheless, recent advances in modern neuroimaging techniques, such as functional magnetic resonance imaging (fMRI) or magnetoencephalography (MEG), have made it possible to investigate the action of insulin in the brain in humans, providing new insights into the pathogenesis of brain insulin resistance and obesity. Using MEG, the clinical relevance of the action of insulin in the brain was first identified, linking cerebral insulin resistance with peripheral insulin resistance, genetic predisposition and weight loss success in obese adults. Although MEG is a suitable tool for measuring brain activity mainly in cortical areas, fMRI provides high spatial resolution for cortical as well as subcortical regions. Thus, the action of insulin can be detected within all eating behaviour relevant regions, which include regions deeply located within the brain, such as the hypothalamus, midbrain and brainstem, as well as regions within the striatum. In this review, we outline recent advances in the field of neuroimaging aiming to investigate the action of insulin in the human brain using different routes of insulin administration. fMRI studies have shown a significant insulin-induced attenuation predominantly in the occipital and prefrontal cortical regions and the hypothalamus, successfully localising insulin-sensitive brain regions in healthy, mostly normal-weight individuals. However, further studies are needed to localise brain areas affected by insulin resistance in obese individuals, which is an important prerequisite for selectively targeting brain insulin resistance in obesity. © 2015 British Society for Neuroendocrinology.

  16. Nanotechnology and human health: Scientific evidence and risk governance

    DEFF Research Database (Denmark)

    Nanotechnology, the science and application of objects smaller that 100 nanometres, is evolving rapidly in many fields. Besides the countless beneficial applications, including in health and medicine, concerns exist on adverse health consequences of unintended human exposure to nanomaterials....... In the 2010 Parma Declaration on Environment and Health, ministers of health and of environment of the 53 Member States of the WHO Regional Office for Europe listed the health implications of nanotechnology and nanoparticles among the key environment and health challenges. The WHO Regional Office for Europe...

  17. Enhanced attentional gain as a mechanism for generalized perceptual learning in human visual cortex.

    Science.gov (United States)

    Byers, Anna; Serences, John T

    2014-09-01

    Learning to better discriminate a specific visual feature (i.e., a specific orientation in a specific region of space) has been associated with plasticity in early visual areas (sensory modulation) and with improvements in the transmission of sensory information from early visual areas to downstream sensorimotor and decision regions (enhanced readout). However, in many real-world scenarios that require perceptual expertise, observers need to efficiently process numerous exemplars from a broad stimulus class as opposed to just a single stimulus feature. Some previous data suggest that perceptual learning leads to highly specific neural modulations that support the discrimination of specific trained features. However, the extent to which perceptual learning acts to improve the discriminability of a broad class of stimuli via the modulation of sensory responses in human visual cortex remains largely unknown. Here, we used functional MRI and a multivariate analysis method to reconstruct orientation-selective response profiles based on activation patterns in the early visual cortex before and after subjects learned to discriminate small offsets in a set of grating stimuli that were rendered in one of nine possible orientations. Behavioral performance improved across 10 training sessions, and there was a training-related increase in the amplitude of orientation-selective response profiles in V1, V2, and V3 when orientation was task relevant compared with when it was task irrelevant. These results suggest that generalized perceptual learning can lead to modified responses in the early visual cortex in a manner that is suitable for supporting improved discriminability of stimuli drawn from a large set of exemplars. Copyright © 2014 the American Physiological Society.

  18. Neural evidence that human emotions share core affective properties.

    Science.gov (United States)

    Wilson-Mendenhall, Christine D; Barrett, Lisa Feldman; Barsalou, Lawrence W

    2013-06-01

    Research on the "emotional brain" remains centered around the idea that emotions like fear, happiness, and sadness result from specialized and distinct neural circuitry. Accumulating behavioral and physiological evidence suggests, instead, that emotions are grounded in core affect--a person's fluctuating level of pleasant or unpleasant arousal. A neuroimaging study revealed that participants' subjective ratings of valence (i.e., pleasure/displeasure) and of arousal evoked by various fear, happiness, and sadness experiences correlated with neural activity in specific brain regions (orbitofrontal cortex and amygdala, respectively). We observed these correlations across diverse instances within each emotion category, as well as across instances from all three categories. Consistent with a psychological construction approach to emotion, the results suggest that neural circuitry realizes more basic processes across discrete emotions. The implicated brain regions regulate the body to deal with the world, producing the affective changes at the core of emotions and many other psychological phenomena.

  19. Geological activity of humans represented in the world heritage sites of India, Italy, and Russia: Evidence of the anthropocene

    Directory of Open Access Journals (Sweden)

    Ansari M K.

    2016-01-01

    Full Text Available The idea of the Anthropocene attracts attention of scientists, policy-makers, and broad public to the geological activity of humans and poses new important questions for the modern stratigraphy. The growth of the Anthropocene-related knowledge and its promotion can be based potentially on the UNESCO World Heritage Sites (WHS. On the one hand, many of these sites provide spectacular evidence of the human activity. On the other hand, these are remarkable tourist attractions. The WHSs of three heritage-rich countries, namely India, Italy, and Russia, have been assessed with regard to how these reflect the geological activity of humans. It is established that 65-90% of all WHSs in each country provide direct and indirect evidence of such an activity (artificial caves, terrace building, etc., which appears to be enough for the general discussion of the idea of the Anthropocene. However, the distribution of the WHSs by their age allows focusing only on the “early” (before 1800 AD start of the Anthropocene, which is not enough for full discussion of the lower limit of this unit. The examples considered in the present study imply that some WHSs alone provide very important pieces of the Anthropocene-related knowledge.

  20. Intracerebral evidence of rhythm transform in the human auditory cortex.

    Science.gov (United States)

    Nozaradan, Sylvie; Mouraux, André; Jonas, Jacques; Colnat-Coulbois, Sophie; Rossion, Bruno; Maillard, Louis

    2017-07-01

    Musical entrainment is shared by all human cultures and the perception of a periodic beat is a cornerstone of this entrainment behavior. Here, we investigated whether beat perception might have its roots in the earliest stages of auditory cortical processing. Local field potentials were recorded from 8 patients implanted with depth-electrodes in Heschl's gyrus and the planum temporale (55 recording sites in total), usually considered as human primary and secondary auditory cortices. Using a frequency-tagging approach, we show that both low-frequency (30 Hz) neural activities in these structures faithfully track auditory rhythms through frequency-locking to the rhythm envelope. A selective gain in amplitude of the response frequency-locked to the beat frequency was observed for the low-frequency activities but not for the high-frequency activities, and was sharper in the planum temporale, especially for the more challenging syncopated rhythm. Hence, this gain process is not systematic in all activities produced in these areas and depends on the complexity of the rhythmic input. Moreover, this gain was disrupted when the rhythm was presented at fast speed, revealing low-pass response properties which could account for the propensity to perceive a beat only within the musical tempo range. Together, these observations show that, even though part of these neural transforms of rhythms could already take place in subcortical auditory processes, the earliest auditory cortical processes shape the neural representation of rhythmic inputs in favor of the emergence of a periodic beat.

  1. Drug interactions at the human placenta: what is the evidence?

    Directory of Open Access Journals (Sweden)

    Miriam eRubinchik-Stern

    2012-07-01

    Full Text Available Pregnant women (and their fetuses are treated with a significant number of prescription and nonprescription medications. Interactions among those drugs may affect their efficacy and toxicity in both mother and fetus. Whereas interactions that result in altered drug concentrations in maternal plasma are detectable, those involving modulation of placental transfer mechanisms are rarely reflected by altered drug concentrations in maternal plasma. Therefore, they are often overlooked. Placental-mediated interactions are possible because the placenta is not only a passive diffusional barrier, but also expresses a variety of influx and efflux transporters and drug metabolizing enzymes. Current data on placental-mediated drug interactions are limited. In rodents, pharmacological or genetic manipulations of placental transporters significantly affect fetal drug exposure. In contrast, studies in human placentae suggest that the magnitude of such interactions is modest in most cases. Nevertheless, under certain circumstances, such interactions may be of clinical significance. This review describes currently known mechanisms of placental-mediated drug interactions and the potential implications of such interactions in humans. Better understanding of those mechanisms is important for minimizing fetal toxicity from drugs while improving their efficacy when directed to treat the fetus.

  2. Population level evidence for seasonality of the human microbiome.

    Science.gov (United States)

    Korownyk, Christina; Liu, Fangwei; Garrison, Scott

    2018-04-01

    The objective of this study is to determine whether human body odors undergo seasonal modulation. We utilized google trends search volume from the United States of America from January 1, 2010 to June 24, 2017 for a number of predetermined body odors. Regression modeling of time series data was completed. Our primary outcome was to determine the proportion of the variability in Internet searches for each unpleasant odor (about the mean) that is explained by a seasonal model. We determined that the seasonal (sinusoidal) model provided a significantly better fit than the null model (best straight line fit) for all searches relating to human body odors (P odor, 60% of the variability in search volume for foot odor, and 58% of the variability in search volume for bad breath. Flatulence and bad breath tended to peak in January, foot odor in February, and Axillary odor in July. We conclude that searching by the general public for information on unpleasant body odors undergoes substantial seasonal variation, with the timing of peaks and troughs varying with the body part involved. The symptom burden of such smells may have a similar seasonal variation, as might the composition of the commensal bacterial microflora that play a role in creating them.

  3. Radioimmunological evidence for beta-endorphin in human cerebrospinal fluid

    International Nuclear Information System (INIS)

    Graf, M.

    1982-01-01

    Both-endomorphin-like immunoreactivity in human cerebrospinal fluid was determined by two different radioimmunoassays. Measurements made using a bought RIA-kit (Immuno Nuclear Corporation) produced results which were too high compared to results from the literature. The procedure for the beta-endophin radioimmunoassay of Hoellt et al. was followed, the various steps studied and in part modified. Here both beta endorphin and beta-lipotropin were labelled with I-125 and a new method introduced for separating I - -125 following labelling. Studies on the specificity of the method revealed that, in addition to beta-endorphin, beta-lipotropin and two further non-identified fluid fractions were also determined but that the specificity of the RIA's could be significantly increased by prior extraction of the fluid with silicic acid. Determinations of beta-endorphin-like immunoreactivity in 28 different human fluids using this RIA gave values from below 20 pg/ml to 70 pg/ml thus confirming literature values. (orig.) [de

  4. Evidence of an association between 10/10 genotype of DAT1 and endophenotypes of attention deficit/hyperactivity disorder.

    Science.gov (United States)

    Agudelo, J A; Gálvez, J M; Fonseca, D J; Mateus, H E; Talero-Gutiérrez, C; Velez-Van-Meerbeke, A

    2015-04-01

    Genetic variance of attention deficit-hyperactivity disorder (ADHD) is a strong determinant of this disorder. The 40 base pairs (bp) variable number tandem repeat (VNTR) located in the 3' untranslated region (UTR) of DAT1 gene increases the expression of the dopamine transporter. Therefore, DAT1 has been associated with susceptibility to ADHD. To determine the association between the VNTR of DAT1 and the phenotype of ADHD or its endophenotypes in a sample of children aged between 6 and 15 years from Bogotá. We selected 73 patients with ADHD and 54 controls. WISC test was applied in all subjects and executive functions were assessed. The VNTR of DAT1 was polymerase chain reaction-amplified. Data regarding population genetics and statistical analysis were obtained. Correlation and association tests between genotype and neuropsychological testing were performed. The DAT1 polymorphism was not associated with ADHD (P=.85). Nevertheless, the 10/10 genotype was found to be correlated with the processing speed index (P<.05). In the hyperactivity subtype, there was a genotypic correlation with some subtests of executive function (cognitive flexibility) (P≤.01). In the combined subtype, the 10/10 genotype was associated with verbal comprehension index of WISC (P<.05). A correlation was found between DAT1 VNTR and the subtest "processing speed index" of WISC and the subtest "cognitive flexibility" of executive functions. To our knowledge, this is the first report to assess DAT1 gene in a Colombian population. Copyright © 2013 Sociedad Española de Neurología. Published by Elsevier Espana. All rights reserved.

  5. Towards an integrative model of visual short-term memory maintenance: Evidence from the effects of attentional control, load, decay, and their interactions in childhood.

    Science.gov (United States)

    Shimi, Andria; Scerif, Gaia

    2017-12-01

    Over the past decades there has been a surge of research aiming to shed light on the nature of capacity limits to visual short-term memory (VSTM). However, an integrative account of this evidence is currently missing. We argue that investigating parameters constraining VSTM in childhood suggests a novel integrative model of VSTM maintenance, and that this in turn informs mechanisms of VSTM maintenance in adulthood. Over 3 experiments with 7-year-olds and young adults (total N=206), we provide evidence for multiple cognitive processes interacting to constrain VSTM performance. While age-related increases in storage capacity are undisputable, we replicate the finding that attentional processes control what information will be encoded and maintained in VSTM in the face of increased competition. Therefore, a central process to the current model is attentional refreshment, a mechanism that it is thought to reactivate and strengthen the signal of the visual representations. Critically, here we also show that attentional influences on VSTM are further constrained by additional factors, traditionally studied to the exclusion of each other, such as memory load and temporal decay. We propose that these processes work synergistically in an elegant manner to capture the adult-end state, whereas their less refined efficiency and modulations in childhood account for the smaller VSTM capacity that 7-year-olds demonstrate compared to older individuals. We conclude that going beyond the investigation of single cognitive mechanisms, to their interactions, holds the promise to understand both developing and fully developed maintenance in VSTM. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. How awareness changes the relative weights of evidence during human decision-making

    NARCIS (Netherlands)

    de Lange, F.P.; van Gaal, S.; Lamme, V.A.F.; Dehaene, S.

    2011-01-01

    Human decisions are based on accumulating evidence over time for different options. Here we ask a simple question: How is the accumulation of evidence affected by the level of awareness of the information? We examined the influence of awareness on decision-making using combined behavioral methods

  7. Evidence for Functional Networks within the Human Brain's White Matter.

    Science.gov (United States)

    Peer, Michael; Nitzan, Mor; Bick, Atira S; Levin, Netta; Arzy, Shahar

    2017-07-05

    Investigation of the functional macro-scale organization of the human cortex is fundamental in modern neuroscience. Although numerous studies have identified networks of interacting functional modules in the gray-matter, limited research was directed to the functional organization of the white-matter. Recent studies have demonstrated that the white-matter exhibits blood oxygen level-dependent signal fluctuations similar to those of the gray-matter. Here we used these signal fluctuations to investigate whether the white-matter is organized as functional networks by applying a clustering analysis on resting-state functional MRI (RSfMRI) data from white-matter voxels, in 176 subjects (of both sexes). This analysis indicated the existence of 12 symmetrical white-matter functional networks, corresponding to combinations of white-matter tracts identified by diffusion tensor imaging. Six of the networks included interhemispheric commissural bridges traversing the corpus callosum. Signals in white-matter networks correlated with signals from functional gray-matter networks, providing missing knowledge on how these distributed networks communicate across large distances. These findings were replicated in an independent subject group and were corroborated by seed-based analysis in small groups and individual subjects. The identified white-matter functional atlases and analysis codes are available at http://mind.huji.ac.il/white-matter.aspx Our results demonstrate that the white-matter manifests an intrinsic functional organization as interacting networks of functional modules, similarly to the gray-matter, which can be investigated using RSfMRI. The discovery of functional networks within the white-matter may open new avenues of research in cognitive neuroscience and clinical neuropsychiatry. SIGNIFICANCE STATEMENT In recent years, functional MRI (fMRI) has revolutionized all fields of neuroscience, enabling identifications of functional modules and networks in the human

  8. How to support action prediction: Evidence from human coordination tasks

    DEFF Research Database (Denmark)

    Vesper, Cordula

    2014-01-01

    When two or more people perform actions together such as shaking hands, playing ensemble music or carrying an object together, they often naturally adjust the spatial and temporal parameters of their movements to facilitate smooth task performance. This paper reviews recent findings from experime......When two or more people perform actions together such as shaking hands, playing ensemble music or carrying an object together, they often naturally adjust the spatial and temporal parameters of their movements to facilitate smooth task performance. This paper reviews recent findings from......”) might be a useful approach also for robotic systems to assist human users, thereby reducing cognitive load and flexibly supporting the acquisition of new skills....

  9. Short report: serologic evidence of human ehrlichiosis in Peru.

    Science.gov (United States)

    Moro, Pedro L; Shah, Jyotsna; Li, Olga; Gilman, Robert H; Harris, Nick; Moro, Manuel H

    2009-02-01

    A serosurvey for human ehrlichiosis caused by Ehrlichia chaffeensis and Anaplasma phagocytophilum was performed in different regions of Peru by using indirect immunofluorescence assays (IFAs). Regions included an urban community in a shantytown in Lima (Pampas) and three rural communities located on the northern coast of Peru (Cura Mori), in the southern Peruvian Andes (Cochapata), and in the Peruvian jungle region (Santo Tomas). An overall E. chaffeensis seroprevalence of 13% (21 of 160) was found by IFA. Seroprevalences in females and males was 15% (16 of 106) and 9% (5 of 53), respectively. Seroprevalences in Cura Mori, Cochapata, Pampas, and Santo Tomas were 25% (10 of 40), 23% (9 of 40), 3% (1 of 40), and 3% (1 of 40), respectively. Seroprevalences in Cura Mori and Cochapata were significantly higher than in Santo Tomas or Pampas (P Peru. Further studies are needed to characterize Ehrlichia species in Peru, their vectors and their clinical significance.

  10. Evident?

    DEFF Research Database (Denmark)

    Plant, Peter

    2012-01-01

    Quality assurance and evidence in career guidance in Europe are often seen as self-evident approaches, but particular interests lie behind......Quality assurance and evidence in career guidance in Europe are often seen as self-evident approaches, but particular interests lie behind...

  11. Evidence of Altered Brain Responses to Nicotine in an Animal Model of Attention Deficit/Hyperactivity Disorder.

    Science.gov (United States)

    Poirier, Guillaume L; Huang, Wei; Tam, Kelly; DiFranza, Joseph R; King, Jean A

    2017-09-01

    Individuals with attention deficit/hyperactivity disorder (ADHD) are susceptible to earlier and more severe nicotine addiction. To shed light on the relationship between nicotine and ADHD, we examined nicotine's effects on functional brain networks in an animal model of ADHD. Awake magnetic resonance imaging was used to compare functional connectivity in adolescent (post-natal day 44 ± 2) males of the spontaneously hypertensive rat (SHR) strain and two control strains, Wistar-Kyoto and Sprague-Dawley (n = 16 each). We analyzed functional connectivity immediately before and after nicotine exposure (0.4 mg/kg base) in naïve animals, using a region-of-interest approach focussing on 16 regions previously implicated in reward and addiction. Relative to the control groups, the SHR strain demonstrated increased functional connectivity between the ventral tegmental area (VTA) and retrosplenial cortex in response to nicotine, suggesting an aberrant response to nicotine. In contrast, increased VTA-substantia nigra connectivity in response to a saline injection in the SHR was absent following a nicotine injection, suggesting that nicotine normalized function in this circuit. In the SHR, nicotine triggered an atypical response in one VTA circuit while normalizing activity in another. The VTA has been widely implicated in drug reward. Our data suggest that increased susceptibility to nicotine addiction in individuals with ADHD may involve altered responses to nicotine involving VTA circuits. Nicotine addiction is more common among individuals with ADHD. We found that two circuits involving the VTA responded differently to nicotine in animals that model ADHD in comparison to two control strains. In one circuit, nicotine normalized activity that was abnormal in the ADHD animals, while in the other circuit nicotine caused an atypical brain response in the ADHD animals. The VTA has been implicated in drug reward. Our results would be consistent with an interpretation that

  12. Evidence of a Flynn Effect in Children's Human Figure Drawings (1902-1968).

    Science.gov (United States)

    Genovese, Jeremy E C

    2018-05-25

    The Flynn effect is the long-term trend for scores on tests of cognitive ability to increase across cohorts. Several samples of children's human figure drawings, published in 1902, 1926, 1963, and 1968, are examined for evidence of a Flynn effect. Results show that larger percentages of children draw more complete human figures over the course of the 20th century.

  13. Drugs associated with teratogenic mechanisms. Part II : a literature review of the evidence on human risks

    NARCIS (Netherlands)

    van Gelder, Marleen M. H. J.; de Jong-van den Berg, Lolkje T. W.; Roeleveld, Nel

    What is the current state of knowledge on the human risks of drugs suspected to be associated with teratogenic mechanisms? Evidence for the presence or absence of human risks of birth defects is scarce or non-existent for the majority of drugs associated with teratogenic mechanisms. Medical drugs

  14. Drugs associated with teratogenic mechanisms. Part II: a literature review of the evidence on human risks

    NARCIS (Netherlands)

    Gelder, M.M.H.J. van; Jong-van den Berg, L.T. de; Roeleveld, N.

    2014-01-01

    STUDY QUESTION: What is the current state of knowledge on the human risks of drugs suspected to be associated with teratogenic mechanisms? SUMMARY ANSWER: Evidence for the presence or absence of human risks of birth defects is scarce or non-existent for the majority of drugs associated with

  15. Lateralized delay period activity marks the focus of spatial attention in working memory: evidence from somatosensory event-related brain potentials.

    Science.gov (United States)

    Katus, Tobias; Eimer, Martin

    2015-04-29

    The short-term retention of sensory information in working memory (WM) is known to be associated with a sustained enhancement of neural activity. What remains controversial is whether this neural trace indicates the sustained storage of information or the allocation of attention. To evaluate the storage and attention accounts, we examined sustained tactile contralateral delay activity (tCDA component) of the event-related potential. The tCDA manifests over somatosensory cortex contralateral to task-relevant tactile information during stimulus retention. Two tactile sample sets (S1, S2) were presented sequentially, separated by 1.5 s. Each set comprised two stimuli, one per hand. Human participants memorized the location of one task-relevant stimulus per sample set and judged whether one of these locations was stimulated again at memory test. The two relevant pulses were unpredictably located on the same hand (stay trials) or on different hands (shift trials). Initially, tCDA components emerged contralateral to the relevant S1 pulse. Sequential loading of WM enhanced the tCDA after S2 was presented on stay trials. On shift trials, the tCDA's polarity reversed after S2 presentation, resulting in delay activity that was now contralateral to the task-relevant S2 pulse. The disappearance of a lateralized neural trace for the relevant S1 pulse did not impair memory accuracy for this stimulus on shift trials. These results contradict the storage account and suggest that delay period activity indicates the sustained engagement of an attention-based rehearsal mechanism. In conclusion, somatosensory delay period activity marks the current focus of attention in tactile WM. Copyright © 2015 the authors 0270-6474/15/356689-07$15.00/0.

  16. Evidence for developmental programming of cerebral laterality in humans.

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    Alexander Jones

    2011-02-01

    Full Text Available Adverse fetal environments are associated with depression, reduced cognitive ability and increased stress responsiveness in later life, but underlying mechanisms are unknown. Environmental pressures on the fetus, resulting from variations in placental function and maternal nutrition, health and stress might alter neurodevelopment, promoting the development of some brain regions over others. As asymmetry of cerebral activity, with greater right hemisphere activity, has been associated with psychopathology, we hypothesized that regional specialization during fetal life might be reflected persistently in the relative activity of the cerebral hemispheres. We tested this hypothesis in 140 healthy 8-9 year-old children, using tympanic membrane temperature to assess relative blood flow to the cerebral hemispheres at rest and following psychosocial stress (Trier Social Stress Test for Children. Their birth weight and placental weight had already been measured when their mothers took part in a previous study of pregnancy outcomes. We found that children who had a smaller weight at birth had evidence of greater blood flow to the right hemisphere than to the left hemisphere (r = -.09, P = .29 at rest; r = -.18, P = .04 following stress. This finding was strengthened if the children had a relatively low birth weight for their placental weight (r = -.17, P = .05 at rest; r = -.31, P = .0005 following stress. Our findings suggest that lateralization of cerebral activity is influenced persistently by early developmental experiences, with possible consequences for long-term neurocognitive function.

  17. Converging Evidence of Ubiquitous Male Bias in Human Sex Perception.

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    Justin Gaetano

    Full Text Available Visually judging the sex of another can be achieved easily in most social encounters. When the signals that inform such judgements are weak (e.g. outdoors at night, observers tend to expect the presence of males-an expectation that may facilitate survival-critical decisions under uncertainty. The present aim was to examine whether this male bias depends on expertise. To that end, Caucasian and Asian observers targeted female and male hand images that were either the same or different to the observers' race (i.e. long term experience was varied while concurrently, the proportion of targets changed across presentation blocks (i.e. short term experience change. It was thus found that: (i observers of own-race stimuli were more likely to report the presence of males and absence of females, however (ii observers of other-race stimuli--while still tending to accept stimuli as male--were not prone to rejecting female cues. Finally, (iii male-biased measures did not track the relative frequency of targets or lures, disputing the notion that male bias derives from prior expectation about the number of male exemplars in a set. Findings are discussed in concert with the pan-stimulus model of human sex perception.

  18. Dynamics of Media Attention

    NARCIS (Netherlands)

    Traag, V.A.; Reinanda, R.; Hicks, J.; van Klinken, G.; Aziz-Alaoui, M.A.; Bertelle, C.; Liu, X.; Olivier, D.

    2014-01-01

    Studies of human attention dynamics analyses how attention is focused on specific topics, issues or people. In online social media, there are clear signs of exogenous shocks, bursty dynamics, and an exponential or powerlaw lifetime distribution. We here analyse the attention dynamics of traditional

  19. Evidence that human papillomavirus causes inverted papilloma is sparse.

    Science.gov (United States)

    Justice, Jeb M; Davis, Kern M; Saenz, Daniel A; Lanza, Donald C

    2014-12-01

    Controversy exists regarding the pathogenesis of inverted papilloma as it relates to the involvement of human papillomavirus (HPV). The purpose of this report is to describe the prevalence of HPV in nondysplastic, "early inverted papilloma" and to summarize HPV detection rates in the general population and in other HPV related neoplasia. This case series report characterizes consecutive inverted papilloma patients from January 2005 to August 2012 with regard to smoking history, dysplasia, and HPV detection rates. Presence or absence of low/high risk HPV was determined by standardized in situ hybridization DNA probes. Medline literature review was performed to determine the prevalence of HPV in inverted papilloma without moderate or severe dysplasia. Thirty-six consecutive patients were identified with an average age of 63.6 (range, 40-84) years; gender: 23 men, 13 women. More than half (55%) were active or former smokers (14% active and 41% former). High/low risk HPV was present in 1 in 36 (2.7%) patients and 1 in 36 (2.7%) had mild dysplasia. In the literature review: (1) HPV was detected in 16.4% of inverted papilloma without dysplasia; (2) oral cavity HPV detection was 4.2% to 11.4% in the normal population; and (3) HPV was normally detected in 85% to 95% of HPV-related neoplasia. Given histological features of inverted papilloma and comparatively low detection rates of HPV in inverted papilloma without dysplasia (2.7%), as well as the summary of the world literature, HPV is not related to the initial pathogenesis of inverted papilloma or inverted papilloma's tendency to persist or recur. It is postulated that since inverted papilloma is more an inflammatory polyp, it is susceptible to secondary HPV infection because of its metaplasia. Tobacco and other causes of respiratory epithelium remodeling are more plausible explanations for the initial tissue transformation to inverted papilloma. © 2014 ARS-AAOA, LLC.

  20. On the evidence for human use and control of fire at Schöningen.

    Science.gov (United States)

    Stahlschmidt, Mareike C; Miller, Christopher E; Ligouis, Bertrand; Hambach, Ulrich; Goldberg, Paul; Berna, Francesco; Richter, Daniel; Urban, Brigitte; Serangeli, Jordi; Conard, Nicholas J

    2015-12-01

    When and how humans began to control fire has been a central debate in Paleolithic archaeology for decades. Fire plays an important role in technology, social organization, subsistence, and manipulation of the environment and is widely seen as a necessary adaptation for the colonization of northern latitudes. Many researchers view purported hearths, burnt wooden implements, and heated flints from Schöningen as providing the best evidence for the control of fire in the Lower Paleolithic of Northern Europe. Here we present results of a multianalytical study of the purported hearths along with a critical examination of other possible evidence of human use or control of fire at Schöningen. We conclude that the analyzed features and artifacts present no convincing evidence for human use or control of fire. Our study also shows that a multianalytical, micro-contextual approach is the best methodology for evaluating claims of early evidence of human-controlled fire. We advise caution with macroscopic, qualitative identification of combustion features, burnt flint, and burnt wood without the application of such techniques as micromorphology, Fourier transform infrared (FTIR) spectroscopy, organic petrology, luminescence, and analysis of mineral magnetic parameters. The lack of evidence for the human control of fire at Schöningen raises the possibility that fire control was not a necessary adaptation for the human settlement of northern latitudes in the Lower Paleolithic. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. Deficits in implicit attention to social signals in schizophrenia and high risk groups: behavioural evidence from a new illusion.

    Directory of Open Access Journals (Sweden)

    Mascha van 't Wout

    Full Text Available BACKGROUND: An increasing body of evidence suggests that the apparent social impairments observed in schizophrenia may arise from deficits in social cognitive processing capacities. The ability to process basic social cues, such as gaze direction and biological motion, effortlessly and implicitly is thought to be a prerequisite for establishing successful social interactions and for construing a sense of "social intuition." However, studies that address the ability to effortlessly process basic social cues in schizophrenia are lacking. Because social cognitive processing deficits may be part of the genetic vulnerability for schizophrenia, we also investigated two groups that have been shown to be at increased risk of developing schizophrenia-spectrum pathology: first-degree relatives of schizophrenia patients and men with Klinefelter syndrome (47,XXY. RESULTS: We compared 28 patients with schizophrenia, 29 siblings of patients with schizophrenia, and 29 individuals with Klinefelter syndrome with 46 matched healthy control subjects on a new paradigm. This paradigm measures one's susceptibility for a bias in distance estimation between two agents that is induced by the implicit processing of gaze direction and biological motion conveyed by these agents. Compared to control subjects, patients with schizophrenia, as well as siblings of patients and Klinefelter men, showed a lack of influence of social cues on their distance judgments. CONCLUSIONS: We suggest that the insensitivity for social cues is a cognitive aspect of schizophrenia that may be seen as an endophenotype as it appears to be present both in relatives who are at increased genetic risk and in a genetic disorder at risk for schizophrenia-spectrum psychopathology. These social cue-processing deficits could contribute, in part, to the difficulties in higher order social cognitive tasks and, hence, to decreased social competence that has been observed in these groups.

  2. Deficits in implicit attention to social signals in schizophrenia and high risk groups: behavioural evidence from a new illusion.

    Science.gov (United States)

    van 't Wout, Mascha; van Rijn, Sophie; Jellema, Tjeerd; Kahn, René S; Aleman, André

    2009-01-01

    An increasing body of evidence suggests that the apparent social impairments observed in schizophrenia may arise from deficits in social cognitive processing capacities. The ability to process basic social cues, such as gaze direction and biological motion, effortlessly and implicitly is thought to be a prerequisite for establishing successful social interactions and for construing a sense of "social intuition." However, studies that address the ability to effortlessly process basic social cues in schizophrenia are lacking. Because social cognitive processing deficits may be part of the genetic vulnerability for schizophrenia, we also investigated two groups that have been shown to be at increased risk of developing schizophrenia-spectrum pathology: first-degree relatives of schizophrenia patients and men with Klinefelter syndrome (47,XXY). We compared 28 patients with schizophrenia, 29 siblings of patients with schizophrenia, and 29 individuals with Klinefelter syndrome with 46 matched healthy control subjects on a new paradigm. This paradigm measures one's susceptibility for a bias in distance estimation between two agents that is induced by the implicit processing of gaze direction and biological motion conveyed by these agents. Compared to control subjects, patients with schizophrenia, as well as siblings of patients and Klinefelter men, showed a lack of influence of social cues on their distance judgments. We suggest that the insensitivity for social cues is a cognitive aspect of schizophrenia that may be seen as an endophenotype as it appears to be present both in relatives who are at increased genetic risk and in a genetic disorder at risk for schizophrenia-spectrum psychopathology. These social cue-processing deficits could contribute, in part, to the difficulties in higher order social cognitive tasks and, hence, to decreased social competence that has been observed in these groups.

  3. Human versus Non-Human Face Processing: Evidence from Williams Syndrome

    Science.gov (United States)

    Santos, Andreia; Rosset, Delphine; Deruelle, Christine

    2009-01-01

    Increased motivation towards social stimuli in Williams syndrome (WS) led us to hypothesize that a face's human status would have greater impact than face's orientation on WS' face processing abilities. Twenty-nine individuals with WS were asked to categorize facial emotion expressions in real, human cartoon and non-human cartoon faces presented…

  4. The Relationship between Humanness and Knowledge Sharing in Malaysia Empirical Evidence from Malaysian Managers

    Directory of Open Access Journals (Sweden)

    Ilona H. Boom

    2012-05-01

    Full Text Available This paper explores whether there is a relationship between humanness and the willingness to share knowledge in Malaysia. Furthermore, the differences between the Malay, Chinese and Indian ethnicities are researched for the presence of humanness and the willingness to share knowledge. Two hundred and fourteen respondents from privately owned companies participated in this research showing that there is a strong relationship between humanness and knowledge sharing. However, the differences between the three ethnicities are small, which is a surprising finding. It can be concluded that people-oriented managers (one of the ways to express humanness are more willing to share knowledge, and differences between ethnicities have no influence in this matter. From these results, it can be recommended to managers and organizations in Malaysia that they pay more attention and be aware of their management style.Stressing the humanness aspects more as they are described could improve the knowledge transfer within companies.

  5. What is the evidence of impaired motor skills and motor control among children with attention deficit hyperactivity disorder (ADHD)? Systematic review of the literature.

    Science.gov (United States)

    Kaiser, M-L; Schoemaker, M M; Albaret, J-M; Geuze, R H

    2014-11-06

    This article presents a review of the studies that have analysed the motor skills of ADHD children without medication and the influence of medication on their motor skills. The following two questions guided the study: What is the evidence of impairment of motor skills and aspects of motor control among children with ADHD aged between 6 and 16 years? What are the effects of ADHD medication on motor skills and motor control? The following keywords were introduced in the main databases: attention disorder and/or ADHD, motor skills and/or handwriting, children, medication. Of the 45 articles retrieved, 30 described motor skills of children with ADHD and 15 articles analysed the influence of ADHD medication on motor skills and motor control. More than half of the children with ADHD have difficulties with gross and fine motor skills. The children with ADHD inattentive subtype seem to present more impairment of fine motor skills, slow reaction time, and online motor control during complex tasks. The proportion of children with ADHD who improved their motor skills to the normal range by using medication varied from 28% to 67% between studies. The children who still show motor deficit while on medication might meet the diagnostic criteria of developmental coordination disorder (DCD). It is important to assess motor skills among children with ADHD because of the risk of reduced participation in activities of daily living that require motor coordination and attention. Copyright © 2014 Elsevier Ltd. All rights reserved.

  6. Review of NASA's Evidence Reports on Human Health Risks. 2015 Letter Report

    Science.gov (United States)

    Scott-Conner, Carol E. H.; Masys, Daniel R.; Liverman, Catharyn T.

    2016-01-01

    NASA has requested a study from the Institute of Medicine (IOM) to provide an independent review of more than 30 evidence reports on human health risks for long duration and exploration spaceflight. The evidence reports, which are publicly available, are categorized into five broad categories: (1) behavioral health and performance; (2) human health countermeasures (with a focus on bone metabolism and orthopedics, nutrition, immunology, and cardiac and pulmonary physiology); (3) radiation; (4) human factors issues; and (5) exploration medical capabilities. The reports are revised on an ongoing basis to incorporate new scientific information. In conducting this study, an IOM ad hoc committee will build on the 2008 IOM report Review of NASA's Human Research Program Evidence Books. That report provided an assessment of the process used for developing the evidence reports and provided an initial review of the evidence reports that had been completed at that time. Each year, NASA staff will identify a set of evidence reports for committee review. Over the course of the study all evidence reports will be reviewed. The committee will hold an annual scientific workshop to receive input on the evidence reports it is reviewing that year and an update on the recent literature. The committee will issue an annual letter report that addresses the following questions relevant to each evidence report: 1. Does the evidence report provide sufficient evidence, as well as sufficient risk context, that the risk is of concern for long-term space missions? 2. Does the evidence report make the case for the research gaps presented? 3. Are there any additional gaps in knowledge or areas of fundamental research that should be considered to enhance the basic understanding of this specific risk? 4. Does the evidence report address relevant interactions among risks? 5. Is input from additional disciplines needed? 6. Is the breadth of the cited literature sufficient? 7. What is the overall

  7. The Sero-epidemiology of Coxiella burnetii in Humans and Cattle, Western Kenya: Evidence from a Cross-Sectional Study.

    Directory of Open Access Journals (Sweden)

    Nicola A Wardrop

    2016-10-01

    Full Text Available Evidence suggests that the intracellular bacterial pathogen Coxiella burnetii (which causes Q fever is widespread, with a near global distribution. While there has been increasing attention to Q fever epidemiology in high-income settings, a recent systematic review highlighted significant gaps in our understanding of the prevalence, spatial distribution and risk factors for Q fever infection across Africa. This research aimed to provide a One Health assessment of Q fever epidemiology in parts of Western and Nyanza Provinces, Western Kenya, in cattle and humans. A cross-sectional survey was conducted: serum samples from 2049 humans and 955 cattle in 416 homesteads were analysed for C. burnetii antibodies. Questionnaires covering demographic, socio-economic and husbandry information were also administered. These data were linked to environmental datasets based on geographical locations (e.g., land cover. Correlation and spatial-cross correlation analyses were applied to assess the potential link between cattle and human seroprevalence. Multilevel regression analysis was used to assess the relationships between a range of socio-economic, demographic and environmental factors and sero-positivity in both humans and animals. The overall sero-prevalence of C. burnetii was 2.5% in humans and 10.5% in cattle, but we found no evidence of correlation between cattle and human seroprevalence either within households, or when incorporating spatial proximity to other households in the survey. Multilevel modelling indicated the importance of several factors for exposure to the organism. Cattle obtained from market (as opposed to those bred in their homestead and those residing in areas with lower precipitation levels had the highest sero-prevalence. For humans, the youngest age group had the highest odds of seropositivity, variations were observed between ethnic groups, and frequent livestock contact (specifically grazing and dealing with abortion material was

  8. The Sero-epidemiology of Coxiella burnetii in Humans and Cattle, Western Kenya: Evidence from a Cross-Sectional Study.

    Science.gov (United States)

    Wardrop, Nicola A; Thomas, Lian F; Cook, Elizabeth A J; de Glanville, William A; Atkinson, Peter M; Wamae, Claire N; Fèvre, Eric M

    2016-10-01

    Evidence suggests that the intracellular bacterial pathogen Coxiella burnetii (which causes Q fever) is widespread, with a near global distribution. While there has been increasing attention to Q fever epidemiology in high-income settings, a recent systematic review highlighted significant gaps in our understanding of the prevalence, spatial distribution and risk factors for Q fever infection across Africa. This research aimed to provide a One Health assessment of Q fever epidemiology in parts of Western and Nyanza Provinces, Western Kenya, in cattle and humans. A cross-sectional survey was conducted: serum samples from 2049 humans and 955 cattle in 416 homesteads were analysed for C. burnetii antibodies. Questionnaires covering demographic, socio-economic and husbandry information were also administered. These data were linked to environmental datasets based on geographical locations (e.g., land cover). Correlation and spatial-cross correlation analyses were applied to assess the potential link between cattle and human seroprevalence. Multilevel regression analysis was used to assess the relationships between a range of socio-economic, demographic and environmental factors and sero-positivity in both humans and animals. The overall sero-prevalence of C. burnetii was 2.5% in humans and 10.5% in cattle, but we found no evidence of correlation between cattle and human seroprevalence either within households, or when incorporating spatial proximity to other households in the survey. Multilevel modelling indicated the importance of several factors for exposure to the organism. Cattle obtained from market (as opposed to those bred in their homestead) and those residing in areas with lower precipitation levels had the highest sero-prevalence. For humans, the youngest age group had the highest odds of seropositivity, variations were observed between ethnic groups, and frequent livestock contact (specifically grazing and dealing with abortion material) was also a risk

  9. Phylogenetic evidence that two distinct Trichuris genotypes infect both humans and non-human primates.

    Directory of Open Access Journals (Sweden)

    Damiana F Ravasi

    Full Text Available Although there has been extensive debate about whether Trichuris suis and Trichuris trichiura are separate species, only one species of the whipworm T. trichiura has been considered to infect humans and non-human primates. In order to investigate potential cross infection of Trichuris sp. between baboons and humans in the Cape Peninsula, South Africa, we sequenced the ITS1-5.8S-ITS2 region of adult Trichuris sp. worms isolated from five baboons from three different troops, namely the Cape Peninsula troop, Groot Olifantsbos troop and Da Gama Park troop. This region was also sequenced from T. trichiura isolated from a human patient from central Africa (Cameroon for comparison. By combining this dataset with Genbank records for Trichuris isolated from other humans, non-human primates and pigs from several different countries in Europe, Asia, and Africa, we confirmed the identification of two distinct Trichuris genotypes that infect primates. Trichuris sp. isolated from the Peninsula baboons fell into two distinct clades that were found to also infect human patients from Cameroon, Uganda and Jamaica (named the CP-GOB clade and China, Thailand, the Czech Republic, and Uganda (named the DG clade, respectively. The divergence of these Trichuris clades is ancient and precedes the diversification of T. suis which clustered closely to the CP-GOB clade. The identification of two distinct Trichuris genotypes infecting both humans and non-human primates is important for the ongoing treatment of Trichuris which is estimated to infect 600 million people worldwide. Currently baboons in the Cape Peninsula, which visit urban areas, provide a constant risk of infection to local communities. A reduction in spatial overlap between humans and baboons is thus an important measure to reduce both cross-transmission and zoonoses of helminthes in Southern Africa.

  10. The Navigation Guide—Evidence-Based Medicine Meets Environmental Health: Integration of Animal and Human Evidence for PFOA Effects on Fetal Growth

    Science.gov (United States)

    Koustas, Erica; Sutton, Patrice; Johnson, Paula I.; Atchley, Dylan S.; Sen, Saunak; Robinson, Karen A.; Axelrad, Daniel A.; Woodruff, Tracey J.

    2014-01-01

    Background: The Navigation Guide is a novel systematic review method to synthesize scientific evidence and reach strength of evidence conclusions for environmental health decision making. Objective: Our aim was to integrate scientific findings from human and nonhuman studies to determine the overall strength of evidence for the question “Does developmental exposure to perfluorooctanoic acid (PFOA) affect fetal growth in humans?” Methods: We developed and applied prespecified criteria to systematically and transparently a) rate the quality of the scientific evidence as “high,” “moderate,” or “low”; b) rate the strength of the human and nonhuman evidence separately as “sufficient,” “limited,” “moderate,” or “evidence of lack of toxicity”; and c) integrate the strength of the human and nonhuman evidence ratings into a strength of the evidence conclusion. Results: We identified 18 epidemiology studies and 21 animal toxicology studies relevant to our study question. We rated both the human and nonhuman mammalian evidence as “moderate” quality and “sufficient” strength. Integration of these evidence ratings produced a final strength of evidence rating in which review authors concluded that PFOA is “known to be toxic” to human reproduction and development based on sufficient evidence of decreased fetal growth in both human and nonhuman mammalian species. Conclusion: We concluded that developmental exposure to PFOA adversely affects human health based on sufficient evidence of decreased fetal growth in both human and nonhuman mammalian species. The results of this case study demonstrate the application of a systematic and transparent methodology, via the Navigation Guide, for reaching strength of evidence conclusions in environmental health. Citation: Lam J, Koustas E, Sutton P, Johnson PI, Atchley DS, Sen S, Robinson KA, Axelrad DA, Woodru