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Sample records for general imitation mechanism

  1. Imitation in Newborn Infants: Exploring the Range of Gestures Imitated and the Underlying Mechanisms.

    Science.gov (United States)

    Meltzoff, Andrew N.; Moore, M. Keith

    1989-01-01

    Evaluated psychological mechanisms underlying imitation of facial actions in 40 newborn infants. Results showed imitation of head movement and a tongue-protrusion gesture. Subjects imitated from memory after displays had stopped. (RJC)

  2. The imitation game: Effects of social cues on 'imitation' are domain-general in nature.

    Science.gov (United States)

    Marsh, Lauren E; Bird, Geoffrey; Catmur, Caroline

    2016-10-01

    Imitation has been hailed as 'social glue', facilitating rapport with others. Previous studies suggest that social cues modulate imitation but the mechanism of such modulation remains underspecified. Here we examine the locus, specificity, and neural basis of the social control of imitation. Social cues (group membership and eye gaze) were manipulated during an imitation task in which imitative and spatial compatibility could be measured independently. Participants were faster to perform compatible compared to incompatible movements in both spatial and imitative domains. However, only spatial compatibility was modulated by social cues: an interaction between group membership and eye gaze revealed more spatial compatibility for ingroup members with direct gaze and outgroup members with averted gaze. The fMRI data were consistent with this finding. Regions associated with the control of imitative responding (temporoparietal junction, inferior frontal gyrus) were more active during imitatively incompatible compared to imitatively compatible trials. However, this activity was not modulated by social cues. On the contrary, an interaction between group, gaze and spatial compatibility was found in the dorsolateral prefrontal cortex in a pattern consistent with reaction times. This region may be exerting control over the motor system to modulate response inhibition. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  3. Teaching children generalized imitation skills: a case report.

    Science.gov (United States)

    Brown, Freddy Jackson; Peace, Natalie; Parsons, Rachel

    2009-03-01

    Generalized imitation plays an important role in the acquisition of new skills, in particular language and communication. In this case report a multiple exemplar training procedure, with an errorless learning phase, was used to teach Ben, a 13-year-old child with severe intellectual disabilities, to imitate behaviours modelled by an adult instructor. After exposure to seven multiple exemplars, Ben learned to imitate novel actions to criterion (i.e. generalized imitation). These skills were maintained at 90 percent at 6 week and 18 week follow-up. In line with earlier research, this article provides some further support for the finding that multiple exemplar training can facilitate the reliable emergence of generalized imitation skills. Topographically similar behaviours during the learning phase can be difficult to discriminate and hence can slow the learning process. Future research could explore how generalized imitation supports the development of basic communication and activity skills.

  4. Understanding and imitating unfamiliar actions: distinct underlying mechanisms.

    Directory of Open Access Journals (Sweden)

    Joana C Carmo

    Full Text Available The human "mirror neuron system" has been proposed to be the neural substrate that underlies understanding and, possibly, imitating actions. However, since the brain activity with mirror properties seems insufficient to provide a good description for imitation of actions outside one's own repertoire, the existence of supplementary processes has been proposed. Moreover, it is unclear whether action observation requires the same neural mechanisms as the explicit access to their meaning. The aim of this study was two-fold as we investigated whether action observation requires different processes depending on 1 whether the ultimate goal is to imitate or understand the presented actions and 2 whether the to-be-imitated actions are familiar or unfamiliar to the subject. Participants were presented with both meaningful familiar actions and meaningless unfamiliar actions that they had to either imitate or discriminate later. Event-related Potentials were used as differences in brain activity could have been masked by the use of other techniques with lower temporal resolution. In the imitation task, a sustained left frontal negativity was more pronounced for meaningless actions than for meaningful ones, starting from an early time-window. Conversely, observing unfamiliar versus familiar actions with the intention of discriminating them led to marked differences over right centro-posterior scalp regions, in both middle and latest time-windows. These findings suggest that action imitation and action understanding may be sustained by dissociable mechanisms: while imitation of unfamiliar actions activates left frontal processes, that are likely to be related to learning mechanisms, action understanding involves dedicated operations which probably require right posterior regions, consistent with their involvement in social interactions.

  5. Understanding the Mechanisms behind Deficits in Imitation: Do Individuals with Autism Know "What" to Imitate and Do They Know "How" to Imitate?

    Science.gov (United States)

    Vanvuchelen, Marleen; Van Schuerbeeck, Lise; Roeyers, Herbert; De Weerdt, Willy

    2013-01-01

    Although imitation problems have been associated with autism for many years, the underlying mechanisms of these problems remain subject to debate. In this article, the question whether imitation problems are caused by selection or correspondence problems is explored and discussed. This review revealed that hypotheses on the nature of imitation…

  6. Dossier Imitation - Introduction générale Special section on ImitationGeneral introduction

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    Odile Petit

    2009-10-01

    Full Text Available Dans ce dossier spécial, nous nous sommes intéressés à l’aspect ontogénique et phylogénique de l’imitation. Nous avons invité des spécialistes du développement de l’enfant et des primatologues à discuter de ce que l’imitation représente pour l’espèce humaine, de sa présence chez des espèces de primates non humains et des éventuelles similarités observées au sein de l’ordre des primates. L’imitation possède une double dimension, cognitive et sociale. En effet, les processus d’imitation impliquent des compétences cognitives qui s’inscrivent dans des contextes sociaux et culturels. Ce mode d’apprentissage soulève de nombreuses questions : Peut-on considérer l’imitation comme une compétence innée ? L’étude de son développement permet-elle de comprendre les mécanismes du fonctionnement cognitif ? L’imitation est-elle uniquement humaine ?This special issue is interested in the ontogeny and the phylogeny of imitation. We have invited experts in developmental psychology and in primatology to discuss the definition of imitation in Human, its existence in non human primate species and to address the question of similarities between the different primate species. Imitation has both a cognitive and a social dimension. Imitation involves, indeed, cognitive processes that are part of social and cultural life. Learning occurs via imitation and several questions can be asked: Is imitation innate? Will studying its ontogeny help understanding its cognitive processes? Finally, is imitation human specific?

  7. A Molecular Analysis of Training Multiple versus Single Manipulations to Establish a Generalized Manipulative Imitation Repertoire

    Science.gov (United States)

    Hartley, Breanne K.

    2009-01-01

    This study evaluates the necessity of training multiple versus single manipulative-imitations per object in order to establish generalized manipulative-imitation. Training took place in Croyden Avenue School's Early Childhood Developmental Delay preschool classroom in Kalamazoo, MI. Two groups of 3 children each were trained to imitate in order to…

  8. Heterogeneous update mechanisms in evolutionary games: Mixing innovative and imitative dynamics

    Science.gov (United States)

    Amaral, Marco Antonio; Javarone, Marco Alberto

    2018-04-01

    Innovation and evolution are two processes of paramount relevance for social and biological systems. In general, the former allows the introduction of elements of novelty, while the latter is responsible for the motion of a system in its phase space. Often, these processes are strongly related, since an innovation can trigger the evolution, and the latter can provide the optimal conditions for the emergence of innovations. Both processes can be studied by using the framework of evolutionary game theory, where evolution constitutes an intrinsic mechanism. At the same time, the concept of innovation requires an opportune mathematical representation. Notably, innovation can be modeled as a strategy, or it can constitute the underlying mechanism that allows agents to change strategy. Here, we analyze the second case, investigating the behavior of a heterogeneous population, composed of imitative and innovative agents. Imitative agents change strategy only by imitating that of their neighbors, whereas innovative ones change strategy without the need for a copying source. The proposed model is analyzed by means of analytical calculations and numerical simulations in different topologies. Remarkably, results indicate that the mixing of mechanisms can be detrimental to cooperation near phase transitions. In those regions, the spatial reciprocity from imitative mechanisms is destroyed by innovative agents, leading to the downfall of cooperation. Our investigation sheds some light on the complex dynamics emerging from the heterogeneity of strategy revision methods, highlighting the role of innovation in evolutionary games.

  9. The temporal relationship between reduction of early imitative responses and the development of attention mechanisms

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    Benga Oana

    2003-12-01

    Full Text Available Abstract Background To determine whether early imitative responses fade out following the maturation of attentional mechanisms, the relationship between primitive imitation behaviors and the development of attention was examined in 4-month-old infants. They were divided into high and low imitators, based on an index of imitation. The status of attention was assessed by studying inhibition of return (IOR. Nine-month-old infants were also tested to confirm the hypothesis. Results The IOR latency data replicate previous results that infants get faster to produce a covert shift of attention with increasing age. However, those 4-month-olds who showed less imitation had more rapid saccades to the cue before target presentation. Conclusion The cortical control of saccade planning appears to be related to an apparent drop in early imitation. We interpret the results as suggesting a relationship between the status of imitation and the neural development of attention-related eye movement.

  10. Imitation Learning Based on an Intrinsic Motivation Mechanism for Efficient Coding

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    Jochen eTriesch

    2013-11-01

    Full Text Available A hypothesis regarding the development of imitation learning is presented that is rooted in intrinsic motivations. It is derived from a recently proposed form of intrinsically motivated learning (IML for efficient coding in active perception, wherein an agent learns to perform actions with its sense organs to facilitate efficient encoding of the sensory data. To this end, actions of the sense organs that improve the encoding of the sensory data trigger an internally generated reinforcement signal. Here it is argued that the same IML mechanism might also support the development of imitation when general actions beyond those of the sense organs are considered: The learner first observes a tutor performing a behavior and learns a model of the the behavior's sensory consequences. The learner then acts itself and receives an internally generated reinforcement signal reflecting how well the sensory consequences of its own behavior are encoded by the sensory model. Actions that are more similar to those of the tutor will lead to sensory signals that are easier to encode and produce a higher reinforcement signal. Through this, the learner's behavior is progressively tuned to make the sensory consequences of its actions match the learned sensory model. I discuss this mechanism in the context of human language acquisition and bird song learning where similar ideas have been proposed. The suggested mechanism also offers an account for the development of mirror neurons and makes a number of predictions. Overall, it establishes a connection between principles of efficient coding, intrinsic motivations and imitation.

  11. Defining Elemental Imitation Mechanisms: A Comparison of Cognitive and Motor-Spatial Imitation Learning across Object- and Computer-Based Tasks

    Science.gov (United States)

    Subiaul, Francys; Zimmermann, Laura; Renner, Elizabeth; Schilder, Brian; Barr, Rachel

    2016-01-01

    During the first 5 years of life, the versatility, breadth, and fidelity with which children imitate change dramatically. Currently, there is no model to explain what underlies such significant changes. To that end, the present study examined whether task-independent but domain-specific--elemental--imitation mechanism explains performance across…

  12. Teaching Generalized Imitation Skills to a Preschooler with Autism Using Video Modeling

    Science.gov (United States)

    Kleeberger, Vickie; Mirenda, Pat

    2010-01-01

    This study examined the effectiveness of video modeling to teach a preschooler with autism to imitate previously mastered and not mastered actions during song and toy play activities. A general case approach was used to examine the instructional universe of preschool songs and select exemplars that were most likely to facilitate generalization.…

  13. Mass Shootings: The Role of the Media in Promoting Generalized Imitation.

    Science.gov (United States)

    Meindl, James N; Ivy, Jonathan W

    2017-03-01

    Mass shootings are a particular problem in the United States, with one mass shooting occurring approximately every 12.5 days. Recently a "contagion" effect has been suggested wherein the occurrence of one mass shooting increases the likelihood of another mass shooting occurring in the near future. Although contagion is a convenient metaphor used to describe the temporal spread of a behavior, it does not explain how the behavior spreads. Generalized imitation is proposed as a better model to explain how one person's behavior can influence another person to engage in similar behavior. Here we provide an overview of generalized imitation and discuss how the way in which the media report a mass shooting can increase the likelihood of another shooting event. Also, we propose media reporting guidelines to minimize imitation and further decrease the likelihood of a mass shooting.

  14. Imitating the Brain with Neurocomputer A "New" Way Towards Artificial General Intelligence

    Institute of Scientific and Technical Information of China (English)

    Tie-Jun Huang

    2017-01-01

    To achieve the artificial general intelligence (AGI),imitate the intelligence? or imitate the brain? This is the question! Most artificial intelligence (AI) approaches set the understanding of the intelligence principle as their premise.This may be correct to implement specific intelligence such as computing,symbolic logic,or what the AlphaGo could do.However,this is not correct for AGI,because to understand the principle of the brain intelligence is one of the most difficult challenges for our human beings.It is not wise to set such a question as the premise of the AGI mission.To achieve AGI,a practical approach is to build the so-called neurocomputer,which could be trained to produce autonomous intelligence and AGI.A neurocomputer imitates the biological neural network with neuromorphic devices which emulate the bio-neurons,synapses and other essential neural components.The neurocomputer could perceive the environment via sensors and interact with other entities via a physical body.The philosophy under the "new" approach,so-called as imitationalism in this paper,is the engineering methodology which has been practiced for thousands of years,and for many cases,such as the invention of the first airplane,succeeded.This paper compares the neurocomputer with the conventional computer.The major progress about neurocomputer is also reviewed.

  15. Neural systems for preparatory control of imitation.

    Science.gov (United States)

    Cross, Katy A; Iacoboni, Marco

    2014-01-01

    Humans have an automatic tendency to imitate others. Previous studies on how we control these tendencies have focused on reactive mechanisms, where inhibition of imitation is implemented after seeing an action. This work suggests that reactive control of imitation draws on at least partially specialized mechanisms. Here, we examine preparatory imitation control, where advance information allows control processes to be employed before an action is observed. Drawing on dual route models from the spatial compatibility literature, we compare control processes using biological and non-biological stimuli to determine whether preparatory imitation control recruits specialized neural systems that are similar to those observed in reactive imitation control. Results indicate that preparatory control involves anterior prefrontal, dorsolateral prefrontal, posterior parietal and early visual cortices regardless of whether automatic responses are evoked by biological (imitative) or non-biological stimuli. These results indicate both that preparatory control of imitation uses general mechanisms, and that preparatory control of imitation draws on different neural systems from reactive imitation control. Based on the regions involved, we hypothesize that preparatory control is implemented through top-down attentional biasing of visual processing.

  16. Human toddlers' attempts to match two simple behaviors provide no evidence for an inherited, dedicated imitation mechanism.

    Directory of Open Access Journals (Sweden)

    Susan S Jones

    Full Text Available Influential theories of imitation have proposed that humans inherit a neural mechanism - an "active intermodal matching " (AIM mechanism or a mirror neuron system - that functions from birth to automatically match sensory input from others' actions to motor programs for performing those same actions, and thus produces imitation. To test these proposals, 160 1- to 2½-year-old toddlers were asked to imitate two simple movements- bending the arm to make an elbow, and moving the bent elbow laterally. Both behaviors were almost certain to be in each child's repertoire, and the lateral movement was goal-directed (used to hit a plastic cup. Thus, one or both behaviors should have been imitable by toddlers with a functioning AIM or mirror neuron system. Each child saw the two behaviors repeated 18 times, and was encouraged to imitate. Children were also asked to locate their own elbows. Almost no children below age 2 imitated either behavior. Instead, younger children gave clear evidence of a developmental progression, from reproducing only the outcome of the models' movements (hitting the object, through trying (but failing to reproduce the model's arm posture and/or the arm-cup relations they had seen, to accurate imitation of arm bending by age 2 and of both movements by age 2½. Across age levels, almost all children who knew the word 'elbow' imitated both behaviors: very few who did not know the word imitated either behavior. The evidence is most consistent with a view of early imitation as the product of a complex system of language, cognitive, social, and motor competencies that develop in infancy. The findings do not rule out a role for an inherited neural mechanism, but they suggest that such a system would not by itself be sufficient to explain imitation at any age.

  17. Human Toddlers’ Attempts to Match Two Simple Behaviors Provide No Evidence for an Inherited, Dedicated Imitation Mechanism

    Science.gov (United States)

    Jones, Susan S.

    2012-01-01

    Influential theories of imitation have proposed that humans inherit a neural mechanism – an “active intermodal matching “ (AIM) mechanism or a mirror neuron system - that functions from birth to automatically match sensory input from others’ actions to motor programs for performing those same actions, and thus produces imitation. To test these proposals, 160 1- to 2½-year-old toddlers were asked to imitate two simple movements– bending the arm to make an elbow, and moving the bent elbow laterally. Both behaviors were almost certain to be in each child’s repertoire, and the lateral movement was goal-directed (used to hit a plastic cup). Thus, one or both behaviors should have been imitable by toddlers with a functioning AIM or mirror neuron system. Each child saw the two behaviors repeated 18 times, and was encouraged to imitate. Children were also asked to locate their own elbows. Almost no children below age 2 imitated either behavior. Instead, younger children gave clear evidence of a developmental progression, from reproducing only the outcome of the models’ movements (hitting the object), through trying (but failing) to reproduce the model’s arm posture and/or the arm-cup relations they had seen, to accurate imitation of arm bending by age 2 and of both movements by age 2½. Across age levels, almost all children who knew the word ‘elbow’ imitated both behaviors: very few who did not know the word imitated either behavior. The evidence is most consistent with a view of early imitation as the product of a complex system of language, cognitive, social, and motor competencies that develop in infancy. The findings do not rule out a role for an inherited neural mechanism, but they suggest that such a system would not by itself be sufficient to explain imitation at any age. PMID:23251500

  18. Impact of Text-Mining and Imitating Strategies on Lexical Richness, Lexical Diversity and General Success in Second Language Writing

    Science.gov (United States)

    Çepni, Sevcan Bayraktar; Demirel, Elif Tokdemir

    2016-01-01

    This study aimed to find out the impact of "text mining and imitating" strategies on lexical richness, lexical diversity and general success of students in their compositions in second language writing. The participants were 98 students studying their first year in Karadeniz Technical University in English Language and Literature…

  19. High-resolution remotely sensed small target detection by imitating fly visual perception mechanism.

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    Huang, Fengchen; Xu, Lizhong; Li, Min; Tang, Min

    2012-01-01

    The difficulty and limitation of small target detection methods for high-resolution remote sensing data have been a recent research hot spot. Inspired by the information capture and processing theory of fly visual system, this paper endeavors to construct a characterized model of information perception and make use of the advantages of fast and accurate small target detection under complex varied nature environment. The proposed model forms a theoretical basis of small target detection for high-resolution remote sensing data. After the comparison of prevailing simulation mechanism behind fly visual systems, we propose a fly-imitated visual system method of information processing for high-resolution remote sensing data. A small target detector and corresponding detection algorithm are designed by simulating the mechanism of information acquisition, compression, and fusion of fly visual system and the function of pool cell and the character of nonlinear self-adaption. Experiments verify the feasibility and rationality of the proposed small target detection model and fly-imitated visual perception method.

  20. High-Resolution Remotely Sensed Small Target Detection by Imitating Fly Visual Perception Mechanism

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    Fengchen Huang

    2012-01-01

    Full Text Available The difficulty and limitation of small target detection methods for high-resolution remote sensing data have been a recent research hot spot. Inspired by the information capture and processing theory of fly visual system, this paper endeavors to construct a characterized model of information perception and make use of the advantages of fast and accurate small target detection under complex varied nature environment. The proposed model forms a theoretical basis of small target detection for high-resolution remote sensing data. After the comparison of prevailing simulation mechanism behind fly visual systems, we propose a fly-imitated visual system method of information processing for high-resolution remote sensing data. A small target detector and corresponding detection algorithm are designed by simulating the mechanism of information acquisition, compression, and fusion of fly visual system and the function of pool cell and the character of nonlinear self-adaption. Experiments verify the feasibility and rationality of the proposed small target detection model and fly-imitated visual perception method.

  1. What's Special about Human Imitation? A Comparison with Enculturated Apes.

    Science.gov (United States)

    Subiaul, Francys

    2016-07-07

    What, if anything, is special about human imitation? An evaluation of enculturated apes' imitation skills, a "best case scenario" of non-human apes' imitation performance, reveals important similarities and differences between this special population of apes and human children. Candidates for shared imitation mechanisms include the ability to imitate various familiar transitive responses and object-object actions that involve familiar tools. Candidates for uniquely derived imitation mechanisms include: imitating novel transitive actions and novel tool-using responses as well as imitating opaque or intransitive gestures, regardless of familiarity. While the evidence demonstrates that enculturated apes outperform non-enculturated apes and perform more like human children, all apes, regardless of rearing history, generally excel at imitating familiar, over-rehearsed responses and are poor, relative to human children, at imitating novel, opaque or intransitive responses. Given the similarities between the sensory and motor systems of preschool age human children and non-human apes, it is unlikely that differences in sensory input and/or motor-output alone explain the observed discontinuities in imitation performance. The special rearing history of enculturated apes-including imitation-specific training-further diminishes arguments suggesting that differences are experience-dependent. Here, it is argued that such differences are best explained by distinct, specialized mechanisms that have evolved for copying rules and responses in particular content domains. Uniquely derived social and imitation learning mechanisms may represent adaptations for learning novel communicative gestures and complex tool-use. Given our species' dependence on both language and tools, mechanisms that accelerated learning in these domains are likely to have faced intense selective pressures, starting with the earliest of human ancestors.

  2. Elements of a comprehensive theory of infant imitation.

    Science.gov (United States)

    Meltzoff, Andrew N

    2017-01-01

    Imitation is central to human development. Imitation involves mapping between the perception and production of actions. Imitation after delays implicates preverbal memory. Imitation of people informs us about infants' processing of social events. A comprehensive theory needs to account for the origins, mechanisms, and functions of imitation. Neonatal imitation illuminates how the initial state engenders and supports rapid social learning.

  3. The Challenges of Imitation for Children with Autism Spectrum Disorders with Implications for General Music Education

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    Scott, Sheila

    2016-01-01

    With emphasis on inclusive education, many music teachers interact with children on the autism spectrum within regular classroom settings. Many of these teachers rely on rote learning to teach a variety of musical skills. This creates difficulties for children on the autism spectrum who respond differently to imitation than their typically…

  4. Imitation and reactor studies of irradiation effect on material mechanic properties

    International Nuclear Information System (INIS)

    Ozhigov, L.S.

    1999-01-01

    Processes of low- and high-temperature radiation embrittlement, radiation creeping and their influence on reactor material properties are considered. Role of imitation experiments in these processes is analysed

  5. Generalized classical mechanics

    International Nuclear Information System (INIS)

    De Leon, M.; Rodrigues, P.R.

    1985-01-01

    The geometrical study of Classical Mechanics shows that the Hamiltonian (respectively, Lagrangian) formalism may be characterized by intrinsical structures canonically defined on the cotangent (respectively, tangent) bundle of a differentiable manifold. A generalized formalism for higher order Lagrangians is developed. Then the Hamiltonian form of the theory is developed. Finally, the Poisson brackets are defined and the conditions under which a mapping is a canonical transformation are studied. The Hamilton-Jacobi equation for this type of mechanics is established. (Auth.)

  6. Automatic Imitation

    Science.gov (United States)

    Heyes, Cecilia

    2011-01-01

    "Automatic imitation" is a type of stimulus-response compatibility effect in which the topographical features of task-irrelevant action stimuli facilitate similar, and interfere with dissimilar, responses. This article reviews behavioral, neurophysiological, and neuroimaging research on automatic imitation, asking in what sense it is "automatic"…

  7. What’s Special about Human Imitation? A Comparison with Enculturated Apes

    Science.gov (United States)

    Subiaul, Francys

    2016-01-01

    What, if anything, is special about human imitation? An evaluation of enculturated apes’ imitation skills, a “best case scenario” of non-human apes’ imitation performance, reveals important similarities and differences between this special population of apes and human children. Candidates for shared imitation mechanisms include the ability to imitate various familiar transitive responses and object–object actions that involve familiar tools. Candidates for uniquely derived imitation mechanisms include: imitating novel transitive actions and novel tool-using responses as well as imitating opaque or intransitive gestures, regardless of familiarity. While the evidence demonstrates that enculturated apes outperform non-enculturated apes and perform more like human children, all apes, regardless of rearing history, generally excel at imitating familiar, over-rehearsed responses and are poor, relative to human children, at imitating novel, opaque or intransitive responses. Given the similarities between the sensory and motor systems of preschool age human children and non-human apes, it is unlikely that differences in sensory input and/or motor-output alone explain the observed discontinuities in imitation performance. The special rearing history of enculturated apes—including imitation-specific training—further diminishes arguments suggesting that differences are experience-dependent. Here, it is argued that such differences are best explained by distinct, specialized mechanisms that have evolved for copying rules and responses in particular content domains. Uniquely derived social and imitation learning mechanisms may represent adaptations for learning novel communicative gestures and complex tool-use. Given our species’ dependence on both language and tools, mechanisms that accelerated learning in these domains are likely to have faced intense selective pressures, starting with the earliest of human ancestors. PMID:27399786

  8. What’s Special about Human Imitation? A Comparison with Enculturated Apes

    Directory of Open Access Journals (Sweden)

    Francys Subiaul

    2016-07-01

    Full Text Available What, if anything, is special about human imitation? An evaluation of enculturated apes’ imitation skills, a “best case scenario” of non-human apes’ imitation performance, reveals important similarities and differences between this special population of apes and human children. Candidates for shared imitation mechanisms include the ability to imitate various familiar transitive responses and object–object actions that involve familiar tools. Candidates for uniquely derived imitation mechanisms include: imitating novel transitive actions and novel tool-using responses as well as imitating opaque or intransitive gestures, regardless of familiarity. While the evidence demonstrates that enculturated apes outperform non-enculturated apes and perform more like human children, all apes, regardless of rearing history, generally excel at imitating familiar, over-rehearsed responses and are poor, relative to human children, at imitating novel, opaque or intransitive responses. Given the similarities between the sensory and motor systems of preschool age human children and non-human apes, it is unlikely that differences in sensory input and/or motor-output alone explain the observed discontinuities in imitation performance. The special rearing history of enculturated apes—including imitation-specific training—further diminishes arguments suggesting that differences are experience-dependent. Here, it is argued that such differences are best explained by distinct, specialized mechanisms that have evolved for copying rules and responses in particular content domains. Uniquely derived social and imitation learning mechanisms may represent adaptations for learning novel communicative gestures and complex tool-use. Given our species’ dependence on both language and tools, mechanisms that accelerated learning in these domains are likely to have faced intense selective pressures, starting with the earliest of human ancestors.

  9. Neural mechanisms of vocal imitation: The role of sleep replay in shaping mirror neurons.

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    Giret, Nicolas; Edeline, Jean-Marc; Del Negro, Catherine

    2017-06-01

    Learning by imitation involves not only perceiving another individual's action to copy it, but also the formation of a memory trace in order to gradually establish a correspondence between the sensory and motor codes, which represent this action through sensorimotor experience. Memory and sensorimotor processes are closely intertwined. Mirror neurons, which fire both when the same action is performed or perceived, have received considerable attention in the context of imitation. An influential view of memory processes considers that the consolidation of newly acquired information or skills involves an active offline reprocessing of memories during sleep within the neuronal networks that were initially used for encoding. Here, we review the recent advances in the field of mirror neurons and offline processes in the songbird. We further propose a theoretical framework that could establish the neurobiological foundations of sensorimotor learning by imitation. We propose that the reactivation of neuronal assemblies during offline periods contributes to the integration of sensory feedback information and the establishment of sensorimotor mirroring activity at the neuronal level. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Action perception and imitation : a tutorial

    NARCIS (Netherlands)

    Bekkering, H; Wohlschlager, A; Prinz, W; Hommel, B

    2002-01-01

    Currently, imitation, or performing an act after perceiving it, is in the focus of attention of researchers from many different disciplines. Although this tutorial attempts to provide some interdisciplinary background, it will concentrate on possible cognitive mechanisms that underlie imitation

  11. Imitation Therapy for Non-Verbal Toddlers

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    Gill, Cindy; Mehta, Jyutika; Fredenburg, Karen; Bartlett, Karen

    2011-01-01

    When imitation skills are not present in young children, speech and language skills typically fail to emerge. There is little information on practices that foster the emergence of imitation skills in general and verbal imitation skills in particular. The present study attempted to add to our limited evidence base regarding accelerating the…

  12. The Prussian and American General Staffs: An Analysis of Cross-Cultural Imitation, Innovation, and Adaptation

    Science.gov (United States)

    1981-03-30

    Weimar period, but the Prussian general staff would never again control the military destinies of the German people. Before its defeat and dissolution...Publishers (New York: International Publishers, 1925), p. 4. 90. Norman Stone, The Eastern Front 1914-1917 (London: Hodder and Stoughton, 1975), p. 61...Lieutenant (later Brigadier General) Arthur L. Wagner was assigned to the school as an instructor in the Department of Military Art. Wagner , a 1875

  13. Imitation, empathy, and mirror neurons.

    Science.gov (United States)

    Iacoboni, Marco

    2009-01-01

    There is a convergence between cognitive models of imitation, constructs derived from social psychology studies on mimicry and empathy, and recent empirical findings from the neurosciences. The ideomotor framework of human actions assumes a common representational format for action and perception that facilitates imitation. Furthermore, the associative sequence learning model of imitation proposes that experience-based Hebbian learning forms links between sensory processing of the actions of others and motor plans. Social psychology studies have demonstrated that imitation and mimicry are pervasive, automatic, and facilitate empathy. Neuroscience investigations have demonstrated physiological mechanisms of mirroring at single-cell and neural-system levels that support the cognitive and social psychology constructs. Why were these neural mechanisms selected, and what is their adaptive advantage? Neural mirroring solves the "problem of other minds" (how we can access and understand the minds of others) and makes intersubjectivity possible, thus facilitating social behavior.

  14. Expecting ankle tilts and wearing an ankle brace influence joint control in an imitated ankle sprain mechanism during walking.

    Science.gov (United States)

    Gehring, Dominic; Wissler, Sabrina; Lohrer, Heinz; Nauck, Tanja; Gollhofer, Albert

    2014-03-01

    A thorough understanding of the functional aspects of ankle joint control is essential to developing effective injury prevention. It is of special interest to understand how neuromuscular control mechanisms and mechanical constraints stabilize the ankle joint. Therefore, the aim of the present study was to determine how expecting ankle tilts and the application of an ankle brace influence ankle joint control when imitating the ankle sprain mechanism during walking. Ankle kinematics and muscle activity were assessed in 17 healthy men. During gait rapid perturbations were applied using a trapdoor (tilting with 24° inversion and 15° plantarflexion). The subjects either knew that a perturbation would definitely occur (expected tilts) or there was only the possibility that a perturbation would occur (potential tilts). Both conditions were conducted with and without a semi-rigid ankle brace. Expecting perturbations led to an increased ankle eversion at foot contact, which was mediated by an altered muscle preactivation pattern. Moreover, the maximal inversion angle (-7%) and velocity (-4%), as well as the reactive muscle response were significantly reduced when the perturbation was expected. While wearing an ankle brace did not influence muscle preactivation nor the ankle kinematics before ground contact, it significantly reduced the maximal ankle inversion angle (-14%) and velocity (-11%) as well as reactive neuromuscular responses. The present findings reveal that expecting ankle inversion modifies neuromuscular joint control prior to landing. Although such motor control strategies are weaker in their magnitude compared with braces, they seem to assist ankle joint stabilization in a close-to-injury situation. Copyright © 2013 Elsevier B.V. All rights reserved.

  15. Quantum mechanics from general relativity

    International Nuclear Information System (INIS)

    Sachs, M.

    1986-01-01

    A generalization of quantum mechanics is demonstrated in the context of general relativity, following from a generally covariant field theory of inertia. Nonrelativistically, the formalism corresponds with linear quantum mechanics. In the limit of special relativity, nonlinearity remains and several new features are derived: (1) Particle-antiparticle pairs do not annihilate; an exact bound state solution is derived corresponding with all experimental facts about annihilation/creation - which, in approximation, gives the blackbody radiation spectrum for a sea of such pairs. (2) A result is proven, without approximation, that is physically equivalent to the Pauli exclusion principle - which, in linear approximation, gives the totally antisymmetrised many-body wave function and Fermi-Dirac statistics. (3) The hydrogen spectrum is derived, including the Lamb shifts, in agreement with experiment; new results are found for high energy electron-proton scattering. (4) Finally, several applications to the elementary particle domain are demonstrated, in agreement with results from experimental high energy physics. (Auth.)

  16. Cognitive mechanisms of visuomotor transformation in movement imitation: examining predictions based on models of apraxia and motor control.

    Science.gov (United States)

    Gravenhorst, Robynne M; Walter, Charles B

    2009-11-01

    When we observe a movement and then reproduce it, how is this visual input transformed into motor output? Studies on stroke patients with apraxia suggest that there may be two distinct routes used for gesture imitation; an indirect route that recruits stored movement memories (motor programs) and a direct route that bypasses them. The present study examined 30 healthy adults ages 18-80 (mean age=44.0 years, SD=19.5) to learn how motor programs are recruited or bypassed in movement imitation depending upon task conditions (whether familiar letters or novel shapes are imitated) and perceptual factors (whether shapes or letters are perceived). Subjects were asked to imitate the movements of a model who formed shapes and letters on a sheer mesh screen, and to report whether they perceived the task as a shape or a letter. Movements were recorded using a Vicon motion analysis system, and subsequently analyzed to determine the degree of difference between the demonstrated and produced movements. As predicted, letter perception on the letter tasks resulted in increased temporal error when the demonstrated stroke order conflicted with subjects' habitual pattern of letter formation. No such interference effects were observed when the letter tasks were perceived as shapes. These findings are discussed in the context of current theories on imitation, and implications for rehabilitation and motor re-learning are presented.

  17. Functional Specificity and Sex Differences in the Neural Circuits Supporting the Inhibition of Automatic Imitation.

    Science.gov (United States)

    Darda, Kohinoor M; Butler, Emily E; Ramsey, Richard

    2018-06-01

    Humans show an involuntary tendency to copy other people's actions. Although automatic imitation builds rapport and affiliation between individuals, we do not copy actions indiscriminately. Instead, copying behaviors are guided by a selection mechanism, which inhibits some actions and prioritizes others. To date, the neural underpinnings of the inhibition of automatic imitation and differences between the sexes in imitation control are not well understood. Previous studies involved small sample sizes and low statistical power, which produced mixed findings regarding the involvement of domain-general and domain-specific neural architectures. Here, we used data from Experiment 1 ( N = 28) to perform a power analysis to determine the sample size required for Experiment 2 ( N = 50; 80% power). Using independent functional localizers and an analysis pipeline that bolsters sensitivity, during imitation control we show clear engagement of the multiple-demand network (domain-general), but no sensitivity in the theory-of-mind network (domain-specific). Weaker effects were observed with regard to sex differences, suggesting that there are more similarities than differences between the sexes in terms of the neural systems engaged during imitation control. In summary, neurocognitive models of imitation require revision to reflect that the inhibition of imitation relies to a greater extent on a domain-general selection system rather than a domain-specific system that supports social cognition.

  18. Gesture Imitation in Schizophrenia

    Science.gov (United States)

    Matthews, Natasha; Gold, Brian J.; Sekuler, Robert; Park, Sohee

    2013-01-01

    Recent evidence suggests that individuals with schizophrenia (SZ) are impaired in their ability to imitate gestures and movements generated by others. This impairment in imitation may be linked to difficulties in generating and maintaining internal representations in working memory (WM). We used a novel quantitative technique to investigate the relationship between WM and imitation ability. SZ outpatients and demographically matched healthy control (HC) participants imitated hand gestures. In Experiment 1, participants imitated single gestures. In Experiment 2, they imitated sequences of 2 gestures, either while viewing the gesture online or after a short delay that forced the use of WM. In Experiment 1, imitation errors were increased in SZ compared with HC. Experiment 2 revealed a significant interaction between imitation ability and WM. SZ produced more errors and required more time to imitate when that imitation depended upon WM compared with HC. Moreover, impaired imitation from WM was significantly correlated with the severity of negative symptoms but not with positive symptoms. In sum, gesture imitation was impaired in schizophrenia, especially when the production of an imitation depended upon WM and when an imitation entailed multiple actions. Such a deficit may have downstream consequences for new skill learning. PMID:21765171

  19. Gesture imitation in schizophrenia.

    Science.gov (United States)

    Matthews, Natasha; Gold, Brian J; Sekuler, Robert; Park, Sohee

    2013-01-01

    Recent evidence suggests that individuals with schizophrenia (SZ) are impaired in their ability to imitate gestures and movements generated by others. This impairment in imitation may be linked to difficulties in generating and maintaining internal representations in working memory (WM). We used a novel quantitative technique to investigate the relationship between WM and imitation ability. SZ outpatients and demographically matched healthy control (HC) participants imitated hand gestures. In Experiment 1, participants imitated single gestures. In Experiment 2, they imitated sequences of 2 gestures, either while viewing the gesture online or after a short delay that forced the use of WM. In Experiment 1, imitation errors were increased in SZ compared with HC. Experiment 2 revealed a significant interaction between imitation ability and WM. SZ produced more errors and required more time to imitate when that imitation depended upon WM compared with HC. Moreover, impaired imitation from WM was significantly correlated with the severity of negative symptoms but not with positive symptoms. In sum, gesture imitation was impaired in schizophrenia, especially when the production of an imitation depended upon WM and when an imitation entailed multiple actions. Such a deficit may have downstream consequences for new skill learning.

  20. Investigating the Relationship between Stable Personality Characteristics and Automatic Imitation

    OpenAIRE

    Butler, Emily E.; Ward, Robert; Ramsey, Richard

    2015-01-01

    Automatic imitation is a cornerstone of nonverbal communication that fosters rapport between interaction partners. Recent research has suggested that stable dimensions of personality are antecedents to automatic imitation, but the empirical evidence linking imitation with personality traits is restricted to a few studies with modest sample sizes. Additionally, atypical imitation has been documented in autism spectrum disorders and schizophrenia, but the mechanisms underpinning these behaviour...

  1. Promoting imitation in young children with autism: a comparison of reciprocal imitation training and video modeling.

    Science.gov (United States)

    Cardon, Teresa A; Wilcox, M Jeanne

    2011-05-01

    The inability to imitate is a salient diagnostic marker for autism. It has been suggested that for children with autism, imitation may be a prerequisite skill that can assist in the development of various skills. Using a multiple baseline design across subjects, the purpose of this research was to determine if two interventions, reciprocal imitation training and video modeling were effective in promoting imitation acquisition in young children with autism. Six boys were matched across various features (i.e., age, language, autism severity) and randomly placed in a treatment condition. Results indicated that all six participants increased their imitation skills to varying degrees in both conditions, and imitation maintained and generalized at higher than baseline levels post treatment.

  2. Mimicry and automatic imitation are not correlated

    Science.gov (United States)

    van Den Bossche, Sofie; Cracco, Emiel; Bardi, Lara; Rigoni, Davide; Brass, Marcel

    2017-01-01

    It is widely known that individuals have a tendency to imitate each other. However, different psychological disciplines assess imitation in different manners. While social psychologists assess mimicry by means of action observation, cognitive psychologists assess automatic imitation with reaction time based measures on a trial-by-trial basis. Although these methods differ in crucial methodological aspects, both phenomena are assumed to rely on similar underlying mechanisms. This raises the fundamental question whether mimicry and automatic imitation are actually correlated. In the present research we assessed both phenomena and did not find a meaningful correlation. Moreover, personality traits such as empathy, autism traits, and traits related to self- versus other-focus did not correlate with mimicry or automatic imitation either. Theoretical implications are discussed. PMID:28877197

  3. Race modulates neural activity during imitation

    Science.gov (United States)

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

    2014-01-01

    Imitation plays a central role in the acquisition of culture. People preferentially imitate others who are self-similar, prestigious or successful. Because race can indicate a person's self-similarity or status, race influences whom people imitate. Prior studies of the neural underpinnings of imitation have not considered the effects of race. Here we measured neural activity with fMRI while European American participants imitated meaningless gestures performed by actors of their own race, and two racial outgroups, African American, and Chinese American. Participants also passively observed the actions of these actors and their portraits. Frontal, parietal and occipital areas were differentially activated while participants imitated actors of different races. More activity was present when imitating African Americans than the other racial groups, perhaps reflecting participants' reported lack of experience with and negative attitudes towards this group, or the group's lower perceived social status. This pattern of neural activity was not found when participants passively observed the gestures of the actors or simply looked at their faces. Instead, during face-viewing neural responses were overall greater for own-race individuals, consistent with prior race perception studies not involving imitation. Our findings represent a first step in elucidating neural mechanisms involved in cultural learning, a process that influences almost every aspect of our lives but has thus far received little neuroscientific study. PMID:22062193

  4. Neural correlates of individual differences in manual imitation fidelity

    Science.gov (United States)

    Braadbaart, Lieke; Waiter, Gordon D.; Williams, Justin H. G.

    2012-01-01

    Imitation is crucial for social learning, and so it is important to identify what determines between-subject variability in imitation fidelity. This might help explain what makes some people, like those with social difficulties such as in autism spectrum disorder (ASD), significantly worse at performance on these tasks than others. A novel paradigm was developed to provide objective measures of imitation fidelity in which participants used a touchscreen to imitate videos of a model drawing different shapes. Comparisons between model and participants' kinematic data provided three measures of imitative fidelity. We hypothesized that imitative ability would predict variation in BOLD signal whilst performing a simple imitation task in the MRI-scanner. In particular, an overall measure of accuracy (correlation between model and imitator) would predict activity in the overarching imitation system, whereas bias would be subject to more general aspects of motor control. Participants lying in the MRI-scanner were instructed to imitate different grips on a handle, or to watch someone or a circle moving the handle. Our hypothesis was partly confirmed as correlation between model and imitator was mediated by somatosensory cortex but also ventromedial prefrontal cortex, and bias was mediated mainly by cerebellum but also by the medial frontal and parietal cortices and insula. We suggest that this variance differentially reflects cognitive functions such as feedback-sensitivity and reward-dependent learning, contributing significantly to variability in individuals' imitative abilities as characterized by objective kinematic measures. PMID:23087625

  5. Neural correlates of individual differences in manual imitation fidelity

    Directory of Open Access Journals (Sweden)

    Lieke eBraadbaart

    2012-10-01

    Full Text Available Imitation is crucial for social learning, and so it is important to identify what determines between-subject variability in imitation fidelity. This might help explain what makes some people, like those with social difficulties such as in Autism Spectrum Disorder, significantly worse at performance on these tasks than others. A novel paradigm was developed to provide objective measures of imitation fidelity in which participants used a touchscreen to imitate videos of a model drawing different shapes. Comparisons between model and participants’ kinematic data provided three measures of imitative fidelity. We hypothesised that imitative ability would predict variation in BOLD signal whilst performing a simple imitation task in the MRI-scanner. In particular, an overall measure of accuracy (correlation between model and imitator would predict activity in the overarching imitation system, whereas bias would be subject to more general aspects of motor control. Participants lying in the MRI-scanner were instructed to imitate different grips on a handle, or to watch someone or a circle moving the handle. Our hypothesis was partly confirmed as correlation between model and imitator was mediated by somatosensory cortex but also ventromedial prefrontal cortex, and bias was mediated mainly by cerebellum but also by the medial frontal and parietal cortices and insula. We suggest that this variance differentially reflects cognitive functions such as feedback-sensitivity and reward-dependent learning, contributing significantly to variability in individuals’ imitative abilities as characterised by objective kinematic measures.

  6. Imitation by combination: preschool age children evidence summative imitation in a novel problem-solving task.

    Science.gov (United States)

    Subiaul, Francys; Krajkowski, Edward; Price, Elizabeth E; Etz, Alexander

    2015-01-01

    Children are exceptional, even 'super,' imitators but comparatively poor independent problem-solvers or innovators. Yet, imitation and innovation are both necessary components of cumulative cultural evolution. Here, we explored the relationship between imitation and innovation by assessing children's ability to generate a solution to a novel problem by imitating two different action sequences demonstrated by two different models, an example of imitation by combination, which we refer to as "summative imitation." Children (N = 181) from 3 to 5 years of age and across three experiments were tested in a baseline condition or in one of six demonstration conditions, varying in the number of models and opening techniques demonstrated. Across experiments, more than 75% of children evidenced summative imitation, opening both compartments of the problem box and retrieving the reward hidden in each. Generally, learning different actions from two different models was as good (and in some cases, better) than learning from 1 model, but the underlying representations appear to be the same in both demonstration conditions. These results show that summative imitation not only facilitates imitation learning but can also result in new solutions to problems, an essential feature of innovation and cumulative culture.

  7. Vocal Imitations of Non-Vocal Sounds

    Science.gov (United States)

    Houix, Olivier; Voisin, Frédéric; Misdariis, Nicolas; Susini, Patrick

    2016-01-01

    Imitative behaviors are widespread in humans, in particular whenever two persons communicate and interact. Several tokens of spoken languages (onomatopoeias, ideophones, and phonesthemes) also display different degrees of iconicity between the sound of a word and what it refers to. Thus, it probably comes at no surprise that human speakers use a lot of imitative vocalizations and gestures when they communicate about sounds, as sounds are notably difficult to describe. What is more surprising is that vocal imitations of non-vocal everyday sounds (e.g. the sound of a car passing by) are in practice very effective: listeners identify sounds better with vocal imitations than with verbal descriptions, despite the fact that vocal imitations are inaccurate reproductions of a sound created by a particular mechanical system (e.g. a car driving by) through a different system (the voice apparatus). The present study investigated the semantic representations evoked by vocal imitations of sounds by experimentally quantifying how well listeners could match sounds to category labels. The experiment used three different types of sounds: recordings of easily identifiable sounds (sounds of human actions and manufactured products), human vocal imitations, and computational “auditory sketches” (created by algorithmic computations). The results show that performance with the best vocal imitations was similar to the best auditory sketches for most categories of sounds, and even to the referent sounds themselves in some cases. More detailed analyses showed that the acoustic distance between a vocal imitation and a referent sound is not sufficient to account for such performance. Analyses suggested that instead of trying to reproduce the referent sound as accurately as vocally possible, vocal imitations focus on a few important features, which depend on each particular sound category. These results offer perspectives for understanding how human listeners store and access long

  8. General presentation of projects mechanisms

    International Nuclear Information System (INIS)

    2003-01-01

    This guide provides recommendations and tools to implement projects mechanisms, in the framework of the kyoto protocol. It precises the place of the projects mechanisms in the display of tools involved in the climatic change fight policies, at the national as international scale. It recalls the main characteristics and the rules of utilization and illustrates the corresponding interests. (A.L.B.)

  9. S-equivalents lagrangians in generalized mechanics

    International Nuclear Information System (INIS)

    Negri, L.J.; Silva, Edna G. da.

    1985-01-01

    The problem of s-equivalent lagrangians is considered in the realm of generalized mechanics. Some results corresponding to the ordinary (non-generalized) mechanics are extended to the generalized case. A theorem for the reduction of the higher order lagrangian description to the usual order is found to be useful for the analysis of generalized mechanical systems and leads to a new class of equivalence between lagrangian functions. Some new perspectives are pointed out. (Author) [pt

  10. Cooperation under indirect reciprocity and imitative trust.

    Science.gov (United States)

    Saavedra, Serguei; Smith, David; Reed-Tsochas, Felix

    2010-10-27

    Indirect reciprocity, a key concept in behavioral experiments and evolutionary game theory, provides a mechanism that allows reciprocal altruism to emerge in a population of self-regarding individuals even when repeated interactions between pairs of actors are unlikely. Recent empirical evidence show that humans typically follow complex assessment strategies involving both reciprocity and social imitation when making cooperative decisions. However, currently, we have no systematic understanding of how imitation, a mechanism that may also generate negative effects via a process of cumulative advantage, affects cooperation when repeated interactions are unlikely or information about a recipient's reputation is unavailable. Here we extend existing evolutionary models, which use an image score for reputation to track how individuals cooperate by contributing resources, by introducing a new imitative-trust score, which tracks whether actors have been the recipients of cooperation in the past. We show that imitative trust can co-exist with indirect reciprocity mechanisms up to a threshold and then cooperation reverses -revealing the elusive nature of cooperation. Moreover, we find that when information about a recipient's reputation is limited, trusting the action of third parties towards her (i.e. imitating) does favor a higher collective cooperation compared to random-trusting and share-alike mechanisms. We believe these results shed new light on the factors favoring social imitation as an adaptive mechanism in populations of cooperating social actors.

  11. Cooperation under indirect reciprocity and imitative trust.

    Directory of Open Access Journals (Sweden)

    Serguei Saavedra

    Full Text Available Indirect reciprocity, a key concept in behavioral experiments and evolutionary game theory, provides a mechanism that allows reciprocal altruism to emerge in a population of self-regarding individuals even when repeated interactions between pairs of actors are unlikely. Recent empirical evidence show that humans typically follow complex assessment strategies involving both reciprocity and social imitation when making cooperative decisions. However, currently, we have no systematic understanding of how imitation, a mechanism that may also generate negative effects via a process of cumulative advantage, affects cooperation when repeated interactions are unlikely or information about a recipient's reputation is unavailable. Here we extend existing evolutionary models, which use an image score for reputation to track how individuals cooperate by contributing resources, by introducing a new imitative-trust score, which tracks whether actors have been the recipients of cooperation in the past. We show that imitative trust can co-exist with indirect reciprocity mechanisms up to a threshold and then cooperation reverses -revealing the elusive nature of cooperation. Moreover, we find that when information about a recipient's reputation is limited, trusting the action of third parties towards her (i.e. imitating does favor a higher collective cooperation compared to random-trusting and share-alike mechanisms. We believe these results shed new light on the factors favoring social imitation as an adaptive mechanism in populations of cooperating social actors.

  12. General principles of quantum mechanics

    International Nuclear Information System (INIS)

    Pauli, W.

    1980-01-01

    This book is a textbook for a course in quantum mechanics. Starting from the complementarity and the uncertainty principle Schroedingers equation is introduced together with the operator calculus. Then stationary states are treated as eigenvalue problems. Furthermore matrix mechanics are briefly discussed. Thereafter the theory of measurements is considered. Then as approximation methods perturbation theory and the WKB approximation are introduced. Then identical particles, spin, and the exclusion principle are discussed. There after the semiclassical theory of radiation and the relativistic one-particle problem are discussed. Finally an introduction is given into quantum electrodynamics. (HSI)

  13. Exploring links among imitation, mental development, and temperament.

    Science.gov (United States)

    Fenstermacher, Susan K; Saudino, Kimberly J

    2016-01-01

    Links among imitation, performance on a standardized test of intellectual development, and laboratory-assessed temperament were explored in 311 24-month old twin pairs. Moderate phenotypic associations were found between imitation, mental development, and temperament dimensions of Affect/Extraversion and Task Orientation. Covariance between imitation and mental development reflected genetic and shared environmental influences, whereas associations between imitation and temperament reflected genetic, shared, and nonshared environmental influences. Genetic factors linking imitation and temperament were the same as those linking temperament and mental development. Nonetheless, approximately 62% of total genetic variance on imitation was independent of genetic influences on mental development and temperament, suggesting that young children's imitation is not simply an index of general cognitive ability or dispositional style but has many underlying genetic influences that are unique.

  14. From self-observation to imitation: visuomotor association on a robotic hand.

    Science.gov (United States)

    Chaminade, Thierry; Oztop, Erhan; Cheng, Gordon; Kawato, Mitsuo

    2008-04-15

    Being at the crux of human cognition and behaviour, imitation has become the target of investigations ranging from experimental psychology and neurophysiology to computational sciences and robotics. It is often assumed that the imitation is innate, but it has more recently been argued, both theoretically and experimentally, that basic forms of imitation could emerge as a result of self-observation. Here, we tested this proposal on a realistic experimental platform, comprising an associative network linking a 16 degrees of freedom robotic hand and a simple visual system. We report that this minimal visuomotor association is sufficient to bootstrap basic imitation. Our results indicate that crucial features of human imitation, such as generalization to new actions, may emerge from a connectionist associative network. Therefore, we suggest that a behaviour as complex as imitation could be, at the neuronal level, founded on basic mechanisms of associative learning, a notion supported by a recent proposal on the developmental origin of mirror neurons. Our approach can be applied to the development of realistic cognitive architectures for humanoid robots as well as to shed new light on the cognitive processes at play in early human cognitive development.

  15. The Action Imitation network and motor imitation in children and adolescents with autism.

    Science.gov (United States)

    Wadsworth, Heather M; Maximo, Jose O; Lemelman, Amy R; Clayton, Kacy; Sivaraman, Soumya; Deshpande, Hrishikesh D; Ver Hoef, Lawrence; Kana, Rajesh K

    2017-02-20

    While deficits in imitation had been reported in children with autism spectrum disorder (ASD), its exact nature remains unclear. A dysfunction in mirroring mechanisms (through action imitation) has been proposed by some studies to explain this, although some recent evidence points against this hypothesis. The current study used behavior and functional MRI to examine the integrated functioning of the regions that are considered part of the Action Imitation network (AIN) in children and adolescents with ASD during a motor imitation task. Fourteen ASD and 15 age-and-IQ-matched typically developing (TD) children were asked to imitate a series of hand gestures in the MRI scanner. Intact performance on imitation (accurate imitation of hand gestures outside the scanner) in both ASD and TD groups was accompanied by significantly lower activity in ASD participants, relative to TD, in right angular gyrus, precentral gyrus, and left middle cingulate. In addition, autism traits were found to be significantly correlated with activation in the right angular gyrus. Overall, the findings of this study support the role of AIN in imitation and a potential difference in the recruitment of this network in ASD children. Copyright © 2016 IBRO. Published by Elsevier Ltd. All rights reserved.

  16. Reciprocal Imitation Following Adult Imitation by Children with Autism

    Science.gov (United States)

    Field, Tiffany; Ezell, Shauna; Nadel, Jacqueline; Grace, Ava; Allender, Susan; Siddalingappa, Vijaya

    2013-01-01

    This study examined the effects of adult imitation and adult playfulness on the imitation, social attention and initiation of new behaviours by non-verbal preschoolers with autism. Videotapes taken from a previous study were recoded for the adult's imitation and playful behaviour and the children's imitation, social attention (looking at…

  17. Investigating the Relationship between Stable Personality Characteristics and Automatic Imitation.

    Directory of Open Access Journals (Sweden)

    Emily E Butler

    Full Text Available Automatic imitation is a cornerstone of nonverbal communication that fosters rapport between interaction partners. Recent research has suggested that stable dimensions of personality are antecedents to automatic imitation, but the empirical evidence linking imitation with personality traits is restricted to a few studies with modest sample sizes. Additionally, atypical imitation has been documented in autism spectrum disorders and schizophrenia, but the mechanisms underpinning these behavioural profiles remain unclear. Using a larger sample than prior studies (N=243, the current study tested whether performance on a computer-based automatic imitation task could be predicted by personality traits associated with social behaviour (extraversion and agreeableness and with disorders of social cognition (autistic-like and schizotypal traits. Further personality traits (narcissism and empathy were assessed in a subsample of participants (N=57. Multiple regression analyses showed that personality measures did not predict automatic imitation. In addition, using a similar analytical approach to prior studies, no differences in imitation performance emerged when only the highest and lowest 20 participants on each trait variable were compared. These data weaken support for the view that stable personality traits are antecedents to automatic imitation and that neural mechanisms thought to support automatic imitation, such as the mirror neuron system, are dysfunctional in autism spectrum disorders or schizophrenia. In sum, the impact that personality variables have on automatic imitation is less universal than initial reports suggest.

  18. Investigating the Relationship between Stable Personality Characteristics and Automatic Imitation.

    Science.gov (United States)

    Butler, Emily E; Ward, Robert; Ramsey, Richard

    2015-01-01

    Automatic imitation is a cornerstone of nonverbal communication that fosters rapport between interaction partners. Recent research has suggested that stable dimensions of personality are antecedents to automatic imitation, but the empirical evidence linking imitation with personality traits is restricted to a few studies with modest sample sizes. Additionally, atypical imitation has been documented in autism spectrum disorders and schizophrenia, but the mechanisms underpinning these behavioural profiles remain unclear. Using a larger sample than prior studies (N=243), the current study tested whether performance on a computer-based automatic imitation task could be predicted by personality traits associated with social behaviour (extraversion and agreeableness) and with disorders of social cognition (autistic-like and schizotypal traits). Further personality traits (narcissism and empathy) were assessed in a subsample of participants (N=57). Multiple regression analyses showed that personality measures did not predict automatic imitation. In addition, using a similar analytical approach to prior studies, no differences in imitation performance emerged when only the highest and lowest 20 participants on each trait variable were compared. These data weaken support for the view that stable personality traits are antecedents to automatic imitation and that neural mechanisms thought to support automatic imitation, such as the mirror neuron system, are dysfunctional in autism spectrum disorders or schizophrenia. In sum, the impact that personality variables have on automatic imitation is less universal than initial reports suggest.

  19. Individuals with congenital amusia imitate pitches more accurately in singing than in speaking: implications for music and language processing.

    Science.gov (United States)

    Liu, Fang; Jiang, Cunmei; Pfordresher, Peter Q; Mantell, James T; Xu, Yi; Yang, Yufang; Stewart, Lauren

    2013-11-01

    In this study, we investigated the impact of congenital amusia, a disorder of musical processing, on speech and song imitation in speakers of a tone language, Mandarin. A group of 13 Mandarin-speaking individuals with congenital amusia and 13 matched controls were recorded while imitating a set of speech and two sets of song stimuli with varying pitch and rhythm patterns. The results indicated that individuals with congenital amusia were worse than controls in both speech and song imitation, in terms of both pitch matching (absolute and relative) and rhythm matching (relative time and number of time errors). Like the controls, individuals with congenital amusia achieved better absolute and relative pitch matching and made fewer pitch interval and contour errors in song than in speech imitation. These findings point toward domain-general pitch (and time) production deficits in congenital amusia, suggesting the presence of shared pitch production mechanisms but distinct requirements for pitch-matching accuracy in language and music processing.

  20. The Impact of Object and Gesture Imitation Training on Language Use in Children with Autism Spectrum Disorder

    Science.gov (United States)

    Ingersoll, Brooke; Lalonde, Katherine

    2010-01-01

    Purpose: "Reciprocal imitation training" (RIT) is a naturalistic behavioral intervention that teaches imitation to children with autism spectrum disorder (ASD) within a social-communicative context. RIT has been shown to be effective at teaching spontaneous, generalized object and gesture imitation. In addition, improvements in imitation are…

  1. Prediction and imitation in speech

    Directory of Open Access Journals (Sweden)

    Chiara eGambi

    2013-06-01

    Full Text Available It has been suggested that intra- and inter-speaker variability in speech are correlated. Interlocutors have been shown to converge on various phonetic dimensions. In addition, speakers imitate the phonetic properties of voices they are exposed to in shadowing, repetition, and even passive listening tasks. We review three theoretical accounts of speech imitation and convergence phenomena: (i the Episodic Theory (ET of speech perception and production (Goldinger, 1998; (ii the Motor Theory (MT of speech perception (Liberman and Whalen, 2000;Galantucci et al., 2006 ; (iii Communication Accommodation Theory (CAT; Giles et al., 1991;Giles and Coupland, 1991. We argue that no account is able to explain all the available evidence. In particular, there is a need to integrate low-level, mechanistic accounts (like ET and MT and higher-level accounts (like CAT. We propose that this is possible within the framework of an integrated theory of production and comprehension (Pickering & Garrod, in press. Similarly to both ET and MT, this theory assumes parity between production and perception. Uniquely, however, it posits that listeners simulate speakers’ utterances by computing forward-model predictions at many different levels, which are then compared to the incoming phonetic input. In our account phonetic imitation can be achieved via the same mechanism that is responsible for sensorimotor adaptation; i.e. the correction of prediction errors. In addition, the model assumes that the degree to which sensory prediction errors lead to motor adjustments is context-dependent. The notion of context subsumes both the preceding linguistic input and non-linguistic attributes of the situation (e.g., the speaker’s and listener’s social identities, their conversational roles, the listener’s intention to imitate.

  2. Own-gender imitation activates the brain's reward circuitry

    Science.gov (United States)

    Iacoboni, Macro; Martin, Alia; Dapretto, Mirella

    2012-01-01

    Imitation is an important component of human social learning throughout life. Theoretical models and empirical data from anthropology and psychology suggest that people tend to imitate self-similar individuals, and that such imitation biases increase the adaptive value (e.g., self-relevance) of learned information. It is unclear, however, what neural mechanisms underlie people's tendency to imitate those similar to themselves. We focused on the own-gender imitation bias, a pervasive bias thought to be important for gender identity development. While undergoing fMRI, participants imitated own- and other-gender actors performing novel, meaningless hand signs; as control conditions, they also simply observed such actions and viewed still portraits of the same actors. Only the ventral and dorsal striatum, orbitofrontal cortex and amygdala were more active when imitating own- compared to other-gender individuals. A Bayesian analysis of the BrainMap neuroimaging database demonstrated that the striatal region preferentially activated by own-gender imitation is selectively activated by classical reward tasks in the literature. Taken together, these findings reveal a neurobiological mechanism associated with the own-gender imitation bias and demonstrate a novel role of reward-processing neural structures in social behavior. PMID:22383803

  3. Generalized mechanics as a representation of the ordinary mechanics

    International Nuclear Information System (INIS)

    Knapecz, G.

    1974-01-01

    It is shown that the generalized mechanics of one masspoint may be interpreted as a special representation of the ordinary mechanics of a system of masspoints. The hormorphism of both representations is shown in the case of two masspoints coupled by a harmonic force. The new representation is applied in the special relativic meachanics of mass-points. (author)

  4. Quantum mechanics as a natural generalization of classical statistical mechanics

    International Nuclear Information System (INIS)

    Xu Laizi; Qian Shangwu

    1994-01-01

    By comparison between equations of motion of geometrical optics (GO) and that of classical statistical mechanics (CSM), it is found that there should be an analogy between GO and CSM instead of GO and classical mechanics (CM). Furthermore, by comparison between the classical limit (CL) of quantum mechanics (QM) and CSM, the authors find that CL of QM is CSM not CM, hence they demonstrated that QM is a natural generalization of CSM instead of CM

  5. Preference reversal for copycat brands: Uncertainty makes imitation feel good

    NARCIS (Netherlands)

    Van Horen, F.; Pieters, R.

    2013-01-01

    Copycat brands try to entice consumers by imitating the trade-dress of leading brands. Recent research suggests that preferences for copycat brands relative to more differentiated brands are generally lower. That is, consumers tend to dislike such "imitation" brands, because of psychological

  6. Imitation in Infancy: The Wealth of the Stimulus

    Science.gov (United States)

    Ray, Elizabeth; Heyes, Cecilia

    2011-01-01

    Imitation requires the imitator to solve the correspondence problem--to translate visual information from modelled action into matching motor output. It has been widely accepted for some 30 years that the correspondence problem is solved by a specialized, innate cognitive mechanism. This is the conclusion of a poverty of the stimulus argument,…

  7. Advanced mechanics and general relativity an introduction to general relativity

    CERN Document Server

    Franklin, Joel

    2010-01-01

    Aimed at advanced undergraduates with background knowledge of classical mechanics and electricity and magnetism, this textbook presents both the particle dynamics relevant to general relativity, and the field dynamics necessary to understand the theory. Focusing on action extremization, the book develops the structure and predictions of general relativity by analogy with familiar physical systems. Topics ranging from classical field theory to minimal surfaces and relativistic strings are covered in a homogeneous manner. Nearly 150 exercises and numerous examples throughout the textbook enable students to test their understanding of the material covered.

  8. Whom Should We Imitate? Imitation Strategy and Industry Knowledge Structure

    DEFF Research Database (Denmark)

    Posen, Hart E.; Yi, Sangyoon; Lee, Jeho

    Imitation is a common practice within and across industries. Recent research has begun to explore the potential of imitation as a purposeful strategy. But the question of what constitutes a “good” imitation strategy is as yet not well understood. This study examines the efficacy of two canonical ...

  9. Parietal and premotor cortices: activation reflects imitation accuracy during observation, delayed imitation and concurrent imitation.

    Science.gov (United States)

    Krüger, Britta; Bischoff, Matthias; Blecker, Carlo; Langhanns, Christine; Kindermann, Stefan; Sauerbier, Isabell; Reiser, Mathias; Stark, Rudolf; Munzert, Jörn; Pilgramm, Sebastian

    2014-10-15

    This study investigated whether activation within areas belonging to the action observation and imitation network reveals a linear relation to the subsequent accuracy of imitating a bimanual rhythmic movement measured via a motion capturing system. 20 participants were scanned with functional magnetic resonance imaging (fMRI) when asked to imitate observed bimanual movements either concurrently versus with a delay (2s) or simply to observe the movements without imitation. Results showed that action observation relates to activation within classic mirror-related areas. Activation patterns were more widespread when participants were asked to imitate the movement. During observation with concurrent imitation, activation in the left inferior parietal lobe (IPL) was associated negatively with imitation accuracy. During observation in the delayed imitation condition, higher subsequent imitation accuracy was coupled with higher activation in the right superior parietal lobe (SPL) and the left parietal operculum (POp). During the delayed imitation itself, a negative association between imitation accuracy and brain activation was revealed in the right ventral premotor cortex (vPMC). We conclude that the IPL is involved in online comparison and visuospatial attention processes during imitation, the SPL provides a kinesthetic blueprint during movement observation, the POp preserves body identity, and the vPMC recruits motor representations--especially when no concurrent visual guidance is possible. Copyright © 2014 Elsevier Inc. All rights reserved.

  10. Imitation and Innovation: The Dual Engines of Cultural Learning.

    Science.gov (United States)

    Legare, Cristine H; Nielsen, Mark

    2015-11-01

    Imitation and innovation work in tandem to support cultural learning in children and facilitate our capacity for cumulative culture. Here we propose an integrated theoretical account of how the unique demands of acquiring instrumental skills and cultural conventions provide insight into when children imitate, when they innovate, and to what degree. For instrumental learning, with an increase in experience, high fidelity imitation decreases and innovation increases. By contrast, for conventional learning, imitative fidelity stays high, regardless of experience, and innovation stays low. We synthesize cutting edge research on the development of imitative flexibility and innovation to provide insight into the social learning mechanisms underpinning the uniquely human mind. Copyright © 2015 Elsevier Ltd. All rights reserved.

  11. A specific deficit of imitation in autism spectrum disorder.

    Science.gov (United States)

    Stewart, Hannah J; McIntosh, Rob D; Williams, Justin H G

    2013-12-01

    Imitation is a potentially crucial aspect of social cognitive development. Although deficits in imitation ability have been widely demonstrated in autism spectrum disorder (ASD), the specificity and significance of the findings is unclear, due largely to methodological limitations. We developed a novel assessment of imitation ability, using objective movement parameters (path length and action duration) derived from a touch-sensitive tablet laptop during drawing actions on an identical tablet. By direct comparison of the kinematics of a model's actions with those of the participant who observed them, measures of imitation accuracy were obtained. By replaying the end-point of the movement as a spot on the screen, imitation accuracy was compared against a "ghost control" condition, with no human actor but only the end-point of the movement seen [object movement reenactment (OMR)]. Hence, demands of the control task were closely matched to the experimental task with respect to motor, memory, and attentional abilities. Adolescents with ASD showed poorer accuracy for copying object size and action duration on both the imitation and OMR tasks, but were significantly more impaired for imitation of object size. Our results provide evidence that some of the imitation deficit in ASD is specific to a self-other mapping problem, and cannot be explained by general factors such as memory, spatial reasoning, motor control, or attention, nor related to the social demands of the testing situation. © 2013 International Society for Autism Research, Wiley Periodicals, Inc.

  12. Group Dynamics in Automatic Imitation.

    Science.gov (United States)

    Gleibs, Ilka H; Wilson, Neil; Reddy, Geetha; Catmur, Caroline

    Imitation-matching the configural body movements of another individual-plays a crucial part in social interaction. We investigated whether automatic imitation is not only influenced by who we imitate (ingroup vs. outgroup member) but also by the nature of an expected interaction situation (competitive vs. cooperative). In line with assumptions from Social Identity Theory), we predicted that both social group membership and the expected situation impact on the level of automatic imitation. We adopted a 2 (group membership target: ingroup, outgroup) x 2 (situation: cooperative, competitive) design. The dependent variable was the degree to which participants imitated the target in a reaction time automatic imitation task. 99 female students from two British Universities participated. We found a significant two-way interaction on the imitation effect. When interacting in expectation of cooperation, imitation was stronger for an ingroup target compared to an outgroup target. However, this was not the case in the competitive condition where imitation did not differ between ingroup and outgroup target. This demonstrates that the goal structure of an expected interaction will determine the extent to which intergroup relations influence imitation, supporting a social identity approach.

  13. Imitation of live and televised models by children one to three years of age.

    Science.gov (United States)

    McCall, R B; Parke, R D; Kavanaugh, R D

    1977-01-01

    The results of these studies indicated that children younger than 1 year possess the cognitive capability of translating a perception of a novel action into their own behavior. However, the likelihood of imitation varied as a function of the nature of the target behavior. For example, actions requiring direct social commerce with the examiner were imitated less frequently than simple motor behaviors with objects, and reproducing gestures was more common than vocalizations. Moreover, imitation seemed to depend upon the child's level of mental development--the imitation of coordinated sequences, which requires the child to associate two external events, lagged behind the imitation of single-unit behaviors. There was no evidence for individual traits of general imitativeness, at least not until symbolic relations were involved. Live models were imitated more than TV models but only prior to age 3. While children under 2 years of age were not facile at imitating sequences of behaviors or delaying performance at short time after modeling, older toddlers readily and accurately imitated televised sequences even after a 24-hour delay. Whereas socially extroverted and fearless children imitated live models more than shy children, TV imitation was not related to temperament, home TV viewing habits, or parental education. Finally, the experience of being imitated may facilitate the social cognition of influencing another person.

  14. Imitation Learning Errors Are Affected by Visual Cues in Both Performance and Observation Phases.

    Science.gov (United States)

    Mizuguchi, Takashi; Sugimura, Ryoko; Shimada, Hideaki; Hasegawa, Takehiro

    2017-08-01

    Mechanisms of action imitation were examined. Previous studies have suggested that success or failure of imitation is determined at the point of observing an action. In other words, cognitive processing after observation is not related to the success of imitation; 20 university students participated in each of three experiments in which they observed a series of object manipulations consisting of four elements (hands, tools, object, and end points) and then imitated the manipulations. In Experiment 1, a specific intially observed element was color coded, and the specific manipulated object at the imitation stage was identically color coded; participants accurately imitated the color coded element. In Experiment 2, a specific element was color coded at the observation but not at the imitation stage, and there were no effects of color coding on imitation. In Experiment 3, participants were verbally instructed to attend to a specific element at the imitation stage, but the verbal instructions had no effect. Thus, the success of imitation may not be determined at the stage of observing an action and color coding can provide a clue for imitation at the imitation stage.

  15. Generalized bond percolation and statistical mechanics

    International Nuclear Information System (INIS)

    Tsallis, C.

    1978-05-01

    A generalization of traditional bond percolation is performed, in the sens that bonds have now the possibility of partially transmitting the information (a fact which leads to the concept of 'fidelity' of the bond), and also in the sens that, besides the normal tendency to equiprobability, the bonds are allowed to substantially change the information. Furthermore the fidelity is allowed, to become an aleatory variable, and the operational rules concerning the associated distribution laws are determined. Thermally quenched random bonds and the whole body of Statistical Mechanics become particular cases of this formalism, which is in general adapted to the treatment of all problems whose main characteristic is to preserve a part of the information through a long path or array (critical phenomena, regime changements, thermal random models, etc). Operationally it provides a quick method for the calculation of the equivalent probability of complex clusters within the traditional bond percolation problem [pt

  16. General mechanism for the 1 /f noise

    Science.gov (United States)

    Yadav, Avinash Chand; Ramaswamy, Ramakrishna; Dhar, Deepak

    2017-08-01

    We consider the response of a memoryless nonlinear device that acts instantaneously, converting an input signal ξ (t ) into an output η (t ) at the same time t . For input Gaussian noise with power-spectrum 1 /fα , the nonlinearity can modify the spectral index of the output to give a spectrum that varies as 1 /fα ' with α'≠α . We show that the value of α' depends on the nonlinear transformation and can be tuned continuously. This provides a general mechanism for the ubiquitous 1 /f noise found in nature.

  17. Identification of general linear mechanical systems

    Science.gov (United States)

    Sirlin, S. W.; Longman, R. W.; Juang, J. N.

    1983-01-01

    Previous work in identification theory has been concerned with the general first order time derivative form. Linear mechanical systems, a large and important class, naturally have a second order form. This paper utilizes this additional structural information for the purpose of identification. A realization is obtained from input-output data, and then knowledge of the system input, output, and inertia matrices is used to determine a set of linear equations whereby we identify the remaining unknown system matrices. Necessary and sufficient conditions on the number, type and placement of sensors and actuators are given which guarantee identificability, and less stringent conditions are given which guarantee generic identifiability. Both a priori identifiability and a posteriori identifiability are considered, i.e., identifiability being insured prior to obtaining data, and identifiability being assured with a given data set.

  18. Neural correlates of phonetic convergence and speech imitation.

    Science.gov (United States)

    Garnier, Maëva; Lamalle, Laurent; Sato, Marc

    2013-01-01

    Speakers unconsciously tend to mimic their interlocutor's speech during communicative interaction. This study aims at examining the neural correlates of phonetic convergence and deliberate imitation, in order to explore whether imitation of phonetic features, deliberate, or unconscious, might reflect a sensory-motor recalibration process. Sixteen participants listened to vowels with pitch varying around the average pitch of their own voice, and then produced the identified vowels, while their speech was recorded and their brain activity was imaged using fMRI. Three degrees and types of imitation were compared (unconscious, deliberate, and inhibited) using a go-nogo paradigm, which enabled the comparison of brain activations during the whole imitation process, its active perception step, and its production. Speakers followed the pitch of voices they were exposed to, even unconsciously, without being instructed to do so. After being informed about this phenomenon, 14 participants were able to inhibit it, at least partially. The results of whole brain and ROI analyses support the fact that both deliberate and unconscious imitations are based on similar neural mechanisms and networks, involving regions of the dorsal stream, during both perception and production steps of the imitation process. While no significant difference in brain activation was found between unconscious and deliberate imitations, the degree of imitation, however, appears to be determined by processes occurring during the perception step. Four regions of the dorsal stream: bilateral auditory cortex, bilateral supramarginal gyrus (SMG), and left Wernicke's area, indeed showed an activity that correlated significantly with the degree of imitation during the perception step.

  19. Homo imitans? Seven reasons why imitation couldn't possibly be associative.

    Science.gov (United States)

    Heyes, Cecilia

    2016-01-19

    Many comparative and developmental psychologists believe that we are Homo imitans; humans are more skilled and prolific imitators than other animals, because we have a special, inborn 'intermodal matching' mechanism that integrates representations of others with representations of the self. In contrast, the associative sequence learning (ASL) model suggests that human infants learn to imitate using mechanisms that they share with other animals, and the rich resources provided by their sociocultural environments. This article answers seven objections to the ASL model: (i) it presents evidence that newborns do not imitate; (ii) argues that infants receive a plentiful supply of the kind of experience necessary for learning to imitate; (iii) suggests that neither infants nor adults can imitate elementally novel actions; (iv) explains why non-human animals have a limited capacity for imitation; (v) discusses the goal-directedness of imitation; (vi) presents evidence that improvement in imitation depends on visual feedback; and (vii) reflects on the view that associative theories steal 'the soul of imitation'. The empirical success of the ASL model indicates that the mechanisms which make imitation possible, by aligning representations of self with representations of others, have been tweaked by cultural evolution, not built from scratch by genetic evolution. © 2015 The Author(s).

  20. Methodological issues in measures of imitative reaction times.

    Science.gov (United States)

    Aicken, Michael D; Wilson, Andrew D; Williams, Justin H G; Mon-Williams, Mark

    2007-04-01

    Ideomotor (IM) theory suggests that observing someone else perform an action activates an internal motor representation of that behaviour within the observer. Evidence supporting the case for an ideomotor theory of imitation has come from studies that show imitative responses to be faster than the same behavioural measures performed in response to spatial cues. In an attempt to replicate these findings, we manipulated the salience of the visual cue and found that we could reverse the advantage of the imitative cue over the spatial cue. We suggest that participants utilised a simple visuomotor mechanism to perform all aspects of this task, with performance being driven by the relative visual salience of the stimuli. Imitation is a more complex motor skill that would constitute an inefficient strategy for rapid performance.

  1. Imitation, Awareness, and Folk Linguistic Artifacts

    Science.gov (United States)

    Brunner, Elizabeth Gentry

    2010-01-01

    Imitations are sophisticated performances displaying regular patterns. The study of imitation allows linguists to understand speakers' perceptions of sociolinguistic variation. In this dissertation, I analyze imitations of non-native accents in order to answer two questions: what can imitation reveal about perception, and how are "folk linguistic…

  2. Doing Justice to the Imitation Game

    Science.gov (United States)

    Lassègue, Jean

    My claim in this article is that the 1950 paper in which Turing describes the world-famous set-up of the Imitation Game is much richer and intriguing than the formalist ersatz coined in the early 1970s under the name "Turing Test". Therefore, doing justice to the Imitation Game implies showing first, that the formalist interpretation misses some crucial points in Turing's line of thought and second, that the 1950 paper should not be understood as the Magna Chartaof strong Artificial Intelligence (AI) but as a work in progressfocused on the notion of Form. This has unexpected consequences about the status of Mind, and from a more general point of view, about the way we interpret the notions of Science and Language.

  3. Higher-derivative generalization of conformal mechanics

    Science.gov (United States)

    Baranovsky, Oleg

    2017-08-01

    Higher-derivative analogs of multidimensional conformal particle and many-body conformal mechanics are constructed. Their Newton-Hooke counterparts are derived by applying appropriate coordinate transformations.

  4. The role of objects and effects in action imitation: Comparing the imitation of object-related actions vs. gestures in 18-month-old infants.

    Science.gov (United States)

    Kim, Ziyon; Óturai, Gabriella; Király, Ildikó; Knopf, Monika

    2015-11-01

    This study aimed to systematically investigate 18-month-old infants' imitation of object-related actions compared to motorically similar gestures. An additional goal of the study was to examine the role of action effects on infants' imitation of target actions. One group of infants (n=17) observed object-related actions and gestures leading to salient effects (sounds or visual resp. social effects), and the other group (n=16) watched the same actions without effects. Furthermore, this study examined whether infants show a consistent imitation ability for object-related actions and gestures. First, the present study showed that 18-month-old infants imitated object-related actions more frequently than gestures. Second, the presence of an effect significantly increased the imitation rate of object-related actions; however, this difference was not found for gestures. Third, indications for a general imitation ability were found as results on an individual level showed that object-related action imitation significantly correlated with gesture imitation. Implications of the results for theory and future studies are discussed with a focus on the role of objects and effects in 18-month-old infants' action imitation. Copyright © 2015 Elsevier Inc. All rights reserved.

  5. Imitation with Intention and Memory: an Experiment

    OpenAIRE

    Astrid Matthey

    2006-01-01

    Three results emerge from a simple experiment on imitation. First, I find behavior which strongly suggests an intention to imitate. Second, players im- itate successful other players rather than repeating successful actions. Third, to find imitation examples, players use several periods of memory. This lends support to learning models with a non-trivial role of memory. The experiment analyzes imitation in an individual learning context. It sup- plements the results obtained for imitation in e...

  6. Imitation versus payoff: Duality of the decision-making process demonstrates criticality and consensus formation

    Science.gov (United States)

    Turalska, M.; West, B. J.

    2014-11-01

    We consider a dual model of decision making, in which an individual forms its opinion based on contrasting mechanisms of imitation and rational calculation. The decision-making model (DMM) implements imitating behavior by means of a network of coupled two-state master equations that undergoes a phase transition at a critical value of a control parameter. The evolutionary spatial game, being a generalization of the prisoner's dilemma game, is used to determine in objective fashion the cooperative or anticooperative strategy adopted by individuals. Interactions between two sources of dynamics increases the domain of initial states attracted to phase transition dynamics beyond that of the DMM network in isolation. Additionally, on average the influence of the DMM on the game increases the final observed fraction of cooperators in the system.

  7. Enhancing voluntary imitation through attention and motor imagery.

    Science.gov (United States)

    Bek, Judith; Poliakoff, Ellen; Marshall, Hannah; Trueman, Sophie; Gowen, Emma

    2016-07-01

    Action observation activates brain areas involved in performing the same action and has been shown to increase motor learning, with potential implications for neurorehabilitation. Recent work indicates that the effects of action observation on movement can be increased by motor imagery or by directing attention to observed actions. In voluntary imitation, activation of the motor system during action observation is already increased. We therefore explored whether imitation could be further enhanced by imagery or attention. Healthy participants observed and then immediately imitated videos of human hand movement sequences, while movement kinematics were recorded. Two blocks of trials were completed, and after the first block participants were instructed to imagine performing the observed movement (Imagery group, N = 18) or attend closely to the characteristics of the movement (Attention group, N = 15), or received no further instructions (Control group, N = 17). Kinematics of the imitated movements were modulated by instructions, with both Imagery and Attention groups being closer in duration, peak velocity and amplitude to the observed model compared with controls. These findings show that both attention and motor imagery can increase the accuracy of imitation and have implications for motor learning and rehabilitation. Future work is required to understand the mechanisms by which these two strategies influence imitation accuracy.

  8. Self-Imitation and Environmental Scaffolding for Robot Teaching

    Directory of Open Access Journals (Sweden)

    Joe Saunders

    2007-03-01

    Full Text Available Imitative learning and learning by observation are social mechanisms that allow a robot to acquire knowledge from a human or another robot. However to be able to obtain skills in this way the robot faces many complex issues, one of which is that of finding solutions to the correspondence problem. Evolutionary predecessors to observational imitation may have been self-imitation where an agent avoids the complexities of the correspondence problem by learning and replicating actions it has experienced through the manipulation of its body. We investigate how a robotic control and teaching system using self-imitation can be constructed with reference to psychological models of motor control and ideas from social scaffolding seen in animals. Within these scaffolded environments sets of competencies can be built by constructing hierarchical state/action memory maps of the robot's interaction within that environment. The scaffolding process provides a mechanism to enable learning to be scaled up. The resulting system allows a human trainer to teach a robot new skills and modify skills that the robot may possess. Additionally the system allows the robot to notify the trainer when it is being taught skills it already has in its repertoire and to direct and focus its attention and sensor resources to relevant parts of the skill being executed. We argue that these mechanisms may be a first step towards the transformation from self-imitation to observational imitation. The system is validated on a physical pioneer robot that is taught using self-imitation to track, follow and point to a patterned object.

  9. Self-imitation and Environmental Scaffolding for Robot Teaching

    Directory of Open Access Journals (Sweden)

    Chrystopher L. Nehaniv

    2008-11-01

    Full Text Available Imitative learning and learning by observation are social mechanisms that allow a robot to acquire knowledge from a human or another robot. However to be able to obtain skills in this way the robot faces many complex issues, one of which is that of finding solutions to the correspondence problem. Evolutionary predecessors to observational imitation may have been self-imitation where an agent avoids the complexities of the correspondence problem by learning and replicating actions it has experienced through the manipulation of its body. We investigate how a robotic control and teaching system using self-imitation can be constructed with reference to psychological models of motor control and ideas from social scaffolding seen in animals. Within these scaffolded environments sets of competencies can be built by constructing hierarchical state/action memory maps of the robot's interaction within that environment. The scaffolding process provides a mechanism to enable learning to be scaled up. The resulting system allows a human trainer to teach a robot new skills and modify skills that the robot may possess. Additionally the system allows the robot to notify the trainer when it is being taught skills it already has in its repertoire and to direct and focus its attention and sensor resources to relevant parts of the skill being executed. We argue that these mechanisms may be a first step towards the transformation from self-imitation to observational imitation. The system is validated on a physical pioneer robot that is taught using self-imitation to track, follow and point to a patterned object.

  10. 46 CFR 154.1200 - Mechanical ventilation system: General.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Mechanical ventilation system: General. 154.1200 Section... CARGOES SAFETY STANDARDS FOR SELF-PROPELLED VESSELS CARRYING BULK LIQUEFIED GASES Design, Construction and Equipment Cargo Area: Mechanical Ventilation System § 154.1200 Mechanical ventilation system: General. (a...

  11. Mechanics of extended masses in general relativity

    International Nuclear Information System (INIS)

    Harte, Abraham I

    2012-01-01

    The 'external' or 'Right' motion of extended bodies is studied in general relativity. Compact material objects of essentially arbitrary shape, spin, internal composition and velocity are allowed as long as there is no direct (non-gravitational) contact with other sources of stress-energy. Physically reasonable linear and angular momenta are proposed for such bodies and exact equations describing their evolution are derived. Changes in the momenta depend on a certain 'effective metric' that is closely related to a non-perturbative generalization of the Detweiler-Whiting R-field originally introduced in the self-force literature. If the effective metric inside a self-gravitating body can be adequately approximated by an appropriate power series, the instantaneous gravitational force and torque exerted on it is shown to be identical to the force and torque exerted on an appropriate test body moving in the effective metric. This result holds to all multipole orders. The only instantaneous effect of a body's self-field is to finitely renormalize the 'bare' multipole moments of its stress-energy tensor. The MiSaTaQuWa expression for the gravitational self-force is recovered as a simple application. A gravitational self-torque is obtained as well. Lastly, it is shown that the effective metric in which objects appear to move is approximately a solution to the vacuum Einstein equation if the physical metric is an approximate solution to Einstein's equation linearized about a vacuum background. (paper)

  12. 25 CFR 141.27 - Trade in imitation Indian crafts prohibited.

    Science.gov (United States)

    2010-04-01

    ... 25 Indians 1 2010-04-01 2010-04-01 false Trade in imitation Indian crafts prohibited. 141.27 Section 141.27 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR FINANCIAL ACTIVITIES BUSINESS PRACTICES ON THE NAVAJO, HOPI AND ZUNI RESERVATIONS General Business Practices § 141.27 Trade in imitation...

  13. Autism Severity and Motor Abilities Correlates of Imitation Situations in Children with Autism Spectrum Disorders

    Science.gov (United States)

    Zachor, Ditza A.; Ilanit, Tzaig; Itzchak, Esther Ben

    2010-01-01

    Impaired performance in a range of imitation tasks has been described in children with autism spectrum disorders (ASD) and several underlying mechanism have been suggested. This study examined whether imitation abilities are related to autism severity and to motor skills. Furthermore, the performance of children with ASD in four imitation…

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

    Science.gov (United States)

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

    2017-01-01

    People preferentially imitate others who are similar to them or have high social status. Such imitative biases are thought to have evolved because they increase the efficiency of cultural acquisition. Here we focused on distinguishing between self-similarity and social status as two candidate mechanisms underlying neural responses to a person’s race during imitation. We used fMRI to measure neural responses when 20 African American (AA) and 20 European American (EA) young adults imitated AA, EA and Chinese American (CA) models and also passively observed their gestures and faces. We found that both AA and EA participants exhibited more activity in lateral fronto-parietal and visual regions when imitating AAs compared to EAs or CAs. These results suggest that racial self-similarity is not likely to modulate neural responses to race during imitation, in contrast with findings from previous neuroimaging studies of face perception and action observation. Furthermore, AA and EA participants associated AAs with lower social status than EAs or CAs, suggesting that the social status associated with different racial groups may instead modulate neural activity during imitation of individuals from those groups. Taken together, these findings suggest that neural responses to race during imitation are driven by socially-learned associations rather than self-similarity. This may reflect the adaptive role of imitation in social learning, where learning from higher-status models can be more beneficial. This study provides neural evidence consistent with evolutionary theories of cultural acquisition. PMID:23813738

  15. A kinematic study on (unintentional imitation in bottlenose dolphins

    Directory of Open Access Journals (Sweden)

    Luisa eSartori

    2015-08-01

    Full Text Available The aim of the present study was to investigate the effect of observing other’s movements on subsequent performance in bottlenose dolphins. The imitative ability of non-human animals has intrigued a number of researchers. So far, however, studies in dolphins have been confined to intentional imitation concerned with the explicit request to imitate other agents. In the absence of instruction to imitate, do dolphins (unintentionally replicate other’s movement features? To test this, dolphins were filmed while reaching and touching a stimulus before and after observing another dolphin (i.e., model performing the same action. All videos were reviewed and segmented in order to extract the relevant movements. A marker was inserted post-hoc via software on the videos upon the anatomical landmark of interest (i.e. rostrum and was tracked throughout the time course of the movement sequence. The movement was analyzed using an in-house software developed to perform two-dimensional (2D post-hoc kinematic analysis. The results indicate that dolphins’ kinematics is sensitive to other’s movement features. Movements performed for the ‘visuomotor priming’ condition were characterized by a kinematic pattern similar to that performed by the observed dolphin (i.e., model. Addressing the issue of spontaneous imitation in bottlenose dolphins might allow ascertaining whether the potential or impulse to produce an imitative action is generated, not just when they intend to imitate, but whenever they watch another conspecific’s behavior. In closing, this will clarify whether motor representational capacity is a by-product of factors specific to humans or whether more general characteristics such as processes of associative learning prompted by high level of encephalization could help to explain the evolution of this ability.

  16. Innovate or imitate? Behavioural technological change

    NARCIS (Netherlands)

    Hommes, C.; Zeppini, P.

    2013-01-01

    We propose a behavioural model of technological change with evolutionary switching between boundedly rational costly innovators and free imitators, and study the endogenous interplay of innovation decisions, market price dynamics and technological progress. Innovation and imitation are strategic

  17. Innovate or imitate? Behavioural technological change

    NARCIS (Netherlands)

    Hommes, C.; Zeppini, P.

    2014-01-01

    We propose a behavioural model of technological change with evolutionary switching between costly innovators and free imitators, and study the endogenous interplay of innovation decisions, market price dynamics and technological progress. Innovation and imitation are strategic substitutes and

  18. How and why do infants imitate? An ideomotor approach to social and imitative learning in infancy (and beyond).

    Science.gov (United States)

    Paulus, Markus

    2014-10-01

    It has been proposed that already in infancy, imitative learning plays a pivotal role in the acquisition of knowledge and abilities. Yet the cognitive mechanisms underlying the acquisition of novel action knowledge through social learning have remained unclear. The present contribution presents an ideomotor approach to imitative learning (IMAIL) in infancy (and beyond) that draws on the ideomotor theory of action control and on recent findings of perception-action matching. According to IMAIL, the central mechanism of imitative and social learning is the acquisition of cascading bidirectional action-effect associations through observation of own and others' actions. First, the observation of the visual effect of own actions leads to the acquisition of first-order action-effect associations, linking motor codes to the action's typical visual effects. Second, observing another person's action leads to motor activation (i.e., motor resonance) due to the first-order associations. This activated motor code then becomes linked to the other salient effects produced by the observed action, leading to the acquisition of (second-order) action-effect associations. These novel action-effect associations enable later imitation of the observed actions. The article reviews recent behavioral and neurophysiological studies with infants and adults that provide empirical support for the model. Furthermore, it is discussed how the model relates to other approaches on social-cognitive development and how developmental changes in imitative abilities can be conceptualized.

  19. The Monosyllable Imitation Test for Toddlers: Influence of Stimulus Characteristics on Imitation, Compliance and Diagnostic Accuracy

    Science.gov (United States)

    Hodges, Rosemary; Munro, Natalie; Baker, Elise; McGregor, Karla; Heard, Rob

    2017-01-01

    Background: Although verbal imitation can provide a valuable window into the developing language abilities of toddlers, some toddlers find verbal imitation challenging and will not comply with tests that involve elicited verbal imitation. The characteristics of stimuli that are offered to toddlers for imitation may influence how easy or hard it is…

  20. Children with Autism Are More Imitative with an Imitative Adult than with Their Parents

    Science.gov (United States)

    Field, Tiffany; Nadel, Jacqueline; Diego, Miguel; Hernandez-Reif, Maria; Russo, Kelly; Vchulek, Diane; Lendi, Kim; Siddalingappa, Vijaya

    2010-01-01

    Children with autism (mean age = 6 years) were videotaped first interacting with a parent and then with an unfamiliar researcher who imitated the child's behaviours. The researcher showed more imitative and playful behaviours than the parents. In turn, the children showed more imitative behaviour when playing with the imitative researcher than…

  1. Engineering a General Education Program: Designing Mechanical Engineering General Education Courses

    Science.gov (United States)

    Fagette, Paul; Chen, Shih-Jiun; Baran, George R.; Samuel, Solomon P.; Kiani, Mohammad F.

    2013-01-01

    The Department of Mechanical Engineering at our institution created two engineering courses for the General Education Program that count towards second level general science credit (traditional science courses are first level). The courses were designed for the general student population based upon the requirements of our General Education Program…

  2. Automatic Imitation in Rhythmical Actions: Kinematic Fidelity and the Effects of Compatibility, Delay, and Visual Monitoring

    Science.gov (United States)

    Eaves, Daniel L.; Turgeon, Martine; Vogt, Stefan

    2012-01-01

    We demonstrate that observation of everyday rhythmical actions biases subsequent motor execution of the same and of different actions, using a paradigm where the observed actions were irrelevant for action execution. The cycle time of the distractor actions was subtly manipulated across trials, and the cycle time of motor responses served as the main dependent measure. Although distractor frequencies reliably biased response cycle times, this imitation bias was only a small fraction of the modulations in distractor speed, as well as of the modulations produced when participants intentionally imitated the observed rhythms. Importantly, this bias was not only present for compatible actions, but was also found, though numerically reduced, when distractor and executed actions were different (e.g., tooth brushing vs. window wiping), or when the dominant plane of movement was different (horizontal vs. vertical). In addition, these effects were equally pronounced for execution at 0, 4, and 8 s after action observation, a finding that contrasts with the more short-lived effects reported in earlier studies. The imitation bias was also unaffected when vision of the hand was occluded during execution, indicating that this effect most likely resulted from visuomotor interactions during distractor observation, rather than from visual monitoring and guidance during execution. Finally, when the distractor was incompatible in both dimensions (action type and plane) the imitation bias was not reduced further, in an additive way, relative to the single-incompatible conditions. This points to a mechanism whereby the observed action’s impact on motor processing is generally reduced whenever this is not useful for motor planning. We interpret these findings in the framework of biased competition, where intended and distractor actions can be represented as competing and quasi-encapsulated sensorimotor streams. PMID:23071623

  3. Automatic imitation in rhythmical actions: kinematic fidelity and the effects of compatibility, delay, and visual monitoring.

    Directory of Open Access Journals (Sweden)

    Daniel L Eaves

    Full Text Available We demonstrate that observation of everyday rhythmical actions biases subsequent motor execution of the same and of different actions, using a paradigm where the observed actions were irrelevant for action execution. The cycle time of the distractor actions was subtly manipulated across trials, and the cycle time of motor responses served as the main dependent measure. Although distractor frequencies reliably biased response cycle times, this imitation bias was only a small fraction of the modulations in distractor speed, as well as of the modulations produced when participants intentionally imitated the observed rhythms. Importantly, this bias was not only present for compatible actions, but was also found, though numerically reduced, when distractor and executed actions were different (e.g., tooth brushing vs. window wiping, or when the dominant plane of movement was different (horizontal vs. vertical. In addition, these effects were equally pronounced for execution at 0, 4, and 8 s after action observation, a finding that contrasts with the more short-lived effects reported in earlier studies. The imitation bias was also unaffected when vision of the hand was occluded during execution, indicating that this effect most likely resulted from visuomotor interactions during distractor observation, rather than from visual monitoring and guidance during execution. Finally, when the distractor was incompatible in both dimensions (action type and plane the imitation bias was not reduced further, in an additive way, relative to the single-incompatible conditions. This points to a mechanism whereby the observed action's impact on motor processing is generally reduced whenever this is not useful for motor planning. We interpret these findings in the framework of biased competition, where intended and distractor actions can be represented as competing and quasi-encapsulated sensorimotor streams.

  4. Imitation, patent protection and welfare

    NARCIS (Netherlands)

    Mukherjee, A.; Pennings, H.P.G.

    2000-01-01

    Once a new technology has been invented it is shown that the innovator has an incentive to postpone technology adoption when the cost of imitation is high and patent protection is strong. With the possibility of licensing it is shown that licensing oftechnology instead of delaying technology

  5. Imitation Pedagogy and Ethical Indoctrination.

    Science.gov (United States)

    Erdmann, Edward

    1993-01-01

    Examines the claim of 16th-century English humanist educators that they prepared their students for civic life by providing not only technical training in language use but ethical and moral training for negotiating basic life situations. Attempts to determine what might have been the role of imitation exercises informing students' ethical…

  6. BOOK REVIEW: Advanced Mechanics and General Relativity Advanced Mechanics and General Relativity

    Science.gov (United States)

    Louko, Jorma

    2011-04-01

    Joel Franklin's textbook `Advanced Mechanics and General Relativity' comprises two partially overlapping, partially complementary introductory paths into general relativity at advanced undergraduate level. Path I starts with the Lagrangian and Hamiltonian formulations of Newtonian point particle motion, emphasising the action principle and the connection between symmetries and conservation laws. The concepts are then adapted to point particle motion in Minkowski space, introducing Lorentz transformations as symmetries of the action. There follows a focused development of tensor calculus, parallel transport and curvature, using examples from Newtonian mechanics and special relativity, culminating in the field equations of general relativity. The Schwarzschild solution is analysed, including a detailed discussion of the tidal forces on a radially infalling observer. Basics of gravitational radiation are examined, highlighting the similarities to and differences from electromagnetic radiation. The final topics in Path I are equatorial geodesics in Kerr and the motion of a relativistic string in Minkowski space. Path II starts by introducing scalar field theory on Minkowski space as a limit of point masses connected by springs, emphasising the action principle, conservation laws and the energy-momentum tensor. The action principle for electromagnetism is introduced, and the coupling of electromagnetism to a complex scalar field is developed in a detailed and pedagogical fashion. A free symmetric second-rank tensor field on Minkowski space is introduced, and the action principle of general relativity is recovered from coupling the second-rank tensor to its own energy-momentum tensor. Path II then merges with Path I and, supplanted with judicious early selections from Path I, can proceed to the Schwarzschild solution. The choice of material in each path is logical and focused. A notable example in Path I is that Lorentz transformations in Minkowki space are introduced

  7. Neuroprosthetic Decoder Training as Imitation Learning.

    Science.gov (United States)

    Merel, Josh; Carlson, David; Paninski, Liam; Cunningham, John P

    2016-05-01

    Neuroprosthetic brain-computer interfaces function via an algorithm which decodes neural activity of the user into movements of an end effector, such as a cursor or robotic arm. In practice, the decoder is often learned by updating its parameters while the user performs a task. When the user's intention is not directly observable, recent methods have demonstrated value in training the decoder against a surrogate for the user's intended movement. Here we show that training a decoder in this way is a novel variant of an imitation learning problem, where an oracle or expert is employed for supervised training in lieu of direct observations, which are not available. Specifically, we describe how a generic imitation learning meta-algorithm, dataset aggregation (DAgger), can be adapted to train a generic brain-computer interface. By deriving existing learning algorithms for brain-computer interfaces in this framework, we provide a novel analysis of regret (an important metric of learning efficacy) for brain-computer interfaces. This analysis allows us to characterize the space of algorithmic variants and bounds on their regret rates. Existing approaches for decoder learning have been performed in the cursor control setting, but the available design principles for these decoders are such that it has been impossible to scale them to naturalistic settings. Leveraging our findings, we then offer an algorithm that combines imitation learning with optimal control, which should allow for training of arbitrary effectors for which optimal control can generate goal-oriented control. We demonstrate this novel and general BCI algorithm with simulated neuroprosthetic control of a 26 degree-of-freedom model of an arm, a sophisticated and realistic end effector.

  8. Neuroprosthetic Decoder Training as Imitation Learning.

    Directory of Open Access Journals (Sweden)

    Josh Merel

    2016-05-01

    Full Text Available Neuroprosthetic brain-computer interfaces function via an algorithm which decodes neural activity of the user into movements of an end effector, such as a cursor or robotic arm. In practice, the decoder is often learned by updating its parameters while the user performs a task. When the user's intention is not directly observable, recent methods have demonstrated value in training the decoder against a surrogate for the user's intended movement. Here we show that training a decoder in this way is a novel variant of an imitation learning problem, where an oracle or expert is employed for supervised training in lieu of direct observations, which are not available. Specifically, we describe how a generic imitation learning meta-algorithm, dataset aggregation (DAgger, can be adapted to train a generic brain-computer interface. By deriving existing learning algorithms for brain-computer interfaces in this framework, we provide a novel analysis of regret (an important metric of learning efficacy for brain-computer interfaces. This analysis allows us to characterize the space of algorithmic variants and bounds on their regret rates. Existing approaches for decoder learning have been performed in the cursor control setting, but the available design principles for these decoders are such that it has been impossible to scale them to naturalistic settings. Leveraging our findings, we then offer an algorithm that combines imitation learning with optimal control, which should allow for training of arbitrary effectors for which optimal control can generate goal-oriented control. We demonstrate this novel and general BCI algorithm with simulated neuroprosthetic control of a 26 degree-of-freedom model of an arm, a sophisticated and realistic end effector.

  9. Preference reversal for copycat brands : Uncertainty makes imitation feel good

    NARCIS (Netherlands)

    van Horen, F.; Pieters, R.

    2013-01-01

    Copycat brands try to entice consumers by imitating the trade-dress of leading brands. Recent research suggests that preferences for copycat brands relative to more differentiated brands are generally lower. That is, consumers tend to dislike such “imitation” brands, because of psychological

  10. Acquisition of Automatic Imitation Is Sensitive to Sensorimotor Contingency

    Science.gov (United States)

    Cook, Richard; Press, Clare; Dickinson, Anthony; Heyes, Cecilia

    2010-01-01

    The associative sequence learning model proposes that the development of the mirror system depends on the same mechanisms of associative learning that mediate Pavlovian and instrumental conditioning. To test this model, two experiments used the reduction of automatic imitation through incompatible sensorimotor training to assess whether mirror…

  11. Copying you copying me: interpersonal motor co-ordination influences automatic imitation.

    Directory of Open Access Journals (Sweden)

    Daniel Joel Shaw

    Full Text Available Moving in a co-ordinated fashion with another individual changes our behaviour towards them; we tend to like them more, find them more attractive, and are more willing to co-operate with them. It is generally assumed that this effect on behaviour results from alterations in representations of self and others. Specifically, through neurophysiological perception-action matching mechanisms, interpersonal motor co-ordination (IMC is believed to forge a neural coupling between actor and observer, which serves to blur boundaries in conceptual self-other representations and causes positive views of the self to be projected onto others. An investigation into this potential neural mechanism is lacking, however. Moreover, the specific components of IMC that might influence this mechanism have not yet been specified. In the present study we exploited a robust behavioural phenomenon--automatic imitation--to assess the degree to which IMC influences neural action observation-execution matching mechanisms. This revealed that automatic imitation is reduced when the actions of another individual are perceived to be synchronised in time, but are spatially incongruent, with our own. We interpret our findings as evidence that IMC does indeed exert an effect on neural perception-action matching mechanisms, but this serves to promote better self-other distinction. Our findings demonstrate that further investigation is required to understand the complex relationship between neural perception-action coupling, conceptual self-other representations, and social behaviour.

  12. Neural activation during imitation with or without performance feedback: An fMRI study.

    Science.gov (United States)

    Zhang, Kaihua; Wang, Hui; Dong, Guangheng; Wang, Mengxing; Zhang, Jilei; Zhang, Hui; Meng, Weixia; Du, Xiaoxia

    2016-08-26

    In our daily lives, we often receive performance feedback (PF) during imitative learning, and we adjust our behaviors accordingly to improve performance. However, little is known regarding the neural mechanisms underlying this learning process. We hypothesized that appropriate PF would enhance neural activation or recruit additional brain areas during subsequent action imitation. Pictures of 20 different finger gestures without any social meaning were shown to participants from the first-person perspective. Imitation with or without PF was investigated by functional magnetic resonance imaging in 30 healthy subjects. The PF was given by a real person or by a computer. PF from a real person induced hyperactivation of the parietal lobe (precuneus and cuneus), cingulate cortex (posterior and anterior), temporal lobe (superior and transverse temporal gyri), and cerebellum (posterior and anterior lobes) during subsequent imitation. The positive PF and negative PF from a real person, induced the activation of more brain areas during the following imitation. The hyperactivation of the cerebellum, posterior cingulate cortex, precuneus, and cuneus suggests that the subjects exhibited enhanced motor control and visual attention during imitation after PF. Additionally, random PF from a computer had a small effect on the next imitation. We suggest that positive and accurate PF may be helpful for imitation learning. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  13. Is selective attention the basis for selective imitation in infants? An eye-tracking study of deferred imitation with 12-month-olds.

    Science.gov (United States)

    Kolling, Thorsten; Oturai, Gabriella; Knopf, Monika

    2014-08-01

    Infants and children do not blindly copy every action they observe during imitation tasks. Research demonstrated that infants are efficient selective imitators. The impact of selective perceptual processes (selective attention) for selective deferred imitation, however, is still poorly described. The current study, therefore, analyzed 12-month-old infants' looking behavior during demonstration of two types of target actions: arbitrary versus functional actions. A fully automated remote eye tracker was used to assess infants' looking behavior during action demonstration. After a 30-min delay, infants' deferred imitation performance was assessed. Next to replicating a memory effect, results demonstrate that infants do imitate significantly more functional actions than arbitrary actions (functionality effect). Eye-tracking data show that whereas infants do not fixate significantly longer on functional actions than on arbitrary actions, amount of fixations and amount of saccades differ between functional and arbitrary actions, indicating different encoding mechanisms. In addition, item-level findings differ from overall findings, indicating that perceptual and conceptual item features influence looking behavior. Looking behavior on both the overall and item levels, however, does not relate to deferred imitation performance. Taken together, the findings demonstrate that, on the one hand, selective imitation is not explainable merely by selective attention processes. On the other hand, notwithstanding this reasoning, attention processes on the item level are important for encoding processes during target action demonstration. Limitations and future studies are discussed. Copyright © 2014 Elsevier Inc. All rights reserved.

  14. Comments on microscopic mechanics, generalizations of classical mechanics and Planck's oscillators

    International Nuclear Information System (INIS)

    Yussouff, M.

    1983-05-01

    The new microscopic mechanics removes the dichotomy of physics into classical and quantum phenomena. Its physical picture and connections with generalizations of classical mechanics are discussed. It gives a new meaning to Bohr's frequency relation and Planck's oscillators. (author)

  15. Imitation, mirror neurons and autism.

    Science.gov (United States)

    Williams, J H; Whiten, A; Suddendorf, T; Perrett, D I

    2001-06-01

    Various deficits in the cognitive functioning of people with autism have been documented in recent years but these provide only partial explanations for the condition. We focus instead on an imitative disturbance involving difficulties both in copying actions and in inhibiting more stereotyped mimicking, such as echolalia. A candidate for the neural basis of this disturbance may be found in a recently discovered class of neurons in frontal cortex, 'mirror neurons' (MNs). These neurons show activity in relation both to specific actions performed by self and matching actions performed by others, providing a potential bridge between minds. MN systems exist in primates without imitative and 'theory of mind' abilities and we suggest that in order for them to have become utilized to perform social cognitive functions, sophisticated cortical neuronal systems have evolved in which MNs function as key elements. Early developmental failures of MN systems are likely to result in a consequent cascade of developmental impairments characterised by the clinical syndrome of autism.

  16. Imitation, mirror neurons and autism

    OpenAIRE

    Williams, Justin H.G.; Whiten, Andrew; Suddendorf, Thomas; Perrett, David I.

    2001-01-01

    Various deficits in the cognitive functioning of people with autism have been documented in recent years but these provide only partial explanations for the condition. We focus instead on an imitative disturbance involving difficulties both in copying actions and in inhibiting more stereotyped mimicking, such as echolalia. A candidate for the neural basis of this disturbance may be found in a recently discovered class of neurons in frontal cortex, 'mirror neurons' (MNs). These neurons show ac...

  17. Voluntary Imitation in Alzheimer’s Disease Patients

    Science.gov (United States)

    Bisio, Ambra; Casteran, Matthieu; Ballay, Yves; Manckoundia, Patrick; Mourey, France; Pozzo, Thierry

    2016-01-01

    Although Alzheimer’s disease (AD) primarily manifests as cognitive deficits, the implicit sensorimotor processes that underlie social interactions, such as automatic imitation, seem to be preserved in mild and moderate stages of the disease, as is the ability to communicate with other persons. Nevertheless, when AD patients face more challenging tasks, which do not rely on automatic processes but on explicit voluntary mechanisms and require the patient to pay attention to external events, the cognitive deficits resulting from the disease might negatively affect patients’ behavior. The aim of the present study was to investigate whether voluntary motor imitation, i.e., a volitional mechanism that involves observing another person’s action and translating this perception into one’s own action, was affected in patients with AD. Further, we tested whether this ability was modulated by the nature of the observed stimulus by comparing the ability to reproduce the kinematic features of a human demonstrator with that of a computerized-stimulus. AD patients showed an intact ability to reproduce the velocity of the observed movements, particularly when the stimulus was a human agent. This result suggests that high-level cognitive processes involved in voluntary imitation might be preserved in mild and moderate stages of AD and that voluntary imitation abilities might benefit from the implicit interpersonal communication established between the patient and the human demonstrator. PMID:27014056

  18. Voluntary imitation in Alzheimer’s disease patients

    Directory of Open Access Journals (Sweden)

    Ambra eBisio

    2016-03-01

    Full Text Available Although Alzheimer's disease (AD primarily manifests as cognitive deficits, the implicit sensorimotor processes that underlie social interactions, such as automatic imitation, seem to be preserved in mild and moderate stages of the disease, as is the ability to communicate with other persons. Nevertheless, when AD patients face more challenging tasks, which do not rely on automatic processes but on explicit voluntary mechanisms and require the patient to pay attention to external events, the cognitive deficits resulting from the disease might negatively affect patients’ behaviour. The aim of the present study was to investigate whether voluntary motor imitation, i.e. a volitional mechanism that involves observing another person’s action and translating this perception into one’s own action, was affected in patients with Alzheimer’s disease. Further, we tested whether this ability was modulated by the nature of the observed stimulus by comparing the ability to reproduce the kinematic features of a human demonstrator with that of a computerized-stimulus. AD patients showed an intact ability to reproduce the velocity of the observed movements, particularly when the stimulus was a human agent. This result suggests that high-level cognitive processes involved in voluntary imitation might be preserved in mild and moderate stages of AD and that voluntary imitation abilities might benefit from the implicit interpersonal communication established between the patient and the human demonstrator.

  19. Enhanced Automatic Action Imitation and Intact Imitation-Inhibition in Schizophrenia.

    Science.gov (United States)

    Simonsen, Arndis; Fusaroli, Riccardo; Skewes, Joshua Charles; Roepstorff, Andreas; Campbell-Meiklejohn, Daniel; Mors, Ole; Bliksted, Vibeke

    2018-02-21

    Imitation plays a key role in social learning and in facilitating social interactions and likely constitutes a basic building block of social cognition that supports higher-level social abilities. Recent findings suggest that patients with schizophrenia have imitation impairments that could contribute to the social impairments associated with the disorder. However, extant studies have specifically assessed voluntary imitation or automatic imitation of emotional stimuli without controlling for potential confounders. The imitation impairments seen might therefore be secondary to other cognitive, motoric, or emotional deficits associated with the disorder. To overcome this issue, we used an automatic imitation paradigm with nonemotional stimuli to assess automatic imitation and the top-down modulation of imitation where participants were required to lift one of 2 fingers according to a number shown on the screen while observing the same or the other finger movement. In addition, we used a control task with a visual cue in place of a moving finger, to isolate the effect of observing finger movement from other visual cueing effects. Data from 33 patients (31 medicated) and 40 matched healthy controls were analyzed. Patients displayed enhanced imitation and intact top-down modulation of imitation. The enhanced imitation seen in patients may have been medication induced as larger effects were seen in patients receiving higher antipsychotic doses. In sum, we did not find an imitation impairment in schizophrenia. The results suggest that previous findings of impaired imitation in schizophrenia might have been due to other cognitive, motoric, and/or emotional deficits.

  20. Imitation Modeling and Institutional Studies

    Directory of Open Access Journals (Sweden)

    Maksim Y. Barbashin

    2017-09-01

    Full Text Available This article discusses the use of imitation modeling in the conduct of institutional research. The institutional approach is based on the observation of social behavior. To understand a social process means to determine the key rules that individuals use, undertaking social actions associated with this process or phenomenon. This does not mean that institutions determine behavioral reactions, although there are a number of social situations where the majority of individuals follow the dominant rules. If the main laws of development of the institutional patterns are known, one can describe most of the social processes accurately. The author believes that the main difficulty with the analysis of institutional processes is their recursive nature: from the standards of behavior one may find the proposed actions of social agents who follow, obey or violate institutions, but the possibility of reconstructive analysis is not obvious. The author demonstrates how the institutional approach is applied to the analysis of social behavior. The article describes the basic principles and methodology of imitation modeling. Imitation modeling reveals the importance of institutions in structuring social transactions. The article concludes that in the long term institutional processes are not determined by initial conditions.

  1. Mechanical similarity as a generalization of scale symmetry

    International Nuclear Information System (INIS)

    Gozzi, E; Mauro, D

    2006-01-01

    In this paper, we study the symmetry known (Landau and Lifshits 1976 Course of Theoretical Physics vol 1: Mechanics (Oxford: Pergamon)) as mechanical similarity (LMS) and present for any monomial potential. We analyse it in the framework of the Koopman-von Neumann formulation of classical mechanics and prove that in this framework the LMS can be given a canonical implementation. We also show that the LMS is a generalization of the scale symmetry which is present only for the inverse square and a few other potentials. Finally, we study the main obstructions which one encounters in implementing the LMS at the quantum-mechanical level

  2. Accent imitation positively affects language attitudes

    OpenAIRE

    Adank, Patti; Stewart, Andrew J.; Connell, Louise; Wood, Jeffrey

    2013-01-01

    People in conversation tend to accommodate the way they speak. It has been assumed that this tendency to imitate each other's speech patterns serves to increase liking between partners in a conversation. Previous experiments examined the effect of perceived social attractiveness on the tendency to imitate someone else's speech and found that vocal imitation increased when perceived attractiveness was higher. The present experiment extends this research by examining the inverse relationship an...

  3. Accent Imitation Positively Affects Language Attitudes

    OpenAIRE

    Patti eAdank; Patti eAdank; Andrew J. Stewart; Louise eConnell; Jeffrey eWood

    2013-01-01

    People in conversation tend to accommodate the way they speak. It has been assumed that this tendency to imitate each other’s speech patterns serves to increase liking between partners in a conversation. Previous experiments examined the effect of perceived social attractiveness on the tendency to imitate someone else’s speech and found that vocal imitation increased when perceived attractiveness was higher. The present experiment extends this research by examining the inverse relationship an...

  4. Age-related changes in learning across early childhood: a new imitation task.

    Science.gov (United States)

    Dickerson, Kelly; Gerhardstein, Peter; Zack, Elizabeth; Barr, Rachel

    2013-11-01

    Imitation plays a critical role in social and cognitive development, but the social learning mechanisms contributing to the development of imitation are not well understood. We developed a new imitation task designed to examine social learning mechanisms across the early childhood period. The new task involves assembly of abstract-shaped puzzle pieces in an arbitrary sequence on a magnet board. Additionally, we introduce a new scoring system that extends traditional goal-directed imitation scoring to include measures of both children's success at copying gestures (sliding the puzzle pieces) and goals (connecting the puzzle pieces). In Experiment 1, we demonstrated an age-invariant baseline from 1.5 to 3.5 years of age, accompanied by age-related changes in success at copying goals and gestures from a live demonstrator. In Experiment 2, we applied our new task to learning following a video demonstration. Imitation performance in the video demonstration group lagged behind that of the live demonstration group, showing a protracted video deficit effect. Across both experiments, children were more likely to copy gestures at earlier ages, suggesting mimicry, and only later copy both goals and gestures, suggesting imitation. Taken together, the findings suggest that different social learning strategies may predominate in imitation learning dependent upon the degree of object affordance, task novelty, and task complexity. © 2012 Wiley Periodicals, Inc.

  5. Brief Report: Pilot Randomized Controlled Trial of Reciprocal Imitation Training for Teaching Elicited and Spontaneous Imitation to Children with Autism

    Science.gov (United States)

    Ingersoll, Brooke

    2010-01-01

    Children with autism exhibit significant deficits in imitation skills. Reciprocal Imitation Training (RIT), a naturalistic imitation intervention, was developed to teach young children with autism to imitate during play. This study used a randomized controlled trial to evaluate the efficacy of RIT on elicited and spontaneous imitation skills in 21…

  6. The neural basis of the imitation drive.

    Science.gov (United States)

    Hanawa, Sugiko; Sugiura, Motoaki; Nozawa, Takayuki; Kotozaki, Yuka; Yomogida, Yukihito; Ihara, Mizuki; Akimoto, Yoritaka; Thyreau, Benjamin; Izumi, Shinichi; Kawashima, Ryuta

    2016-01-01

    Spontaneous imitation is assumed to underlie the acquisition of important skills by infants, including language and social interaction. In this study, functional magnetic resonance imaging (fMRI) was used to examine the neural basis of 'spontaneously' driven imitation, which has not yet been fully investigated. Healthy participants were presented with movie clips of meaningless bimanual actions and instructed to observe and imitate them during an fMRI scan. The participants were subsequently shown the movie clips again and asked to evaluate the strength of their 'urge to imitate' (Urge) for each action. We searched for cortical areas where the degree of activation positively correlated with Urge scores; significant positive correlations were observed in the right supplementary motor area (SMA) and bilateral midcingulate cortex (MCC) under the imitation condition. These areas were not explained by explicit reasons for imitation or the kinematic characteristics of the actions. Previous studies performed in monkeys and humans have implicated the SMA and MCC/caudal cingulate zone in voluntary actions. This study also confirmed the functional connectivity between Urge and imitation performance using a psychophysiological interaction analysis. Thus, our findings reveal the critical neural components that underlie spontaneous imitation and provide possible reasons why infants imitate spontaneously. © The Author (2015). Published by Oxford University Press.

  7. The effect of different imitation models on theaccuracy and speed of imitation of movement.

    Science.gov (United States)

    Nishizawa, Hitomi; Kimura, Teiji; Goh, Ah-Cheng

    2015-11-01

    [Purpose] The purpose of this study was to compare the accuracy, speed and subjective ease of imitation of movement using three different imitation models. [Subjects] Thirty-four right-handed healthy males participated in this study. [Methods] The imitation task chosen for this study was an asymmetric combined motion of the upper and lower limbs. Three kinds of imitation models were displayed on a screen as follows: a) third person perspective mirror imitation (3PM), b) third person perspective anatomical imitation (3PA), and c) first person perspective ipsilateral imitation (1PI). Subjects were instructed to imitate the movement shown on a screen as quickly and as accurately as possible. They executed four sets of the movement with each set consisting of one trial of each of the three imitation models. [Results] 3PM was the most accurate, and 1PI was the fastest in speed and subjective ease of imitation, compared with the other two imitation models. [Conclusion] These results suggest that 1PI and 3PM, which do not require mental rotation of the movement task as required by 3PA, should be considered more suitable imitation models for teaching healthy subjects how to move.

  8. Constrained generalized mechanics. The second-order case

    International Nuclear Information System (INIS)

    Tapia, V.

    1985-01-01

    The Dirac formalism for constrained systems is developed for systems described by a Lagrangian depending on up to a second-order time derivatives of the generalized co-ordinates (accelerations). It turns out that for a Lagrangian of this kind differing by a total time derivative from a Lagrangian depending on only up to first-order time-derivatives of the generalized co-ordinates (velocities), both classical mechanics at the Lagrangian level are the same; at the Hamiltonian level the two classical mechanics differ conceptually even when the solutions to both sets of Hamiltonian equations of motion are the same

  9. Conditional imitation might promote cooperation under high temptations to defect

    Science.gov (United States)

    Dai, Qionglin; Li, Haihong; Cheng, Hongyan; Qian, Xiaolan; Zhang, Mei; Yang, Junzhong

    2012-07-01

    In this paper we introduce a conditional imitation rule into an evolutionary game, in which the imitation probabilities of individuals are determined by a function of payoff difference and two crucial parameters μ and σ. The parameter μ characterizes the most adequate goal for individuals and the parameter σ characterizes the tolerance of individuals. By using the pair approximation method and numerical simulations, we find an anomalous cooperation enhancement in which the cooperation level shows a nonmonotonic variation with the increase of temptation. The parameter μ affects the regime of the payoff parameter which supports the anomalous cooperation enhancement, whereas the parameter σ plays a decisive role on the appearance of the nonmonotonic variation of the cooperation level. Furthermore, to give explicit implications for the parameters μ and σ we present an alterative form of the conditional imitation rule based on the benefit and the cost incurred to individuals during strategy updates. In this way, we also provide a phenomenological interpretation for the nonmonotonic behavior of cooperation with the increase of temptation. The results give a clue that a higher cooperation level could be obtained under adverse environments for cooperation by applying the conditional imitation rule, which is possible to be manipulated in real life. More generally, the results in this work might point out an efficient way to maintain cooperation in the risky environments to cooperators.

  10. Vibrational mechanics nonlinear dynamic effects, general approach, applications

    CERN Document Server

    Blekhman, Iliya I

    2000-01-01

    This important book deals with vibrational mechanics - the new, intensively developing section of nonlinear dynamics and the theory of nonlinear oscillations. It offers a general approach to the study of the effect of vibration on nonlinear mechanical systems.The book presents the mathematical apparatus of vibrational mechanics which is used to describe such nonlinear effects as the disappearance and appearance under vibration of stable positions of equilibrium and motions (i.e. attractors), the change of the rheological properties of the media, self-synchronization, self-balancing, the vibrat

  11. The association between imitation recognition and socio-communicative competencies in chimpanzees (Pan troglodytes).

    Science.gov (United States)

    Pope, Sarah M; Russell, Jamie L; Hopkins, William D

    2015-01-01

    Imitation recognition provides a viable platform from which advanced social cognitive skills may develop. Despite evidence that non-human primates are capable of imitation recognition, how this ability is related to social cognitive skills is unknown. In this study, we compared imitation recognition performance, as indicated by the production of testing behaviors, with performance on a series of tasks that assess social and physical cognition in 49 chimpanzees. In the initial analyses, we found that males were more responsive than females to being imitated and engaged in significantly greater behavior repetitions and testing sequences. We also found that subjects who consistently recognized being imitated performed better on social but not physical cognitive tasks, as measured by the Primate Cognitive Test Battery. These findings suggest that the neural constructs underlying imitation recognition are likely associated with or among those underlying more general socio-communicative abilities in chimpanzees. Implications regarding how imitation recognition may facilitate other social cognitive processes, such as mirror self-recognition, are discussed.

  12. Imitation and matching of meaningless gestures: distinct involvement from motor and visual imagery.

    Science.gov (United States)

    Lesourd, Mathieu; Navarro, Jordan; Baumard, Josselin; Jarry, Christophe; Le Gall, Didier; Osiurak, François

    2017-05-01

    The aim of the present study was to understand the underlying cognitive processes of imitation and matching of meaningless gestures. Neuropsychological evidence obtained in brain damaged patients, has shown that distinct cognitive processes supported imitation and matching of meaningless gestures. Left-brain damaged (LBD) patients failed to imitate while right-brain damaged (RBD) patients failed to match meaningless gestures. Moreover, other studies with brain damaged patients showed that LBD patients were impaired in motor imagery while RBD patients were impaired in visual imagery. Thus, we hypothesize that imitation of meaningless gestures might rely on motor imagery, whereas matching of meaningless gestures might be based on visual imagery. In a first experiment, using a correlational design, we demonstrated that posture imitation relies on motor imagery but not on visual imagery (Experiment 1a) and that posture matching relies on visual imagery but not on motor imagery (Experiment 1b). In a second experiment, by manipulating directly the body posture of the participants, we demonstrated that such manipulation evokes a difference only in imitation task but not in matching task. In conclusion, the present study provides direct evidence that the way we imitate or we have to compare postures depends on motor imagery or visual imagery, respectively. Our results are discussed in the light of recent findings about underlying mechanisms of meaningful and meaningless gestures.

  13. Reafferent copies of imitated actions in the right superior temporal cortex

    Science.gov (United States)

    Iacoboni, Marco; Koski, Lisa M.; Brass, Marcel; Bekkering, Harold; Woods, Roger P.; Dubeau, Marie-Charlotte; Mazziotta, John C.; Rizzolatti, Giacomo

    2001-01-01

    Imitation is a complex phenomenon, the neural mechanisms of which are still largely unknown. When individuals imitate an action that already is present in their motor repertoire, a mechanism matching the observed action onto an internal motor representation of that action should suffice for the purpose. When one has to copy a new action, however, or to adjust an action present in one's motor repertoire to a different observed action, an additional mechanism is needed that allows the observer to compare the action made by another individual with the sensory consequences of the same action made by himself. Previous experiments have shown that a mechanism that directly matches observed actions on their motor counterparts exists in the premotor cortex of monkeys and humans. Here we report the results of functional magnetic resonance experiments, suggesting that in the superior temporal sulcus, a higher order visual region, there is a sector that becomes active both during hand action observation and during imitation even in the absence of direct vision of the imitator's hand. The motor-related activity is greater during imitation than during control motor tasks. This newly identified region has all the requisites for being the region at which the observed actions, and the reafferent motor-related copies of actions made by the imitator, interact. PMID:11717457

  14. Accent imitation positively affects language attitudes.

    Science.gov (United States)

    Adank, Patti; Stewart, Andrew J; Connell, Louise; Wood, Jeffrey

    2013-01-01

    People in conversation tend to accommodate the way they speak. It has been assumed that this tendency to imitate each other's speech patterns serves to increase liking between partners in a conversation. Previous experiments examined the effect of perceived social attractiveness on the tendency to imitate someone else's speech and found that vocal imitation increased when perceived attractiveness was higher. The present experiment extends this research by examining the inverse relationship and examines how overt vocal imitation affects attitudes. Participants listened to sentences spoken by two speakers of a regional accent (Glaswegian) of English. They vocally repeated (speaking in their own accent without imitating) the sentences spoken by a Glaswegian speaker, and subsequently imitated sentences spoken by a second Glaswegian speaker (order counterbalanced across participants). After each repeating or imitation session, participants completed a questionnaire probing the speakers' perceived power, competence, and social attractiveness. Imitating had a positive effect on the perceived social attractiveness of the speaker compared to repeating. These results are interpreted in light of Communication Accommodation Theory.

  15. Virtual Battlespace Behavior Generation Through Class Imitation

    Science.gov (United States)

    2011-03-01

    to improve believability in an empirically measurable way, we focus on incorporating verifiability into our agent behaviors. Throughout the rest of...accuracy for low values of α. 39 The “Stealth” class imitation accuracies are also interesting. Not only is it inca - pable of imitating the appropriate

  16. Imitation in Undergraduate Teaching and Learning

    Science.gov (United States)

    Zhou, Jiangyuan; Guo, Wei

    2016-01-01

    Research in developmental psychology and neuroscience has demonstrated the critical role of imitation in human learning. Self-report questionnaires collected from 456 undergraduate students in two U.S. institutions and one Chinese institution demonstrated that undergraduate students from both U.S. and Chinese cultures used various imitations in…

  17. Accent Imitation Positively Affects Language Attitudes

    Directory of Open Access Journals (Sweden)

    Patti eAdank

    2013-05-01

    Full Text Available People in conversation tend to accommodate the way they speak. It has been assumed that this tendency to imitate each other’s speech patterns serves to increase liking between partners in a conversation. Previous experiments examined the effect of perceived social attractiveness on the tendency to imitate someone else’s speech and found that vocal imitation increased when perceived attractiveness was higher. The present experiment extends this research by examining the inverse relationship and examines how overt vocal imitation affects attitudes. Participants listened to sentences spoken by two speakers of a regional accent (Glaswegian of English. They vocally repeated (speaking in their own accent without imitating the sentences spoken by a Glaswegian speaker, and subsequently imitated sentences spoken by a second Glaswegian speaker (order counterbalanced across participants. After each repeating or imitation session, participants completed a questionnaire probing the speakers’ perceived power, competence, and social attractiveness. Imitating had a positive effect on the perceived social attractiveness of the speaker compared to repeating. These results are interpreted in light of Communication Accommodation Theory.

  18. Imitation and speech: commonalities within Broca's area.

    Science.gov (United States)

    Kühn, Simone; Brass, Marcel; Gallinat, Jürgen

    2013-11-01

    The so-called embodiment of communication has attracted considerable interest. Recently a growing number of studies have proposed a link between Broca's area's involvement in action processing and its involvement in speech. The present quantitative meta-analysis set out to test whether neuroimaging studies on imitation and overt speech show overlap within inferior frontal gyrus. By means of activation likelihood estimation (ALE), we investigated concurrence of brain regions activated by object-free hand imitation studies as well as overt speech studies including simple syllable and more complex word production. We found direct overlap between imitation and speech in bilateral pars opercularis (BA 44) within Broca's area. Subtraction analyses revealed no unique localization neither for speech nor for imitation. To verify the potential of ALE subtraction analysis to detect unique involvement within Broca's area, we contrasted the results of a meta-analysis on motor inhibition and imitation and found separable regions involved for imitation. This is the first meta-analysis to compare the neural correlates of imitation and overt speech. The results are in line with the proposed evolutionary roots of speech in imitation.

  19. Quantum-mechanical generalization of the Biot-Savart law

    International Nuclear Information System (INIS)

    Fassio-Canuto, L.

    1978-01-01

    The complex geometrical considerations involved in deriving the magnetic field due to a current of assigned geometry can be considerably simplified and, therefore, generalized if one employs the field-theoretical relation between the field Asub(μ) and the current jsub(μ). In the general case of a current with helicoidal structure, the magnetic field can be found for any point of space. The particular cases of the loop, the solenoid and the straight wire are then easily derived. The rationale for wanting to generalize the classical Biot-Savart law to include quantum-mechanical effects is discussed in the light of a more general program intended to study the origin of magnetic fields in collapsed objects. (author)

  20. A 'general boundary' formulation for quantum mechanics and quantum gravity

    International Nuclear Information System (INIS)

    Oeckl, Robert

    2003-01-01

    I propose to formalize quantum theories as topological quantum field theories in a generalized sense, associating state spaces with boundaries of arbitrary (and possibly finite) regions of space-time. I further propose to obtain such 'general boundary' quantum theories through a generalized path integral quantization. I show how both, non-relativistic quantum mechanics and quantum field theory can be given a 'general boundary' formulation. Surprisingly, even in the non-relativistic case, features normally associated with quantum field theory emerge from consistency conditions. This includes states with arbitrary particle number and pair creation. I also note how three-dimensional quantum gravity is an example for a realization of both proposals and suggest to apply them to four-dimensional quantum gravity

  1. Noncommutative unification of general relativity and quantum mechanics

    International Nuclear Information System (INIS)

    Heller, Michael; Pysiak, Leszek; Sasin, Wieslaw

    2005-01-01

    We present a model unifying general relativity and quantum mechanics based on a noncommutative geometry. This geometry is developed in terms of a noncommutative algebra A which is defined on a transformation groupoid Γ given by the action of a noncompact group G on the total space E of a principal fiber bundle over space-time M. The case is important since to obtain physical effects predicted by the model we should assume that G is a Lorentz group or some of its representations. We show that the generalized Einstein equation of the model has the form of the eigenvalue equation for the generalized Ricci operator, and all relevant operators in the quantum sector of the model are random operators; we study their dynamics. We also show that the model correctly reproduces general relativity and the usual quantum mechanics. It is interesting that the latter is recovered by performing the measurement of any observable. In the act of such a measurement the model 'collapses' to the usual quantum mechanics

  2. Generalized Statistical Mechanics at the Onset of Chaos

    Directory of Open Access Journals (Sweden)

    Alberto Robledo

    2013-11-01

    Full Text Available Transitions to chaos in archetypal low-dimensional nonlinear maps offer real and precise model systems in which to assess proposed generalizations of statistical mechanics. The known association of chaotic dynamics with the structure of Boltzmann–Gibbs (BG statistical mechanics has suggested the potential verification of these generalizations at the onset of chaos, when the only Lyapunov exponent vanishes and ergodic and mixing properties cease to hold. There are three well-known routes to chaos in these deterministic dissipative systems, period-doubling, quasi-periodicity and intermittency, which provide the setting in which to explore the limit of validity of the standard BG structure. It has been shown that there is a rich and intricate behavior for both the dynamics within and towards the attractors at the onset of chaos and that these two kinds of properties are linked via generalized statistical-mechanical expressions. Amongst the topics presented are: (i permanently growing sensitivity fluctuations and their infinite family of generalized Pesin identities; (ii the emergence of statistical-mechanical structures in the dynamics along the routes to chaos; (iii dynamical hierarchies with modular organization; and (iv limit distributions of sums of deterministic variables. The occurrence of generalized entropy properties in condensed-matter physical systems is illustrated by considering critical fluctuations, localization transition and glass formation. We complete our presentation with the description of the manifestations of the dynamics at the transitions to chaos in various kinds of complex systems, such as, frequency and size rank distributions and complex network images of time series. We discuss the results.

  3. Automatic imitation: A meta-analysis.

    Science.gov (United States)

    Cracco, Emiel; Bardi, Lara; Desmet, Charlotte; Genschow, Oliver; Rigoni, Davide; De Coster, Lize; Radkova, Ina; Deschrijver, Eliane; Brass, Marcel

    2018-05-01

    Automatic imitation is the finding that movement execution is facilitated by compatible and impeded by incompatible observed movements. In the past 15 years, automatic imitation has been studied to understand the relation between perception and action in social interaction. Although research on this topic started in cognitive science, interest quickly spread to related disciplines such as social psychology, clinical psychology, and neuroscience. However, important theoretical questions have remained unanswered. Therefore, in the present meta-analysis, we evaluated seven key questions on automatic imitation. The results, based on 161 studies containing 226 experiments, revealed an overall effect size of g z = 0.95, 95% CI [0.88, 1.02]. Moderator analyses identified automatic imitation as a flexible, largely automatic process that is driven by movement and effector compatibility, but is also influenced by spatial compatibility. Automatic imitation was found to be stronger for forced choice tasks than for simple response tasks, for human agents than for nonhuman agents, and for goalless actions than for goal-directed actions. However, it was not modulated by more subtle factors such as animacy beliefs, motion profiles, or visual perspective. Finally, there was no evidence for a relation between automatic imitation and either empathy or autism. Among other things, these findings point toward actor-imitator similarity as a crucial modulator of automatic imitation and challenge the view that imitative tendencies are an indicator of social functioning. The current meta-analysis has important theoretical implications and sheds light on longstanding controversies in the literature on automatic imitation and related domains. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

  4. Quantum mechanics vs. general covariance in gravity and string models

    International Nuclear Information System (INIS)

    Martinec, E.J.

    1984-01-01

    Quantization of simple low-dimensional systems embodying general covariance is studied. Functional methods are employed in the calculation of effective actions for fermionic strings and 1 + 1 dimensional gravity. The author finds that regularization breaks apparent symmetries of the theory, providing new dynamics for the string and non-trivial dynamics for 1 + 1 gravity. The author moves on to consider the quantization of some generally covariant systems with a finite number of physical degrees of freedom, assuming the existence of an invariant cutoff. The author finds that the wavefunction of the universe in these cases is given by the solution to simple quantum mechanics problems

  5. Mirror Neurons, Embodied Cognitive Agents and Imitation Learning

    Czech Academy of Sciences Publication Activity Database

    Wiedermann, Jiří

    2003-01-01

    Roč. 22, č. 6 (2003), s. 545-559 ISSN 1335-9150 R&D Projects: GA ČR GA201/02/1456 Institutional research plan: CEZ:AV0Z1030915 Keywords : complete agents * mirror neurons * embodied cognition * imitation learning * sensorimotor control Subject RIV: BA - General Mathematics Impact factor: 0.254, year: 2003 http://www.cai.sk/ojs/index.php/cai/article/view/468

  6. Mirror Neurons, Embodied Cognitive Agents and Imitation Learning

    OpenAIRE

    Wiedermann, Jiří

    2003-01-01

    Mirror neurons are a relatively recent discovery; it has been conjectured that these neurons play an important role in imitation learning and other cognitive phenomena. We will study a possible place and role of mirror neurons in the neural architecture of embodied cognitive agents. We will formulate and investigate the hypothesis that mirror neurons serve as a mechanism which coordinates the multimodal (i.e., motor, perceptional and proprioceptive) information and completes it so that the ag...

  7. Generalized Poisson processes in quantum mechanics and field theory

    International Nuclear Information System (INIS)

    Combe, P.; Rodriguez, R.; Centre National de la Recherche Scientifique, 13 - Marseille; Hoegh-Krohn, R.; Centre National de la Recherche Scientifique, 13 - Marseille; Sirugue, M.; Sirugue-Collin, M.; Centre National de la Recherche Scientifique, 13 - Marseille

    1981-01-01

    In section 2 we describe more carefully the generalized Poisson processes, giving a realization of the underlying probability space, and we characterize these processes by their characteristic functionals. Section 3 is devoted to the proof of the previous formula for quantum mechanical systems, with possibly velocity dependent potentials and in section 4 we give an application of the previous theory to some relativistic Bose field models. (orig.)

  8. Quantum mechanics in general relativity and its special - relativistic limit

    International Nuclear Information System (INIS)

    Tagirov, Eh.A.

    1998-01-01

    Quantum mechanics of a neutral point-like particle in the general Riemannian space-time is constructed starting with the general Fock representation of the quantum scalar field. The known ambiguity of the representation is removed by the requirement that the quasi-one-particle wave functions in configurational space should admit the Born probabilistic interpretation after a transformation, generally nonlocal, and therefore may be considered as the one-particle wave functions. Operators of momentum and spatial position of a particle acting in the space of these transformed wave functions are deduced consecutively from basic naturally defined operators of the observables in the Fock space. They coincide with the canonical ones only in the case of the infinite velocity of light. In particular, even in the Minkowski space-time and inertial frames of reference , the operators of curvilinear coordinates do not commute

  9. Deep imitation learning for 3D navigation tasks.

    Science.gov (United States)

    Hussein, Ahmed; Elyan, Eyad; Gaber, Mohamed Medhat; Jayne, Chrisina

    2018-01-01

    Deep learning techniques have shown success in learning from raw high-dimensional data in various applications. While deep reinforcement learning is recently gaining popularity as a method to train intelligent agents, utilizing deep learning in imitation learning has been scarcely explored. Imitation learning can be an efficient method to teach intelligent agents by providing a set of demonstrations to learn from. However, generalizing to situations that are not represented in the demonstrations can be challenging, especially in 3D environments. In this paper, we propose a deep imitation learning method to learn navigation tasks from demonstrations in a 3D environment. The supervised policy is refined using active learning in order to generalize to unseen situations. This approach is compared to two popular deep reinforcement learning techniques: deep-Q-networks and Asynchronous actor-critic (A3C). The proposed method as well as the reinforcement learning methods employ deep convolutional neural networks and learn directly from raw visual input. Methods for combining learning from demonstrations and experience are also investigated. This combination aims to join the generalization ability of learning by experience with the efficiency of learning by imitation. The proposed methods are evaluated on 4 navigation tasks in a 3D simulated environment. Navigation tasks are a typical problem that is relevant to many real applications. They pose the challenge of requiring demonstrations of long trajectories to reach the target and only providing delayed rewards (usually terminal) to the agent. The experiments show that the proposed method can successfully learn navigation tasks from raw visual input while learning from experience methods fail to learn an effective policy. Moreover, it is shown that active learning can significantly improve the performance of the initially learned policy using a small number of active samples.

  10. Elicited Imitation for Brazilian Portuguese

    Directory of Open Access Journals (Sweden)

    Lonsdale, Deryle W.

    2015-01-01

    Full Text Available Elicited imitation (EI is an approach to measuring oral proficiency that consists of having test takers hear a sentence and repeat the sentence exactly as they heard it. Though indirect in nature, EI has successfully shown to correlate with previously established oral proficiency examinations, such as the Oral Proficiency Interview (OPI (Lonsdale and Christensen 2014, Matsushita and Lonsdale 2014, Millard 2011, Thompson 2013. This paper discusses the development, administration, and evaluation of an EI test for the Brazilian Portuguese language. We first discuss the relevant background of oral proficiency examination and EI. After presenting the pertinent research questions, we explain the methodology used to develop the EI test, recruit participants, and administer the test. We present the results and analysis and then summarize the findings, limitations, and possible future work

  11. The perils of the imitation age.

    Science.gov (United States)

    Bonabeau, Eric

    2004-06-01

    Imitation exerts enormous influence over society, and business and finance in particular. And its influence has grown as the avenues by which people imitate--and are imitated--have multiplied and the process has gotten faster. Thousands of communications channels make it possible for virtually anyone in the developed world to know, almost instantaneously, what others do, think, believe, claim, or predict. More significantly, we can and do act upon such knowledge. The resulting fads and fashions, bubbles and crashes are ever more frequent, severe, and complex. The information age has cast up more than its share of paradoxes, including this one: When information is plentiful, we often use it not to make better decisions but to imitate others--and their mistakes. In consumer purchases, financial markets, and corporate strategy, what others do matters more to us than the facts. When there's too much information, imitation becomes a convenient heuristic. This is the basis for a self-referential society. Imitation has its virtues, but it also promotes instability and unpredictability. That's because, by definition a multiplier, it can swell a single opinion into a mass movement or catapult the smallest player to the forefront of a market. Mastering the dynamics of self-reference won't ensure mastery of its consequences. But businesses that understand how imitation works can at least attempt to gird themselves against its worst effects--by accounting for it in their forecasts and risk-management plans, by becoming more sensitive to unexpectedly changing circumstances, and by avoiding mindless imitation of other companies' moves. In some instances, they may even be able to build strategies around self-reference and use the tools of imitation to capture new business. That won't make the world any less confusing. But it may make it more profitable.

  12. Selective and faithful imitation at 12 and 15 months.

    Science.gov (United States)

    Hilbrink, Elma E; Sakkalou, Elena; Ellis-Davies, Kate; Fowler, Nia C; Gattis, Merideth

    2013-11-01

    Research on imitation in infancy has primarily focused on what and when infants imitate. More recently, however, the question why infants imitate has received renewed attention, partly motivated by the finding that infants sometimes selectively imitate the actions of others and sometimes faithfully imitate, or overimitate, the actions of others. The present study evaluates the hypothesis that this varying imitative behavior is related to infants' social traits. To do so, we assessed faithful and selective imitation longitudinally at 12 and 15 months, and extraversion at 15 months. At both ages, selective imitation was dependent on the causal structure of the act. From 12 to 15 months, selective imitation decreased while faithful imitation increased. Furthermore, infants high in extraversion were more faithful imitators than infants low in extraversion. These results demonstrate that the onset of faithful imitation is earlier than previously thought, but later than the onset of selective imitation. The observed relation between extraversion and faithful imitation supports the hypothesis that faithful imitation is driven by the social motivations of the infant. We call this relation the King Louie Effect: like the orangutan King Louie in The Jungle Book, infants imitate faithfully due to a growing interest in the interpersonal nature of interactions. © 2013 John Wiley & Sons Ltd.

  13. Imitation explains the propagation, not the stability of animal culture.

    Science.gov (United States)

    Claidière, Nicolas; Sperber, Dan

    2010-02-22

    For acquired behaviour to count as cultural, two conditions must be met: it must propagate in a social group, and it must remain stable across generations in the process of propagation. It is commonly assumed that imitation is the mechanism that explains both the spread of animal culture and its stability. We review the literature on transmission chain studies in chimpanzees (Pan troglodytes) and other animals, and we use a formal model to argue that imitation, which may well play a major role in the propagation of animal culture, cannot be considered faithful enough to explain its stability. We consider the contribution that other psychological and ecological factors might make to the stability of animal culture observed in the wild.

  14. A comprehensive account of sound sequence imitation in the songbird.

    Directory of Open Access Journals (Sweden)

    Maren Westkott

    2016-07-01

    Full Text Available The amazing imitation capabilities of songbirds show that they can memorize sensory sequences and transform them into motor activities which in turn generate the original sound sequences. This suggests that the bird's brain can learn 1. to reliably reproduce spatio-temporal sensory representations and 2. to transform them into corresponding spatio-temporal motor activations by using an inverse mapping. Neither the synaptic mechanisms nor the network architecture enabling these two fundamental aspects of imitation learning are known. We propose an architecture of coupled neuronal modules that mimick areas in the song bird and show that a unique synaptic plasticity mechanism can serve to learn both, sensory sequences in a recurrent neuronal network, as well as an inverse model that transforms the sensory memories into the corresponding motor activations. The proposed membrane potential dependent learning rule together with the architecture that includes basic features of the bird's brain represents the first comprehensive account of bird imitation learning based on spiking neurons.

  15. The perception of musical spontaneity in improvised and imitated jazz performances

    Directory of Open Access Journals (Sweden)

    Annerose eEngel

    2011-05-01

    Full Text Available The ability to evaluate spontaneity in human behavior is called upon in the aesthetic appreciation of dramatic arts and music. The current study addresses the behavioral and brain mechanisms that mediate the perception of spontaneity in music performance. In a functional Magnetic Resonance Imaging experiment, 22 jazz musicians listened to piano melodies and judged whether they were improvised or imitated. Judgment accuracy (mean 55%; range 44-65%, which was low but above chance, was positively correlated with musical experience and empathy. Analysis of listeners’ hemodynamic responses revealed that amygdala activation was stronger for improvisations than imitations. This activation correlated with the variability of performance timing and intensity (loudness in the melodies, suggesting that the amygdala is involved in the detection of behavioral uncertainty. An analysis based on the subjective classification of melodies according to listeners’ judgments revealed that a network including the pre-supplementary motor area, frontal operculum, and anterior insula was most strongly activated for melodies judged to be improvised. This may reflect the increased engagement of an action simulation network when melodic predictions are rendered challenging due to perceived instability in the performer’s actions. Taken together, our results suggest that, while certain brain regions in skilled individuals may be generally sensitive to objective cues to spontaneity in human behavior, the ability to evaluate spontaneity accurately depends upon whether an individual’s action-related experience and perspective taking skills enable faithful internal simulation of the given behavior.

  16. The perception of musical spontaneity in improvised and imitated jazz performances.

    Science.gov (United States)

    Engel, Annerose; Keller, Peter E

    2011-01-01

    The ability to evaluate spontaneity in human behavior is called upon in the esthetic appreciation of dramatic arts and music. The current study addresses the behavioral and brain mechanisms that mediate the perception of spontaneity in music performance. In a functional magnetic resonance imaging experiment, 22 jazz musicians listened to piano melodies and judged whether they were improvised or imitated. Judgment accuracy (mean 55%; range 44-65%), which was low but above chance, was positively correlated with musical experience and empathy. Analysis of listeners' hemodynamic responses revealed that amygdala activation was stronger for improvisations than imitations. This activation correlated with the variability of performance timing and intensity (loudness) in the melodies, suggesting that the amygdala is involved in the detection of behavioral uncertainty. An analysis based on the subjective classification of melodies according to listeners' judgments revealed that a network including the pre-supplementary motor area, frontal operculum, and anterior insula was most strongly activated for melodies judged to be improvised. This may reflect the increased engagement of an action simulation network when melodic predictions are rendered challenging due to perceived instability in the performer's actions. Taken together, our results suggest that, while certain brain regions in skilled individuals may be generally sensitive to objective cues to spontaneity in human behavior, the ability to evaluate spontaneity accurately depends upon whether an individual's action-related experience and perspective taking skills enable faithful internal simulation of the given behavior.

  17. Deficits in motor abilities and developmental fractionation of imitation performance in high-functioning autism spectrum disorders.

    Science.gov (United States)

    Biscaldi, Monica; Rauh, Reinhold; Irion, Lisa; Jung, Nikolai H; Mall, Volker; Fleischhaker, Christian; Klein, Christoph

    2014-07-01

    The co-occurrence of motor and imitation disabilities often characterises the spectrum of deficits seen in patients with autism spectrum disorders (ASD). Whether these seemingly separate deficits are inter-related and whether, in particular, motor deficits contribute to the expression of imitation deficits is the topic of the present study and was investigated by comparing these deficits' cross-sectional developmental trajectories. To that end, different components of motor performance assessed in the Zurich Neuromotor Assessment and imitation abilities for facial movements and non-meaningful gestures were tested in 70 subjects (aged 6-29 years), including 36 patients with high-functioning ASD and 34 age-matched typically developed (TD) participants. The results show robust deficits in probands with ASD in timed motor performance and in the quality of movement, which are all independent of age, with one exception. Only diadochokinesis improves moderately with increasing age in ASD probands. Imitation of facial movements and of non-meaningful hand, finger, hand finger gestures not related to social context or tool use is also impaired in ASD subjects, but in contrast to motor performance this deficit overall improves with age. A general imitation factor, extracted from the highly inter-correlated imitation tests, is differentially correlated with components of neuromotor performance in ASD and TD participants. By developmentally fractionating developmentally stable motor deficits from developmentally dynamic imitation deficits, we infer that imitation deficits are primarily cognitive in nature.

  18. The mechanism of suppression: a component of general comprehension skill.

    Science.gov (United States)

    Gernsbacher, M A; Faust, M E

    1991-03-01

    We investigated whether the cognitive mechanism of suppression underlies differences in adult comprehension skill. Less skilled comprehenders reject less efficiently the inappropriate meanings of ambiguous words (e.g., the playing card vs. garden tool meaning of spade), the incorrect forms of homophones (e.g., patients vs. patience), the highly typical but absent members of scenes (e.g., a tractor in a farm scene), and words superimposed on pictures or pictures surrounding words. However, less skilled comprehenders are not less cognizant of what is contextually appropriate; in fact, they benefit from a biasing context just as much (and perhaps more) as more skilled comprehenders do. Thus, less skilled comprehenders do not have difficulty enhancing contextually appropriate information. Instead, we suggest that less skilled comprehenders suffer from a less efficient suppression mechanism, which we conclude is an important component of general comprehension skill.

  19. On imitation among young and blind children

    Directory of Open Access Journals (Sweden)

    Maria Rita Campello Rodrigues

    2016-07-01

    Full Text Available This article investigates the imitation among young and blind children. The survey was conducted as a mosaic in the time since the field considerations were taken from two areas: a professional experience with early stimulation of blind babies and a workshop with blind and low vision young between 13-18 years. By statingthe situated trace of knowledge, theresearch indicates that imitation among blind young people can be one of the ways of creating a common world among young blind and sighted people. Imitation among blind young is a multi-sensory process that requires a body experience, including both blind and people who see. The paper concludes with an indication of the unique character of imitation and at the same time, with the affirmation of its relevance to the development and inclusion process of both the child and the young blind.

  20. The control of automatic imitation based on bottom-up and top-down cues to animacy: insights from brain and behavior.

    Science.gov (United States)

    Klapper, André; Ramsey, Richard; Wigboldus, Daniël; Cross, Emily S

    2014-11-01

    Humans automatically imitate other people's actions during social interactions, building rapport and social closeness in the process. Although the behavioral consequences and neural correlates of imitation have been studied extensively, little is known about the neural mechanisms that control imitative tendencies. For example, the degree to which an agent is perceived as human-like influences automatic imitation, but it is not known how perception of animacy influences brain circuits that control imitation. In the current fMRI study, we examined how the perception and belief of animacy influence the control of automatic imitation. Using an imitation-inhibition paradigm that involves suppressing the tendency to imitate an observed action, we manipulated both bottom-up (visual input) and top-down (belief) cues to animacy. Results show divergent patterns of behavioral and neural responses. Behavioral analyses show that automatic imitation is equivalent when one or both cues to animacy are present but reduces when both are absent. By contrast, right TPJ showed sensitivity to the presence of both animacy cues. Thus, we demonstrate that right TPJ is biologically tuned to control imitative tendencies when the observed agent both looks like and is believed to be human. The results suggest that right TPJ may be involved in a specialized capacity to control automatic imitation of human agents, rather than a universal process of conflict management, which would be more consistent with generalist theories of imitative control. Evidence for specialized neural circuitry that "controls" imitation offers new insight into developmental disorders that involve atypical processing of social information, such as autism spectrum disorders.

  1. Imitation inhibition in children with Tourette syndrome.

    Science.gov (United States)

    Brandt, Valerie Cathérine; Moczydlowski, Agnes; Jonas, Melanie; Boelmans, Kai; Bäumer, Tobias; Brass, Marcel; Münchau, Alexander

    2017-08-12

    Echopraxia, that is, the open and automatic imitation of other peoples' actions, is common in patients with Gilles de la Tourette syndrome, autism spectrum disorder, and also those with frontal lobe lesions. While systematic reaction time tasks have confirmed increased automatic imitation in the latter two groups, adult patients with Tourette syndrome appear to compensate for automatic imitation tendencies by an overall slowing in response times. However, whether children with Tourette syndrome are already able to inhibit automatic imitation tendencies has not been investigated. Fifteen children with Tourette syndrome and 15 healthy children (aged 7-12 years) performed an imitation inhibition paradigm. Participants were asked to respond to an auditory cue by lifting their index finger or their little finger. Participants were simultaneously presented with either compatible or incompatible visual stimuli. Overall responses in children with Tourette syndrome were slower than in healthy children. Although responses were faster in compatible than in incompatible trials in both groups, this 'interference effect' was smaller in children with Tourette syndrome. Children with Tourette syndrome have a smaller interference effect than healthy children, indicating an enhanced ability to behaviourally control automatic imitation tendencies at the cost of reacting slower. The results suggest that children with Tourette syndrome already employ different or additional inhibition strategies compared to healthy children. © 2017 The British Psychological Society.

  2. Bimanual Gesture Imitation in Alzheimer's Disease.

    Science.gov (United States)

    Sanin, G Nter; Benke, Thomas

    2017-01-01

    Unimanual gesture production or imitation has often been studied in Alzheimer's disease (AD) during apraxia testing. In the present study, it was hypothesized that bimanual motor tasks may be a sensitive method to detect impairments of motor cognition in AD due to increased demands on the cognitive system. We investigated bimanual, meaningless gesture imitation in 45 AD outpatients, 38 subjects with mild cognitive impairment (MCI), and 50 normal controls (NC) attending a memory clinic. Participants performed neuropsychological background testing and three tasks: the Interlocking Finger Test (ILF), Imitation of Alternating Hand Movements (AHM), and Bimanual Rhythm Tapping (BRT). The tasks were short and easy to administer. Inter-rater reliability was high across all three tests. AD patients performed significantly poorer than NC and MCI participants; a deficit to imitate bimanual gestures was rarely found in MCI and NC participants. Sensitivity to detect AD ranged from 0.5 and 0.7, specificity beyond 0.9. ROC analyses revealed good diagnostic accuracy (0.77 to 0.92). Impairment to imitate bimanual gestures was mainly predicted by diagnosis and disease severity. Our findings suggest that an impairment to imitate bimanual, meaningless gestures is a valid disease marker of mild to moderate AD and can easily be assessed in memory clinic settings. Based on our preliminary findings, it appears to be a separate impairment which can be distinguished from other cognitive deficits.

  3. How were Imitations of Samian Formed?

    Directory of Open Access Journals (Sweden)

    Tino Leleković

    2018-05-01

    Full Text Available This article examines the variety of the locally made ceramic group known as Pannonian slipped ware (Pannonische Glanztonware - PGW. For the Roman provincial archaeology of Pannonia this group has particular meaning because it is perceived as a regional amalgam of Roman imperial taste and local Celtic traditions. This phenomenon is even more intriguing given that almost all the imitations were burnished grey and black, differing significantly from terra sigillata originals. The quality of the imitations clearly indicates that such colouring was not a consequence of a technological deficiency, but a clear expression of local taste and demand. Imitations that were made subsequently, later in the second century, show that the preference for black/grey slipped imitations of terra sigillata persisted in this region, obviously representing a distinctive alternative to the ever-present red gloss terra sigillata that was later imported from Gaul and Germania. A re-examination of other sites in the region and contextualisation of published material shows that this was not an isolated phenomenon, but that these imitations were part of a regional ceramic group known as Pannonian slipped ware (PSW. Several aspects of these imitations could be explored, but the task of this article is to investigate why these vessels were made as they were by comparing the PSW finds with original terra sigillata found in the region to determine patterns of differences and similarities.

  4. Imitative and best response behaviors in a nonlinear Cournotian setting

    Science.gov (United States)

    Cerboni Baiardi, Lorenzo; Naimzada, Ahmad K.

    2018-05-01

    We consider the competition among quantity setting players in a deterministic nonlinear oligopoly framework characterized by an isoelastic demand curve. Players are characterized by having heterogeneous decisional mechanisms to set their outputs: some players are imitators, while the remaining others adopt a rational-like rule according to which their past decisions are adjusted towards their static expectation best response. The Cournot-Nash production level is a stationary state of our model together with a further production level that can be interpreted as the competitive outcome in case only imitators are present. We found that both the number of players and the relative fraction of imitators influence stability of the Cournot-Nash equilibrium with an ambiguous role, and double instability thresholds may be observed. Global analysis shows that a wide variety of complex dynamic scenarios emerge. Chaotic trajectories as well as multi-stabilities, where different attractors coexist, are robust phenomena that can be observed for a wide spectrum of parameter sets.

  5. Acquisition of automatic imitation is sensitive to sensorimotor contingency.

    Science.gov (United States)

    Cook, Richard; Press, Clare; Dickinson, Anthony; Heyes, Cecilia

    2010-08-01

    The associative sequence learning model proposes that the development of the mirror system depends on the same mechanisms of associative learning that mediate Pavlovian and instrumental conditioning. To test this model, two experiments used the reduction of automatic imitation through incompatible sensorimotor training to assess whether mirror system plasticity is sensitive to contingency (i.e., the extent to which activation of one representation predicts activation of another). In Experiment 1, residual automatic imitation was measured following incompatible training in which the action stimulus was a perfect predictor of the response (contingent) or not at all predictive of the response (noncontingent). A contingency effect was observed: There was less automatic imitation indicative of more learning in the contingent group. Experiment 2 replicated this contingency effect and showed that, as predicted by associative learning theory, it can be abolished by signaling trials in which the response occurs in the absence of an action stimulus. These findings support the view that mirror system development depends on associative learning and indicate that this learning is not purely Hebbian. If this is correct, associative learning theory could be used to explain, predict, and intervene in mirror system development.

  6. Promoting Imitation in Young Children with Autism: A Comparison of Reciprocal Imitation Training and Video Modeling

    Science.gov (United States)

    Cardon, Teresa A.; Wilcox, M. Jeanne

    2011-01-01

    The inability to imitate is a salient diagnostic marker for autism. It has been suggested that for children with autism, imitation may be a prerequisite skill that can assist in the development of various skills. Using a multiple baseline design across subjects, the purpose of this research was to determine if two interventions, reciprocal…

  7. A κ-generalized statistical mechanics approach to income analysis

    International Nuclear Information System (INIS)

    Clementi, F; Gallegati, M; Kaniadakis, G

    2009-01-01

    This paper proposes a statistical mechanics approach to the analysis of income distribution and inequality. A new distribution function, having its roots in the framework of κ-generalized statistics, is derived that is particularly suitable for describing the whole spectrum of incomes, from the low–middle income region up to the high income Pareto power-law regime. Analytical expressions for the shape, moments and some other basic statistical properties are given. Furthermore, several well-known econometric tools for measuring inequality, which all exist in a closed form, are considered. A method for parameter estimation is also discussed. The model is shown to fit remarkably well the data on personal income for the United States, and the analysis of inequality performed in terms of its parameters is revealed as very powerful

  8. The problem of time quantum mechanics versus general relativity

    CERN Document Server

    Anderson, Edward

    2017-01-01

    This book is a treatise on time and on background independence in physics. It first considers how time is conceived of in each accepted paradigm of physics: Newtonian, special relativity, quantum mechanics (QM) and general relativity (GR). Substantial differences are moreover uncovered between what is meant by time in QM and in GR. These differences jointly source the Problem of Time: Nine interlinked facets which arise upon attempting concurrent treatment of the QM and GR paradigms, as is required in particular for a background independent theory of quantum gravity. A sizeable proportion of current quantum gravity programs - e.g. geometrodynamical and loop quantum gravity approaches to quantum GR, quantum cosmology, supergravity and M-theory - are background independent in this sense. This book's foundational topic is thus furthermore of practical relevance in the ongoing development of quantum gravity programs. This book shows moreover that eight of the nine facets of the Problem of Time already occur upon ...

  9. A κ-generalized statistical mechanics approach to income analysis

    Science.gov (United States)

    Clementi, F.; Gallegati, M.; Kaniadakis, G.

    2009-02-01

    This paper proposes a statistical mechanics approach to the analysis of income distribution and inequality. A new distribution function, having its roots in the framework of κ-generalized statistics, is derived that is particularly suitable for describing the whole spectrum of incomes, from the low-middle income region up to the high income Pareto power-law regime. Analytical expressions for the shape, moments and some other basic statistical properties are given. Furthermore, several well-known econometric tools for measuring inequality, which all exist in a closed form, are considered. A method for parameter estimation is also discussed. The model is shown to fit remarkably well the data on personal income for the United States, and the analysis of inequality performed in terms of its parameters is revealed as very powerful.

  10. Statistical mechanics of sparse generalization and graphical model selection

    International Nuclear Information System (INIS)

    Lage-Castellanos, Alejandro; Pagnani, Andrea; Weigt, Martin

    2009-01-01

    One of the crucial tasks in many inference problems is the extraction of an underlying sparse graphical model from a given number of high-dimensional measurements. In machine learning, this is frequently achieved using, as a penalty term, the L p norm of the model parameters, with p≤1 for efficient dilution. Here we propose a statistical mechanics analysis of the problem in the setting of perceptron memorization and generalization. Using a replica approach, we are able to evaluate the relative performance of naive dilution (obtained by learning without dilution, following by applying a threshold to the model parameters), L 1 dilution (which is frequently used in convex optimization) and L 0 dilution (which is optimal but computationally hard to implement). Whereas both L p diluted approaches clearly outperform the naive approach, we find a small region where L 0 works almost perfectly and strongly outperforms the simpler to implement L 1 dilution

  11. Variant at serotonin transporter gene predicts increased imitation in toddlers: relevance to the human capacity for cumulative culture.

    Science.gov (United States)

    Schroeder, Kari Britt; Asherson, Philip; Blake, Peter R; Fenstermacher, Susan K; Saudino, Kimberly J

    2016-04-01

    Cumulative culture ostensibly arises from a set of sociocognitive processes which includes high-fidelity production imitation, prosociality and group identification. The latter processes are facilitated by unconscious imitation or social mimicry. The proximate mechanisms of individual variation in imitation may thus shed light on the evolutionary history of the human capacity for cumulative culture. In humans, a genetic component to variation in the propensity for imitation is likely. A functional length polymorphism in the serotonin transporter gene, the short allele at 5HTTLPR, is associated with heightened responsiveness to the social environment as well as anatomical and activational differences in the brain's imitation circuity. Here, we evaluate whether this polymorphism contributes to variation in production imitation and social mimicry. Toddlers with the short allele at 5HTTLPR exhibit increased social mimicry and increased fidelity of demonstrated novel object manipulations. Thus, the short allele is associated with two forms of imitation that may underlie the human capacity for cumulative culture. The short allele spread relatively recently, possibly due to selection, and its frequency varies dramatically on a global scale. Diverse observations can be unified via conceptualization of 5HTTLPR as influencing the propensity to experience others' emotions, actions and sensations, potentially through the mirror mechanism. © 2016 The Author(s).

  12. Thallium Toxicity: General Issues, Neurological Symptoms, and Neurotoxic Mechanisms.

    Science.gov (United States)

    Osorio-Rico, Laura; Santamaria, Abel; Galván-Arzate, Sonia

    2017-01-01

    Thallium (Tl + ) is a ubiquitous natural trace metal considered as the most toxic among heavy metals. The ionic ratio of Tl + is similar to that of potassium (K + ), therefore accounting for the replacement of the latter during enzymatic reactions. The principal organelle damaged after Tl + exposure is mitochondria. Studies on the mechanisms of Tl + include intrinsic pathways altered and changes in antiapoptotic and proapoptotic proteins, cytochrome c, and caspases. Oxidative damage pathways increase after Tl + exposure to produce reactive oxygen species (ROS), changes in physical properties of the cell membrane caused by lipid peroxidation, and concomitant activation of antioxidant mechanisms. These processes are likely to account for the neurotoxic effects of the metal. In humans, Tl + is absorbed through the skin and mucous membranes and then is widely distributed throughout the body to be accumulated in bones, renal medulla, liver, and the Central Nervous System. Given the growing relevance of Tl + intoxication, in recent years there is a notorious increase in the number of reports attending Tl + pollution in different countries. In this sense, the neurological symptoms produced by Tl + and its neurotoxic effects are gaining attention as they represent a serious health problem all over the world. Through this review, we present an update to general information about Tl + toxicity, making emphasis on some recent data about Tl + neurotoxicity, as a field requiring attention at the clinical and preclinical levels.

  13. Multiple-event probability in general-relativistic quantum mechanics

    International Nuclear Information System (INIS)

    Hellmann, Frank; Mondragon, Mauricio; Perez, Alejandro; Rovelli, Carlo

    2007-01-01

    We discuss the definition of quantum probability in the context of 'timeless' general-relativistic quantum mechanics. In particular, we study the probability of sequences of events, or multievent probability. In conventional quantum mechanics this can be obtained by means of the 'wave function collapse' algorithm. We first point out certain difficulties of some natural definitions of multievent probability, including the conditional probability widely considered in the literature. We then observe that multievent probability can be reduced to single-event probability, by taking into account the quantum nature of the measuring apparatus. In fact, by exploiting the von-Neumann freedom of moving the quantum/classical boundary, one can always trade a sequence of noncommuting quantum measurements at different times, with an ensemble of simultaneous commuting measurements on the joint system+apparatus system. This observation permits a formulation of quantum theory based only on single-event probability, where the results of the wave function collapse algorithm can nevertheless be recovered. The discussion also bears on the nature of the quantum collapse

  14. Statistical mechanics of learning orthogonal signals for general covariance models

    International Nuclear Information System (INIS)

    Hoyle, David C

    2010-01-01

    Statistical mechanics techniques have proved to be useful tools in quantifying the accuracy with which signal vectors are extracted from experimental data. However, analysis has previously been limited to specific model forms for the population covariance C, which may be inappropriate for real world data sets. In this paper we obtain new statistical mechanical results for a general population covariance matrix C. For data sets consisting of p sample points in R N we use the replica method to study the accuracy of orthogonal signal vectors estimated from the sample data. In the asymptotic limit of N,p→∞ at fixed α = p/N, we derive analytical results for the signal direction learning curves. In the asymptotic limit the learning curves follow a single universal form, each displaying a retarded learning transition. An explicit formula for the location of the retarded learning transition is obtained and we find marked variation in the location of the retarded learning transition dependent on the distribution of population covariance eigenvalues. The results of the replica analysis are confirmed against simulation

  15. A developmental approach of imitation to study the emergence of mirror neurons in a sensory-motor controller

    Directory of Open Access Journals (Sweden)

    Gaussier Philippe

    2011-12-01

    Full Text Available Mirror neurons have often been considered as the explanation of how primates can imitate. In this paper, we show that a simple neural network architecture that learns visuo-motor associations can be enough to let low level imitation emerge without a priori mirror neurons. Adding sequence learning mechanisms and action inhibition allows to perform deferred imitation of gestures demonstrated visually or by body manipulation. With the building of a cognitive map giving the capability of learning plans, we can study in our model the emergence of both low level and high level resonances highlighted by Rizzolatti et al.

  16. Effects of stimulus response compatibility on covert imitation of vowels.

    Science.gov (United States)

    Adank, Patti; Nuttall, Helen; Bekkering, Harold; Maegherman, Gwijde

    2018-03-13

    When we observe someone else speaking, we tend to automatically activate the corresponding speech motor patterns. When listening, we therefore covertly imitate the observed speech. Simulation theories of speech perception propose that covert imitation of speech motor patterns supports speech perception. Covert imitation of speech has been studied with interference paradigms, including the stimulus-response compatibility paradigm (SRC). The SRC paradigm measures covert imitation by comparing articulation of a prompt following exposure to a distracter. Responses tend to be faster for congruent than for incongruent distracters; thus, showing evidence of covert imitation. Simulation accounts propose a key role for covert imitation in speech perception. However, covert imitation has thus far only been demonstrated for a select class of speech sounds, namely consonants, and it is unclear whether covert imitation extends to vowels. We aimed to demonstrate that covert imitation effects as measured with the SRC paradigm extend to vowels, in two experiments. We examined whether covert imitation occurs for vowels in a consonant-vowel-consonant context in visual, audio, and audiovisual modalities. We presented the prompt at four time points to examine how covert imitation varied over the distracter's duration. The results of both experiments clearly demonstrated covert imitation effects for vowels, thus supporting simulation theories of speech perception. Covert imitation was not affected by stimulus modality and was maximal for later time points.

  17. Cognitive Control Structures in the Imitation Learning of Spatial Sequences and Rhythms-An fMRI Study.

    Science.gov (United States)

    Sakreida, Katrin; Higuchi, Satomi; Di Dio, Cinzia; Ziessler, Michael; Turgeon, Martine; Roberts, Neil; Vogt, Stefan

    2018-03-01

    Imitation learning involves the acquisition of novel motor patterns based on action observation (AO). We used event-related functional magnetic resonance imaging to study the imitation learning of spatial sequences and rhythms during AO, motor imagery (MI), and imitative execution in nonmusicians and musicians. While both tasks engaged the fronto-parietal mirror circuit, the spatial sequence task recruited posterior parietal and dorsal premotor regions more strongly. The rhythm task involved an additional network for auditory working memory. This partial dissociation supports the concept of task-specific mirror mechanisms. Two regions of cognitive control were identified: 1) dorsolateral prefrontal cortex (DLPFC) was found to be more strongly activated during MI of novel spatial sequences, which allowed us to extend the 2-level model of imitation learning by Buccino et al. (2004) to spatial sequences. 2) During imitative execution of both tasks, the posterior medial frontal cortex was robustly activated, along with the DLPFC, which suggests that both regions are involved in the cognitive control of imitation learning. The musicians' selective behavioral advantage for rhythm imitation was reflected cortically in enhanced sensory-motor processing during AO and by the absence of practice-related activation differences in DLPFC during rhythm execution. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  18. A damage mechanics based general purpose interface/contact element

    Science.gov (United States)

    Yan, Chengyong

    Most of the microelectronics packaging structures consist of layered substrates connected with bonding materials, such as solder or epoxy. Predicting the thermomechanical behavior of these multilayered structures is a challenging task in electronic packaging engineering. In a layered structure the most complex part is always the interfaces between the strates. Simulating the thermo-mechanical behavior of such interfaces, is the main theme of this dissertation. The most commonly used solder material, Pb-Sn alloy, has a very low melting temperature 180sp°C, so that the material demonstrates a highly viscous behavior. And, creep usually dominates the failure mechanism. Hence, the theory of viscoplasticity is adapted to describe the constitutive behavior. In a multilayered assembly each layer has a different coefficient of thermal expansion. Under thermal cycling, due to heat dissipated from circuits, interfaces and interconnects experience low cycle fatigue. Presently, the state-of-the art damage mechanics model used for fatigue life predictions is based on Kachanov (1986) continuum damage model. This model uses plastic strain as a damage criterion. Since plastic strain is a stress path dependent value, the criterion does not yield unique damage values for the same state of stress. In this dissertation a new damage evolution equation based on the second law of thermodynamic is proposed. The new criterion is based on the entropy of the system and it yields unique damage values for all stress paths to the final state of stress. In the electronics industry, there is a strong desire to develop fatigue free interconnections. The proposed interface/contact element can also simulate the behavior of the fatigue free Z-direction thin film interconnections as well as traditional layered interconnects. The proposed interface element can simulate behavior of a bonded interface or unbonded sliding interface, also called contact element. The proposed element was verified against

  19. Intonation processing in congenital amusia: discrimination, identification and imitation.

    Science.gov (United States)

    Liu, Fang; Patel, Aniruddh D; Fourcin, Adrian; Stewart, Lauren

    2010-06-01

    This study investigated whether congenital amusia, a neuro-developmental disorder of musical perception, also has implications for speech intonation processing. In total, 16 British amusics and 16 matched controls completed five intonation perception tasks and two pitch threshold tasks. Compared with controls, amusics showed impaired performance on discrimination, identification and imitation of statements and questions that were characterized primarily by pitch direction differences in the final word. This intonation-processing deficit in amusia was largely associated with a psychophysical pitch direction discrimination deficit. These findings suggest that amusia impacts upon one's language abilities in subtle ways, and support previous evidence that pitch processing in language and music involves shared mechanisms.

  20. GENERAL EQUATIONS OF CARBONIZATION OF EUCALYPTUS SPP KINETIC MECHANISMS

    Directory of Open Access Journals (Sweden)

    Túlio Jardim Raad

    2006-06-01

    Full Text Available In the present work, a set of general equations related to kinetic mechanism of wood compound carbonization: hemicelluloses, cellulose and lignin was obtained by Avrami-Eroffev and Arrhenius equations and Thermogravimetry of Eucalyptus cloeziana, Eucalyptus camaldulensis, Corymbia citriodora, Eucalyptus urophylla and Eucalyptus grandis samples, TG-Isothermal and TG-Dynamic. The different thermal stabilities and decomposition temperature bands of those species compounds were applied as strategy to obtain the kinetic parameters: activation energy, exponential factor and reaction order. The kinetic model developed was validated by thermogravimetric curves from carbonization of others biomass such as coconut. The kinetic parameters found were - Hemicelluloses: E=98,6 kJmol, A=3,5x106s-1 n=1,0; - Cellulose: E=182,2 kJmol, A=1,2x1013s-1 n=1,5; - Lignin: E=46,6 kJmol, A=2,01s-1 n=0,41. The set of equations can be implemented in a mathematical model of wood carbonization simulation (with heat and mass transfer equations with the aim of optimizing the control and charcoal process used to produce pig iron.

  1. General aspects of solid on liquid growth mechanisms

    International Nuclear Information System (INIS)

    Laux, E; Charmet, J; Haquette, H; Banakh, O; Jeandupeux, L; Graf, B; Keppner, H

    2009-01-01

    Liquids, in general, tend to have a lower density as solids and therefore it is not straightforward to deposit solid over liquids in a way that the liquid becomes hermetically sealed under the solid layer. The authors review that several phenomena that can easily be observed in nature are only due to particular anomalies and solid on liquid is rather an exception as the rule. Natural solid on liquid systems are lacking of thermal, mechanical or chemical stability. It is not surprising, that one is not at all used thinking about to e.g. replace the gate oxide in a thin film transistor by a thin film of oil, or, to find in other microsystems functional liquids between a stack of thin solid films. However, once this becomes a serious option, a large variety of new Microsystems with new functionalities can be easily designed. In another paper (this conference and [1]) the authors pioneered that the polymer Parylene (poly(p-xylylene)) can be deposited on liquids coming already quite close to the above mentioned vision. In this paper the authors ask if one can synthesize other solid on liquid systems and surprisingly conclude, based on experimental evidence, that solid on liquid deposition seems to rather be the rule and not the exception.

  2. One interpretation for both Quantum Mechanics and General Relativity

    Energy Technology Data Exchange (ETDEWEB)

    Halewijn, Ewoud

    2014-07-01

    In reconciling General Relativity with Quantum Mechanics, it is challenging to resolve the combined mathematical equations and to find an interpretation that makes sense ontologically. Such an interpretation has been developed by quantizing descriptive components in both the theories and other views. The resulting micro-components have been re-integrated within the scope of known gaps between science and 'the real world'. The odd peculiarities in these theories have been made look 'normal' by fully untraditionally answering fundamental questions. The interpretation is suggesting that we define time as a discrete operator and its eigenvalues as constraints on space-time manifolds, in order to reconcile the mathematical equations. Outside the mathematical arena we suggest reconsidering the concepts of Black Holes, the Big Bang, the epistemological problem of perception in philosophy and the supposed clash between scientific and the spiritual worldviews. It is concluded that developing one consistent ontological interpretation for both theorie is possible. It is a weird story, but it is making powerful suggestions for reviewing some of our fundamental convictions.

  3. The Imitation Game: Alan Turings enigmatiske imitationsspil

    DEFF Research Database (Denmark)

    Bentzen, Martin Mose

    2015-01-01

    Alan Turing revolutionerede computervidenskaben og modtog først verdens anerkendelse længe efter sin død. Nu sætter filmen 'The Imitation Game', der har premiere i Danmark 29. januar 2015, fokus på det oversete geni.......Alan Turing revolutionerede computervidenskaben og modtog først verdens anerkendelse længe efter sin død. Nu sætter filmen 'The Imitation Game', der har premiere i Danmark 29. januar 2015, fokus på det oversete geni....

  4. Thermal imitators with single directional invisibility

    Science.gov (United States)

    Wang, Ruizhe; Xu, Liujun; Huang, Jiping

    2017-12-01

    Thermal metamaterials have been intensively studied during the past years to achieve the long-standing dream of invisibility, illusion, and other inconceivable thermal phenomena. However, many thermal metamaterials can only exhibit omnidirectional thermal response, which take on the distinct feature of geometrical isotropy. In this work, we theoretically design and experimentally fabricate a pair of thermal imitators by applying geometrical anisotropy provided by elliptical/ellipsoidal particles and layered structures. This pair of thermal imitators possesses thermal invisibility in one direction, while having thermal opacity in other directions. This work may open a gate in designing direction-dependent thermal metamaterials.

  5. Developing an effective IM/IT strategy.

    Science.gov (United States)

    Kramer, Sarah; Walker, Joanne; Falk, Will

    2009-01-01

    Healthcare organizations and systems around the world lag far behind banking, manufacturing, travel and other industries in their use of information management/information technology (IM/IT) to deliver high-quality products and services. Across Canada, healthcare organizations, as well as governments, understand that information and information technology are needed to deliver quality care and to sustain our publicly funded health system. However, insufficient funding, few experienced resources, lack of strong leadership and absence of clear business/clinical rationale have restricted innovation and advancement in the use of IM/IT to improve healthcare delivery and patient outcomes.

  6. Over-imitation is not automatic: context sensitivity in children's overimitation and action interpretation of causally irrelevant actions.

    Science.gov (United States)

    Keupp, Stefanie; Behne, Tanya; Zachow, Joanna; Kasbohm, Alina; Rakoczy, Hannes

    2015-02-01

    Recent research has documented the robust tendency of children to "over-imitate," that is, to copy causally irrelevant action elements in goal-directed action sequences. Different explanations for over-imitation have been proposed. Causal accounts claim that children mistakenly perceive such action elements as causally relevant and, therefore, imitate them. Affiliation accounts claim that children over-imitate to affiliate with the model. Normative accounts claim that children conceive of causally irrelevant actions as essential parts of an overarching conventional activity. These different accounts generally hold the same predictions regarding children's imitative response. However, it is possible to distinguish between them when one considers additional parameters. The normative account predicts wide-ranging flexibility with regard to action interpretation and the occurrence of over-imitation. First, it predicts spontaneous protest against norm violators who omit the causally irrelevant actions. Second, children should perform the causally irrelevant actions less frequently, and criticize others less frequently for omitting them, when the actions take place in a different context from the one of the initial demonstration. Such flexibility is not predicted by causal accounts and is predicted for only a limited range of contexts by affiliation accounts. Study 1 investigated children's own imitative response and found less over-imitation when children acted in a different context from when they acted in the same context as the initial demonstration. In Study 2, children criticized a puppet less frequently for omitting irrelevant actions when the puppet acted in a different context. The results support the notion that over-imitation is not an automatic and inflexible phenomenon. Copyright © 2014 Elsevier Inc. All rights reserved.

  7. Consumer evaluation of copycat brands : The effect of imitation type

    NARCIS (Netherlands)

    van Horen, F.; Pieters, R.

    2012-01-01

    Copycat brands imitate the trade dress of a leader brand to free ride on the latter's equity. Copycats can imitate the distinctive perceptual features of the leader brand, such as the lilac color of the Milka chocolate brand, or they can imitate the underlying meaning or theme of the leader brand,

  8. Kinematic Measures of Imitation Fidelity in Primary School Children

    Science.gov (United States)

    Williams, Justin H. G.; Casey, Jackie M.; Braadbaart, Lieke; Culmer, Peter R.; Mon-Williams, Mark

    2014-01-01

    We sought to develop a method for measuring imitation accuracy objectively in primary school children. Children imitated a model drawing shapes on the same computer-tablet interface they saw used in video clips, allowing kinematics of model and observers' actions to be directly compared. Imitation accuracy was reported as a correlation reflecting…

  9. Shadow-Reading: Affordances for Imitation in the Language Classroom

    Science.gov (United States)

    de Guerrero, María C. M.; Commander, Millie

    2013-01-01

    Imitation has a fundamental role in learning and development within Vygotskyan sociocultural theory. In this study, we adopt a sociocultural theory view of imitation as an intentional, meaningful, and transformative process leading learners to higher developmental levels. The study centers on instances of imitation that occurred as adult learners…

  10. Imitation of Para-Phonological Detail Following Left Hemisphere Lesions

    Science.gov (United States)

    Kappes, Juliane; Baumgaertner, Annette; Peschke, Claudia; Goldenberg, Georg; Ziegler, Wolfram

    2010-01-01

    Imitation in speech refers to the unintentional transfer of phonologically irrelevant acoustic-phonetic information of auditory input into speech motor output. Evidence for such imitation effects has been explained within the framework of episodic theories. However, it is largely unclear, which neural structures mediate speech imitation and how…

  11. Imitation in Fragile X Syndrome: Implications for Autism

    Science.gov (United States)

    Macedoni-Luksic, Marta; Greiss-Hess, Laura; Rogers, Sally J.; Gosar, David; Lemons-Chitwood, Kerrie; Hagerman, Randi

    2009-01-01

    To address the specific impairment of imitation in autism, the imitation abilities of 22 children with fragile X syndrome (FXS) with and without autism were compared. Based on previous research, we predicted that children with FXS and autism would have significantly more difficulty with non-meaningful imitation tasks. After controlling for…

  12. Nurturance and Imitation: The Mediating Role of Attraction

    Science.gov (United States)

    Parton, David A.; Siebold, James R.

    1975-01-01

    Describes two experiments which examine the relationship between nurturance, attraction, and imitation. The results showed a significant relationship between nurturance and attraction and no relationship between nurturance and imitation. This suggests that positive relationships between nurturance and imitation are mediated by the child's…

  13. Imitation and Creativity: Beneficial Effects of Propulsion Strategies and Specificity

    Science.gov (United States)

    Mecca, Jensen T.; Mumford, Michael D.

    2014-01-01

    Prior studies examining imitation of exemplar solutions have produced a mixed pattern of findings with some studies indicating that exemplar imitation contributes to creative problem-solving and other studies indicating that it may inhibit creative problem-solving. In the present effort, it is argued that the effects of exemplar imitation on…

  14. A Cross-Cultural Comparison of Children's Imitative Flexibility

    Science.gov (United States)

    Clegg, Jennifer M.; Legare, Cristine H.

    2016-01-01

    Recent research with Western populations has demonstrated that children use imitation flexibly to engage in both instrumental and conventional learning. Evidence for children's imitative flexibility in non-Western populations is limited, however, and has only assessed imitation of instrumental tasks. This study (N = 142, 6- to 8-year-olds)…

  15. Consumer evaluation of copycat brands: The effect of imitation type

    NARCIS (Netherlands)

    Van Horen, F.; Pieters, R.

    2012-01-01

    Copycat brands imitate the trade dress of a leader brand to free ride on the latter's equity. Copycats can imitate the distinctive perceptual features of the leader brand, such as the lilac color of the Milka chocolate brand, or they can imitate the underlying meaning or theme of the leader brand,

  16. Bend-imitating theory and electron scattering in sharply-bent quantum nanowires

    International Nuclear Information System (INIS)

    Vakhnenko, O.O.

    2011-01-01

    The concept of bend-imitating description as applied to the one-electron quantum mechanics in sharply-bent ideal electron waveguides and its development into a self consistent theory are presented. In the framework of bend-imitating approach, the investigation of the electron scattering in a doubly-bent 2D quantum wire with S-like bend has been made, and the explicit dependences of the transmission and reflection coefficients on geometrical parameters of a structure, as well as on the electron energy, have been obtained. The total elimination of the mixing between the scattering channels of a S-like bent quantum wire is predicted.

  17. Comparative Cognition: Action Imitation Using Episodic Memory.

    Science.gov (United States)

    Crystal, Jonathon D

    2016-12-05

    Humans encounter a myriad of actions or events and later recall some of these events using episodic memory. New research suggests that dogs can imitate recently encountered actions using episodic memory. Copyright © 2016 Elsevier Ltd. All rights reserved.

  18. Pathological Imitative Behavior and Response Preparation in Schizophrenia.

    Science.gov (United States)

    Dankinas, Denisas; Melynyte, Sigita; Siurkute, Aldona; Dapsys, Kastytis

    2017-08-01

    Pathological imitative behavior (ehopraxia) is occasionally observed in schizophrenia patients. However, only a severe form of echopraxia can be detected with the help of a direct observation. Therefore, our goal was to study a latent form of pathological imitative behavior in this disorder, which is indicated by an increase of imitative tendencies. In our study, 14 schizophrenia patients and 15 healthy subjects were employed in two tasks: (a) in an imitative task they had to copy a hand action seen on a screen; (b) in a counter-imitative task they had to make a different movement (which involves an inhibition of prepotent imitative tendency that is impaired in case of pathological imitative behavior). Imitative tendencies were assessed by an interference score - a difference between counter-imitative and imitative response parameters. We also studied a response preparation in both groups by employing precueing probabilistic information. Our results revealed that schizophrenia patients were able to employ probabilistic information to prepare properly not only the imitative, but also the counter-imitative responses, the same as the healthy subjects did. Nevertheless, we detected increased prepotent imitative tendencies in schizophrenia patients, what indicates the latent pathological imitative behavior in case of this disorder. The obtained results suggest that in the case of schizophrenia problems with pathological imitative behavior more likely occurred in executive rather than in the preparatory stage of response. Our findings can help to detect a latent echopraxia in schizophrenia patients that cannot be revealed by direct observation. © The Author 2017. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  19. Effect of meaning on apraxic finger imitation deficits.

    Science.gov (United States)

    Achilles, E I S; Fink, G R; Fischer, M H; Dovern, A; Held, A; Timpert, D C; Schroeter, C; Schuetz, K; Kloetzsch, C; Weiss, P H

    2016-02-01

    Apraxia typically results from left-hemispheric (LH), but also from right-hemispheric (RH) stroke, and often impairs gesture imitation. Especially in LH stroke, it is important to differentiate apraxia-induced gesture imitation deficits from those due to co-morbid aphasia and associated semantic deficits, possibly influencing the imitation of meaningful (MF) gestures. To explore this issue, we first investigated if the 10 supposedly meaningless (ML) gestures of a widely used finger imitation test really carry no meaning, or if the test also contains MF gestures, by asking healthy subjects (n=45) to classify these gestures as MF or ML. Most healthy subjects (98%) classified three of the 10 gestures as clearly MF. Only two gestures were considered predominantly ML. We next assessed how imitation in stroke patients (255 LH, 113 RH stroke) is influenced by gesture meaning and how aphasia influences imitation of LH stroke patients (n=208). All patients and especially patients with imitation deficits (17% of LH, 27% of RH stroke patients) imitated MF gestures significantly better than ML gestures. Importantly, meaningfulness-scores of all 10 gestures significantly predicted imitation scores of patients with imitation deficits. Furthermore, especially in LH stroke patients with imitation deficits, the severity of aphasia significantly influenced the imitation of MF, but not ML gestures. Our findings in a large patient cohort support current cognitive models of imitation and strongly suggest that ML gestures are particularly sensitive to detect imitation deficits while minimising confounding effects of aphasia which affect the imitation of MF gestures in LH stroke patients. Copyright © 2015 Elsevier Ltd. All rights reserved.

  20. Nonequilibrium statistical mechanics in the general theory of relativity. I. A general formalism

    International Nuclear Information System (INIS)

    Israel, W.; Kandrup, H.E.

    1984-01-01

    This is the first in a series of papers, the overall objective of which is the formulation of a new covariant approach to nonequilibrium statistical mechanics in classical general relativity. The objecct here is the development of a tractable theory for self-gravitating systems. It is argued that the ''state'' of an N-particle system may be characterized by an N-particle distribution function, defined in an 8N-dimensional phase space, which satisfies a collection of N conservation equations. By mapping the true physics onto a fictitious ''background'' spacetime, which may be chosen to satisfy some ''average'' field equations, one then obtains a useful covariant notion of ''evolution'' in response to a fluctuating ''gravitational force.'' For many cases of practical interest, one may suppose (i) that these fluctuating forces satisfy linear field equations and (ii) that they may be modeled by a direct interaction. In this case, one can use a relativistic projection operator formalism to derive exact closed equations for the evolution of such objects as an appropriately defined reduced one-particle distribution function. By capturing, in a natural way, the notion of a dilute gas, or impulse, approximation, one is then led to a comparatively simple equation for the one-particle distribution. If, furthermore, one treats the effects of the fluctuating forces as ''localized'' in space and time, one obtains a tractable kinetic equation which reduces, in the Newtonian limit, to the stardard Landau equation

  1. Imitation of Body Postures and Hand Movements in Children with Specific Language Impairment

    Science.gov (United States)

    Marton, Klara

    2009-01-01

    Within the domain-general theory of language impairment, this study examined body posture and hand movement imitation in children with specific language impairment (SLI) and in their age-matched peers. Participants included 40 children with SLI (5 years 3 months to 6 years 10 months of age) and 40 children with typical language development (5…

  2. Perception-action coupling and imitation in autism spectrum disorder.

    Science.gov (United States)

    Nadel, Jacqueline

    2015-04-01

    This paper focuses on the key function of imitation in motor and social development of typically developing infants and low-functioning children with autism spectrum disorder (ASD). We suggest that it might also be a developmental cornerstone for other neurodevelopmental disorders. Why this suggestion? First, imitation just requires relating one's motor patterns to perceived motor patterns. This is always possible if the actions seen are not beyond the individual's motor scope; for instance, newborn infants can already imitate tongue protrusion, eye blinking, or mouth opening, because these movements are part of their foetal repertoire. Second, imitation is a 'use it or lose it' capacity: the more it is used, the more the repertoire grows (plasticity). Finally, imitation is an efficient tool for two main adaptive functions: learning and communication. Imitation-based communication is available through the use of the two facets of imitation: imitating and being imitated. The two facets afford two roles that the partners can exchange as a turn-taking while they synchronize matched activities. Neuroimaging studies of interactive imitation have shown that such communicative systems involve a coordination of bottom-up and top-down processes. In this line, imitation is a booster of development that can also be of benefit for children with neurodevelopmental disorders. © 2015 The Authors. Developmental Medicine & Child Neurology © 2015 Mac Keith Press.

  3. Phonetic imitation by young children and its developmental changes.

    Science.gov (United States)

    Nielsen, Kuniko

    2014-12-01

    In the current study, the author investigated the developmental course of phonetic imitation in childhood, and further evaluated existing accounts of phonetic imitation. Sixteen preschoolers, 15 third graders, and 18 college students participated in the current study. An experiment with a modified imitation paradigm with a picture-naming task was conducted, in which participants' voice-onset time (VOT) was compared before and after they were exposed to target speech with artificially increased VOT. Extended VOT in the target speech was imitated by preschoolers and 3rd graders as well as adults, confirming previous findings in phonetic imitation. Furthermore, an age effect of phonetic imitation was observed; namely, children showed greater imitation than adults, whereas the degree of imitation was comparable between preschoolers and 3rd graders. No significant effect of gender or word specificity was observed. Young children imitated fine phonetic details of the target speech, and greater degree of phonetic imitation was observed in children compared to adults. These findings suggest that the degree of phonetic imitation negatively correlates with phonological development.

  4. General aspects of the mechanical integrity of canisters

    International Nuclear Information System (INIS)

    Saario, Timo

    2007-01-01

    This paper attempts to introduce a new point of view to the mechanical integrity of the canisters, 'mechanical integrity evolutionary path'. The mechanical integrity evolutionary path is a description of development of the critical parameters involved in the prevailing degradation modes as a function of time. The degradation mechanisms considered are: mechanical overload; creep; and stress corrosion cracking. For each degradation mechanism one may consider two different states; initial state; critical state. The initial state considered will be different for different degradation mechanisms. For example stress corrosion cracking (SCC), which involves electrochemical steps is not possible without a surface covering aqueous phase. Thus, potentially, the initial state for SCC is that existing after saturation. On the other hand, the initial state for a possible mechanical overload can be different in different periods during the mechanical integrity evolutionary path. During the handling and transport stages the initial state is 'ex works', while during a glaciation the initial state has been altered due to creep, corrosion and possible SCC processes. The canister will go through mechanical overload during saturation and bentonite swelling phases and it will deform to fit the form of the insert. The initial state for this period is 'ex works', with e.g. manufacturing defects. The insert is designed to bear the load after closing the gap. In the 'ex works' state directionality of the mechanical properties has been raised lately as a new issue worth checking. Within the projected evolutionary path two events have been especially considered; seismic events and glaciation. A glacier 2 km thick would increase the hydrostatic pressure with 20 MPa if there were a mechanism transmitting the load into the aqueous phase. Remembering what makes ice skating possible such a mechanism seems plausible. For mechanical overload the critical state is relatively straightforward to

  5. General aspects of the mechanical integrity of canisters

    Energy Technology Data Exchange (ETDEWEB)

    Saario, Timo [VTT Materials and Building (Finland)

    2007-09-15

    This paper attempts to introduce a new point of view to the mechanical integrity of the canisters, 'mechanical integrity evolutionary path'. The mechanical integrity evolutionary path is a description of development of the critical parameters involved in the prevailing degradation modes as a function of time. The degradation mechanisms considered are: mechanical overload; creep; and stress corrosion cracking. For each degradation mechanism one may consider two different states; initial state; critical state. The initial state considered will be different for different degradation mechanisms. For example stress corrosion cracking (SCC), which involves electrochemical steps is not possible without a surface covering aqueous phase. Thus, potentially, the initial state for SCC is that existing after saturation. On the other hand, the initial state for a possible mechanical overload can be different in different periods during the mechanical integrity evolutionary path. During the handling and transport stages the initial state is 'ex works', while during a glaciation the initial state has been altered due to creep, corrosion and possible SCC processes. The canister will go through mechanical overload during saturation and bentonite swelling phases and it will deform to fit the form of the insert. The initial state for this period is 'ex works', with e.g. manufacturing defects. The insert is designed to bear the load after closing the gap. In the 'ex works' state directionality of the mechanical properties has been raised lately as a new issue worth checking. Within the projected evolutionary path two events have been especially considered; seismic events and glaciation. A glacier 2 km thick would increase the hydrostatic pressure with 20 MPa if there were a mechanism transmitting the load into the aqueous phase. Remembering what makes ice skating possible such a mechanism seems plausible. For mechanical overload the critical

  6. Generalized contexts and consistent histories in quantum mechanics

    International Nuclear Information System (INIS)

    Losada, Marcelo; Laura, Roberto

    2014-01-01

    We analyze a restriction of the theory of consistent histories by imposing that a valid description of a physical system must include quantum histories which satisfy the consistency conditions for all states. We prove that these conditions are equivalent to imposing the compatibility conditions of our formalism of generalized contexts. Moreover, we show that the theory of consistent histories with the consistency conditions for all states and the formalism of generalized context are equally useful representing expressions which involve properties at different times

  7. Generalized statistical mechanics approaches to earthquakes and tectonics

    Science.gov (United States)

    Papadakis, Giorgos; Michas, Georgios

    2016-01-01

    Despite the extreme complexity that characterizes the mechanism of the earthquake generation process, simple empirical scaling relations apply to the collective properties of earthquakes and faults in a variety of tectonic environments and scales. The physical characterization of those properties and the scaling relations that describe them attract a wide scientific interest and are incorporated in the probabilistic forecasting of seismicity in local, regional and planetary scales. Considerable progress has been made in the analysis of the statistical mechanics of earthquakes, which, based on the principle of entropy, can provide a physical rationale to the macroscopic properties frequently observed. The scale-invariant properties, the (multi) fractal structures and the long-range interactions that have been found to characterize fault and earthquake populations have recently led to the consideration of non-extensive statistical mechanics (NESM) as a consistent statistical mechanics framework for the description of seismicity. The consistency between NESM and observations has been demonstrated in a series of publications on seismicity, faulting, rock physics and other fields of geosciences. The aim of this review is to present in a concise manner the fundamental macroscopic properties of earthquakes and faulting and how these can be derived by using the notions of statistical mechanics and NESM, providing further insights into earthquake physics and fault growth processes. PMID:28119548

  8. Neural activation differences in amputees during imitation of intact versus amputee movements

    Directory of Open Access Journals (Sweden)

    William F Cusack

    2012-06-01

    Full Text Available The mirror neuron system has been attributed with increased activation in motor-related cortical areas upon viewing of another’s actions. Recent work suggests that limb movements that are similar and dissimilar in appearance to that of the viewer equivalently activate the mirror neuron system. It is unclear if this result can be observed in the action encoding areas in amputees who use prosthetic devices. Intact subjects and upper extremity amputee prosthesis users were recruited to view video demonstrations of tools being used by an intact actor and a prosthetic device user. All subjects were asked to pantomime the movements seen in the video while recording electroencephalography. Intact subjects showed equivalent left parietofrontal activity during imitation after watching the intact or prosthetic arm. Likewise, when prosthesis users imitated prosthesis demonstrations, typical left parietofrontal activation was observed during planning. When prosthesis users imitated intact actors, a new pattern was revealed which showed greater bilateral parietal and occipital activity during movement planning (p<0.001. This change may be required for prosthesis users to imitate movements in which the limb states between the observed and the observer do not match. The finding that prosthesis users imitating other prosthesis users showed typical left parietofrontal activation suggests that these subjects engage normal planning related activity when they are able to imitate a limb matching their own. This result has significant implications on rehabilitation, as standard therapy involves training with an intact occupational therapist, which could necessitate atypical planning mechanisms in amputees when learning to use their prosthesis.

  9. General presentation of the core mechanical behaviour approach in France

    International Nuclear Information System (INIS)

    Bernard, A.; Dorsselaere, J.P. van

    1984-01-01

    This French review paper presents the evolution along time of the FBR core mechanical behaviour approach, from RAPSODIE to SPX2, through PHENIX and SPX1: core designs, knowledge of the irradiation laws, project criterias, calculation codes, and R and D fields. (author)

  10. Re-examination of Oostenbroek et al. (2016): evidence for neonatal imitation of tongue protrusion.

    Science.gov (United States)

    Meltzoff, Andrew N; Murray, Lynne; Simpson, Elizabeth; Heimann, Mikael; Nagy, Emese; Nadel, Jacqueline; Pedersen, Eric J; Brooks, Rechele; Messinger, Daniel S; Pascalis, Leonardo De; Subiaul, Francys; Paukner, Annika; Ferrari, Pier F

    2017-09-27

    The meaning, mechanism, and function of imitation in early infancy have been actively discussed since Meltzoff and Moore's (1977) report of facial and manual imitation by human neonates. Oostenbroek et al. (2016) claim to challenge the existence of early imitation and to counter all interpretations so far offered. Such claims, if true, would have implications for theories of social-cognitive development. Here we identify 11 flaws in Oostenbroek et al.'s experimental design that biased the results toward null effects. We requested and obtained the authors' raw data. Contrary to the authors' conclusions, new analyses reveal significant tongue-protrusion imitation at all four ages tested (1, 3, 6, and 9 weeks old). We explain how the authors missed this pattern and offer five recommendations for designing future experiments. Infant imitation raises fundamental issues about action representation, social learning, and brain-behavior relations. The debate about the origins and development of imitation reflects its importance to theories of developmental science. © 2017 John Wiley & Sons Ltd.

  11. Repeated imitation makes human vocalizations more word-like.

    Science.gov (United States)

    Edmiston, Pierce; Perlman, Marcus; Lupyan, Gary

    2018-03-14

    People have long pondered the evolution of language and the origin of words. Here, we investigate how conventional spoken words might emerge from imitations of environmental sounds. Does the repeated imitation of an environmental sound gradually give rise to more word-like forms? In what ways do these forms resemble the original sounds that motivated them (i.e. exhibit iconicity)? Participants played a version of the children's game 'Telephone'. The first generation of participants imitated recognizable environmental sounds (e.g. glass breaking, water splashing). Subsequent generations imitated the previous generation of imitations for a maximum of eight generations. The results showed that the imitations became more stable and word-like, and later imitations were easier to learn as category labels. At the same time, even after eight generations, both spoken imitations and their written transcriptions could be matched above chance to the category of environmental sound that motivated them. These results show how repeated imitation can create progressively more word-like forms while continuing to retain a resemblance to the original sound that motivated them, and speak to the possible role of human vocal imitation in explaining the origins of at least some spoken words. © 2018 The Author(s).

  12. Emulation, imitation, over-imitation and the scope of culture for child and chimpanzee.

    Science.gov (United States)

    Whiten, Andrew; McGuigan, Nicola; Marshall-Pescini, Sarah; Hopper, Lydia M

    2009-08-27

    We describe our recent studies of imitation and cultural transmission in chimpanzees and children, which question late twentieth-century characterizations of children as imitators, but chimpanzees as emulators. As emulation entails learning only about the results of others' actions, it has been thought to curtail any capacity to sustain cultures. Recent chimpanzee diffusion experiments have by contrast documented a significant capacity for copying local behavioural traditions. Additionally, in recent 'ghost' experiments with no model visible, chimpanzees failed to replicate the object movements on which emulation is supposed to focus. We conclude that chimpanzees rely more on imitation and have greater cultural capacities than previously acknowledged. However, we also find that they selectively apply a range of social learning processes that include emulation. Recent studies demonstrating surprisingly unselective 'over-imitation' in children suggest that children's propensity to imitate has been underestimated too. We discuss the implications of these developments for the nature of social learning and culture in the two species. Finally, our new experiments directly address cumulative cultural learning. Initial results demonstrate a relative conservatism and conformity in chimpanzees' learning, contrasting with cumulative cultural learning in young children. This difference may contribute much to the contrast in these species' capacities for cultural evolution.

  13. Generalized space and linear momentum operators in quantum mechanics

    International Nuclear Information System (INIS)

    Costa, Bruno G. da; Borges, Ernesto P.

    2014-01-01

    We propose a modification of a recently introduced generalized translation operator, by including a q-exponential factor, which implies in the definition of a Hermitian deformed linear momentum operator p ^ q , and its canonically conjugate deformed position operator x ^ q . A canonical transformation leads the Hamiltonian of a position-dependent mass particle to another Hamiltonian of a particle with constant mass in a conservative force field of a deformed phase space. The equation of motion for the classical phase space may be expressed in terms of the generalized dual q-derivative. A position-dependent mass confined in an infinite square potential well is shown as an instance. Uncertainty and correspondence principles are analyzed

  14. The Mechanism of Suppression: A Component of General Comprehension Skill

    OpenAIRE

    Gernsbacher, Morton Ann; Faust, Mark E.

    1991-01-01

    We investigated whether the cognitive mechanism of suppression underlies differences in adult comprehension skill. Less skilled comprehenders reject less efficiently the inappropriate meanings of ambiguous words (e.g., the playing card vs. garden tool meaning of spade), the incorrect forms of homophones (e.g., patients vs. patience), the highly typical but absent members of scenes (e.g., a tractor in a farm scene), and words superimposed on pictures or pictures surrounding words. However, les...

  15. The shared circuits model (SCM): how control, mirroring, and simulation can enable imitation, deliberation, and mindreading.

    Science.gov (United States)

    Hurley, Susan

    2008-02-01

    Imitation, deliberation, and mindreading are characteristically human sociocognitive skills. Research on imitation and its role in social cognition is flourishing across various disciplines. Imitation is surveyed in this target article under headings of behavior, subpersonal mechanisms, and functions of imitation. A model is then advanced within which many of the developments surveyed can be located and explained. The shared circuits model (SCM) explains how imitation, deliberation, and mindreading can be enabled by subpersonal mechanisms of control, mirroring, and simulation. It is cast at a middle, functional level of description, that is, between the level of neural implementation and the level of conscious perceptions and intentional actions. The SCM connects shared informational dynamics for perception and action with shared informational dynamics for self and other, while also showing how the action/perception, self/other, and actual/possible distinctions can be overlaid on these shared informational dynamics. It avoids the common conception of perception and action as separate and peripheral to central cognition. Rather, it contributes to the situated cognition movement by showing how mechanisms for perceiving action can be built on those for active perception.;>;>The SCM is developed heuristically, in five layers that can be combined in various ways to frame specific ontogenetic or phylogenetic hypotheses. The starting point is dynamic online motor control, whereby an organism is closely attuned to its embedding environment through sensorimotor feedback. Onto this are layered functions of prediction and simulation of feedback, mirroring, simulation of mirroring, monitored inhibition of motor output, and monitored simulation of input. Finally, monitored simulation of input specifying possible actions plus inhibited mirroring of such possible actions can generate information about the possible as opposed to actual instrumental actions of others, and the

  16. Imitation, Objects, Tools, and the Rudiments of Language in Human Ontogeny

    Science.gov (United States)

    Meltzoff, A. N.

    2013-01-01

    Human beings are imitative generalists. We can immediately imitate a wide range of behaviors with great facility, whether they be vocal maneuvers, body postures, or actions on objects. The ontogeny of this skill has been an enduring question in developmental psychology. Classical theory holds that the ability to imitate facial gestures is a milestone that is passed at about one year. Before this time infants are thought to lack the perceptual-cognitive sophistication necessary to match a gesture they can see with one they cannot see themselves perform. A second developmental milestone is the capacity for deferred imitation, i.e. imitation of an absent model. This is said to emerge at about 18 months, in close synchrony with other higher-order activities such as object permanence and tool use, as part of a general cognitive shift from a purely sensory-motor level of functioning to one that allows language. Research suggests that the imitative capacity of young infants has been underestimated. Human infants are capable of imitating facial gestures at birth, with infants less than one day old manifesting this skill. Moreover recent experiments have established deferred imitation well before the predicted age of 18 months. Studies discussed here show that 9-month-olds can duplicate acts after a delay of 24 hours, and that 14-month-olds can retain and duplicate as many as five actions over a 1-week delay. These new findings re-raise questions about the relation between nonverbal cognitive development and language development: What aspects, if any, of these two domains are linked? A hypothesis is delineated that predicts certain very specific relations between particular cognitive and semantic achievements during the one-word stage, and data are reported supporting this hypothesis. Specifically, relations are reported between: (a) the development of object permanence and the use of words encoding disappearance, (b) means-ends understanding (as manifest in tool use) and

  17. Corrosion resistance of zirconium: general mechanisms, behaviour in nitric acid

    International Nuclear Information System (INIS)

    Pinard Legry, G.

    1990-01-01

    Corrosion resistance of zirconium results from the strong affinity of this metal for oxygen; as a result a thin protective oxide film is spontaneously formed in air or aqueous media, its thickness and properties depending on the physicochemical conditions at the interface. This film passivates the underlying metal but obviously if the passive film is partially or completely removed, localised or generalised corrosion phenomena will occur. In nitric acid, this depassivation may be chemical (fluorides) or mechanical (straining, creep, fretting). In these cases it is useful to determine the physicochemical conditions (concentration, temperature, potential, stress) which will have to be observed to use safely zirconium and its alloys in nitric acid solutions [fr

  18. Selective and Faithful Imitation at 12 and 15 Months

    Science.gov (United States)

    Hilbrink, Elma E.; Sakkalou, Elena; Ellis-Davies, Kate; Fowler, Nia C.; Gattis, Merideth

    2013-01-01

    Research on imitation in infancy has primarily focused on "what" and "when" infants imitate. More recently, however, the question why infants imitate has received renewed attention, partly motivated by the finding that infants sometimes selectively imitate the actions of others and sometimes faithfully imitate, or overimitate,…

  19. Davidson's generalization of the Fenyes-Nelson stochastic model of quantum mechanics

    International Nuclear Information System (INIS)

    Shucker, D.S.

    1980-01-01

    Davidson's generalization of the Fenyes-Nelson stochastic model of quantum mechanics is discussed. It is shown that this author's previous results concerning the Fenyes-Nelson process extend to the more general theory of Davidson. (orig.)

  20. Observation and imitation of actions performed by humans, androids, and robots: an EMG study

    Science.gov (United States)

    Hofree, Galit; Urgen, Burcu A.; Winkielman, Piotr; Saygin, Ayse P.

    2015-01-01

    Understanding others’ actions is essential for functioning in the physical and social world. In the past two decades research has shown that action perception involves the motor system, supporting theories that we understand others’ behavior via embodied motor simulation. Recently, empirical approach to action perception has been facilitated by using well-controlled artificial stimuli, such as robots. One broad question this approach can address is what aspects of similarity between the observer and the observed agent facilitate motor simulation. Since humans have evolved among other humans and animals, using artificial stimuli such as robots allows us to probe whether our social perceptual systems are specifically tuned to process other biological entities. In this study, we used humanoid robots with different degrees of human-likeness in appearance and motion along with electromyography (EMG) to measure muscle activity in participants’ arms while they either observed or imitated videos of three agents produce actions with their right arm. The agents were a Human (biological appearance and motion), a Robot (mechanical appearance and motion), and an Android (biological appearance and mechanical motion). Right arm muscle activity increased when participants imitated all agents. Increased muscle activation was found also in the stationary arm both during imitation and observation. Furthermore, muscle activity was sensitive to motion dynamics: activity was significantly stronger for imitation of the human than both mechanical agents. There was also a relationship between the dynamics of the muscle activity and motion dynamics in stimuli. Overall our data indicate that motor simulation is not limited to observation and imitation of agents with a biological appearance, but is also found for robots. However we also found sensitivity to human motion in the EMG responses. Combining data from multiple methods allows us to obtain a more complete picture of action

  1. Observation and Imitation of Actions Performed by Humans, Androids and Robots: An EMG study

    Directory of Open Access Journals (Sweden)

    Galit eHofree

    2015-06-01

    Full Text Available Understanding others’ actions is essential for functioning in the physical and social world. In the past two decades research has shown that action perception involves the motor system, supporting theories that we understand others’ behavior via embodied motor simulation. Recently, action perception has been facilitated by using well-controlled artificial stimuli, such as robots. One key question this approach enables is what aspects of similarity between the observer and the observed agent facilitate motor simulation? Since humans have evolved among other humans and animals, using artificial stimuli such as robots allows us to probe whether our social perceptual systems are tuned to process other biological entities. In this study, we used humanoid robots with different degrees of humanlikeness in appearance and motion along with electromyography (EMG to measure muscle activity in participants’ arms while they either observed or imitated videos of three agents produce actions with their right arm. The agents were a Human (biological appearance and motion, a Robot (mechanical appearance and motion and an Android (biological appearance, mechanical motion. Right arm muscle activity increased when participants imitated all agents. Increased muscle activation was found also in the stationary arm both during imitation and observation. Furthermore, muscle activity was sensitive to motion dynamics: activity was significantly stronger for imitation of the human than both mechanical agents. There was also a relationship between the dynamics of the muscle activity and motion dynamics in stimuli. Overall our data indicate that motor simulation is not limited to observation and imitation of agents with a biological appearance, but is also found for robots. However we also found sensitivity to human motion in the EMG responses. Combining data from multiple methods allows us to obtain a more complete picture of action understanding and the underlying

  2. Decaying states as complex energy eigenvectors in generalized quantum mechanics

    International Nuclear Information System (INIS)

    Sudarshan, E.C.G.; Chiu, C.B.; Gorini, V.

    1977-04-01

    The problem of particle decay is reexamined within the Hamiltonian formalism. By deforming contours of integration, the survival amplitude is expressed as a sum of purely exponential contributions arising from the simple poles of the resolvent on the second sheet plus a background integral along a complex contour GAMMA running below the location of the poles. One observes that the time dependence of the survival amplitude in the small time region is strongly correlated to the asymptotic behaviour of the energy spectrum of the system; one computes the small time behavior of the survival amplitude for a wide variety of asymptotic behaviors. In the special case of the Lee model, using a formal procedure of analytic continuation, it is shown that a complete set of complex energy eigenvectors of the Hamiltonian can be associated with the poles of the resolvent of the background contour GAMMA. These poles and points along GAMMA correspond to the discrete and the continuum states respectively. In this context, each unstable particle is associated with a well defined object, which is a discrete generalized eigenstate of the Hamiltonian having a complex eigenvalue, with its real and negative imaginary parts being the mass and half width of the particle respectively. Finally, one briefly discusses the analytic continuation of the scattering amplitude within this generalized scheme, and notes the appearance of ''redundant poles'' which do not correspond to discrete solutions of the modified eigenvalue problem

  3. General-relativistic celestial mechanics. II. Translational equations of motion

    International Nuclear Information System (INIS)

    Damour, T.; Soffel, M.; Xu, C.

    1992-01-01

    The translational laws of motion for gravitationally interacting systems of N arbitrarily composed and shaped, weakly self-gravitating, rotating, deformable bodies are obtained at the first post-Newtonian approximation of general relativity. The derivation uses our recently introduced multi-reference-system method and obtains the translational laws of motion by writing that, in the local center-of-mass frame of each body, relativistic inertial effects combine with post-Newtonian self- and externally generated gravitational forces to produce a global equilibrium (relativistic generalization of d'Alembert's principle). Within the first post-Newtonian approximation [i.e., neglecting terms of order (v/c) 4 in the equations of motion], our work is the first to obtain complete and explicit results, in the form of infinite series, for the laws of motion of arbitrarily composed and shaped bodies. We first obtain the laws of motion of each body as an infinite series exhibiting the coupling of all the (Blanchet-Damour) post-Newtonian multipole moments of this body to the post-Newtonian tidal moments (recently defined by us) felt by this body. We then give the explicit expression of these tidal moments in terms of post-Newtonian multipole moments of the other bodies

  4. A cross-cultural comparison of children's imitative flexibility.

    Science.gov (United States)

    Clegg, Jennifer M; Legare, Cristine H

    2016-09-01

    Recent research with Western populations has demonstrated that children use imitation flexibly to engage in both instrumental and conventional learning. Evidence for children's imitative flexibility in non-Western populations is limited, however, and has only assessed imitation of instrumental tasks. This study (N = 142, 6- to 8-year-olds) demonstrates both cultural continuity and cultural variation in imitative flexibility. Children engage in higher imitative fidelity for conventional tasks than for instrumental tasks in both an industrialized, Western culture (United States), and a subsistence-based, non-Western culture (Vanuatu). Children in Vanuatu engage in higher imitative fidelity of instrumental tasks than in the United States, a potential consequence of cultural variation in child socialization for conformity. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  5. Is there a relativistic nonlinear generalization of quantum mechanics?

    Energy Technology Data Exchange (ETDEWEB)

    Elze, Hans-Thomas [Dipartimento di Fisica ' Enrico Fermi' , Largo Pontecorvo 3, I-56127 Pisa (Italy)

    2007-05-15

    Yes, there is. - A new kind of gauge theory is introduced, where the minimal coupling and corresponding covariant derivatives are defined in the space of functions pertaining to the functional Schroedinger picture of a given field theory. While, for simplicity, we study the example of a U(1) symmetry, this kind of gauge theory can accommodate other symmetries as well. We consider the resulting relativistic nonlinear extension of quantum mechanics and show that it incorporates gravity in the (0+1)-dimensional limit, where it leads to the Schroedinger-Newton equations. Gravity is encoded here into a universal nonlinear extension of quantum theory. The probabilistic interpretation, i.e. Born's rule, holds provided the underlying model has only dimensionless parameters.

  6. Study of General health, resiliency, and defense mechanisms in patients with migraine headache

    Directory of Open Access Journals (Sweden)

    Alireza Aghayusefi

    2013-06-01

    Full Text Available Background: Migraine is a neurological disease that the etiology, several factors affect its onset or its exacerbation. One of the factors affecting disease is psychological factors such as defense mechanisms, resiliency, and general health. This study assessed the relationship between general health, resiliency, and general defense mechanisms, and also predicts the general health of people with migraine headaches that have a high resiliency and use mature defense mechanisms. Material and Methods: 50 women with migraine headache in the city of Bushehr using defense mechanisms, resiliency, and general health questionnaires were studied. For statistical analysis, Pearson correlation and multiple regression tests were used by SPSS 17 software. Results: The results showed that most of the defense mechanisms of migraine sufferers are Immature and Neuroticism. There is significant negative correlation between the deterioration of general health and resiliency as well as the mature defense mechanism (p=0/003, and also there is a significant positive correlation between this deterioration with neuroticism (p=0/040 and immature defense mechanisms (p=0/041. On the other hand there is significant negative correlation between resiliencies with immature (p=0/009 and neuroticism defense mechanisms (p=0/04, and also with mature defense mechanism has a significant positive correlation (p=0/003. Also, as more people use the mature defense mechanism, their deterioration of general health will be reduced, but this relationship will be stronger with the presence of resiliency. So migraine people use the mature defense mechanisms with high resiliency will have more favorable general health (less deterioration of general health. Conclusion: This study showed that migraine patients use the mature defense mechanisms with high resiliency will have more favorable general health (less deterioration of general health.

  7. Imitating model of the electronic regulator frequencies of rotation of the automobile diesel engine

    OpenAIRE

    Тырловой, С. И.

    2011-01-01

    The imitating model of an frequency electronic regulator of rotation of high-speed diesel engine an automobile diesel engine with the distributive fuel pump of Bosch company is resulted. Is executed simulation transitive modes of a diesel engine with mechanic and electronic regulators. Deterioration influence plungers steams on dinamic and economic indicators of a diesel engine is analysed. Operational indicators of a diesel engine with mechanic and electronic regulators are compared. The obt...

  8. Performance of motor imitation in children with and without dyspraxia.

    Science.gov (United States)

    Ruttanathantong, Korrawan; Siritaratiwat, Wantana; Sriphetcharawut, Sarinya; Emasithi, Alongkot; Saengsuwan, Jiamjit; Saengsuwan, Jittima

    2013-07-01

    Motor imitation is truly essential for young children to learn new motor skills, social behavior and skilled acts or praxis. The present study aimed to investigate motor imitation ability between typically-developing children and dyspraxic children and to examine the development trends in both children groups. The comparison ofmotor imitation was studied in 55 typically-developing children and 59 dyspraxic children aged 5 to 8 years. The Motor Imitation subtest consisted of two sections, imitation of postures and imitation of verbal instructions. Typically-developing children and dyspraxic children were examined for developmental trends. The independent samples t-test was used to analyze the differences between both groups. Two-way analysis of variance (ANOVA) was used to analyze inter-age differences for each age group. The results revealed significant differences between dyspraxic and typically-developing children. Both typically-developing and dyspraxic children demonstrated age trends. The older children scored higher than younger children. Imitation is a primary learning strategy of young children. It is essential that children with dyspraxia receive early detection and need effective intervention. Typically-developing children and dyspraxic children showed higher mean score on the Imitation of Posture section than the Verbal Instructions section. Motor imitation competency, therefore, changes and improves with age.

  9. The shared neural basis of empathy and facial imitation accuracy.

    Science.gov (United States)

    Braadbaart, L; de Grauw, H; Perrett, D I; Waiter, G D; Williams, J H G

    2014-01-01

    Empathy involves experiencing emotion vicariously, and understanding the reasons for those emotions. It may be served partly by a motor simulation function, and therefore share a neural basis with imitation (as opposed to mimicry), as both involve sensorimotor representations of intentions based on perceptions of others' actions. We recently showed a correlation between imitation accuracy and Empathy Quotient (EQ) using a facial imitation task and hypothesised that this relationship would be mediated by the human mirror neuron system. During functional Magnetic Resonance Imaging (fMRI), 20 adults observed novel 'blends' of facial emotional expressions. According to instruction, they either imitated (i.e. matched) the expressions or executed alternative, pre-prescribed mismatched actions as control. Outside the scanner we replicated the association between imitation accuracy and EQ. During fMRI, activity was greater during mismatch compared to imitation, particularly in the bilateral insula. Activity during imitation correlated with EQ in somatosensory cortex, intraparietal sulcus and premotor cortex. Imitation accuracy correlated with activity in insula and areas serving motor control. Overlapping voxels for the accuracy and EQ correlations occurred in premotor cortex. We suggest that both empathy and facial imitation rely on formation of action plans (or a simulation of others' intentions) in the premotor cortex, in connection with representations of emotional expressions based in the somatosensory cortex. In addition, the insula may play a key role in the social regulation of facial expression. © 2013.

  10. The influence of group membership on cross-contextual imitation.

    Science.gov (United States)

    Genschow, Oliver; Schindler, Simon

    2016-08-01

    Research on mimicry has demonstrated that individuals imitate in-group members more strongly than out-group members. In the present study, we tested whether such top-down modulation also applies for more extreme forms of direct mapping, such as for cross-contextual imitation settings, in which individuals imitate others' movements without sharing a common goal or context. Models on self-other control suggest that top-down modulations are based merely on a direct link between social sensory processing and imitation. That is, perceived similarities between oneself and another person is sufficient to amplify a shared representation between own and others' actions, which then trigger imitation. However, motivational accounts explain such findings with the assumption that individuals are motivated to affiliate with others. Because imitation is linked to positive social consequences, individuals should imitate in-group members more strongly than out-group members. We tested these two theoretical accounts against each other by applying a cross-contextual imitation paradigm. The results demonstrate that in-group members are more strongly cross-contextually imitated than out-group members the higher individuals' motivation to affiliate with the in-group is. This supports motivational models but not self-other control accounts. Further theoretical implications are discussed.

  11. Yarbus's Conceptions on the General Mechanisms of Color Perception.

    Science.gov (United States)

    Nikolaev, Petr P; Rozhkova, Galina I

    2015-01-01

    In the last series of papers published during 1975 to 1980, Alfred Yarbus tried to formulate general conceptions concerning the basic principles of retinal image processing in the human visual system. The original ideas of Yarbus were based on the results of his numerous and various experiments carried out with extraordinary inventiveness and great skill. Being concentrated primarily on the problems of color vision, Alfred Yarbus dreamed of elaborating a comprehensive model that would simulate visual information processing at the monocular precognitive level in the visual system of humans with normal trichromatic color perception. In this article, the most important of Yarbus' experimental paradigms, findings, statements, and conclusions are systematized and considered in relation to the classical theories of color perception and, in particular, fundamental theses of the Nyberg school. The perceptual model developed by Alfred Yarbus remained incomplete. Nevertheless, it is already evident that some intrinsic contradictions make it inadequate in terms of comprehensive modeling. However, certain partial advantages deserve more thorough appreciation and further investigation. © The Author(s) 2015.

  12. GENERAL MECHANISMS OF CITATION SYSTEM OF SCIENTIFIC ARTICLES

    Directory of Open Access Journals (Sweden)

    Віктор Дмитрович ГОГУНСЬКИЙ

    2016-02-01

    Full Text Available Transformation competitive environment of higher education in the creation of effective mechanisms of management research encourages research teams and individual researchers to analyze their activity Publication search methods for improvement of citations of scientific publications. The paper analyzed the life cycle of scientific publications and show that the way to promote scientific articles in the world community inherent properties of Markov processes. Application of Markov chains allows top ground the need for active participation of the authors in the distribution of its publications in different scientometric databases, repositories of scientific and social networks. Markov model to describe decomposition of scientists made certain discrete states and proposed a schematic diagram of transitions between them. The model's 5A fully reflect the properties of the system. Communication influences the probability of changing system states with consistent movement along the trajectory from a lack of information about the publication to familiarize with it because of the positive attitude to state its citation. This is a must as well as a negative attitude to the publications. Proved that improve performance citation of scientific publications in the case of using Google Scholar, ORCID, Mendeley, Academia, ResearchGate, and others. The active participation of authors in their publications available in these systems leads to an increase in the proportion of articles that are available to colleagues in the global scientific community that is becoming one of the factors of increase in citations.

  13. The avian egg exhibits general allometric invariances in mechanical design.

    Science.gov (United States)

    Juang, Jia-Yang; Chen, Pin-Yi; Yang, Da-Chang; Wu, Shang-Ping; Yen, An; Hsieh, Hsin-I

    2017-10-27

    The avian egg exhibits extraordinary diversity in size, shape and color, and has a key role in avian adaptive radiations. Despite extensive work, our understanding of the underlying principles that guide the "design" of the egg as a load-bearing structure remains incomplete, especially over broad taxonomic scales. Here we define a dimensionless number C, a function of egg weight, stiffness and dimensions, to quantify how stiff an egg is with respect to its weight after removing geometry-induced rigidity. We analyze eggs of 463 bird species in 36 orders across five orders of magnitude in body mass, and find that C number is nearly invariant for most species, including tiny hummingbirds and giant elephant birds. This invariance or "design guideline" dictates that evolutionary changes in shell thickness and Young's modulus, both contributing to shell stiffness, are constrained by changes in egg weight. Our analysis illuminates unique reproductive strategies of brood parasites, kiwis, and megapodes, and quantifies the loss of safety margin for contact incubation due to artificial selection and environmental toxins. Our approach provides a mechanistic framework for a better understanding of the mechanical design of the avian egg, and may provide clues to the evolutionary origin of contact incubation of amniote eggs.

  14. Cooperation guided by the coexistence of imitation dynamics and aspiration dynamics in structured populations

    Science.gov (United States)

    Xu, Kuangyi; Li, Kun; Cong, Rui; Wang, Long

    2017-02-01

    In the framework of the evolutionary game theory, two fundamentally different mechanisms, the imitation process and the aspiration-driven dynamics, can be adopted by players to update their strategies. In the former case, individuals imitate the strategy of a more successful peer, while in the latter case individuals change their strategies based on a comparison of payoffs they collect in the game to their own aspiration levels. Here we explore how cooperation evolves for the coexistence of these two dynamics. Intriguingly, cooperation reaches its lowest level when a certain moderate fraction of individuals pick aspiration-level-driven rule while the others choose pairwise comparison rule. Furthermore, when individuals can adjust their update rules besides their strategies, either imitation dynamics or aspiration-driven dynamics will finally take over the entire population, and the stationary cooperation level is determined by the outcome of competition between these two dynamics. We find that appropriate synergetic effects and moderate aspiration level boost the fixation probability of aspiration-driven dynamics most effectively. Our work may be helpful in understanding the cooperative behavior induced by the coexistence of imitation dynamics and aspiration dynamics in the society.

  15. Imitation modelling in metallography; Imitatsionnye metody issledovania v radiatsionnom metallovedenii

    Energy Technology Data Exchange (ETDEWEB)

    Pechenyakov, I; Georgiev, J [Bylgarska Akademiya na Naukite, Sofia (Bulgaria). Inst. po Metaloznanie i Tekhnologiya na Metalite

    1996-12-31

    A brief review of investigations made in the Institute of Metallography at the Bulgarian Academy of Sciences applying modern imitation methods is presented. Radiation damage in metals and alloys after ion implantation, H{sub 2} or He glow discharge exposure and electrolytic hydrogenation has been used to study crystal lattice changes and their effect on physical properties. Surface modification of steel samples of various composition have been studied. An apparatus for quantitative H{sub 2} determination has been constructed and methods for measurement of H{sub 2} permeability and H{sub 2} diffusion coefficients in metal alloys have been proposed. The correlation between H{sub 2} concentration, mechanical characteristics and physical properties of construction steel samples has been studied.

  16. Intracellular transport driven by cytoskeletal motors: General mechanisms and defects

    Science.gov (United States)

    Appert-Rolland, C.; Ebbinghaus, M.; Santen, L.

    2015-09-01

    Cells are the elementary units of living organisms, which are able to carry out many vital functions. These functions rely on active processes on a microscopic scale. Therefore, they are strongly out-of-equilibrium systems, which are driven by continuous energy supply. The tasks that have to be performed in order to maintain the cell alive require transportation of various ingredients, some being small, others being large. Intracellular transport processes are able to induce concentration gradients and to carry objects to specific targets. These processes cannot be carried out only by diffusion, as cells may be crowded, and quite elongated on molecular scales. Therefore active transport has to be organized. The cytoskeleton, which is composed of three types of filaments (microtubules, actin and intermediate filaments), determines the shape of the cell, and plays a role in cell motion. It also serves as a road network for a special kind of vehicles, namely the cytoskeletal motors. These molecules can attach to a cytoskeletal filament, perform directed motion, possibly carrying along some cargo, and then detach. It is a central issue to understand how intracellular transport driven by molecular motors is regulated. The interest for this type of question was enhanced when it was discovered that intracellular transport breakdown is one of the signatures of some neuronal diseases like the Alzheimer. We give a survey of the current knowledge on microtubule based intracellular transport. Our review includes on the one hand an overview of biological facts, obtained from experiments, and on the other hand a presentation of some modeling attempts based on cellular automata. We present some background knowledge on the original and variants of the TASEP (Totally Asymmetric Simple Exclusion Process), before turning to more application oriented models. After addressing microtubule based transport in general, with a focus on in vitro experiments, and on cooperative effects in the

  17. Body odors promote automatic imitation in autism.

    Science.gov (United States)

    Parma, Valentina; Bulgheroni, Maria; Tirindelli, Roberto; Castiello, Umberto

    2013-08-01

    Autism spectrum disorders comprise a range of neurodevelopmental pathologies characterized, among other symptoms, by impaired social interactions. Individuals with this diagnosis are reported to often identify people by repetitively sniffing pieces of clothing or the body odor of family members. Since body odors are known to initiate and mediate many different social behaviors, smelling the body odor of a family member might constitute a sensory-based action promoting social contact. In light of this, we hypothesized that the body odor of a family member would facilitate the appearance of automatic imitation, an essential social skill known to be impaired in autism. We recruited 20 autistic and 20 typically developing children. Body odors were collected from the children's mothers' axillae. A child observed a model (their mother or a stranger mother) execute (or not) a reach-to-grasp action toward an object. Subsequently, she performed the same action. The object was imbued with the child's mother's odor, a stranger mother's odor, or no odor. The actions were videotaped, and movement time was calculated post hoc via a digitalization technique. Automatic imitation effects-expressed in terms of total movement time reduction-appear in autistic children only when exposed to objects paired with their own mother's odor. The maternal odor, which conveys a social message otherwise neglected, helps autistic children to covertly imitate the actions of others. Our results represent a starting point holding theoretical and practical relevance for the development of new strategies to enhance communication and social behavior among autistic individuals. Copyright © 2013 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.

  18. Defective imitation of finger configurations in patients with damage in the right or left hemispheres: An integration disorder of visual and somatosensory information?

    Science.gov (United States)

    Okita, Manabu; Yukihiro, Takashi; Miyamoto, Kenzo; Morioka, Shu; Kaba, Hideto

    2017-04-01

    To explore the mechanism underlying the imitation of finger gestures, we devised a simple imitation task in which the patients were instructed to replicate finger configurations in two conditions: one in which they could see their hand (visual feedback: VF) and one in which they could not see their hand (non-visual feedback: NVF). Patients with left brain damage (LBD) or right brain damage (RBD), respectively, were categorized into two groups based on their scores on the imitation task in the NVF condition: the impaired imitation groups (I-LBD and I-RBD) who failed two or more of the five patterns and the control groups (C-LBD and C-RBD) who made one or no errors. We also measured the movement-production times for imitation. The I-RBD group performed significantly worse than the C-RBD group even in the VF condition. In contrast, the I-LBD group was selectively impaired in the NVF condition. The I-LBD group performed the imitations at a significantly slower rate than the C-LBD group in both the VF and NVF conditions. These results suggest that impaired imitation in patients with LBD is partly due to an abnormal integration of visual and somatosensory information based on the task specificity of the NVF condition. Copyright © 2017 Elsevier Inc. All rights reserved.

  19. Imitation as faithful copying of a novel technique in marmoset monkeys.

    Directory of Open Access Journals (Sweden)

    Bernhard Voelkl

    Full Text Available Imitative learning has received great attention due to its supposed role in the development of culture and the cognitive demands it poses on the individual. Evidence for imitation in non-human primate species, therefore, could shed light on the early origins of proto-cultural traits in the primate order. Imitation has been defined as the learning of an act by seeing it done or, more specifically, as the copying of a novel or otherwise improbable act. But despite a century of research and the detection of mirror neurons the empirical basis for this most advanced form of observational learning is weak. Few, if any, studies have shown that the observer has learned the response topography, i.e., the specific action by which the response is made. In an experimental set-up we confronted marmoset monkeys (Callithrix jacchus with a conspecific model that was previously trained to open a plastic box in a peculiar way. Employing detailed motion analyses we show that the observers precisely copied the movement patterns of the novel action demonstrated by the model. A discriminant analysis classified 13 out of 14 observer movements (92.86% as model movements and only one as non-observer movement. This evidence of imitation in non-human primates questions the dominant opinion that imitation is a human-specific ability. Furthermore, the high matching degree suggests that marmosets possess the neuronal mechanism to code the actions of others and to map them onto their own motor repertoire, rather than priming existing motor-templates.

  20. Ritual, Imitation and Education in R. S. Peters

    Science.gov (United States)

    Warnick, Bryan R.

    2009-01-01

    This article reconstructs R. S. Peters' underlying theory of ritual in education, highlighting his proposed link between ritual and the imitation of teachers. Rituals set the stage for the imitation of teachers and they invite students to experience practices whose value is not easily discernable from the outside. For Peters, rituals facilitate…

  1. Infants Show Stability of Goal-Directed Imitation

    Science.gov (United States)

    Sakkalou, Elena; Ellis-Davies, Kate; Fowler, Nia C.; Hilbrink, Elma E.; Gattis, Merideth

    2013-01-01

    Previous studies have reported that infants selectively reproduce observed actions and have argued that this selectivity reflects understanding of intentions and goals, or goal-directed imitation. We reasoned that if selective imitation of goal-directed actions reflects understanding of intentions, infants should demonstrate stability across…

  2. Atypical Social Modulation of Imitation in Autism Spectrum Conditions

    Science.gov (United States)

    Cook, Jennifer L.; Bird, Geoffrey

    2012-01-01

    Appropriate modulation of imitation according to social context is important for successful social interaction. In the present study we subliminally primed high-functioning adults with ASC and age- and IQ-matched controls with either a pro- or non- social attitude. Following priming, an automatic imitation paradigm was used to acquire an index of…

  3. Reinforcement of Infant Vocalizations through Contingent Vocal Imitation

    Science.gov (United States)

    Pelaez, Martha; Virues-Ortega, Javier; Gewirtz, Jacob L.

    2011-01-01

    Maternal vocal imitation of infant vocalizations is highly prevalent during face-to-face interactions of infants and their caregivers. Although maternal vocal imitation has been associated with later verbal development, its potentially reinforcing effect on infant vocalizations has not been explored experimentally. This study examined the…

  4. The diverging force of imitation: integrating cognitive science and hermeneutics

    NARCIS (Netherlands)

    Keestra, M.

    2008-01-01

    Recent research on infant and animal imitation and on mirror neuron systems has brought imitation back in focus in psychology and cognitive science. This topic has always been important for philosophical hermeneutics as well, focusing on theory and method of understanding. Unfortunately, relations

  5. Training Social Cognition: From Imitation to Theory of Mind

    Science.gov (United States)

    Santiesteban, Idalmis; White, Sarah; Cook, Jennifer; Gilbert, Sam J.; Heyes, Cecilia; Bird, Geoffrey

    2012-01-01

    Evidence for successful socio-cognitive training in typical adults is rare. This study attempted to improve Theory of Mind (ToM) and visual perspective taking in healthy adults by training participants to either imitate or to inhibit imitation. Twenty-four hours after training, all participants completed tests of ToM and visual perspective taking.…

  6. The Neural Basis of Vocal Pitch Imitation in Humans.

    Science.gov (United States)

    Belyk, Michel; Pfordresher, Peter Q; Liotti, Mario; Brown, Steven

    2016-04-01

    Vocal imitation is a phenotype that is unique to humans among all primate species, and so an understanding of its neural basis is critical in explaining the emergence of both speech and song in human evolution. Two principal neural models of vocal imitation have emerged from a consideration of nonhuman animals. One hypothesis suggests that putative mirror neurons in the inferior frontal gyrus pars opercularis of Broca's area may be important for imitation. An alternative hypothesis derived from the study of songbirds suggests that the corticostriate motor pathway performs sensorimotor processes that are specific to vocal imitation. Using fMRI with a sparse event-related sampling design, we investigated the neural basis of vocal imitation in humans by comparing imitative vocal production of pitch sequences with both nonimitative vocal production and pitch discrimination. The strongest difference between these tasks was found in the putamen bilaterally, providing a striking parallel to the role of the analogous region in songbirds. Other areas preferentially activated during imitation included the orofacial motor cortex, Rolandic operculum, and SMA, which together outline the corticostriate motor loop. No differences were seen in the inferior frontal gyrus. The corticostriate system thus appears to be the central pathway for vocal imitation in humans, as predicted from an analogy with songbirds.

  7. The Role of Elicited Verbal Imitation in Toddlers' Word Learning

    Science.gov (United States)

    Hodges, Rosemary; Munro, Natalie; Baker, Elise; McGregor, Karla; Docking, Kimberley; Arciuli, Joanne

    2016-01-01

    This study is about the role of elicited verbal imitation in toddler word learning. Forty-eight toddlers were taught eight nonwords linked to referents. During training, they were asked to imitate the nonwords. Naming of the referents was tested at three intervals (one minute later [uncued], five minutes, and 1-7 days later [cued]) and recognition…

  8. Imitation and Education: A Philosophical Inquiry into Learning by Example

    Science.gov (United States)

    Warnick, Bryan R.

    2008-01-01

    "Imitation and Education" provides an in-depth reassessment of learning by example that places imitation in a larger social context. It is the first book to bring together ancient educational thought and startling breakthroughs in the fields of cognitive science, psychology, and philosophy to reconsider how we learn from the lives of…

  9. Methodological Issues in Measures of Imitative Reaction Times

    Science.gov (United States)

    Aicken, Michael D.; Wilson, Andrew D.; Williams, Justin H. G.; Mon-Williams, Mark

    2007-01-01

    Ideomotor (IM) theory suggests that observing someone else perform an action activates an internal motor representation of that behaviour within the observer. Evidence supporting the case for an ideomotor theory of imitation has come from studies that show imitative responses to be faster than the same behavioural measures performed in response to…

  10. Impact of imitation processes on the effectiveness of ring vaccination.

    Science.gov (United States)

    Wells, Chad R; Tchuenche, Jean M; Meyers, Lauren Ancel; Galvani, Alison P; Bauch, Chris T

    2011-11-01

    Ring vaccination can be a highly effective control strategy for an emerging disease or in the final phase of disease eradication, as witnessed in the eradication of smallpox. However, the impact of behavioural dynamics on the effectiveness of ring vaccination has not been explored in mathematical models. Here, we analyze a series of stochastic models of voluntary ring vaccination. Contacts of an index case base vaccinating decisions on their own individual payoffs to vaccinate or not vaccinate, and they can also imitate the behaviour of other contacts of the index case. We find that including imitation changes the probability of containment through ring vaccination considerably. Imitation can cause a strong majority of contacts to choose vaccination in some cases, or to choose non-vaccination in other cases-even when the equivalent solution under perfectly rational (non-imitative) behaviour yields mixed choices. Moreover, imitation processes can result in very different outcomes in different stochastic realizations sampled from the same parameter distributions, by magnifying moderate tendencies toward one behaviour or the other: in some realizations, imitation causes a strong majority of contacts not to vaccinate, while in others, imitation promotes vaccination and reduces the number of secondary infections. Hence, the effectiveness of ring vaccination can depend significantly and unpredictably on imitation processes. Therefore, our results suggest that risk communication efforts should be initiated early in an outbreak when ring vaccination is to be applied, especially among subpopulations that are heavily influenced by peer opinions.

  11. Neonatal imitation and an epigenetic account of mirror neuron development.

    Science.gov (United States)

    Simpson, Elizabeth A; Fox, Nathan A; Tramacere, Antonella; Ferrari, Pier F

    2014-04-01

    Neonatal imitation should not exclusively be considered at the population-level; instead, we propose that inconsistent findings regarding its occurrence result from important individual differences in imitative responses. We also highlight what we consider to be a false dichotomy of genetic versus learning accounts of the development of mirror neurons, and instead suggest a more parsimonious epigenetic perspective.

  12. A Generalized Nonlocal Calculus with Application to the Peridynamics Model for Solid Mechanics

    OpenAIRE

    Alali, Bacim; Liu, Kuo; Gunzburger, Max

    2014-01-01

    A nonlocal vector calculus was introduced in [2] that has proved useful for the analysis of the peridynamics model of nonlocal mechanics and nonlocal diffusion models. A generalization is developed that provides a more general setting for the nonlocal vector calculus that is independent of particular nonlocal models. It is shown that general nonlocal calculus operators are integral operators with specific integral kernels. General nonlocal calculus properties are developed, including nonlocal...

  13. The role of imitation in video-based interventions for children with autism.

    Science.gov (United States)

    Lindsay, C J; Moore, D W; Anderson, A; Dillenburger, K

    2013-08-01

    The aim of this paper is to bridge the gap between the corpus of imitation research and video-based intervention (VBI) research, and consider the impact imitation skills may be having on VBI outcomes and highlight potential areas for improving efficacy. A review of the imitation literature was conducted focusing on imitation skill deficits in children with autism followed by a critical review of the video modelling literature focusing on pre-intervention assessment of imitation skills and the impact imitation deficits may have on VBI outcomes. Children with autism have specific imitation deficits, which may impact VBI outcomes. Imitation training or procedural modifications made to videos may accommodate for these deficits. There are only six studies where VBI researchers have taken pre-intervention imitation assessments using an assortment of imitation measures. More research is required to develop a standardised multi-dimensional imitation assessment battery that can better inform VBI.

  14. Poor neuro-motor tuning of the human larynx: a comparison of sung and whistled pitch imitation

    Science.gov (United States)

    Johnson, Joseph F.; Kotz, Sonja A.

    2018-01-01

    Vocal imitation is a hallmark of human communication that underlies the capacity to learn to speak and sing. Even so, poor vocal imitation abilities are surprisingly common in the general population and even expert vocalists cannot match the precision of a musical instrument. Although humans have evolved a greater degree of control over the laryngeal muscles that govern voice production, this ability may be underdeveloped compared with control over the articulatory muscles, such as the tongue and lips, volitional control of which emerged earlier in primate evolution. Human participants imitated simple melodies by either singing (i.e. producing pitch with the larynx) or whistling (i.e. producing pitch with the lips and tongue). Sung notes were systematically biased towards each individual's habitual pitch, which we hypothesize may act to conserve muscular effort. Furthermore, while participants who sung more precisely also whistled more precisely, sung imitations were less precise than whistled imitations. The laryngeal muscles that control voice production are under less precise control than the oral muscles that are involved in whistling. This imprecision may be due to the relatively recent evolution of volitional laryngeal-motor control in humans, which may be tuned just well enough for the coarse modulation of vocal-pitch in speech. PMID:29765635

  15. Neural Substrates of Social Emotion Regulation: A fMRI Study on Imitation and Expressive Suppression to Dynamic Facial Signals

    Directory of Open Access Journals (Sweden)

    Pascal eVrticka

    2013-02-01

    Full Text Available Emotion regulation is crucial for successfully engaging in social interactions. Yet, little is known about the neural mechanisms controlling behavioral responses to emotional expressions perceived in the face of other people, which constitute a key element of interpersonal communication. Here, we investigated brain systems involved in social emotion perception and regulation, using functional magnetic resonance imaging (fMRI in 20 healthy participants who saw dynamic facial expressions of either happiness or sadness, and were asked to either imitate the expression or to suppress any expression on their own face (in addition to a gender judgment control task. fMRI results revealed higher activity in regions associated with emotion (e.g., the insula, motor function (e.g., motor cortex, and theory of mind during imitation. Activity in dorsal cingulate cortex was also increased during imitation, possibly reflecting greater action monitoring or conflict with own feeling states. In addition, premotor regions were more strongly activated during both imitation and suppression, suggesting a recruitment of motor control for both the production and inhibition of emotion expressions. Expressive suppression produced increases in dorsolateral and lateral prefrontal cortex typically related to cognitive control. These results suggest that voluntary imitation and expressive suppression modulate brain responses to emotional signals perceived from faces, by up- and down-regulating activity in distributed subcortical and cortical networks that are particularly involved in emotion, action monitoring, and cognitive control.

  16. Heavy Metal Contaminated Soil Imitation Biological Treatment Overview

    Science.gov (United States)

    Pan, Chang; Chen, Jun; Wu, Ke; Zhou, Zhongkai; Cheng, Tingting

    2018-01-01

    In this paper, the treatment methods of heavy metal pollution in soils were analyzed, the existence and transformation of heavy metals in soil were explored, and the mechanism of heavy metal absorption by plants was studied. It was concluded that the main form of plants absorb heavy metals in the soil is exchangeable. The main mechanism was that the plant cell wall can form complex with heavy metals, so that heavy metals fixed on the cell wall, and through the selective absorption of plasma membrane into the plant body. In addition, the adsorption mechanism of the adsorbed material was analyzed. According to the results of some researchers, it was found that the mechanism of adsorption of heavy metals was similar to that of plants. According to this, using adsorbent material as the main material, Imitate the principle of plant absorption of heavy metals in the soil to removing heavy metals in the soil at one-time and can be separated from the soil after adsorption to achieve permanent removal of heavy metals in the soil was feasibility.

  17. Imitating winner or sympathizing loser? Quadratic effects on cooperative behavior in prisoners' dilemma games

    Science.gov (United States)

    Lu, Peng

    2015-10-01

    Cooperation is vital in human societies and therefore is widely investigated in the evolutionary game theory. Varieties of mechanisms have been proposed to overcome temptation and promote cooperation. Existing studies usually believe that agents are rational, but irrationalism such as emotions and feelings matters as well. Winner and loser are defined by their payoffs. In addition to admiring and imitating winners, the mechanism of sympathizing and imitating losers is introduced into the model as an alternative action rule, and each one plays the prisoners' dilemma game with eight neighbors under the influence of both irrationalism and rationalism. Rationalism refers to imitating winner to get highest payoff, and irrationalism means that people sympathize and adopt the actions of losers. As it is widely recognized that temptation reduces cooperation, this study focuses on the effect of sympathy on cooperation within a certain group or society. If it overcomes temptation that leads to defection, sympathy will be a powerful mechanism to promote cooperative behavior. Simulation results indicate that sympathy and temptation shares similar quadratic relationships with cooperation. Both sympathy and temptation undermine cooperation below their thresholds, and they both promote cooperation above their thresholds. Temptation not only reduces cooperation but also promote it as temptation goes beyond the threshold. Although sympathy is a good merit or human nature that is beneficial to society, a crisis or collapse of cooperation is inevitable when the sympathy propensity is relatively smaller. After cooperation reaches a minimal bottom, it then rises increasingly and dramatically, which brings a much brighter future of the society.

  18. Symmetry of Hamiltonian and conserved quantity for a system of generalized classical mechanics

    International Nuclear Information System (INIS)

    Zhang Yi

    2011-01-01

    This paper focuses on a new symmetry of Hamiltonian and its conserved quantity for a system of generalized classical mechanics. The differential equations of motion of the system are established. The definition and the criterion of the symmetry of Hamiltonian of the system are given. A conserved quantity directly derived from the symmetry of Hamiltonian of the generalized classical mechanical system is given. Since a Hamilton system is a special case of the generalized classical mechanics, the results above are equally applicable to the Hamilton system. The results of the paper are the generalization of a theorem known for the existing nonsingular equivalent Lagrangian. Finally, two examples are given to illustrate the application of the results. (electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics)

  19. Generalized linear elastic fracture mechanics: an application to a crack touching the bimaterial interface

    Czech Academy of Sciences Publication Activity Database

    Náhlík, Luboš; Šestáková, L.; Hutař, Pavel; Knésl, Zdeněk

    2011-01-01

    Roč. 452-453, - (2011), s. 445-448 ISSN 1013-9826 R&D Projects: GA AV ČR(CZ) KJB200410803; GA ČR GA101/09/1821 Institutional research plan: CEZ:AV0Z20410507 Keywords : generalized stress intensity factor * bimaterial interface * composite materials * strain energy density factor * fracture criterion * generalized linear elastic fracture mechanics Subject RIV: JL - Materials Fatigue, Friction Mechanics

  20. Contextual imitation of intransitive body actions in a Beluga whale (Delphinapterus leucas): A “do as other does” study

    Science.gov (United States)

    Hernández-Lloreda, Mª Victoria; Esteban, José-Antonio; Colmenares, Fernando; Aboitiz, Francisco; Call, Josep

    2017-01-01

    Cetaceans are remarkable for exhibiting group-specific behavioral traditions or cultures in several behavioral domains (e.g., calls, behavioral tactics), and the question of whether they can be acquired socially, for example through imitative processes, remains open. Here we used a “Do as other does” paradigm to experimentally study the ability of a beluga to imitate familiar intransitive (body-oriented) actions demonstrated by a conspecific. The participant was first trained to copy three familiar behaviors on command (training phase) and then was tested for her ability to generalize the learned “Do as the other does” command to a different set of three familiar behaviors (testing phase). We found that the beluga (1) was capable of learning the copy command signal “Do what-the-other-does”; (2) exhibited high matching accuracy for trained behaviors (mean = 84% of correct performance) after making the first successful copy on command; (3) copied successfully the new set of three familiar generalization behaviors that were untrained to the copy command (range of first copy = 12 to 35 trials); and (4) deployed a high level of matching accuracy (mean = 83%) after making the first copy of an untrained behavior on command. This is the first evidence of contextual imitation of intransitive (body-oriented) movements in the beluga and adds to the reported findings on production imitation of sounds in this species and production imitation of sounds and motor actions in several cetaceans, especially dolphins and killer whales. Collectively these findings highlight the notion that cetaceans have a natural propensity at skillfully and proficiently matching the sounds and body movements demonstrated by conspecifics, a fitness-enhancing propensity in the context of cooperative hunting and anti-predatory defense tactics, and of alliance formation strategies that have been documented in these species’ natural habitats. Future work should determine if the beluga can

  1. Frequency-dependent oscillatory neural profiles during imitation.

    Science.gov (United States)

    Sugata, Hisato; Hirata, Masayuki; Tamura, Yuichi; Onishi, Hisao; Goto, Tetsu; Araki, Toshihiko; Yorifuji, Shiro

    2017-04-10

    Imitation is a complex process that includes higher-order cognitive and motor function. This process requires an observation-execution matching system that transforms an observed action into an identical movement. Although the low-gamma band is thought to reflect higher cognitive processes, no studies have focused on it. Here, we used magnetoencephalography (MEG) to examine the neural oscillatory changes including the low-gamma band during imitation. Twelve healthy, right-handed participants performed a finger task consisting of four conditions (imitation, execution, observation, and rest). During the imitation and execution conditions, significant event-related desynchronizations (ERDs) were observed at the left frontal, central, and parietal MEG sensors in the alpha, beta, and low-gamma bands. Functional connectivity analysis at the sensor level revealed an imitation-related connectivity between a group of frontal sensors and a group of parietal sensors in the low-gamma band. Furthermore, source reconstruction with synthetic aperture magnetometry showed significant ERDs in the low-gamma band in the left sensorimotor area and the middle frontal gyrus (MFG) during the imitation condition when compared with the other three conditions. Our results suggest that the oscillatory neural activities of the low-gamma band at the sensorimotor area and MFG play an important role in the observation-execution matching system related to imitation.

  2. Frequency-dependent oscillatory neural profiles during imitation

    Science.gov (United States)

    Sugata, Hisato; Hirata, Masayuki; Tamura, Yuichi; Onishi, Hisao; Goto, Tetsu; Araki, Toshihiko; Yorifuji, Shiro

    2017-01-01

    Imitation is a complex process that includes higher-order cognitive and motor function. This process requires an observation-execution matching system that transforms an observed action into an identical movement. Although the low-gamma band is thought to reflect higher cognitive processes, no studies have focused on it. Here, we used magnetoencephalography (MEG) to examine the neural oscillatory changes including the low-gamma band during imitation. Twelve healthy, right-handed participants performed a finger task consisting of four conditions (imitation, execution, observation, and rest). During the imitation and execution conditions, significant event-related desynchronizations (ERDs) were observed at the left frontal, central, and parietal MEG sensors in the alpha, beta, and low-gamma bands. Functional connectivity analysis at the sensor level revealed an imitation-related connectivity between a group of frontal sensors and a group of parietal sensors in the low-gamma band. Furthermore, source reconstruction with synthetic aperture magnetometry showed significant ERDs in the low-gamma band in the left sensorimotor area and the middle frontal gyrus (MFG) during the imitation condition when compared with the other three conditions. Our results suggest that the oscillatory neural activities of the low-gamma band at the sensorimotor area and MFG play an important role in the observation-execution matching system related to imitation. PMID:28393878

  3. Imitation dynamics in a game of traffic

    Science.gov (United States)

    Paissan, Gabriel; Abramson, Guillermo

    2013-04-01

    We study a model of traffic where drivers adopt different behavioral strategies. These can be cooperative or defective according to a driver abiding or not by a traffic rule. Drivers can change their strategy by imitating the majority, with a rule that depends on the strategies with which they have interacted. These interactions occur at intersections, where vehicles pay a temporal cost according to their strategy. We analyze the conditions under which different strategy compositions represent an advantage in the system velocity. We found that the cooperators' mean speed is higher than the defectors' even when the vehicle density is large. However, defectors can obtain benefits in their mean speed when they are a minority in an essentially cooperative population. The presence of a core of educated drivers, who persist firmly in a cooperative behavior, optimizes the speed in the system, especially for intermediate values of vehicular density and higher temporal costs.

  4. A possible generalization of the concept of symmetry in analytical mechanics

    International Nuclear Information System (INIS)

    Grigore, D.R.

    1987-09-01

    A theorem of Lee Hwa Chung suggests a possible generalization of the symmetry concept in classical mechanics. It is shown that the theory of Konstant-Souriau-Kirillov can be adapted to this more general case. The theory is illustrated with a number of exaples.(author)

  5. General Mechanical Repair. Minor Automotive Maintenance, Small Engine [Repair, and] Welding: Competency Test Package.

    Science.gov (United States)

    Hamlin, Larry

    This document contains the competency test package for three sections of a general mechanical repair course: minor automotive maintenance, small engine mechanics, and welding. Following a list of the common essential elements for trade and industrial education, competency tests for the three sections are provided. Each test includes unit name,…

  6. 16 CFR 304.5 - Marking requirements for imitation political items.

    Science.gov (United States)

    2010-01-01

    ... 16 Commercial Practices 1 2010-01-01 2010-01-01 false Marking requirements for imitation political... imitation political items. (a) An imitation political item which is manufactured in the United States, or...) An imitation political item of incusable material shall be incused with the calendar year in sans...

  7. Teaching Imitation to Young Children with Disabilities: A Review of the Literature

    Science.gov (United States)

    Ledford, Jennifer R.; Wolery, Mark

    2011-01-01

    Imitation is a primary means through which children learn new skills. Most children learn to imitate without being taught but some children with disabilities fail to develop or use imitation in the absence of direct instruction. The importance of teaching imitation to children with disabilities has been acknowledged, with studies appearing as…

  8. 16 CFR 304.6 - Marking requirements for imitation numismatic items.

    Science.gov (United States)

    2010-01-01

    ... 16 Commercial Practices 1 2010-01-01 2010-01-01 false Marking requirements for imitation... for imitation numismatic items. (a) An imitation numismatic item which is manufactured in the United... the item. (3) An imitation numismatic item of incusable material shall be incused with the word “COPY...

  9. An estimate of intensity of windy resuspension during imitation of agricultural work

    International Nuclear Information System (INIS)

    Drugachenok, M.A.; Kudryashov, V.P.; Mironov, V.P.

    1996-01-01

    Estimation of intensity of wind rising at imitation of agricultural works. During special experiment for imitation of the agricultural activity which has been carried out in the summer of 1993, the characteristics of radioactive contamination of a surface of ground, density of radioactive fallout, concentration of radionuclides and their distribution on height of surface layer of atmosphere are measured. The value of intensity of secondary wind rising in conditions of dry weather are received. At mechanical influence on ground the intensity of wind rising exceeds on 3-4 order a background value of this parameter which are (4-6)*10 -11 1/c. The received numerical value of intensity of wind rising can be used for forecasting of inhalation intake of radionuclides in organism of the person during agricultural works. 3 tabs., 10 refs

  10. Humanoid Cognitive Robots That Learn by Imitating: Implications for Consciousness Studies

    Directory of Open Access Journals (Sweden)

    James A. Reggia

    2018-01-01

    Full Text Available While the concept of a conscious machine is intriguing, producing such a machine remains controversial and challenging. Here, we describe how our work on creating a humanoid cognitive robot that learns to perform tasks via imitation learning relates to this issue. Our discussion is divided into three parts. First, we summarize our previous framework for advancing the understanding of the nature of phenomenal consciousness. This framework is based on identifying computational correlates of consciousness. Second, we describe a cognitive robotic system that we recently developed that learns to perform tasks by imitating human-provided demonstrations. This humanoid robot uses cause–effect reasoning to infer a demonstrator’s intentions in performing a task, rather than just imitating the observed actions verbatim. In particular, its cognitive components center on top-down control of a working memory that retains the explanatory interpretations that the robot constructs during learning. Finally, we describe our ongoing work that is focused on converting our robot’s imitation learning cognitive system into purely neurocomputational form, including both its low-level cognitive neuromotor components, its use of working memory, and its causal reasoning mechanisms. Based on our initial results, we argue that the top-down cognitive control of working memory, and in particular its gating mechanisms, is an important potential computational correlate of consciousness in humanoid robots. We conclude that developing high-level neurocognitive control systems for cognitive robots and using them to search for computational correlates of consciousness provides an important approach to advancing our understanding of consciousness, and that it provides a credible and achievable route to ultimately developing a phenomenally conscious machine.

  11. Muecas: A Multi-Sensor Robotic Head for Affective Human Robot Interaction and Imitation

    Directory of Open Access Journals (Sweden)

    Felipe Cid

    2014-04-01

    Full Text Available This paper presents a multi-sensor humanoid robotic head for human robot interaction. The design of the robotic head, Muecas, is based on ongoing research on the mechanisms of perception and imitation of human expressions and emotions. These mechanisms allow direct interaction between the robot and its human companion through the different natural language modalities: speech, body language and facial expressions. The robotic head has 12 degrees of freedom, in a human-like configuration, including eyes, eyebrows, mouth and neck, and has been designed and built entirely by IADeX (Engineering, Automation and Design of Extremadura and RoboLab. A detailed description of its kinematics is provided along with the design of the most complex controllers. Muecas can be directly controlled by FACS (Facial Action Coding System, the de facto standard for facial expression recognition and synthesis. This feature facilitates its use by third party platforms and encourages the development of imitation and of goal-based systems. Imitation systems learn from the user, while goal-based ones use planning techniques to drive the user towards a final desired state. To show the flexibility and reliability of the robotic head, the paper presents a software architecture that is able to detect, recognize, classify and generate facial expressions in real time using FACS. This system has been implemented using the robotics framework, RoboComp, which provides hardware-independent access to the sensors in the head. Finally, the paper presents experimental results showing the real-time functioning of the whole system, including recognition and imitation of human facial expressions.

  12. The imitator of nuclear explosion signals for field operations

    International Nuclear Information System (INIS)

    Wang Lusong; Xie Yujun; Tan Youjin; Wang Liping

    1999-01-01

    According to the present system of the nuclear explosion monitoring equipment (NEME), the imitator of nuclear explosion signals for field operation is urgently needed by NEME, which has been fitted out to the army and some new types that will be finalized soon. The authors have made the imitator for the equipment, and as the cause of this research, it can be used not only in training and maintenance for army but also in research and production for scientific research institutions and industrial enterprise. Function of this imitator is to imitate the NEMP, the light and shock wave signals of nuclear explosion in proper order. The time difference of the process accords with the true location of nuclear explosion. This research is of great military importance

  13. The role of communication and imitation in limit order markets

    Science.gov (United States)

    Tedeschi, G.; Iori, G.; Gallegati, M.

    2009-10-01

    In this paper we develop an order driver market model with heterogeneous traders that imitate each other on different network structures. We assess how imitations among otherway noise traders, can give rise to well known stylized facts such as fat tails and volatility clustering. We examine the impact of communication and imitation on the statistical properties of prices and order flows when changing the networks' structure, and show that the imitation of a given, fixed agent, called “guru", can generate clustering of volatility in the model. We also find a positive correlation between volatility and bid-ask spread, and between fat-tailed fluctuations in asset prices and gap sizes in the order book. in here

  14. Application of imitation for energy calibration of silicon semiconductor detectors

    CERN Document Server

    Aivazyan, G M; Mikaelyan, M A

    2003-01-01

    An effective method is described for energy calibration of semiconductor detectors (SCD) with different thickness. The method is based on imitating the charge on the input of the preamplifier deposited in SCD by known energy ionizing particles, the imitation being performed by a pulser with a partial with use of alpha-active sources. The results of laboratory studies of the described method are given with detectors of either large, 50-1000 mu m, or small, 18-20 mu m, thickness

  15. On the Evolution of Behaviors through Embodied Imitation.

    Science.gov (United States)

    Erbas, Mehmet D; Bull, Larry; Winfield, Alan F T

    2015-01-01

    This article describes research in which embodied imitation and behavioral adaptation are investigated in collective robotics. We model social learning in artificial agents with real robots. The robots are able to observe and learn each others' movement patterns using their on-board sensors only, so that imitation is embodied. We show that the variations that arise from embodiment allow certain behaviors that are better adapted to the process of imitation to emerge and evolve during multiple cycles of imitation. As these behaviors are more robust to uncertainties in the real robots' sensors and actuators, they can be learned by other members of the collective with higher fidelity. Three different types of learned-behavior memory have been experimentally tested to investigate the effect of memory capacity on the evolution of movement patterns, and results show that as the movement patterns evolve through multiple cycles of imitation, selection, and variation, the robots are able to, in a sense, agree on the structure of the behaviors that are imitated.

  16. A Network Model of Observation and Imitation of Speech

    Science.gov (United States)

    Mashal, Nira; Solodkin, Ana; Dick, Anthony Steven; Chen, E. Elinor; Small, Steven L.

    2012-01-01

    Much evidence has now accumulated demonstrating and quantifying the extent of shared regional brain activation for observation and execution of speech. However, the nature of the actual networks that implement these functions, i.e., both the brain regions and the connections among them, and the similarities and differences across these networks has not been elucidated. The current study aims to characterize formally a network for observation and imitation of syllables in the healthy adult brain and to compare their structure and effective connectivity. Eleven healthy participants observed or imitated audiovisual syllables spoken by a human actor. We constructed four structural equation models to characterize the networks for observation and imitation in each of the two hemispheres. Our results show that the network models for observation and imitation comprise the same essential structure but differ in important ways from each other (in both hemispheres) based on connectivity. In particular, our results show that the connections from posterior superior temporal gyrus and sulcus to ventral premotor, ventral premotor to dorsal premotor, and dorsal premotor to primary motor cortex in the left hemisphere are stronger during imitation than during observation. The first two connections are implicated in a putative dorsal stream of speech perception, thought to involve translating auditory speech signals into motor representations. Thus, the current results suggest that flow of information during imitation, starting at the posterior superior temporal cortex and ending in the motor cortex, enhances input to the motor cortex in the service of speech execution. PMID:22470360

  17. Nonverbal imitation skills in children with specific language delay.

    Science.gov (United States)

    Dohmen, Andrea; Chiat, Shula; Roy, Penny

    2013-10-01

    Research in children with language problems has focussed on verbal deficits, and we have less understanding of children's deficits with nonverbal sociocognitive skills which have been proposed to be important for language acquisition. This study was designed to investigate elicited nonverbal imitation in children with specific language delay (SLD). It is argued that difficulties in nonverbal imitation, which do not involve the processing of structural aspects of language, may be indicative of sociocognitive deficits. Participants were German-speaking typically developing children (n=60) and children with SLD (n=45) aged 2-3 ½ years. A novel battery of tasks measured their ability to imitate a range of nonverbal target acts that to a greater or lesser extent involve sociocognitive skills (body movements, instrumental acts on objects, pretend acts). Significant group differences were found for all body movement and pretend act tasks, but not for the instrumental act tasks. The poorer imitative performance of the SLD sample was not explained by motor or nonverbal cognitive skills. Thus, it appeared that the nature of the task affected children's imitation performance. It is argued that the ability to establish a sense of connectedness with the demonstrator was at the core of children's imitation difficulty in the SLD sample. Copyright © 2013 Elsevier Ltd. All rights reserved.

  18. Social imitation versus strategic choice, or consensus versus cooperation, in the networked Prisoner's Dilemma

    Science.gov (United States)

    Vilone, Daniele; Ramasco, José J.; Sánchez, Angel; Miguel, Maxi San

    2014-08-01

    The interplay of social and strategic motivations in human interactions is a largely unexplored topic in collective social phenomena. Whether individuals' decisions are taken in a purely strategic basis or due to social pressure without a rational background crucially influences the model outcome. Here we study a networked Prisoner's Dilemma in which decisions are made either based on the replication of the most successful neighbor's strategy (unconditional imitation) or by pure social imitation following an update rule inspired by the voter model. The main effects of the voter dynamics are an enhancement of the final consensus, i.e., asymptotic states are generally uniform, and a promotion of cooperation in certain regions of the parameter space as compared to the outcome of purely strategic updates. Thus, voter dynamics acts as an interface noise and has a similar effect as a pure random noise; furthermore, its influence is mostly independent of the network heterogeneity. When strategic decisions are made following other update rules such as the replicator or Moran processes, the dynamic mixed state found under unconditional imitation for some parameters disappears, but an increase of cooperation in certain parameter regions is still observed. Comparing our results with recent experiments on the Prisoner's Dilemma, we conclude that such a mixed dynamics may explain moody conditional cooperation among the agents.

  19. Imitate or innovate: Competition of strategy updating attitudes in spatial social dilemma games

    Science.gov (United States)

    Danku, Zsuzsa; Wang, Zhen; Szolnoki, Attila

    2018-01-01

    Evolution is based on the assumption that competing players update their strategies to increase their individual payoffs. However, while the applied updating method can be different, most of previous works proposed uniform models where players use identical way to revise their strategies. In this work we explore how imitation-based or learning attitude and innovation-based or myopic best-response attitude compete for space in a complex model where both attitudes are available. In the absence of additional cost the best response trait practically dominates the whole snow-drift game parameter space which is in agreement with the average payoff difference of basic models. When additional cost is involved then the imitation attitude can gradually invade the whole parameter space but this transition happens in a highly nontrivial way. However, the role of competing attitudes is reversed in the stag-hunt parameter space where imitation is more successful in general. Interestingly, a four-state solution can be observed for the latter game which is a consequence of an emerging cyclic dominance between possible states. These phenomena can be understood by analyzing the microscopic invasion processes, which reveals the unequal propagation velocities of strategies and attitudes.

  20. Imitation learning of car driving skills with decision trees and random forests

    Directory of Open Access Journals (Sweden)

    Cichosz Paweł

    2014-09-01

    Full Text Available Machine learning is an appealing and useful approach to creating vehicle control algorithms, both for simulated and real vehicles. One common learning scenario that is often possible to apply is learning by imitation, in which the behavior of an exemplary driver provides training instances for a supervised learning algorithm. This article follows this approach in the domain of simulated car racing, using the TORCS simulator. In contrast to most prior work on imitation learning, a symbolic decision tree knowledge representation is adopted, which combines potentially high accuracy with human readability, an advantage that can be important in many applications. Decision trees are demonstrated to be capable of representing high quality control models, reaching the performance level of sophisticated pre-designed algorithms. This is achieved by enhancing the basic imitation learning scenario to include active retraining, automatically triggered on control failures. It is also demonstrated how better stability and generalization can be achieved by sacrificing human-readability and using decision tree model ensembles. The methodology for learning control models contributed by this article can be hopefully applied to solve real-world control tasks, as well as to develop video game bots

  1. Imitative and Direct Learning as Interacting Factors in Life History Evolution.

    Science.gov (United States)

    Bullinaria, John A

    2017-01-01

    The idea that lifetime learning can have a significant effect on life history evolution has recently been explored using a series of artificial life simulations. These involved populations of competing individuals evolving by natural selection to learn to perform well on simplified abstract tasks, with the learning consisting of identifying regularities in their environment. In reality, there is more to learning than that type of direct individual experience, because it often includes a substantial degree of social learning that involves various forms of imitation of what other individuals have learned before them. This article rectifies that omission by incorporating memes and imitative learning into revised versions of the previous approach. To do this reliably requires formulating and testing a general framework for meme-based simulations that will enable more complete investigations of learning as a factor in any life history evolution scenarios. It does that by simulating imitative information transfer in terms of memes being passed between individuals, and developing a process for merging that information with the (possibly inconsistent) information acquired by direct experience, leading to a consistent overall body of learning. The proposed framework is tested on a range of learning variations and a representative set of life history factors to confirm the robustness of the approach. The simulations presented illustrate the types of interactions and tradeoffs that can emerge, and indicate the kinds of species-specific models that could be developed with this approach in the future.

  2. General-Covariant Quantum Mechanics of Dirac Particle in Curved Space-Times

    International Nuclear Information System (INIS)

    Tagirov, Eh.A.

    1994-01-01

    A general covariant analog of the standard non-relativistic Quantum Mechanics with relativistic corrections in normal geodesic frames in the general Riemannian space-time is constructed for the Dirac particle. Not only the Pauli equation with hermitian Hamiltonian and the pre-Hilbert structure of space of its solutions but also the matrix elements of hermitian operators of momentum, (curvilinear) spatial coordinates and spin of the particle are deduced as general-covariant asymptotic approximation in c -2 , c being the velocity of light, to their naturally determined general-relativistic pre images. It is shown that the Hamiltonian in the Pauli equation originated by the Dirac equation is unitary equivalent to the operator of energy, originated by the metric energy-momentum tensor of the spinor field. Commutation and other properties of the observables connected with the considered change of geometrical background of Quantum Mechanics are briefly discussed. 7 refs

  3. Operator algebras for general one-dimensional quantum mechanical potentials with discrete spectrum

    International Nuclear Information System (INIS)

    Wuensche, Alfred

    2002-01-01

    We define general lowering and raising operators of the eigenstates for one-dimensional quantum mechanical potential problems leading to discrete energy spectra and investigate their associative algebra. The Hamilton operator is quadratic in these lowering and raising operators and corresponding representations of operators for action and angle are found. The normally ordered representation of general operators using combinatorial elements such as partitions is derived. The introduction of generalized coherent states is discussed. Linear laws for the spacing of the energy eigenvalues lead to the Heisenberg-Weyl group and general quadratic laws of level spacing to unitary irreducible representations of the Lie group SU(1, 1) that is considered in detail together with a limiting transition from this group to the Heisenberg-Weyl group. The relation of the approach to quantum deformations is discussed. In two appendices, the classical and quantum mechanical treatment of the squared tangent potential is presented as a special case of a system with quadratic level spacing

  4. Spontaneous cross-species imitation in interactions between chimpanzees and zoo visitors.

    Science.gov (United States)

    Persson, Tomas; Sauciuc, Gabriela-Alina; Madsen, Elainie Alenkær

    2018-01-01

    Imitation is a cornerstone of human development, serving both a cognitive function (e.g. in the acquisition and transmission of skills and knowledge) and a social-communicative function, whereby the imitation of familiar actions serves to maintain social interaction and promote prosociality. In nonhuman primates, this latter function is poorly understood, or even claimed to be absent. In this observational study, we documented interactions between chimpanzees and zoo visitors and found that the two species imitated each other at a similar rate, corresponding to almost 10% of all produced actions. Imitation appeared to accomplish a social-communicative function, as cross-species interactions that contained imitative actions lasted significantly longer than interactions without imitation. In both species, physical proximity promoted cross-species imitation. Overall, imitative precision was higher among visitors than among chimpanzees, but this difference vanished in proximity contexts, i.e. in the indoor environment. Four of five chimpanzees produced imitations; three of them exhibited comparable imitation rates, despite large individual differences in level of cross-species interactivity. We also found that chimpanzees evidenced imitation recognition, yet only when visitors imitated their actions (as opposed to postures). Imitation recognition was expressed by returned imitation in 36% of the cases, and all four imitating chimpanzees engaged in so-called imitative games. Previously regarded as unique to early human socialization, such games serve to maintain social engagement. The results presented here indicate that nonhuman apes exhibit spontaneous imitation that can accomplish a communicative function. The study raises a number of novel questions for imitation research and highlights the imitation of familiar behaviours as a relevant-yet thus far understudied-research topic.

  5. Multiple-event probability in general-relativistic quantum mechanics. II. A discrete model

    International Nuclear Information System (INIS)

    Mondragon, Mauricio; Perez, Alejandro; Rovelli, Carlo

    2007-01-01

    We introduce a simple quantum mechanical model in which time and space are discrete and periodic. These features avoid the complications related to continuous-spectrum operators and infinite-norm states. The model provides a tool for discussing the probabilistic interpretation of generally covariant quantum systems, without the confusion generated by spurious infinities. We use the model to illustrate the formalism of general-relativistic quantum mechanics, and to test the definition of multiple-event probability introduced in a companion paper [Phys. Rev. D 75, 084033 (2007)]. We consider a version of the model with unitary time evolution and a version without unitary time evolution

  6. General structure of quantum mechanics. The objections raised by Einstein, Podolsky and Rosen

    International Nuclear Information System (INIS)

    Laloe, F.

    1981-01-01

    First, the general formulation of quantum mechanics is briefly presented, with the so called 'Copenhagen interpretation', and a few very simple examples are given. Then, the general experimental scheme imagined by Einstein, Podolsky and Rosen is discussed in detail, for two correlated spin 1/2 particules, in terms of the elements of physical reality which can be attached to the system. A macroscopic analogue is given, in order to emphasize how strange the language of quantum mechanics may become when applied to every day life phenomena, where all correlation phenomena are explained in terms of a common cause in the past. Finally, the notions of separability, locality and determinism are introduced [fr

  7. Anti-hydrogen: The cusp between quantum mechanics and general relativity

    International Nuclear Information System (INIS)

    Noyes, H.P.

    1992-09-01

    We argue that the crossing (CPT) symmetry of relativistic quantum mechanics requires that both the coulombic and the Newtonian force between pairs of particles will reverse when one is replaced by its anti-particle. For consistency, this requires a theory in which both the equivalence principles and gauge invariance are abandoned. thus whether anti-hydrogen ''falls'' up or down will provide an experiment crusis separating general relativity and gauge invariance from this version of quantum mechanics

  8. Jomon pottery: cord-imitating decoration

    Directory of Open Access Journals (Sweden)

    Irina Zhushchikhovskaya

    2007-12-01

    Full Text Available The paper discusses the decoration of pottery of the Neolithic Jomon culture (Japanese Archipelago, 13600–900 BC. The comb-impressed pattern produced by various kinds of cord or rope stamps is considered as the ‘calling card’ of Jomon pottery from the earliest cultural periods to the latest. Another kind of decoration recognized recently uses the cord not as a patterning tool, but as an essential motif of decorative composition. High relief elements imitate cordage forms and structures – knots, loops, hanging cord, net, etc. This kind of decoration corresponds to the pottery of Mid-dle Jomon period (3500–2500 BC sites located in northern and north-eastern Honshu and southern Hokkaido. It is supposed that the introduction of images of real material object into the field of decorative art was reasoned by the meaning of cord and cordage as cultural signs during the Middle Jomon period. Interesting parallels to some cordage structures reconstructed on Middle Jomon pottery decoration are well known in traditional Japanese culture of VI–XX cc. Analytical interpretation of this resemblance may became the subject of special research.

  9. Untrained chimpanzees (Pan troglodytes schweinfurthii fail to imitate novel actions.

    Directory of Open Access Journals (Sweden)

    Claudio Tennie

    Full Text Available Social learning research in apes has focused on social learning in the technical (problem solving domain - an approach that confounds action and physical information. Successful subjects in such studies may have been able to perform target actions not as a result of imitation learning but because they had learnt some technical aspect, for example, copying the movements of an apparatus (i.e., different forms of emulation learning.Here we present data on action copying by non-enculturated and untrained chimpanzees when physical information is removed from demonstrations. To date, only one such study (on gesture copying in a begging context has been conducted--with negative results. Here we have improved this methodology and have also added non-begging test situations (a possible confound of the earlier study. Both familiar and novel actions were used as targets. Prior to testing, a trained conspecific demonstrator was rewarded for performing target actions in view of observers. All but one of the tested chimpanzees already failed to copy familiar actions. When retested with a novel target action, also the previously successful subject failed to copy--and he did so across several contexts.Chimpanzees do not seem to copy novel actions, and only some ever copy familiar ones. Due to our having tested only non-enculturated and untrained chimpanzees, the performance of our test subjects speak more than most other studies of the general (dis-ability of chimpanzees to copy actions, and especially novel actions.

  10. Untrained Chimpanzees (Pan troglodytes schweinfurthii) Fail to Imitate Novel Actions

    Science.gov (United States)

    Tennie, Claudio; Call, Josep; Tomasello, Michael

    2012-01-01

    Background Social learning research in apes has focused on social learning in the technical (problem solving) domain - an approach that confounds action and physical information. Successful subjects in such studies may have been able to perform target actions not as a result of imitation learning but because they had learnt some technical aspect, for example, copying the movements of an apparatus (i.e., different forms of emulation learning). Methods Here we present data on action copying by non-enculturated and untrained chimpanzees when physical information is removed from demonstrations. To date, only one such study (on gesture copying in a begging context) has been conducted – with negative results. Here we have improved this methodology and have also added non-begging test situations (a possible confound of the earlier study). Both familiar and novel actions were used as targets. Prior to testing, a trained conspecific demonstrator was rewarded for performing target actions in view of observers. All but one of the tested chimpanzees already failed to copy familiar actions. When retested with a novel target action, also the previously successful subject failed to copy – and he did so across several contexts. Conclusion Chimpanzees do not seem to copy novel actions, and only some ever copy familiar ones. Due to our having tested only non-enculturated and untrained chimpanzees, the performance of our test subjects speak more than most other studies of the general (dis-)ability of chimpanzees to copy actions, and especially novel actions. PMID:22905102

  11. Effects of imitating gestures during encoding or during retrieval of novel verbs on children's test performance.

    Science.gov (United States)

    de Nooijer, Jacqueline A; van Gog, Tamara; Paas, Fred; Zwaan, Rolf A

    2013-09-01

    Research has shown that observing and imitating gestures can foster word learning and that imitation might be more beneficial than observation, which is in line with theories of Embodied Cognition. This study investigated when imitation of gestures is most effective, using a 2×2×2×3 mixed design with between-subjects factors Imitation during Encoding (IE; Yes/No) and Imitation during Retrieval (IR; Yes/No), and within-subjects factors Time of Testing (Immediate/Delayed) and Verb Type (Object manipulation/Locomotion/Abstract). Primary school children (N=115) learned 15 novel verbs (five of each type). They were provided with a verbal definition and a video of the gesture. Depending on assigned condition, they additionally received no imitation instructions, instructions to imitate the gesture immediately (i.e., during encoding; IE), instructions to imitate (from memory) during the first posttest (i.e., during retrieval; IR), or both (IE-IR). Based on the literature, all three imitation conditions could be predicted to be more effective than no imitation. On an immediate and delayed posttest, only the object-manipulation verbs were differentially affected by instructional method, with IE and IR being more effective than no imitation on the immediate test; IE-IR and no imitation did not differ significantly. After a one week delay, only IR was more effective than no imitation, suggesting that imitation during retrieval is most effective for learning object-manipulation words. Copyright © 2013 Elsevier B.V. All rights reserved.

  12. A general theorem on the transition probabilities of a quantum mechanical system with spatial degeneracy

    NARCIS (Netherlands)

    Tolhoek, H.A.; Groot, S.R. de

    1949-01-01

    In the general case of a quantum mechanical system with a Hamiltonian that is invariant for rotations spatial degeneracy will exist. So the initial state must be characterized except by the energy also by e.g. the magnetic quantum number. Both for emission of light and electrons plus neutrinos

  13. On the correspondence between the dynamics with odd and even brackets and generalized Nambu's mechanics

    International Nuclear Information System (INIS)

    Makhaldiani, N.; Voskresenskaya, O.

    1998-01-01

    We consider selected problems of Hamiltonization and integrability of a general dynamical system described by a system of ordinary differential equations; odd and even symplectic structures; a new approach to the linearization of non-linear systems by the extended Hamiltonian and Nambu's mechanics

  14. A generalization of Fenyes-Nelson stochastic model of quantum mechanics

    International Nuclear Information System (INIS)

    Davidson, M.

    1979-01-01

    It is shown that the stochastic model of Fenyes and Nelson can be generalized in such a way that the diffusion constant of the Markov theory becomes a free parameter. This extra freedom allows one to identify quantum mechanics with a class of Markov processes with diffusion constants varying from 0 to infinity. (Auth.)

  15. General Mechanical Repair. Minor Automotive Maintenance, Small Engine [Repair, and] Welding: Curriculum Guide and Lesson Plans.

    Science.gov (United States)

    Hamlin, Larry

    This document contains a curriculum guide and lesson plans for a general mechanical repair course with three sections: minor automotive maintenance, small engine repair, and welding. The curriculum guide begins with a matrix that relates the lesson plans to essential elements of math, science, language arts, and social studies and to Texas…

  16. General Mechanical Repair. Minor Automotive Maintenance, Small Engine [Repair, and] Welding: Student Manual.

    Science.gov (United States)

    Hamlin, Larry

    This document is a student manual for a general mechanical repair course. Following a list of common essential elements of trade and industrial education, the manual is divided into three sections. The first section, on minor automotive maintenance, contains 13 units: automotive shop safety; engine principles; fuel system operation and repair;…

  17. General Mechanical Repair 2. Minor Automotive Maintenance, Small Engine [Repair, and] Welding. Curriculum Guide.

    Science.gov (United States)

    Hamlin, Larry

    This curriculum guide provides materials for teachers to use in developing a 1-year course in general mechanical repair as part of the trade and industrial education curriculum. The guide contains the following: (1) essential elements common to all trade and industrial courses; (2) an instructional delivery outline (teaching sequence) for the…

  18. Enactivism and neonatal imitation: conceptual and empirical considerations and clarifications.

    Science.gov (United States)

    Lodder, Paul; Rotteveel, Mark; van Elk, Michiel

    2014-01-01

    Recently within social cognition it has been argued that understanding others is primarily characterized by dynamic and second person interactive processes, rather than by taking a third person observational stance. Within this enactivist view of intersubjective understanding, researchers differ in their claims regarding the innateness of such processes. Here we proposed to distinguish nativist enactivists-who argue that studies on neonatal imitation support the view that infants already have a non-mentalistic embodied form of intersubjective understanding present at birth-from empiricist enactivists, who claim that those intersubjective processes are learned through social interaction. In this article, we critically examine the empirical studies on neonate imitation and conclude that the available evidence is at least mixed for most types of specific gesture imitations. In the end, only the tongue protrusion imitation appears to be consistent across different studies. If neonates imitate only one single gesture, then a more parsimonious explanation for the tongue protrusion effect could be put forward. Consequently, the nativist enactivist claim that understanding others depends on second person interactive processes already present at birth seems no longer plausible. Although other strands of evidence provide converging evidence for the importance of intersubjective processes in adult social cognition, the available evidence on neonatal imitation calls for a more careful view on the innateness of such processes and suggests that this way of interacting needs to be learned over time. Therefore the available empirical evidence on neonate imitation is in our view compatible with the empiricist enactivist position, but not with the nativist enactivist position.

  19. Children's Representation and Imitation of Events: How Goal Organization Influences 3-Year-Old Children's Memory for Action Sequences.

    Science.gov (United States)

    Loucks, Jeff; Mutschler, Christina; Meltzoff, Andrew N

    2017-09-01

    Children's imitation of adults plays a prominent role in human cognitive development. However, few studies have investigated how children represent the complex structure of observed actions which underlies their imitation. We integrate theories of action segmentation, memory, and imitation to investigate whether children's event representation is organized according to veridical serial order or a higher level goal structure. Children were randomly assigned to learn novel event sequences either through interactive hands-on experience (Study 1) or via storybook (Study 2). Results demonstrate that children's representation of observed actions is organized according to higher level goals, even at the cost of representing the veridical temporal ordering of the sequence. We argue that prioritizing goal structure enhances event memory, and that this mental organization is a key mechanism of social-cognitive development in real-world, dynamic environments. It supports cultural learning and imitation in ecologically valid settings when social agents are multitasking and not demonstrating one isolated goal at a time. Copyright © 2016 Cognitive Science Society, Inc.

  20. Mathematica® for Theoretical Physics Electrodynamics, Quantum Mechanics, General Relativity and Fractals

    CERN Document Server

    Baumann, Gerd

    2005-01-01

    Mathematica for Theoretical Physics: Electrodynamics, Quantum Mechanics, General Relativity, and Fractals This second edition of Baumann's Mathematica® in Theoretical Physics shows readers how to solve physical problems and deal with their underlying theoretical concepts while using Mathematica® to derive numeric and symbolic solutions. Each example and calculation can be evaluated by the reader, and the reader can change the example calculations and adopt the given code to related or similar problems. The second edition has been completely revised and expanded into two volumes: The first volume covers classical mechanics and nonlinear dynamics. Both topics are the basis of a regular mechanics course. The second volume covers electrodynamics, quantum mechanics, relativity, and fractals and fractional calculus. New examples have been added and the representation has been reworked to provide a more interactive problem-solving presentation. This book can be used as a textbook or as a reference work, by student...

  1. Mechanism design of reverse auction on concession period and generalized quality for PPP projects

    Institute of Scientific and Technical Information of China (English)

    Xianjia WANG; Shiwei WU

    2017-01-01

    Reverse auctions of PPP projects usually require the bid to specify several characteristics of quality and the concession period to be fulfilled.This paper sets up a summary function of generalized quality,which contributes to reducing the dimensions of information.Thus,the multidimensional reverse auction model of a PPP project can be replaced by a two-dimensional direct mechanism based on the concession period and the generalized quality.Based on the theory of the revelation principle,the feasibility conditions,equilibrium solution and generalized quality requirements of such a mechanism,considering the influence of a variable investment structure are described.Moreover,two feasible multidimensional reverse auctions for implementing such a direct mechanism:Adjusting the scoring function and establishing a special reverse auction rule are built.The analysis shows that in these types of reverse auctions,optimal allocation can be achieved,the social benefit under the incomplete information will be maximized,and the private sector with the highest integrated management level wins the bid.In such a direct mechanism,the investment and financial pressure of the public sector can be reduced.

  2. Study on generalized Toda mechanics system with loop algebra L(Dr)

    International Nuclear Information System (INIS)

    Zhu Qiao; Yang Zhanying; Shi Kangjie

    2005-01-01

    The authors generalize the Toda mechanics system with long range interaction to the case of Loop algebra L(D r ). By using a pair of ordered positive integer (X, Y) to describe Toda chains, authors extract the equation of motion and the Hamiltonian structure of this system for (3, 2) Toda chain. It turns out that both extra coordinates and standard Toda variables are Poisson non-commutative in the case of nontrivial generalization, and for some case, extra variables appear linearly on the right hand side of the Poisson bracket. (authors)

  3. Dipole mechanism of spontaneous breaking of N = 2 supersymmetry. II. Reformulation and generalization in harmonic superspace

    International Nuclear Information System (INIS)

    Ohta, N.

    1985-01-01

    After elucidating the component structure of N = 2 supersymmetric gauge theories in the harmonic superspace formalism with central charges, we reformulate our previous dipole mechanism of spontaneous breaking of N = 2 supersymmetry free from the Nambu-Goldstone-fermion difficulties in this formalism. This allows a generalization of our previous model of generating finiteness-preserving mass terms for scalar hypermultiplets; we can also obtain the gauge-fermion and scalar mass terms together with specific cubic interactions for scalar fields. The mechanism is equivalent to the so-called spurion method

  4. Moessbauer study of the firing process of the imitative ancient sky-blue Jun porcelain

    International Nuclear Information System (INIS)

    Gao Zhengyao; Chen Xiande

    1994-01-01

    Moessbauer spectra of the imitative ancient Jun porcelain indicate that the glaze and body materials contain Fe 2 O 3 , Fe 3 O 4 and structural iron. It is clear that during the firing process, the glaze undergoes dehydration, dehydroxylation, vitrification and recrystallization. The Fe 2+ quadrupole splitting value of the paramagnetic peak of the body material is high even at low firing temperatures. For the body material, the distinction between dehydration and dehydroxylation is not clear. The changes of magnetism of the glaze and body materials in the firing process and the coloring mechanism of the sky-blue Jun porcelain are analyzed in the present paper. (orig.)

  5. Organizational Performance: Integration of the Value, Rarity, Imitability and Organization Framework in Project Management

    Directory of Open Access Journals (Sweden)

    Ronielton Rezende Oliveira

    2017-08-01

    Full Text Available Organizational performance is often associated with competitive advantage. In strategy studie saimed at expanding communication on a global vision of organizations and their initiatives, strategic project management stands out, whichis related to the mechanisms and set of management decisions that determine long term organizational performance. This study verify how the Resource-based view adds value to organizational initiatives seeking to achieve organizational performance through projects. The study considers strategic management practiced by the project managers o asto present a conceptual framework with four propositions that demonstrate the integration of the Value, Rarity, Imitability and Organization framework with project management and its relations to organizational performance.

  6. Stationary plasma source of heavy ions for imitating research at the separator

    International Nuclear Information System (INIS)

    Yuferov, V.B.; Sharyj, S.V.; Seroshtanov, V.A.

    2008-01-01

    The imitation gas mix choice for experimenting on the demonstration imitation separator have been grounded. The construction of plasma source is changed. The research of operating conditions and contrastive analysis of received characteristics have been carry out

  7. Boron Stress Activates the General Amino Acid Control Mechanism and Inhibits Protein Synthesis

    Science.gov (United States)

    Uluisik, Irem; Kaya, Alaattin; Fomenko, Dmitri E.; Karakaya, Huseyin C.; Carlson, Bradley A.; Gladyshev, Vadim N.; Koc, Ahmet

    2011-01-01

    Boron is an essential micronutrient for plants, and it is beneficial for animals. However, at high concentrations boron is toxic to cells although the mechanism of this toxicity is not known. Atr1 has recently been identified as a boron efflux pump whose expression is upregulated in response to boron treatment. Here, we found that the expression of ATR1 is associated with expression of genes involved in amino acid biosynthesis. These mechanisms are strictly controlled by the transcription factor Gcn4 in response to boron treatment. Further analyses have shown that boron impaired protein synthesis by promoting phosphorylation of eIF2α in a Gcn2 kinase dependent manner. The uncharged tRNA binding domain (HisRS) of Gcn2 is necessary for the phosphorylation of eIF2α in the presence of boron. We postulate that boron exerts its toxic effect through activation of the general amino acid control system and inhibition of protein synthesis. Since the general amino acid control pathway is conserved among eukaryotes, this mechanism of boron toxicity may be of general importance. PMID:22114689

  8. Boron stress activates the general amino acid control mechanism and inhibits protein synthesis.

    Directory of Open Access Journals (Sweden)

    Irem Uluisik

    Full Text Available Boron is an essential micronutrient for plants, and it is beneficial for animals. However, at high concentrations boron is toxic to cells although the mechanism of this toxicity is not known. Atr1 has recently been identified as a boron efflux pump whose expression is upregulated in response to boron treatment. Here, we found that the expression of ATR1 is associated with expression of genes involved in amino acid biosynthesis. These mechanisms are strictly controlled by the transcription factor Gcn4 in response to boron treatment. Further analyses have shown that boron impaired protein synthesis by promoting phosphorylation of eIF2α in a Gcn2 kinase dependent manner. The uncharged tRNA binding domain (HisRS of Gcn2 is necessary for the phosphorylation of eIF2α in the presence of boron. We postulate that boron exerts its toxic effect through activation of the general amino acid control system and inhibition of protein synthesis. Since the general amino acid control pathway is conserved among eukaryotes, this mechanism of boron toxicity may be of general importance.

  9. Application of imitation for energy calibration of silicon semiconductor detectors

    International Nuclear Information System (INIS)

    Aivazyan, G.M.; Badalyan, H.V.; Mikaelyan, M.A.

    2003-01-01

    An effective method is described for energy calibration of semiconductor detectors (SCD) with different thickness. The method is based on imitating the charge on the input of the preamplifier deposited in SCD by known energy ionizing particles, the imitation being performed by a pulser with a partial with use of α-active sources. The results of laboratory studies of the described method are given with detectors of either large, 50-1000μm, or small, 18-20 μm, thickness

  10. Spatial affects and imitations in OWS and Distortion

    DEFF Research Database (Denmark)

    Samson, Kristine

    the notions of affect (Thrift 2008, Ash & Amin 2002, Anderson & Holden 2008) and imitation (Tarde 1903), the paper will discuss recent urban crowd movements. OWS has spread a global social activist movement using affective bodily means of communication, whereas Distortion is a cultural street festival taking...... manner. For instance, both crowds do not merely gather and organize in terms of verbal communication, rather they organize virally, visually and through bodily affects and imitation. In that sense they appropriate urban space and its architectural design ”like viruses that hop between people, thereby...

  11. Chameleons: Electrocardiogram Imitators of ST-Segment Elevation Myocardial Infarction.

    Science.gov (United States)

    Nable, Jose V; Lawner, Benjamin J

    2015-08-01

    The imperative for timely reperfusion therapy for patients presenting with ST-segment elevation myocardial infarction (STEMI) underscores the need for clinicians to have an understanding of how to distinguish patterns of STEMI from its imitators. These imitating diagnoses may confound an evaluation, potentially delaying necessary therapy. Although numerous diagnoses may mimic STEMI, several morphologic clues may allow the physician to determine if the pattern is concerning for either STEMI or a mimicking diagnosis. Furthermore, obtaining a satisfactory history, comparing previous electrocardiograms, and assessing serial tests may provide valuable clues. Copyright © 2015 Elsevier Inc. All rights reserved.

  12. Multidimensional Generalized Functions in Aeroacoustics and Fluid Mechanics. Part 1; Basic Concepts and Operations

    Science.gov (United States)

    Farassat, Fereidoun; Myers, Michael K.

    2011-01-01

    This paper is the first part of a three part tutorial on multidimensional generalized functions (GFs) and their applications in aeroacoustics and fluid mechanics. The subject is highly fascinating and essential in many areas of science and, in particular, wave propagation problems. In this tutorial, we strive to present rigorously and clearly the basic concepts and the tools that are needed to use GFs in applications effectively and with ease. We give many examples to help the readers in understanding the mathematical ideas presented here. The first part of the tutorial is on the basic concepts of GFs. Here we define GFs, their properties and some common operations on them. We define the important concept of generalized differentiation and then give some interesting elementary and advanced examples on Green's functions and wave propagation problems. Here, the analytic power of GFs in applications is demonstrated with ease and elegance. Part 2 of this tutorial is on the diverse applications of generalized derivatives (GDs). Part 3 is on generalized Fourier transformations and some more advanced topics. One goal of writing this tutorial is to convince readers that, because of their powerful operational properties, GFs are absolutely essential and useful in engineering and physics, particularly in aeroacoustics and fluid mechanics.

  13. Goal-Directed and Goal-Less Imitation in Autism Spectrum Disorder

    Science.gov (United States)

    Wild, Kelly S.; Poliakoff, Ellen; Jerrison, Andrew; Gowen, Emma

    2012-01-01

    To investigate how people with Autism are affected by the presence of goals during imitation, we conducted a study to measure movement kinematics and eye movements during the imitation of goal-directed and goal-less hand movements. Our results showed that a control group imitated changes in movement kinematics and increased the level that they…

  14. A Qualitative Analysis of Imitation Performances of Preschoolers with Down Syndrome

    Science.gov (United States)

    Vanvuchelen, Marleen

    2016-01-01

    A number of studies suggest that imitation is a characteristic strength in children with Down Syndrome (DS). The present study aims to discover whether imitation performances are qualitatively phenotypical in DS. Eight preschoolers with DS were matched on chronological, mental, language and imitation age with 8 preschoolers with intellectual…

  15. The Role of Modality and Register in Imitation by Adults and Children

    Science.gov (United States)

    Ward, Nancy Ann

    2013-01-01

    Research has shown that both adults and children will imitate acoustic properties of the speech around them. In fact, studies on adults have shown that this convergence occurs even when the subject simply sees, but does not hear, the interlocutor. Not only does visual speech elicit imitation on its own, but also imitation is greater for…

  16. The Intersubjective and Transitional Function of Imitation in Early Grandparent-Infant Grandchild Interaction

    Science.gov (United States)

    Kokkinaki, Theano; Pratikaki, Anastasia

    2014-01-01

    Primary objective: Research has provided evidence of the intersubjective function of imitation in grandparent-infant interaction based on the basic aspects of imitation. This lacks the systematic investigation of behaviour dynamics framing spontaneous imitation. The aim of this study was to compare the dyadic expressive behaviours (vocal, kinetic…

  17. 25 CFR 304.1 - Penalties for imitation or unauthorized use.

    Science.gov (United States)

    2010-04-01

    ... 25 Indians 2 2010-04-01 2010-04-01 false Penalties for imitation or unauthorized use. 304.1... SILVER, USE OF GOVERNMENT MARK § 304.1 Penalties for imitation or unauthorized use. The use of Government trade-marks in an unauthorized manner, or the colorable imitation of such marks, is subject to the...

  18. Deferred Imitation in 9-Month-Olds: How Do Model and Task Characteristics Matter across Cultures?

    Science.gov (United States)

    Teiser, Johanna; Lamm, Bettina; Böning, Mirjam; Graf, Frauke; Gudi, Helene; Goertz, Claudia; Fassbender, Ina; Freitag, Claudia; Spangler, Sibylle; Teubert, Manuel; Lohaus, Arnold; Schwarzer, Gudrun; Knopf, Monika; Keller, Heidi

    2014-01-01

    Studies investigating imitation are usually conducted with adult models in Western contexts; therefore, the influence of cultural context and the model's age on infants' imitation is largely unknown. This study assessed deferred imitation in 9-month-old infants from the German middle-class ("N" = 44) and the ethnic group of Nso in rural…

  19. Brief Report: Effect of a Focused Imitation Intervention on Social Functioning in Children with Autism

    Science.gov (United States)

    Ingersoll, Brooke

    2012-01-01

    Imitation is an early skill thought to play a role in social development, leading some to suggest that teaching imitation to children with autism should lead to improvements in social functioning. This study used a randomized controlled trial to evaluate the effect of a focused imitation intervention on initiation of joint attention and…

  20. Effects of Reinforcement on Peer Imitation in a Small Group Play Context

    Science.gov (United States)

    Barton, Erin E.; Ledford, Jennifer R.

    2018-01-01

    Children with disabilities often have deficits in imitation skills, particularly in imitating peers. Imitation is considered a behavioral cusp--which, once learned, allows a child to access additional and previously unavailable learning opportunities. In the current study, researchers examined the efficacy of contingent reinforcement delivered…

  1. A Parent-Implemented Intervention to Improve Imitation Skills by Children with Autism: A Pilot Study

    Science.gov (United States)

    Zaghlawan, Hasan Y.; Ostrosky, Michaelene M.

    2016-01-01

    The purpose of this exploratory study was to examine the effects of a modified reciprocal imitation training (RIT) on the imitation skills of children with autism. Two parents were trained and coached to use the modified RIT with their young children with autism in home settings. The modified RIT was composed of contingent imitation, descriptive…

  2. Deferred Imitation and Social Communication in Speaking and Nonspeaking Children with Autism

    Science.gov (United States)

    Strid, Karin; Heimann, Mikael; Gillberg, Christopher; Smith, Lars; Tjus, Tomas

    2013-01-01

    Deferred imitation and early social communication skills were compared among speaking and nonspeaking children with autism and children developing typically. Overall, the children with autism showed a lower frequency on measures of deferred imitation and social communication compared with typically developing children. Deferred imitation was…

  3. Reality check: Prior exposure facilitates picture book imitation by 15-month-old infants.

    Science.gov (United States)

    Simcock, Gabrielle; Heron-Delaney, Michelle

    2016-11-01

    We examined whether 15-month-olds could imitate a novel action sequence from a picture book, and whether or not pre-exposure to the objects before reading the book would facilitate imitation. We found that infants only imitated from a picture book above baseline when they had previously interacted with the objects. Copyright © 2016. Published by Elsevier Inc.

  4. The Effect of Narrative Cues on Infants' Imitation from Television and Picture Books

    Science.gov (United States)

    Simcock, Gabrielle; Garrity, Kara; Barr, Rachel

    2011-01-01

    Infants can imitate a novel action sequence from television and picture books, yet there has been no direct comparison of infants' imitation from the 2 types of media. Varying the narrative cues available during the demonstration and test, the current experiments measured 18- and 24-month-olds' imitation from television and picture books. Infants…

  5. Imitation and "Theory of Mind" Competencies in Discrimination of Autism from Other Neurodevelopmental Disorders

    Science.gov (United States)

    Perra, Oliver; Williams, Justin H. G.; Whiten, Andrew; Fraser, Lesley; Benzie, Helen; Perrett, David I.

    2008-01-01

    Several studies have reported imitative deficits in autism spectrum disorder (ASD). However, it is still debated if imitative deficits are specific to ASD or shared with clinical groups with similar mental impairment and motor difficulties. We investigated whether imitative tasks can be used to discriminate ASD children from typically developing…

  6. The Development of Imitation in Children 1-3 Years Old. Final Report.

    Science.gov (United States)

    McCall, Robert B.; And Others

    Five studies investigated the development of imitation in children 1-3 years old. Results indicated that children as young as 12 months possess the cognitive capability of translating a perception of an action into their own behavior, but imitation varies as actions requiring direct social commerce with the examiner are imitated less frequently…

  7. Does Immediate Imitation Influence Long-Term Memory for Observed Actions?

    Science.gov (United States)

    Abravanel, Eugene

    1991-01-01

    Describes research on young children's long-term memory under 2 conditions of acquisition: direct imitation followed by a 10-minute delay, or deferred imitation. Children were able to encode and retain as much from visual pickup of modeled acts as from feedback obtained through imitation. (Author/GH)

  8. Folding to Curved Surfaces: A Generalized Design Method and Mechanics of Origami-based Cylindrical Structures

    Science.gov (United States)

    Wang, Fei; Gong, Haoran; Chen, Xi; Chen, C. Q.

    2016-09-01

    Origami structures enrich the field of mechanical metamaterials with the ability to convert morphologically and systematically between two-dimensional (2D) thin sheets and three-dimensional (3D) spatial structures. In this study, an in-plane design method is proposed to approximate curved surfaces of interest with generalized Miura-ori units. Using this method, two combination types of crease lines are unified in one reprogrammable procedure, generating multiple types of cylindrical structures. Structural completeness conditions of the finite-thickness counterparts to the two types are also proposed. As an example of the design method, the kinematics and elastic properties of an origami-based circular cylindrical shell are analysed. The concept of Poisson’s ratio is extended to the cylindrical structures, demonstrating their auxetic property. An analytical model of rigid plates linked by elastic hinges, consistent with numerical simulations, is employed to describe the mechanical response of the structures. Under particular load patterns, the circular shells display novel mechanical behaviour such as snap-through and limiting folding positions. By analysing the geometry and mechanics of the origami structures, we extend the design space of mechanical metamaterials and provide a basis for their practical applications in science and engineering.

  9. Frequency-dependent failure mechanisms of nanocrystalline gold interconnect lines under general alternating current

    Science.gov (United States)

    Luo, X. M.; Zhang, B.; Zhang, G. P.

    2014-09-01

    Thermal fatigue failure of metallization interconnect lines subjected to alternating currents (AC) is becoming a severe threat to the long-term reliability of micro/nanodevices with increasing electrical current density/power. Here, thermal fatigue failure behaviors and damage mechanisms of nanocrystalline Au interconnect lines on the silicon glass substrate have been investigated by applying general alternating currents (the pure alternating current coupled with a direct current (DC) component) with different frequencies ranging from 0.05 Hz to 5 kHz. We observed both thermal fatigue damages caused by Joule heating-induced cyclic strain/stress and electromigration (EM) damages caused by the DC component. Besides, the damage formation showed a strong electrically-thermally-mechanically coupled effect and frequency dependence. At lower frequencies, thermal fatigue damages were dominant and the main damage forms were grain coarsening with grain boundary (GB) cracking/voiding and grain thinning. At higher frequencies, EM damages took over and the main damage forms were GB cracking/voiding of smaller grains and hillocks. Furthermore, the healing effect of the reversing current was considered to elucidate damage mechanisms of the nanocrystalline Au lines generated by the general AC. Lastly, a modified model was proposed to predict the lifetime of the nanocrystalline metal interconnect lines, i.e., that was a competing drift velocity-based approach based on the threshold time required for reverse diffusion/healing to occur.

  10. Surfacing the Depths: Thoughts on Imitation, Resonance and Growth

    Science.gov (United States)

    Music, Graham

    2005-01-01

    This paper examines some of the research on imitation that shows it to be much more than simply a behavioural or reflex response, but rather an aspect of the growth of genuine social and psychological interaction and part of an intersubjective process that includes the representation of object relationships. Differentiations between mind,…

  11. Amblyomma imitator Ticks as Vectors of Rickettsia rickettsii, Mexico

    Science.gov (United States)

    Oliveira, Karla A.; Pinter, Adriano; Medina-Sanchez, Aaron; Boppana, Venkata D.; Wikel, Stephen K.; Saito, Tais B.; Shelite, Thomas; Blanton, Lucas; Popov, Vsevolod; Teel, Pete D.; Walker, David H.; Galvao, Marcio A.M.; Mafra, Claudio

    2010-01-01

    Real-time PCR of Amblyomma imitator tick egg masses obtained in Nuevo Leon State, Mexico, identified a Rickettsia species. Sequence analyses of 17-kD common antigen and outer membrane protein A and B gene fragments showed to it to be R. rickettsii, which suggested a potential new vector for this bacterium. PMID:20678325

  12. The physical imitation experiments of nuclear belt weight scaler

    International Nuclear Information System (INIS)

    Shi Qicun; Wang Mingqian; Sun Jinhua; Li Zhonghao

    1993-01-01

    The physical imitation experiments of the nuclear belt weight scaler (NBWS) were performed with a coal-loaded belt. The linearity, repetition and long-time stability; of the NBWS were measured. And the influence of pile shape, load bias and the composition of coal on weight calculation were studied

  13. Imitative learning as a connector of collective brains.

    Directory of Open Access Journals (Sweden)

    José F Fontanari

    Full Text Available The notion that cooperation can aid a group of agents to solve problems more efficiently than if those agents worked in isolation is prevalent in computer science and business circles. Here we consider a primordial form of cooperation - imitative learning - that allows an effective exchange of information between agents, which are viewed as the processing units of a social intelligence system or collective brain. In particular, we use agent-based simulations to study the performance of a group of agents in solving a cryptarithmetic problem. An agent can either perform local random moves to explore the solution space of the problem or imitate a model agent - the best performing agent in its influence network. There is a trade-off between the number of agents N and the imitation probability p, and for the optimal balance between these parameters we observe a thirtyfold diminution in the computational cost to find the solution of the cryptarithmetic problem as compared with the independent search. If those parameters are chosen far from the optimal setting, however, then imitative learning can impair greatly the performance of the group.

  14. Imitation by Second-Borns in Adult-Sibling Dyads.

    Science.gov (United States)

    Hodapp, Albert F.; LaVoie, Joseph C.

    Five- to seven-year-old second-born children from white, middle-class, intact families were the subjects for this study. Older siblings served as role model for each child, and the parent surrogate models were selected from a pool and trained to act as the child's real parent. The imitation task emphasized verbal, postural, and motor responses of…

  15. Imitating Cooperation and the Formation of long-term Relationships

    DEFF Research Database (Denmark)

    Schumacher, Heiner

    2013-01-01

    We study the infinitely repeated prisoner’s dilemma with the option to maintain or to quit relationships. We show that if agents imitate successful strategies infrequently, defection is not dynamically stable and cooperation emerges regardless of the initial distribution of strategies....

  16. Mirror Me: Imitative Responses in Adults with Autism

    Science.gov (United States)

    Schunke, Odette; Schöttle, Daniel; Vettorazzi, Eik; Brandt, Valerie; Kahl, Ursula; Bäumer, Tobias; Ganos, Christos; David, Nicole; Peiker, Ina; Engel, Andreas K; Brass, Marcel; Münchau, Alexander

    2016-01-01

    Dysfunctions of the human mirror neuron system have been postulated to underlie some deficits in autism spectrum disorders including poor imitative performance and impaired social skills. Using three reaction time experiments addressing mirror neuron system functions under simple and complex conditions, we examined 20 adult autism spectrum…

  17. MIMETISME ET IMITATION : UNE REVUE DE LA LITTERATURE

    African Journals Online (AJOL)

    l‟imitation «des idées pures», mais aussi l‟existence d‟un type de protection de .... gion qui diffuse les caractéristiques de la mode d‟une organisation à une autre. ... d‟amélioration des performances mais par besoin de légitimité. La.

  18. Using Imitation with Congenitally Deafblind Adults: Establishing Meaningful Communication Partnerships

    Science.gov (United States)

    Hart, Paul

    2006-01-01

    All congenitally deafblind people are potential communication partners. The key question for practitioners is how to help them achieve that potential. Imitation offers a particularly powerful means of doing so because it allows both partners to occupy a joint dyadic space, where the process of repairing the damaged communication partnerships that…

  19. Behavioral tagging is a general mechanism of long-term memory formation.

    Science.gov (United States)

    Ballarini, Fabricio; Moncada, Diego; Martinez, Maria Cecilia; Alen, Nadia; Viola, Haydée

    2009-08-25

    In daily life, memories are intertwined events. Little is known about the mechanisms involved in their interactions. Using two hippocampus-dependent (spatial object recognition and contextual fear conditioning) and one hippocampus-independent (conditioned taste aversion) learning tasks, we show that in rats subjected to weak training protocols that induce solely short term memory (STM), long term memory (LTM) is promoted and formed only if training sessions took place in contingence with a novel, but not familiar, experience occurring during a critical time window around training. This process requires newly synthesized proteins induced by novelty and reveals a general mechanism of LTM formation that begins with the setting of a "learning tag" established by a weak training. These findings represent the first comprehensive set of evidences indicating the existence of a behavioral tagging process that in analogy to the synaptic tagging and capture process, need the creation of a transient, protein synthesis-independent, and input specific tag.

  20. The Temporal Signature of Memories: Identification of a General Mechanism for Dynamic Memory Replay in Humans

    Science.gov (United States)

    Michelmann, Sebastian; Bowman, Howard; Hanslmayr, Simon

    2016-01-01

    Reinstatement of dynamic memories requires the replay of neural patterns that unfold over time in a similar manner as during perception. However, little is known about the mechanisms that guide such a temporally structured replay in humans, because previous studies used either unsuitable methods or paradigms to address this question. Here, we overcome these limitations by developing a new analysis method to detect the replay of temporal patterns in a paradigm that requires participants to mentally replay short sound or video clips. We show that memory reinstatement is accompanied by a decrease of low-frequency (8 Hz) power, which carries a temporal phase signature of the replayed stimulus. These replay effects were evident in the visual as well as in the auditory domain and were localized to sensory-specific regions. These results suggest low-frequency phase to be a domain-general mechanism that orchestrates dynamic memory replay in humans. PMID:27494601

  1. The Temporal Signature of Memories: Identification of a General Mechanism for Dynamic Memory Replay in Humans.

    Directory of Open Access Journals (Sweden)

    Sebastian Michelmann

    2016-08-01

    Full Text Available Reinstatement of dynamic memories requires the replay of neural patterns that unfold over time in a similar manner as during perception. However, little is known about the mechanisms that guide such a temporally structured replay in humans, because previous studies used either unsuitable methods or paradigms to address this question. Here, we overcome these limitations by developing a new analysis method to detect the replay of temporal patterns in a paradigm that requires participants to mentally replay short sound or video clips. We show that memory reinstatement is accompanied by a decrease of low-frequency (8 Hz power, which carries a temporal phase signature of the replayed stimulus. These replay effects were evident in the visual as well as in the auditory domain and were localized to sensory-specific regions. These results suggest low-frequency phase to be a domain-general mechanism that orchestrates dynamic memory replay in humans.

  2. WWER type reactor primary loop imitation on large test loop facility in MARIA reactor

    International Nuclear Information System (INIS)

    Moldysh, A.; Strupchevski, A.; Kmetek, Eh.; Spasskov, V.P.; Shumskij, A.M.

    1982-01-01

    At present in Poland in cooperation with USSR a nuclear water loop test facility (WL) in 'MARIA' reactor in Sverke is under construction. The program objective is to investigate processes occuring in WWER reactor under emergency conditions, first of all after the break of the mainprimary loop circulation pipe-line. WL with the power of about 600 kW consists of three major parts: 1) an active loop, imitating the undamaged loops of the WWER reactor; 2) a passive loop assignedfor modelling the broken loop of the WWER reactor; 3) the emergency core cooling system imitating the corresponding full-scale system. The fuel rod bundle consists of 18 1 m long rods. They were fabricated according to the standard WWER fuel technology. In the report some general principles of WWERbehaviour imitation under emergency conditions are given. They are based on the operation experience obtained from 'SEMISCALE' and 'LOFT' test facilities in the USA. A description of separate modelling factors and criteria effects on the development of 'LOCA'-type accident is presented (the break cross-section to the primary loop volume ratio, the pressure differential between inlet and outlet reactor chambers, the pressure drop rate in the loop, the coolant flow rate throuh the core etc.). As an example a comparison of calculated flow rate variations for the WWER-1000 reactor and the model during the loss-of-coolant accident with the main pipe-line break at the core inlet is given. Calculations have been carried out with the use of TECH'-M code [ru

  3. Lethality of patients with rheumatoid arthritis depending on adalimumab administration: imitation modeling

    Directory of Open Access Journals (Sweden)

    D V Goryachev

    2009-01-01

    Full Text Available Lethality of pts with rheumatoid arthritis (RA exceeds mortality values in general population. Possibility of disease modifying anti-rheumatic drugs (DMARD influence on RA pts lethality has been widely discussed lately in scientific works. Objective. To determine possible lethality diminishment in Russian population of RA pts with one of biological drugs TNFα antagonist adalimumab. Material and methods. Model construction is based on the fact of lethality dependence on pt functional state assessed by HAQ. Model simulating progression of functional disability in pts with RA visiting medical institutions of Russia was made (RAISER study. 3 model variants for imitation of consecutive change of DMARDs including adalimumab were done. First consecution assessed DMARD change in the next chain: adalimumab-methotrexate-sulfasalazine-leflunomide-azathioprine-cyclosporine-palliative therapy. Second consecution: adalimumab administration after failure of first 3 DMARDs. Third consecution considered only change of synthetic DMARDs without adalimumab inclusion. Model imitated participation of 3000 pts in every consecution. Prognosis horizon was 12 years. Age of pts and initial HAQ distribution were get from results of epidemiological RAISER study. Calculation was done on the base of elevation of standardized lethality level (SLL in population of RA pts in average from 135% to 300%. SLL values from 80 to 320% were used depending on functional disability degree with converting to Russian values of age-specific lethality coefficient for 1999. Results. Lethality in treatment consecutions including adalimumab was significantly lower. To the end of 12th year in group not using adalimumab, using it at once and using it after 376 DMARDs respectively 65,1%, 71,6% and 71,1% of pts were still alive. Conclusion. Significant decrease of lethality with adalimumab inclusion in consecution of DMARD change during treatment of RA pts was demonstrated with imitation modeling

  4. Identification of Imitation Cheese and Imitation Ice Cream Based on Vegetable Fat Using NMR Spectroscopy and Chemometrics

    Directory of Open Access Journals (Sweden)

    Yulia B. Monakhova

    2013-01-01

    Full Text Available Vegetable oils and fats may be used as cheap substitutes for milk fat to manufacture imitation cheese or imitation ice cream. In this study, 400 MHz nuclear magnetic resonance (NMR spectroscopy of the fat fraction of the products was used in the context of food surveillance to validate the labeling of milk-based products. For sample preparation, the fat was extracted using an automated Weibull-Stoldt methodology. Using principal component analysis (PCA, imitation products can be easily detected. In both cheese and ice cream, a differentiation according to the type of raw material (milk fat and vegetable fat was possible. The loadings plot shows that imitation products were distinguishable by differences in their fatty acid ratios. Furthermore, a differentiation of several types of cheese (Edamer, Gouda, Emmentaler, and Feta was possible. Quantitative data regarding the composition of the investigated products can also be predicted from the same spectra using partial least squares (PLS regression. The models obtained for 13 compounds in cheese (R2 0.75–0.95 and 17 compounds in ice cream (R2 0.83–0.99 (e.g., fatty acids and esters were suitable for a screening analysis. NMR spectroscopy was judged as suitable for the routine analysis of dairy products based on milk or on vegetable fat substitutes.

  5. Identification of Imitation Cheese and Imitation Ice Cream Based on Vegetable Fat Using NMR Spectroscopy and Chemometrics

    Science.gov (United States)

    Monakhova, Yulia B.; Godelmann, Rolf; Andlauer, Claudia; Kuballa, Thomas; Lachenmeier, Dirk W.

    2013-01-01

    Vegetable oils and fats may be used as cheap substitutes for milk fat to manufacture imitation cheese or imitation ice cream. In this study, 400 MHz nuclear magnetic resonance (NMR) spectroscopy of the fat fraction of the products was used in the context of food surveillance to validate the labeling of milk-based products. For sample preparation, the fat was extracted using an automated Weibull-Stoldt methodology. Using principal component analysis (PCA), imitation products can be easily detected. In both cheese and ice cream, a differentiation according to the type of raw material (milk fat and vegetable fat) was possible. The loadings plot shows that imitation products were distinguishable by differences in their fatty acid ratios. Furthermore, a differentiation of several types of cheese (Edamer, Gouda, Emmentaler, and Feta) was possible. Quantitative data regarding the composition of the investigated products can also be predicted from the same spectra using partial least squares (PLS) regression. The models obtained for 13 compounds in cheese (R 2 0.75–0.95) and 17 compounds in ice cream (R 2 0.83–0.99) (e.g., fatty acids and esters) were suitable for a screening analysis. NMR spectroscopy was judged as suitable for the routine analysis of dairy products based on milk or on vegetable fat substitutes. PMID:26904597

  6. Human infants' understanding of social imitation: Inferences of affiliation from third party observations.

    Science.gov (United States)

    Powell, Lindsey J; Spelke, Elizabeth S

    2018-01-01

    Imitation is ubiquitous in positive social interactions. For adult and child observers, it also supports inferences about the participants in such interactions and their social relationships, but the origins of these inferences are obscure. Do infants attach social significance to this form of interaction? Here we test 4- to 5.5-month-old infants' interpretation of imitation, asking if the imitative interactions they observe support inferences of social affiliation, across 10 experimental conditions that varied the modality of the imitation (movement vs. sound), the roles of specific characters (imitators vs. targets), the number of characters in the displays (3 vs. 5), and the number of parties initiating affiliative test events (1 vs. 2). These experiments, together with one experiment conducted with 12-month-old infants, yielded three main findings. First, infants expect that characters who engaged in imitation will approach and affiliate with the characters whom they imitated. Second, infants show no evidence of expecting that characters who were targets of imitation will approach and affiliate with their imitators. Third, analyzing imitative interactions is difficult for young infants, whose expectations vary in strength depending on the number of characters to be tracked and the number of affiliative actors to be compared. These findings have implications for our understanding of social imitation, and they provide methods for advancing understanding of other aspects of early social cognitive development. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Intact Automatic Imitation and Typical Spatial Compatibility in Autism Spectrum Disorder: Challenging the Broken Mirror Theory.

    Science.gov (United States)

    Sowden, Sophie; Koehne, Svenja; Catmur, Caroline; Dziobek, Isabel; Bird, Geoffrey

    2016-02-01

    A lack of imitative behavior is frequently described as a core feature of Autism Spectrum Disorder (ASD), and is consistent with claims of mirror neuron system dysfunction in these individuals. Previous research has questioned this characterization of ASD however, arguing that when tests of automatic imitation are used--which do not require higher-level cognitive processing--imitative behavior is intact or even enhanced in individuals with ASD. In Experiment 1, 60 adult individuals with ASD and a matched Control group completed an automatic imitation task in which they were required to perform an index or a middle finger lift while observing a hand making either the same, or the alternate, finger movement. Both groups demonstrated a significant imitation effect whereby actions were executed faster when preceded by observation of the same action, than when preceded by the alternate action. The magnitude of this "imitation effect" was statistically indistinguishable in the ASD and Control groups. Experiment 2 utilized an improved automatic imitation paradigm to demonstrate that, when automatic imitation effects are isolated from those due to spatial compatibility, increasing autism symptom severity is associated with an increased tendency to imitate. Notably, there was no association between autism symptom severity and spatial compatibility, demonstrating the specificity of the link between ASD symptoms and increased imitation. These results provide evidence against claims of a lack of imitative behavior in ASD, and challenge the "Broken Mirror Theory of Autism." © 2015 International Society for Autism Research, Wiley Periodicals, Inc.

  8. Imitation Assessment and Its Utility to the Diagnosis of Autism: Evidence from Consecutive Clinical Preschool Referrals for Suspected Autism

    Science.gov (United States)

    Vanvuchelen, Marleen; Roeyers, Herbert; De Weerdt, Willy

    2011-01-01

    The present study sought to examine imitation difficulties as a risk factor for autism. Imitation aptitude was examined in 86 preschoolers suspected of autism (1.9-4.5 years) using the Preschool Imitation and Praxis Scale (PIPS). Differences between imitation, language, motor age-equivalents and nonverbal mental age were used to predict the…

  9. A statistical mechanical approach for the computation of the climatic response to general forcings

    Directory of Open Access Journals (Sweden)

    V. Lucarini

    2011-01-01

    Full Text Available The climate belongs to the class of non-equilibrium forced and dissipative systems, for which most results of quasi-equilibrium statistical mechanics, including the fluctuation-dissipation theorem, do not apply. In this paper we show for the first time how the Ruelle linear response theory, developed for studying rigorously the impact of perturbations on general observables of non-equilibrium statistical mechanical systems, can be applied with great success to analyze the climatic response to general forcings. The crucial value of the Ruelle theory lies in the fact that it allows to compute the response of the system in terms of expectation values of explicit and computable functions of the phase space averaged over the invariant measure of the unperturbed state. We choose as test bed a classical version of the Lorenz 96 model, which, in spite of its simplicity, has a well-recognized prototypical value as it is a spatially extended one-dimensional model and presents the basic ingredients, such as dissipation, advection and the presence of an external forcing, of the actual atmosphere. We recapitulate the main aspects of the general response theory and propose some new general results. We then analyze the frequency dependence of the response of both local and global observables to perturbations having localized as well as global spatial patterns. We derive analytically several properties of the corresponding susceptibilities, such as asymptotic behavior, validity of Kramers-Kronig relations, and sum rules, whose main ingredient is the causality principle. We show that all the coefficients of the leading asymptotic expansions as well as the integral constraints can be written as linear function of parameters that describe the unperturbed properties of the system, such as its average energy. Some newly obtained empirical closure equations for such parameters allow to define such properties as an explicit function of the unperturbed forcing

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

    Science.gov (United States)

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

    2010-09-14

    Action video game play benefits performance in an array of sensory, perceptual, and attentional tasks that go well beyond the specifics of game play [1-9]. That a training regimen may induce improvements in so many different skills is notable because the majority of studies on training-induced learning report improvements on the trained task but limited transfer to other, even closely related, tasks ([10], but see also [11-13]). Here we ask whether improved probabilistic inference may explain such broad transfer. By using a visual perceptual decision making task [14, 15], the present study shows for the first time that action video game experience does indeed improve probabilistic inference. A neural model of this task [16] establishes how changing a single parameter, namely the strength of the connections between the neural layer providing the momentary evidence and the layer integrating the evidence over time, captures improvements in action-gamers behavior. These results were established in a visual, but also in a novel auditory, task, indicating generalization across modalities. Thus, improved probabilistic inference provides a general mechanism for why action video game playing enhances performance in a wide variety of tasks. In addition, this mechanism may serve as a signature of training regimens that are likely to produce transfer of learning. Copyright © 2010 Elsevier Ltd. All rights reserved.

  11. Exact Descriptions of General Relativity Derived from Newtonian Mechanics within Curved Geometries

    Science.gov (United States)

    Savickas, David

    2015-04-01

    General relativity and Newtonian mechanics are shown to be exactly related when Newton's second law is written in a curved geometry by using the physical components of a vector as is defined in tensor calculus. By replacing length within the momentum's velocity by the vector metric in a curved geometry the second law can then be shown to be exactly identical to the geodesic equation of motion occurring in general relativity. When time's vector direction is constant, as similarly occurs in Newtonian mechanics, this equation can be reduced to a curved three-dimensional equation of motion that yields the the Schwarzschild equations of motion for an isolated particle. They can be used to describe gravitational behavior for any array of masses for which the Newtonian gravitational potential is known, and is shown to describe a mass particle's behavior in the gravitational field of a thin mass-rod. This use of Newton's laws allows relativistic behavior to be described in a physically comprehensible manner. D. Savickas, Int. J. Mod. Phys. D 23 1430018, (2014).

  12. Fostering Social Cognition through an Imitation- and Synchronization-Based Dance/Movement Intervention in Adults with Autism Spectrum Disorder: A Controlled Proof-of-Concept Study.

    Science.gov (United States)

    Koehne, Svenja; Behrends, Andrea; Fairhurst, Merle T; Dziobek, Isabel

    2016-01-01

    Since social cognition is impaired in individuals with autism spectrum disorder (ASD), this study aimed at establishing the efficacy of a newly developed imitation- and synchronization-based dance/movement intervention (SI-DMI) in fostering emotion inference and empathic feelings (emotional reaction to feelings of others) in adults with high-functioning ASD. Fifty-five adults with ASD (IQ ≥85) who were blinded to the aim of the study were assigned to receive either 10 weeks of a dance/movement intervention focusing on interpersonal movement imitation and synchronization (SI-DMI, n = 27) or a control movement intervention (CMI, n = 24) focusing on individual motor coordination (2 participants from each group declined before baseline testing). The primary outcome measure was the objective Multifaceted Empathy Test targeting emotion inference and empathic feelings. Secondary outcomes were scores on the self-rated Interpersonal Reactivity Index. The well-established automatic imitation task and synchronization finger-tapping task were used to quantify effects on imitation and synchronization functions, complemented by the more naturalistic Assessment of Spontaneous Interaction in Movement. Intention-to-treat analyses revealed that from baseline to 3 months, patients treated with SI-DMI showed a significantly larger improvement in emotion inference (d = 0.58), but not empathic feelings, than those treated with CMI (d = -0.04). On the close generalization level, SI-DMI increased synchronization skills and imitation tendencies, as well as whole-body imitation/synchronization and movement reciprocity/dialogue, compared to CMI. SI-DMI can be successful in promoting emotion inference in adults with ASD and warrants further investigation. © 2015 S. Karger AG, Basel.

  13. The Social Modulation of Imitation Fidelity in School-Age Children

    Science.gov (United States)

    Marsh, Lauren E.; Ropar, Danielle; Hamilton, Antonia F. de C.

    2014-01-01

    Children copy the actions of others with high fidelity, even when they are not causally relevant. This copying of visibly unnecessary actions is termed overimitation. Many competing theories propose mechanisms for overimitation behaviour. The present study examines these theories by studying the social factors that lead children to overimitate actions. Ninety-four children aged 5- to 8-years each completed five trials of an overimitation task. Each trial provided the opportunity to overimitate an action on familiar objects with minimal causal reasoning demands. Social cues (live or video demonstration) and eye contact from the demonstrator were manipulated. After the imitation, children's ratings of action rationality were collected. Substantial overimitation was seen which increased with age. In older children, overimitation was higher when watching a live demonstrator and when eye contact was absent. Actions rated as irrational were more likely to be imitated than those rated as rational. Children overimitated actions on familiar objects even when they rated those actions as irrational, suggesting that failure of causal reasoning cannot be driving overimitation. Our data support social explanations of overimitation and show that the influence of social factors increases with age over the 5- to 8-year-old age range. PMID:24465913

  14. The social modulation of imitation fidelity in school-age children.

    Directory of Open Access Journals (Sweden)

    Lauren E Marsh

    Full Text Available Children copy the actions of others with high fidelity, even when they are not causally relevant. This copying of visibly unnecessary actions is termed overimitation. Many competing theories propose mechanisms for overimitation behaviour. The present study examines these theories by studying the social factors that lead children to overimitate actions. Ninety-four children aged 5- to 8-years each completed five trials of an overimitation task. Each trial provided the opportunity to overimitate an action on familiar objects with minimal causal reasoning demands. Social cues (live or video demonstration and eye contact from the demonstrator were manipulated. After the imitation, children's ratings of action rationality were collected. Substantial overimitation was seen which increased with age. In older children, overimitation was higher when watching a live demonstrator and when eye contact was absent. Actions rated as irrational were more likely to be imitated than those rated as rational. Children overimitated actions on familiar objects even when they rated those actions as irrational, suggesting that failure of causal reasoning cannot be driving overimitation. Our data support social explanations of overimitation and show that the influence of social factors increases with age over the 5- to 8-year-old age range.

  15. Status and Power Do Not Modulate Automatic Imitation of Intransitive Hand Movements.

    Directory of Open Access Journals (Sweden)

    Harry Farmer

    Full Text Available The tendency to mimic the behaviour of others is affected by a variety of social factors, and it has been argued that such "mirroring" is often unconsciously deployed as a means of increasing affiliation during interpersonal interactions. However, the relationship between automatic motor imitation and status/power is currently unclear. This paper reports five experiments that investigated whether social status (Experiments 1, 2, and 3 or power (Experiments 4 and 5 had a moderating effect on automatic imitation (AI in finger-movement tasks, using a series of different manipulations. Experiments 1 and 2 manipulated the social status of the observed person using an associative learning task. Experiment 3 manipulated social status via perceived competence at a simple computer game. Experiment 4 manipulated participants' power (relative to the actors in a card-choosing task. Finally, Experiment 5 primed participants using a writing task, to induce the sense of being powerful or powerless. No significant interactions were found between congruency and social status/power in any of the studies. Additionally, Bayesian hypothesis testing indicated that the null hypothesis should be favoured over the experimental hypothesis in all five studies. These findings are discussed in terms of their implications for AI tasks, social effects on mimicry, and the hypothesis of mimicry as a strategic mechanism to promote affiliation.

  16. Medical mechatronics which imitates living organisms. Seitai ni manabu iyo mechatronics

    Energy Technology Data Exchange (ETDEWEB)

    Ikuta, K. (Kyushu Inst. of Technology, Fukuoka (Japan))

    1991-11-01

    Medical equipments which aim at replacement of biological functions require some different mechatronic elements from industrial ones and such medical equipments are being developed with the object of imitating the functions of living organisms. Research and development of actuators and transmission devices with new principles modelling the functions of living organisms are presented. Servoactuators of small size and large output for their weights are constructedby the use of shape memory alloy. Prototypes of active endoscope and active catheter have been manufactured. A prototype of a cybernetic actuator have been manufactured by imitating flexible motion characteristics of biological muscle systems by the use of piezoelectric devices. A rotor-type cybernetic actuator consists of a pair of layered piezoelectric devices and a rotor with a small gap inbetween. A linear tvpe cybernetic actuator consists of piezoelectric devices for restricting the actuator and impact driving. A transmission mechanism of a new principle whose features are safety, no noise and nodusts is designed by the use of non-contact magnetic gears. 10 refs., 6 figs.

  17. The Born-Infeld vortices induced from a generalized Higgs mechanism.

    Science.gov (United States)

    Han, Xiaosen

    2016-04-01

    We construct self-dual Born-Infeld vortices induced from a generalized Higgs mechanism. Two specific models of the theory are of focused interest where the Higgs potential is either of a | ϕ | 4 - or | ϕ | 6 -type. For the | ϕ | 4 -model, we obtain a sharp existence and uniqueness theorem for doubly periodic and planar vortices. For doubly periodic solutions, a necessary and sufficient condition for the existence is explicitly derived in terms of the vortex number, the Born-Infeld parameter, and the size of the periodic lattice domain. For the | ϕ | 6 -model, we show that both topological and non-topological vortices are present. This new phenomenon distinguishes the model from the classical Born-Infeld-Higgs theory studied earlier in the literature. A series of results regarding doubly periodic, topological, and non-topological vortices in the | ϕ | 6 -model are also established.

  18. Kundalini Yoga for Generalized Anxiety Disorder: An Exploration of Treatment Efficacy and Possible Mechanisms.

    Science.gov (United States)

    Gabriel, M G; Curtiss, Joshua; Hofmann, Stefan G; Khalsa, Sat Bir S

    2018-04-26

    The aim of this study was to examine the efficacy of Kundalini Yoga in reducing symptoms of generalized anxiety disorder (GAD) compared to a common treatment-as-usual condition using cognitive techniques. A secondary objective was to explore potential treatment mechanisms. Females aged 24 to 75 years with GAD ( n = 49) received either an 8-week Kundalini Yoga intervention ( n = 34) or an 8-week treatment-as-usual condition ( n = 15). The yoga condition resulted in lower levels of anxiety relative to the treatment-as-usual condition. Furthermore, changes in somatic symptoms mediated treatment outcome for Kundalini Yoga. Kundalini Yoga may show promise as a treatment for GAD, and this treatment might convey its effect on symptom severity by reducing somatic symptoms.

  19. A general procedure for thermomechanical calibration of nano/micro-mechanical resonators

    International Nuclear Information System (INIS)

    Hauer, B.D.; Doolin, C.; Beach, K.S.D.; Davis, J.P.

    2013-01-01

    We describe a general procedure to calibrate the detection of a nano/micro-mechanical resonator’s displacement as it undergoes thermal Brownian motion. A brief introduction to the equations of motion for such a resonator is presented, followed by a detailed derivation of the corresponding power spectral density (PSD) function, which is identical in all situations aside from a system-dependent effective mass value. The effective masses for a number of different resonator geometries are determined using both finite element method (FEM) modeling and analytical calculations. -- Highlights: •Model micro- and nanomechanical resonators displaced by their own thermal motion. •Review the theoretical framework for describing thermomechanical systems. •Present a recipe for measurement calibration on devices of arbitrary shape. •Point out and correct inconsistencies in the existing literature. •Provide an authoritative guide and reference for practitioners in this area

  20. A general procedure for thermomechanical calibration of nano/micro-mechanical resonators

    Energy Technology Data Exchange (ETDEWEB)

    Hauer, B.D., E-mail: bhauer@ualberta.ca; Doolin, C.; Beach, K.S.D., E-mail: kbeach@ualberta.ca; Davis, J.P., E-mail: jdavis@ualberta.ca

    2013-12-15

    We describe a general procedure to calibrate the detection of a nano/micro-mechanical resonator’s displacement as it undergoes thermal Brownian motion. A brief introduction to the equations of motion for such a resonator is presented, followed by a detailed derivation of the corresponding power spectral density (PSD) function, which is identical in all situations aside from a system-dependent effective mass value. The effective masses for a number of different resonator geometries are determined using both finite element method (FEM) modeling and analytical calculations. -- Highlights: •Model micro- and nanomechanical resonators displaced by their own thermal motion. •Review the theoretical framework for describing thermomechanical systems. •Present a recipe for measurement calibration on devices of arbitrary shape. •Point out and correct inconsistencies in the existing literature. •Provide an authoritative guide and reference for practitioners in this area.

  1. Generalized correlation of indefiniteness coordinate-impulse in quantum mechanics and theory of brownian movement

    International Nuclear Information System (INIS)

    Sukhanov, A.D.

    2004-01-01

    Generalized correlations of the Schroedinger indefinitenesses are shown to have the meaning of the fundamental restrictions as to characteristics of space of states in any probability-like theory. Quantum mechanics, as well as, theory of the brownian movement at arbitrary space of time fall in the category of the mentioned theories. One compared correlations of coordinates-pulse indefinitenesses within the mentioned theory with the similar correlation of indefinitenesses for microparticle under the Gaussian wave packet state. One determined that in case of profound distinction in mathematical tools of two theories one observes their conceptual resemblance. It manifests itself under the alternative conditions - short times in one theory correspond to long ones in another theory and vice versa, while in any of the mentioned theories uncontrollable effect of either quantum or thermal type is of crucial importance [ru

  2. Mirroring "meaningful" actions: sensorimotor learning modulates imitation of goal-directed actions.

    Science.gov (United States)

    Catmur, Caroline; Heyes, Cecilia

    2017-06-19

    Imitation is important in the development of social and technological skills throughout the lifespan. Experiments investigating the acquisition and modulation of imitation (and of its proposed neural substrate, the mirror neuron system) have produced evidence that the capacity for imitation depends on associative learning in which connections are formed between sensory and motor representations of actions. However, evidence that the development of imitation depends on associative learning has been found only for non-goal-directed actions. One reason for the lack of research on goal-directed actions is that imitation of such actions is commonly confounded with the tendency to respond in a spatially compatible manner. However, since the most prominent account of mirror neuron function, and hence of imitation, suggests that these cells encode goal-directed actions, it is important to establish whether sensorimotor learning can also modulate imitation of goal-directed actions. Experiment 1 demonstrated that imitation of goal-directed grasping can be measured while controlling for spatial compatibility, and Experiment 2 showed that this imitation effect can be modulated by sensorimotor training. Together these data support the hypothesis that the capacity for behavioural imitation, and the properties of the mirror neuron system, are constructed in the course of development through associative learning.

  3. An Analysis of British Tourists’ Purchasing Behavior of Imitation Products: A Case of Fethiye

    Directory of Open Access Journals (Sweden)

    Aydan Bekar

    2015-03-01

    Full Text Available The trade of imitation products is increasing rapidly in global scale due to some reasons such as globalization and branding, advancing production technology, high-profit, low risk and low legal sanctions. Manufacturers of imitation products use the advantages of the brand name they produce without a budget of development and promotion activities. Tourists are among consumer group of imitation products. In Fethiye where this study was conducted, it was observed that the number of stores and markets in which imitation products were sold increased with the beginning of holiday season and this number decreased with the end of the season. This observation led to the thought that the target group of dealers of imitation products was foreign tThis study was carried out with 109 British tourists taking their holiday in Fethiye, to examine their purchase behavior towards imitation products. The research data was collected by a questionnaire. According to the study results, it was determined that price was an important factor in tourists’ purchasing imitation products; more than half of the tourists thought imitation products would contribute to the economy of Turkey; that they approved trade of imitation products and they were satisfied with the quality of imitation products

  4. The problematic estimation of "imitation effects" in multilevel models

    Directory of Open Access Journals (Sweden)

    2003-09-01

    Full Text Available It seems plausible that a person's demographic behaviour may be influenced by that among other people in the community, for example because of an inclination to imitate. When estimating multilevel models from clustered individual data, some investigators might perhaps feel tempted to try to capture this effect by simply including on the right-hand side the average of the dependent variable, constructed by aggregation within the clusters. However, such modelling must be avoided. According to simulation experiments based on real fertility data from India, the estimated effect of this obviously endogenous variable can be very different from the true effect. Also the other community effect estimates can be strongly biased. An "imitation effect" can only be estimated under very special assumptions that in practice will be hard to defend.

  5. A meta-analysis of imitation abilities in individuals with autism spectrum disorders.

    Science.gov (United States)

    Edwards, Laura A

    2014-06-01

    Although imitation impairments are often reported in individuals with autism spectrum disorders (ASD), previous work has not yet determined whether these impairments are significant, specific to ASD, and present across the entire spectrum. This report of 53 studies on imitation in ASD seeks to determine whether individuals with ASD show significant imitation deficits, the magnitude of these deficits, and whether they are specific to ASD. Using standard meta-analytic techniques in a random-effects model, the data reviewed suggest that individuals with ASD show deficits in imitation, performing on average 0.81 SDs below individuals without ASD on imitation tasks. This deficit was specific to the condition of having ASD. Moderator analyses revealed that the average Autism Diagnostic Observation Schedule (ADOS) scores of groups of ASD participants were significantly and strongly negatively associated with the imitation abilities of these subjects, but average participant IQ was not associated with imitation abilities. Study setting, novelty of actions, format of imitation tasks (live vs. not), number of actions to imitate, or verbal prompts were not found to significantly affect the sizes of the imitation differences between individuals with and without ASD. The manner in which imitation was operationalized, however, had significant effects on whether imitation deficits were found between individuals with and without ASD. In tests that measured imitation of both form and end points, participants with ASD showed significant deficits compared with those without ASD; on tests of end point emulation only, individuals with ASD showed no deficits. © 2014 International Society for Autism Research, Wiley Periodicals, Inc.

  6. The Influence of Facial Signals on the Automatic Imitation of Hand Actions.

    Science.gov (United States)

    Butler, Emily E; Ward, Robert; Ramsey, Richard

    2016-01-01

    Imitation and facial signals are fundamental social cues that guide interactions with others, but little is known regarding the relationship between these behaviors. It is clear that during expression detection, we imitate observed expressions by engaging similar facial muscles. It is proposed that a cognitive system, which matches observed and performed actions, controls imitation and contributes to emotion understanding. However, there is little known regarding the consequences of recognizing affective states for other forms of imitation, which are not inherently tied to the observed emotion. The current study investigated the hypothesis that facial cue valence would modulate automatic imitation of hand actions. To test this hypothesis, we paired different types of facial cue with an automatic imitation task. Experiments 1 and 2 demonstrated that a smile prompted greater automatic imitation than angry and neutral expressions. Additionally, a meta-analysis of this and previous studies suggests that both happy and angry expressions increase imitation compared to neutral expressions. By contrast, Experiments 3 and 4 demonstrated that invariant facial cues, which signal trait-levels of agreeableness, had no impact on imitation. Despite readily identifying trait-based facial signals, levels of agreeableness did not differentially modulate automatic imitation. Further, a Bayesian analysis showed that the null effect was between 2 and 5 times more likely than the experimental effect. Therefore, we show that imitation systems are more sensitive to prosocial facial signals that indicate "in the moment" states than enduring traits. These data support the view that a smile primes multiple forms of imitation including the copying actions that are not inherently affective. The influence of expression detection on wider forms of imitation may contribute to facilitating interactions between individuals, such as building rapport and affiliation.

  7. Are Imitation and Replication Mirror Image Problems?

    DEFF Research Database (Denmark)

    Håkanson, Lars

    2005-01-01

    -spanning mechanisms. Since these investments are specific to the context in which they take place and to the transactions that they enable, they cannot easily be organized through arm's length contracts. Firms exist because they have a relative advantage over markets in the integration of diverse knowledge. However...

  8. Interorganizational imitation and acquisitions of high-tech ventures

    OpenAIRE

    Ozmel, Umit; Reuer, J. J.; Wu, Cheng-Wei

    2017-01-01

    Research summary: This article shows that there is a positive association between the changes in the number of prior acquisitions or the changes in the prominence of prior acquirers within the focal venture's subfield and the venture's likelihood to be acquired. Results are in line with the existence of frequency- and trait-based imitation in acquisitions targeting tech ventures. More importantly, these positive associations are more pronounced when (a) exogenous technological uncertainty wit...

  9. General equilibrium effects of a supply side GHG mitigation option under the Clean Development Mechanism.

    Science.gov (United States)

    Timilsina, Govinda R; Shrestha, Ram M

    2006-09-01

    The Clean Development Mechanism (CDM) under the Kyoto Protocol to the United Nations Framework Convention on Climate Change is considered a key instrument to encourage developing countries' participation in the mitigation of global climate change. Reduction of greenhouse gas (GHG) emissions through the energy supply and demand side activities are the main options to be implemented under the CDM. This paper analyses the general equilibrium effects of a supply side GHG mitigation option-the substitution of thermal power with hydropower--in Thailand under the CDM. A static multi-sector general equilibrium model has been developed for the purpose of this study. The key finding of the study is that the substitution of electricity generation from thermal power plants with that from hydropower plants would increase economic welfare in Thailand. The supply side option would, however, adversely affect the gross domestic product (GDP) and the trade balance. The percentage changes in economic welfare, GDP and trade balance increase with the level of substitution and the price of certified emission reduction (CER) units.

  10. General relativistic continuum mechanics and the post-Newtonian equations of motion

    International Nuclear Information System (INIS)

    Morrill, T.H.

    1991-01-01

    Aspects are examined of general relativistic continuum mechanics. Perfectly elastic materials are dealt with but not exclusively. The derivation of their equations of motion is emphasized, in the post-Newtonian approximation. A reformulation is presented based on the tetrad formalism, of Carter and Quintana's theory of general relativistic elastic continua. A field Lagrangian is derived describing perfect material media; show that the usual covariant conservations law for perfectly elastic media is fully equivalent to the Euler-Lagrange equations describing these same media; and further show that the equations of motion for such materials follow directly from Einstein's field equations. In addition, a version of this principle shows that the local mass density in curved space-time partially depends on the amount and distribution of mass energy in the entire universe and is related to the mass density that would occur if space-time were flat. The total Lagrangian was also expanded in an EIH (Einstein, Infeld, Hoffmann) series to obtain a total post-Newtonian Lagrangian. The results agree with those found by solving Einstein's equations for the metric coefficients and by deriving the post-Newtonian equations of motion from the covariant conservation law

  11. Appplication of a general fluid mechanics program to NTP system modeling

    International Nuclear Information System (INIS)

    Lee, S.K.

    1993-01-01

    An effort is currently underway at NASA and the Department of Energy (DOE) to develop an accurate model for predicting nuclear thermal propulsion (NTP) system performance. The objective of the effort is to develop several levels of computer programs which vary in detail and complexity according to user's needs. The current focus is on the Level 1 steady-state, parametric system model. This system model will combine a general fluid mechanics program, SAFSIM, with the ability to analyze turbines, pumps, nozzles, and reactor physics. SAFSIM (System Analysis Flow SIMulator) is a FORTRAN computer program that simulates integrated performance of systems involving fluid mechanics, heat transfer, and reactor dynamics. SAFSIM has the versatility to allow simulation of almost any system, including a nuclear reactor system. The focus of this paper is the validation of SAFSIM's capabilities as a base computational engine for a nuclear thermal propulsion system model. Validation is being accomplished by modeling of a nuclear engine test using SAFSIM and comparing the results to known experimental data

  12. A generalized allosteric mechanism for cis-regulated cyclic nucleotide binding domains.

    Directory of Open Access Journals (Sweden)

    Alexandr P Kornev

    2008-04-01

    Full Text Available Cyclic nucleotides (cAMP and cGMP regulate multiple intracellular processes and are thus of a great general interest for molecular and structural biologists. To study the allosteric mechanism of different cyclic nucleotide binding (CNB domains, we compared cAMP-bound and cAMP-free structures (PKA, Epac, and two ionic channels using a new bioinformatics method: local spatial pattern alignment. Our analysis highlights four major conserved structural motifs: 1 the phosphate binding cassette (PBC, which binds the cAMP ribose-phosphate, 2 the "hinge," a flexible helix, which contacts the PBC, 3 the beta(2,3 loop, which provides precise positioning of an invariant arginine from the PBC, and 4 a conserved structural element consisting of an N-terminal helix, an eight residue loop and the A-helix (N3A-motif. The PBC and the hinge were included in the previously reported allosteric model, whereas the definition of the beta(2,3 loop and the N3A-motif as conserved elements is novel. The N3A-motif is found in all cis-regulated CNB domains, and we present a model for an allosteric mechanism in these domains. Catabolite gene activator protein (CAP represents a trans-regulated CNB domain family: it does not contain the N3A-motif, and its long range allosteric interactions are substantially different from the cis-regulated CNB domains.

  13. Preschool children's proto-episodic memory assessed by deferred imitation.

    Science.gov (United States)

    Burns, Patrick; Russell, Charlotte; Russell, James

    2015-01-01

    In two experiments, both employing deferred imitation, we studied the developmental origins of episodic memory in two- to three-year-old children by adopting a "minimalist" view of episodic memory based on its What-When-Where ("WWW": spatiotemporal plus semantic) content. We argued that the temporal element within spatiotemporal should be the order/simultaneity of the event elements, but that it is not clear whether the spatial content should be egocentric or allocentric. We also argued that episodic recollection should be configural (tending towards all-or-nothing recall of the WWW elements). Our first deferred imitation experiment, using a two-dimensional (2D) display, produced superior-to-chance performance after 2.5 years but no evidence of configural memory. Moreover, performance did not differ from that on a What-What-What control task. Our second deferred imitation study required the children to reproduce actions on an object in a room, thereby affording layout-based spatial cues. In this case, not only was there superior-to-chance performance after 2.5 years but memory was also configural at both ages. We discuss the importance of allocentric spatial cues in episodic recall in early proto-episodic memory and reflect on the possible role of hippocampal development in this process.

  14. Teaching UAVs to Race With Observational Imitation Learning

    KAUST Repository

    Li, Guohao

    2018-03-03

    Recent work has tackled the problem of autonomous navigation by imitating a teacher and learning an end-to-end policy, which directly predicts controls from raw images. However, these approaches tend to be sensitive to mistakes by the teacher and do not scale well to other environments or vehicles. To this end, we propose a modular network architecture that decouples perception from control, and is trained using Observational Imitation Learning (OIL), a novel imitation learning variant that supports online training and automatic selection of optimal behavior from observing multiple teachers. We apply our proposed methodology to the challenging problem of unmanned aerial vehicle (UAV) racing. We develop a simulator that enables the generation of large amounts of synthetic training data (both UAV captured images and its controls) and also allows for online learning and evaluation. We train a perception network to predict waypoints from raw image data and a control network to predict UAV controls from these waypoints using OIL. Our modular network is able to autonomously fly a UAV through challenging race tracks at high speeds. Extensive experiments demonstrate that our trained network outperforms its teachers, end-to-end baselines, and even human pilots in simulation. The supplementary video can be viewed at https://youtu.be/PeTXSoriflc

  15. Teaching UAVs to Race With Observational Imitation Learning

    KAUST Repository

    Li, Guohao; Mueller, Matthias; Casser, Vincent; Smith, Neil; Michels, Dominik L.; Ghanem, Bernard

    2018-01-01

    Recent work has tackled the problem of autonomous navigation by imitating a teacher and learning an end-to-end policy, which directly predicts controls from raw images. However, these approaches tend to be sensitive to mistakes by the teacher and do not scale well to other environments or vehicles. To this end, we propose a modular network architecture that decouples perception from control, and is trained using Observational Imitation Learning (OIL), a novel imitation learning variant that supports online training and automatic selection of optimal behavior from observing multiple teachers. We apply our proposed methodology to the challenging problem of unmanned aerial vehicle (UAV) racing. We develop a simulator that enables the generation of large amounts of synthetic training data (both UAV captured images and its controls) and also allows for online learning and evaluation. We train a perception network to predict waypoints from raw image data and a control network to predict UAV controls from these waypoints using OIL. Our modular network is able to autonomously fly a UAV through challenging race tracks at high speeds. Extensive experiments demonstrate that our trained network outperforms its teachers, end-to-end baselines, and even human pilots in simulation. The supplementary video can be viewed at https://youtu.be/PeTXSoriflc

  16. Cultural differences in the imitation and transmission of inefficient actions.

    Science.gov (United States)

    Corriveau, Kathleen H; DiYanni, Cara J; Clegg, Jennifer M; Min, Grace; Chin, Jason; Nasrini, Jad

    2017-09-01

    Across two studies, we explored cultural differences in children's imitation and transmission of inefficient actions. Chinese American and Caucasian American preschoolers (N=115) viewed either one or three models using two inefficient tools to perform two different tasks. In the video, when the model(s) performed the task, only the inefficient tool was available; thus, their choice to use that tool could be considered rational. Next, children were invited to complete the task with either the inefficient tool or an efficient alternative. Whereas the two cultural groups imitated a single model at similar rates, Chinese American children imitated significantly more than Caucasian American children after viewing a consensus. Similar results were found when exploring differences in information transmission. The Chinese American children were significantly more likely than their Caucasian American peers to instruct using an inefficient tool when they had initially viewed a consensus demonstrate it. We discuss these findings with respect to differences in children's use of social versus task-specific cues for learning and teaching. Copyright © 2017 Elsevier Inc. All rights reserved.

  17. General method for calculating polarization electric fields produced by auroral Cowling mechanism and application examples

    Science.gov (United States)

    Vanhamäki, Heikki; Amm, Olaf; Fujii, Ryo; Yoshikawa, Aki; Ieda, Aki

    2013-04-01

    The Cowling mechanism is characterized by the generation of polarization space charges in the ionosphere in consequence of a partial or total blockage of FAC flowing between the ionosphere and the magnetosphere. Thus a secondary polarization electric field builds up in the ionosphere, which guarantees that the whole (primary + secondary) ionospheric current system is again in balance with the FAC. In the Earth's ionosphere the Cowling mechanism is long known to operate in the equatorial electrojet, and several studies indicate that it is important also in auroral current systems. We present a general method for calculate the secondary polarization electric field, when the ionospheric conductances, the primary (modeled) or the total (measured) electric field, and the Cowling efficiency are given. Here the Cowling efficiency is defined as the fraction of the divergent Hall current canceled by secondary Pedersen current. In contrast to previous studies, our approach is a general solution which is not limited to specific geometrical setups (like an auroral arc), and all parameters may have any kind of spatial dependence. The solution technique is based on spherical elementary current (vector) systems (SECS). This way, we avoid the need to specify explicit boundary conditions for the searched polarization electric field or its potential, which would be required if the problem was solved in a differential equation approach. Instead, we solve an algebraic matrix equation, for which the implicit boundary condition that the divergence of the polarization electric field vanishes outside our analysis area is sufficient. In order to illustrate the effect of Cowling mechanism on ionospheric current systems, we apply our method to two simple models of auroral electrodynamic situations: 1) a mesoscale strong conductance enhancement in the early morning sector within a relatively weak southward primary electric field, 2) a morning sector auroral arc with only a weak conductance

  18. The effect of narrative cues on infants' imitation from television and picture books.

    Science.gov (United States)

    Simcock, Gabrielle; Garrity, Kara; Barr, Rachel

    2011-01-01

    Infants can imitate a novel action sequence from television and picture books, yet there has been no direct comparison of infants' imitation from the 2 types of media. Varying the narrative cues available during the demonstration and test, the current experiments measured 18- and 24-month-olds' imitation from television and picture books. Infants imitated from both media types when full narrative cues (Experiment 1; N = 76) or empty, meaningless narration (Experiment 2; N = 135) accompanied the demonstrations, but they imitated more from television than books. In Experiment 3 (N = 27), infants imitated from a book based on narration alone, without the presence of pictures. These results are discussed in relation to age-related changes in cognitive flexibility and infants' emerging symbolic understanding. © 2011 The Authors. Child Development © 2011 Society for Research in Child Development, Inc.

  19. The effect of narrative cues on infants’ imitation from television and picture books

    Science.gov (United States)

    Simcock, Gabrielle; Garrity, Kara; Barr, Rachel

    2011-01-01

    Infants can imitate a novel action sequence from television and picture books; yet there has been no direct comparison of infants’ imitation from the two types of media. Varying the narrative cues available during the demonstration and test, we measured 18- and 24-month-olds’ imitation from television and picture books. Infants imitated from both media types when full narrative cues (Experiment 1; N = 76) or empty, meaningless narration (Experiment 2; N = 135) accompanied the demonstrations, but they imitated more from television than books. In Experiment 3 (N = 27), infants imitated from a book based on narration alone, without the presence of pictures. These results are discussed in relation to age-related changes in cognitive flexibility and infants’ emerging symbolic understanding. PMID:21883157

  20. Imitation of the characteristics of the wind turbine based on DC motor

    Institute of Scientific and Technical Information of China (English)

    LIU Qihui; HE Yikang; ZHAO Rende

    2007-01-01

    This paper analyzed the operating principles and power and torque characteristics of the wind turbine and the direct current motor(DC motor),and investigated the operating characteristics of the wind turbine compared to that of the DC motor.The torque imitation scheme,which has good performance and high feasibility,together with the whole wind turbine imitation system,was provided.The wind turbine imitation system includes not only a hardware platform composed of PC,data-collection board and thyristor-based velocity-regulator,but also monitor software of wind turbine imitation.The experimental results of different occasions verify the correctness and feasibility of the wind turbine imitation scheme proposed in this paper,which provided a valid idea for wind turbine imitation and investigation of wind power generation techniques in the laboratory.

  1. An Investigation of the Mechanism Underlying Teacher Aggression: Testing I[superscript 3] Theory and the General Aggression Model

    Science.gov (United States)

    Montuoro, Paul; Mainhard, Tim

    2017-01-01

    Background: Considerable research has investigated the deleterious effects of teachers responding aggressively to students who misbehave, but the mechanism underlying this dysfunctional behaviour remains unknown. Aims: This study investigated whether the mechanism underlying teacher aggression follows I[superscript 3] theory or General Aggression…

  2. The Moessbauer experiment on the clays and the imitative ancient porcelains

    International Nuclear Information System (INIS)

    Gao Zhengyao; Chen Songhua

    1995-12-01

    It is analyzed that Moessbauer parameter variations of clays from the famous sites of ancient kilns change with temperature, time and atmosphere in firing process. The variation of the Moessbauer parameters of the imitative ancient Chinese Ru porcelain sky-green glaze with the firing conditions is studied in detail. The Moessbauer spectra show that the sky-green glaze contains three kinds of iron minerals, i.e. the structural iron (Fe 2+ and Fe 3+ ); Fe 2 O 3 and Fe 3 O 4 ; The relative intensity of the paramagnetic peak Fe 2+ increases and the magnetic ratio of the magnetic peak decreases with increasing temperature. Based on the variation of the quadrupole splitting (QS) of the paramagnetic peak Fe 2+ , the phase transformation characteristics of the sky-green glaze in the firing process is discussed. The coloring mechanism of the sky-green glaze and the variation of its magnetism in the firing process are also investigated. The variation of the hyperfine interaction parameters and the variable mechanism of the sky-green glaze at liquid helium temperature is studied. Moessbauer spectra of the imitative ancient blue Jun porcelain indicate that the glaze and boby materials contain Fe 2 O 3 , Fe 3 O 4 and structural iron. It is clear that during the firing process, the glaze undergoes dehydration, dehydroxylation, vitrification and recrystallization. The Fe 2+ quadrupole splitting value of the paramagnetic peak of the body material is rather high even at low firing temperature. The distinction between dehydration and dehyroxylation is not clear. The changes of magnetism of the glaze and body materials in the firing process and coloring mechanism of the sky-blue Jun porcelain are analyzed

  3. Experience of developing the imitators of the fuel element for the WWER reactors

    International Nuclear Information System (INIS)

    Balashov, S.M.; Boltenko, Eh.A.; Vinogradov, V.A.

    1998-01-01

    Peculiarities of designs of fuel elements imitators for the WWER-type reactors of nominal capacity and with single-ended current feed positioning are considered. The data on the filler heat conductivity and the results of tests and application of the fuel elements imitators at various testing facilities are presented. The possibility of equipping one of the non operating WWER reactors with the fuel element imitators for conduct of large-scale experiment is indicated

  4. The history of imitation in learning theory: the language acquisition process.

    OpenAIRE

    Kymissis, E; Poulson, C L

    1990-01-01

    The concept of imitation has undergone different analyses in the hands of different learning theorists throughout the history of psychology. From Thorndike's connectionism to Pavlov's classical conditioning, Hull's monistic theory, Mowrer's two-factor theory, and Skinner's operant theory, there have been several divergent accounts of the conditions that produce imitation and the conditions under which imitation itself may facilitate language acquisition. In tracing the roots of the concept of...

  5. IMITATION STRATEGIES FOR SME’S LEARNING PROCESS TOWARDS INNOVATION STRATEGIES

    Directory of Open Access Journals (Sweden)

    Rina Sulistiyani

    2013-01-01

    The research results are as follow: the learning experience to use imitation strategy which covers stages of imitation, research, development and  creation. This learning process is the result of interaction between personal and behavior factors, as well as the enabler and barriers. The owners of leather small industries which leave the imitation strategy and switch to innovation strategy are craftsmen who have an entrepreneurial spirit. they are able to balance entrepreneurial and business aspects.

  6. Mathematica for Theoretical Physics: Electrodynamics, Quantum Mechanics, General Relativity and Fractals

    International Nuclear Information System (INIS)

    Heusler, Stefan

    2006-01-01

    The main focus of the second, enlarged edition of the book Mathematica for Theoretical Physics is on computational examples using the computer program Mathematica in various areas in physics. It is a notebook rather than a textbook. Indeed, the book is just a printout of the Mathematica notebooks included on the CD. The second edition is divided into two volumes, the first covering classical mechanics and nonlinear dynamics, the second dealing with examples in electrodynamics, quantum mechanics, general relativity and fractal geometry. The second volume is not suited for newcomers because basic and simple physical ideas which lead to complex formulas are not explained in detail. Instead, the computer technology makes it possible to write down and manipulate formulas of practically any length. For researchers with experience in computing, the book contains a lot of interesting and non-trivial examples. Most of the examples discussed are standard textbook problems, but the power of Mathematica opens the path to more sophisticated solutions. For example, the exact solution for the perihelion shift of Mercury within general relativity is worked out in detail using elliptic functions. The virial equation of state for molecules' interaction with Lennard-Jones-like potentials is discussed, including both classical and quantum corrections to the second virial coefficient. Interestingly, closed solutions become available using sophisticated computing methods within Mathematica. In my opinion, the textbook should not show formulas in detail which cover three or more pages-these technical data should just be contained on the CD. Instead, the textbook should focus on more detailed explanation of the physical concepts behind the technicalities. The discussion of the virial equation would benefit much from replacing 15 pages of Mathematica output with 15 pages of further explanation and motivation. In this combination, the power of computing merged with physical intuition would

  7. General Description of the Mechanic Design of the Pressure Vessel and the Internal Mechanical Component of the CAREM Reactor

    International Nuclear Information System (INIS)

    Diez, F.; Horro, R.

    2000-01-01

    This paper presents a brief description of the CAREM reactor pressure vessel and its main internal mechanical components and summarizes the functional requirements and approaches applied for their design, together with a review of the normative applicable in each case

  8. Neonatal Imitation: Theory, Experimental Design, and Significance for the Field of Social Cognition.

    Science.gov (United States)

    Vincini, Stefano; Jhang, Yuna; Buder, Eugene H; Gallagher, Shaun

    2017-01-01

    Neonatal imitation has rich implications for neuroscience, developmental psychology, and social cognition, but there is little consensus about this phenomenon. The primary empirical question, whether or not neonatal imitation exists, is not settled. Is it possible to give a balanced evaluation of the theories and methodologies at stake so as to facilitate real progress with respect to the primary empirical question? In this paper, we address this question. We present the operational definition of differential imitation and discuss why it is important to keep it in mind. The operational definition indicates that neonatal imitation may not look like prototypical imitation and sets non-obvious requirements on what can count as evidence for imitation. We also examine the principal explanations for the extant findings and argue that two theories, the arousal hypothesis and the Association by Similarity Theory, which interprets neonatal imitation as differential induction of spontaneous behavior through similarity, offer better explanations than the others. With respect to methodology, we investigate what experimental design can best provide evidence for imitation, focusing on how differential induction may be maximized and detected. Finally, we discuss the significance of neonatal imitation for the field of social cognition. Specifically, we propose links with theories of social interaction and direct social perception. Overall, our goals are to help clarify the complex theoretical issues at stake and suggest fruitful guidelines for empirical research.

  9. Neonatal Imitation: Theory, Experimental Design, and Significance for the Field of Social Cognition

    Directory of Open Access Journals (Sweden)

    Stefano Vincini

    2017-08-01

    Full Text Available Neonatal imitation has rich implications for neuroscience, developmental psychology, and social cognition, but there is little consensus about this phenomenon. The primary empirical question, whether or not neonatal imitation exists, is not settled. Is it possible to give a balanced evaluation of the theories and methodologies at stake so as to facilitate real progress with respect to the primary empirical question? In this paper, we address this question. We present the operational definition of differential imitation and discuss why it is important to keep it in mind. The operational definition indicates that neonatal imitation may not look like prototypical imitation and sets non-obvious requirements on what can count as evidence for imitation. We also examine the principal explanations for the extant findings and argue that two theories, the arousal hypothesis and the Association by Similarity Theory, which interprets neonatal imitation as differential induction of spontaneous behavior through similarity, offer better explanations than the others. With respect to methodology, we investigate what experimental design can best provide evidence for imitation, focusing on how differential induction may be maximized and detected. Finally, we discuss the significance of neonatal imitation for the field of social cognition. Specifically, we propose links with theories of social interaction and direct social perception. Overall, our goals are to help clarify the complex theoretical issues at stake and suggest fruitful guidelines for empirical research.

  10. Mechanisms for Creating a Psychologically Safe Learning Environment in an Educational Institution of General Education

    Directory of Open Access Journals (Sweden)

    Leonova O.I.,

    2014-11-01

    Full Text Available At the moment the question of how to create and maintain the psychological safety of the educational environment of the school is not sufficiently studied. Meanwhile, there has been proved its positive effect on the psychological health of students, their emotional and personal well-being, the formation of a meta-subjective and personal educational outcomes. This paper describes a study the purpose of which was to examine and verify empiricaly the features of management activities in the educational organization to create a psychologically safe learning environment. We studied personality traits of the Head of an educational organization by the procedure "Troubleshooting leadership abilities" (E. Zharikova, E. Krushelnytsky, techniques "Diagnosis of the level of burnout" (V.V. Boyko, methods of self-management style assessment (A.V. Agrashenkova, modified by E.P. Ilyin, and methods for rapid assessment of health, activity, mood (SAN. We proposed mechanisms to solve the problem of creating a comfortable and safe learning environment in the educational organization of general education

  11. Culture in the mind's mirror: how anthropology and neuroscience can inform a model of the neural substrate for cultural imitative learning.

    Science.gov (United States)

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

    2009-01-01

    Cultural neuroscience, the study of how cultural experience shapes the brain, is an emerging subdiscipline in the neurosciences. Yet, a foundational question to the study of culture and the brain remains neglected by neuroscientific inquiry: "How does cultural information get into the brain in the first place?" Fortunately, the tools needed to explore the neural architecture of cultural learning - anthropological theories and cognitive neuroscience methodologies - already exist; they are merely separated by disciplinary boundaries. Here we review anthropological theories of cultural learning derived from fieldwork and modeling; since cultural learning theory suggests that sophisticated imitation abilities are at the core of human cultural learning, we focus our review on cultural imitative learning. Accordingly we proceed to discuss the neural underpinnings of imitation and other mechanisms important for cultural learning: learning biases, mental state attribution, and reinforcement learning. Using cultural neuroscience theory and cognitive neuroscience research as our guides, we then propose a preliminary model of the neural architecture of cultural learning. Finally, we discuss future studies needed to test this model and fully explore and explain the neural underpinnings of cultural imitative learning.

  12. Synthetic multielement standards used for instrumental neutron activation analysis as rock imitations

    International Nuclear Information System (INIS)

    Leypunskaya, D.I.; Drynkin, V.I.; Belenky, B.V.; Kolomijtsev, M.A.; Dundera, V.Yu.; Pachulia, N.V.

    1975-01-01

    Complex (multielemental) standards representing microelement composition of standard rocks such as trap ST-1 (USSR), gabbrodiorite SGD-1 (USSR), albitized granite SG-1 (USSR), basalt BCR-1 (USA) and granodiorite GSP-1 (USA) have been synthesized. It has been shown that the concentration of each microelement in the synthetic standards can be given with a high precision. Comparative investigation has been carried out of the synthetic imitations and the above natural standard rocks. It has been found that the result of the instrumental neutron activation analysis using the synthetic standards is as good as in the case when natural standard rocks are used. The results obtained have been also used for substantiation of the versatility of the method used for standard preparation, i.e. a generalization has been made of a possibility of using this method for the preparation of synthetic standards representing the microelement composition of any natural rocks with various compositions and concentrations of microelements. (T.G.)

  13. Index hypergeometric transform and imitation of analysis of Berezin kernels on hyperbolic spaces

    International Nuclear Information System (INIS)

    Neretin, Yu A

    2001-01-01

    The index hypergeometric transform (also called the Olevskii transform or the Jacobi transform) generalizes the spherical transform in L 2 on rank 1 symmetric spaces (that is, real, complex, and quaternionic Lobachevskii spaces). The aim of this paper is to obtain properties of the index hypergeometric transform imitating the analysis of Berezin kernels on rank 1 symmetric spaces. The problem of the explicit construction of a unitary operator identifying L 2 and a Berezin space is also discussed. This problem reduces to an integral expression (the Λ-function), which apparently cannot be expressed in a finite form in terms of standard special functions. (Only for certain special values of the parameter can this expression be reduced to the so-called Volterra type special functions.) Properties of this expression are investigated. For some series of symmetric spaces of large rank the above operator of unitary equivalence can be expressed in terms of the determinant of a matrix of Λ-functions

  14. THE METHOD OF PNEUMATIC IMITATION OF WEIGHT-BEARING IN CHILDREN WITH SHIN FRACTURES

    Directory of Open Access Journals (Sweden)

    N. Yu. Serova

    2012-01-01

    Full Text Available The article contains a comparative analysis of shin fracture treatment in 102 children at the age of 4–18 years old. The main group consisted of 51 (50% children, who received postoperative treatment according to the method of pneumatic imitation of weightbearing both on health and injured limbs with «Korvit» apparatus. The control group consisted of 51 (50% patients who did not received the afore-mentioned method of postoperative treatment. The groups were comparable on age, trauma mechanism and localization, surgical operation and complex postoperative therapy. Children of the first group were found to have shorter period of time needed to achievement of pain relief, soft tissue swelling decrease, restoration of the movements in adjacent joints and somatometry values normalization, which allowed earlier verticalization and shorter period of hospitalization.

  15. Second Language Word Learning through Repetition and Imitation: Functional Networks as a Function of Learning Phase and Language Distance.

    Science.gov (United States)

    Ghazi-Saidi, Ladan; Ansaldo, Ana Ines

    2017-01-01

    Introduction and Aim : Repetition and imitation are among the oldest second language (L2) teaching approaches and are frequently used in the context of L2 learning and language therapy, despite some heavy criticism. Current neuroimaging techniques allow the neural mechanisms underlying repetition and imitation to be examined. This fMRI study examines the influence of verbal repetition and imitation on network configuration. Integration changes within and between the cognitive control and language networks were studied, in a pair of linguistically close languages (Spanish and French), and compared to our previous work on a distant language pair (Ghazi-Saidi et al., 2013). Methods : Twelve healthy native Spanish-speaking (L1) adults, and 12 healthy native Persian-speaking adults learned 130 new French (L2) words, through a computerized audiovisual repetition and imitation program. The program presented colored photos of objects. Participants were instructed to look at each photo and pronounce its name as closely as possible to the native template (imitate). Repetition was encouraged as many times as necessary to learn the object's name; phonological cues were provided if necessary. Participants practiced for 15 min, over 30 days, and were tested while naming the same items during fMRI scanning, at week 1 (shallow learning phase) and week 4 (consolidation phase) of training. To compare this set of data with our previous work on Persian speakers, a similar data analysis plan including accuracy rates (AR), response times (RT), and functional integration values for the language and cognitive control network at each measure point was included, with further L1-L2 direct comparisons across the two populations. Results and Discussion : The evidence shows that learning L2 words through repetition induces neuroplasticity at the network level. Specifically, L2 word learners showed increased network integration after 3 weeks of training, with both close and distant language

  16. Task-dependent and distinct roles of the temporoparietal junction and inferior frontal cortex in the control of imitation.

    Science.gov (United States)

    Hogeveen, Jeremy; Obhi, Sukhvinder S; Banissy, Michael J; Santiesteban, Idalmis; Press, Clare; Catmur, Caroline; Bird, Geoffrey

    2015-07-01

    The control of neurological networks supporting social cognition is crucially important for social interaction. In particular, the control of imitation is directly linked to interaction quality, with impairments associated with disorders characterized by social difficulties. Previous work suggests inferior frontal cortex (IFC) and the temporoparietal junction (TPJ) are involved in controlling imitation, but the functional roles of these areas remain unclear. Here, transcranial direct current stimulation (tDCS) was used to enhance cortical excitability at IFC and the TPJ prior to the completion of three tasks: (i) a naturalistic social interaction during which increased imitation is known to improve rapport, (ii) a choice reaction time task in which imitation needs to be inhibited for successful performance and (iii) a non-imitative control task. Relative to sham stimulation, stimulating IFC improved the context-dependent control of imitation-participants imitated more during the social interaction and less during the imitation inhibition task. In contrast, stimulating the TPJ reduced imitation in the inhibition task without affecting imitation during social interaction. Neither stimulation site affected the non-imitative control task. These data support a model in which IFC modulates imitation directly according to task demands, whereas TPJ controls task-appropriate shifts in attention toward representation of the self or the other, indirectly impacting upon imitation. © The Author (2014). Published by Oxford University Press.

  17. An Evaluation of Imitation Recognition Abilities in Typically Developing Children and Young Children with Autism Spectrum Disorder.

    Science.gov (United States)

    Berger, Natalie I; Ingersoll, Brooke

    2015-08-01

    Previous work has indicated that both typically developing children and children with Autism Spectrum Disorder (ASD) display a range of imitation recognition behaviors in response to a contingent adult imitator. However, it is unknown how the two groups perform comparatively on this construct. In this study, imitation recognition behaviors for children with ASD and typically developing children were observed during periods of contingent imitation imbedded in a naturalistic imitation task. Results from this study indicate that children with ASD are impaired in their ability to recognize being imitated relative to typically developing peers as demonstrated both by behaviors representing basic social attention and more mature imitation recognition. Display of imitation recognition behaviors was independent of length of contingent imitation period in typically developing children, but rate of engagement in imitation recognition behaviors was positively correlated with length of contingent imitation period in children with ASD. Exploratory findings also suggest a link between the ability to demonstrate recognition of being imitated and ASD symptom severity, language, and object imitation for young children with ASD. © 2015 International Society for Autism Research, Wiley Periodicals, Inc.

  18. Imitation, Sign Language Skill and the Developmental Ease of Language Understanding (D-ELU) Model.

    Science.gov (United States)

    Holmer, Emil; Heimann, Mikael; Rudner, Mary

    2016-01-01

    Imitation and language processing are closely connected. According to the Ease of Language Understanding (ELU) model (Rönnberg et al., 2013) pre-existing mental representation of lexical items facilitates language understanding. Thus, imitation of manual gestures is likely to be enhanced by experience of sign language. We tested this by eliciting imitation of manual gestures from deaf and hard-of-hearing (DHH) signing and hearing non-signing children at a similar level of language and cognitive development. We predicted that the DHH signing children would be better at imitating gestures lexicalized in their own sign language (Swedish Sign Language, SSL) than unfamiliar British Sign Language (BSL) signs, and that both groups would be better at imitating lexical signs (SSL and BSL) than non-signs. We also predicted that the hearing non-signing children would perform worse than DHH signing children with all types of gestures the first time (T1) we elicited imitation, but that the performance gap between groups would be reduced when imitation was elicited a second time (T2). Finally, we predicted that imitation performance on both occasions would be associated with linguistic skills, especially in the manual modality. A split-plot repeated measures ANOVA demonstrated that DHH signers imitated manual gestures with greater precision than non-signing children when imitation was elicited the second but not the first time. Manual gestures were easier to imitate for both groups when they were lexicalized than when they were not; but there was no difference in performance between familiar and unfamiliar gestures. For both groups, language skills at T1 predicted imitation at T2. Specifically, for DHH children, word reading skills, comprehension and phonological awareness of sign language predicted imitation at T2. For the hearing participants, language comprehension predicted imitation at T2, even after the effects of working memory capacity and motor skills were taken into

  19. Imitation, sign language skill and the Developmental Ease of Language Understanding (D-ELU model

    Directory of Open Access Journals (Sweden)

    Emil eHolmer

    2016-02-01

    Full Text Available Imitation and language processing are closely connected. According to the Ease of Language Understanding (ELU model (Rönnberg et al., 2013 pre-existing mental representation of lexical items facilitates language understanding. Thus, imitation of manual gestures is likely to be enhanced by experience of sign language. We tested this by eliciting imitation of manual gestures from deaf and hard-of-hearing (DHH signing and hearing non-signing children at a similar level of language and cognitive development. We predicted that the DHH signing children would be better at imitating gestures lexicalized in their own sign language (Swedish Sign Language, SSL than unfamiliar British Sign Language (BSL signs, and that both groups would be better at imitating lexical signs (SSL and BSL than non-signs. We also predicted that the hearing non-signing children would perform worse than DHH signing children with all types of gestures the first time (T1 we elicited imitation, but that the performance gap between groups would be reduced when imitation was elicited a second time (T2. Finally, we predicted that imitation performance on both occasions would be associated with linguistic skills, especially in the manual modality. A split-plot repeated measures ANOVA demonstrated that DHH signers imitated manual gestures with greater precision than non-signing children when imitation was elicited the second but not the first time. Manual gestures were easier to imitate for both groups when they were lexicalized than when they were not; but there was no difference in performance between familiar and unfamiliar gestures. For both groups, language skills at the T1 predicted imitation at T2. Specifically, for DHH children, word reading skills, comprehension and phonological awareness of sign language predicted imitation at T2. For the hearing participants, language comprehension predicted imitation at T2, even after the effects of working memory capacity and motor skills

  20. Imitation of snack food intake among normal-weight and overweight children.

    Science.gov (United States)

    Bevelander, Kirsten E; Lichtwarck-Aschoff, Anna; Anschütz, Doeschka J; Hermans, Roel C J; Engels, Rutger C M E

    2013-01-01

    This study investigated whether social modeling of palatable food intake might partially be explained by the direct imitation of a peer reaching for snack food and further, assessed the role of the children's own weight status on their likelihood of imitation during the social interaction. Real-time observations during a 10-min play situation in which 68 participants (27.9% overweight) interacted with normal-weight confederates (instructed peers) were conducted. Children's imitated and non-imitated responses to the confederate's food picking movements were compared using a paired sample t-test. In addition, the pattern of likelihood of imitation was tested using multilevel proportional hazard models in a survival analysis framework. Children were more likely to eat after observing a peer reaching for snack food than without such a cue [t (67) = 5.69, P imitation responses during a social interaction based on their weight status (HR = 2.6, P = 0.03, 95% CI = 1.09-6.20). Overweight children were almost twice as likely to imitate, whereas normal-weight children had a smaller chance to imitate at the end of the interaction. Further, the mean difference in the likelihood of imitation suggest that overweight children might be less likely to imitate in the beginning of the interaction than normal-weight children. The findings provide preliminary evidence that children's imitation food picking movements may partly contribute to social modeling effects on palatable food intake. That is, a peer reaching for food is likely to trigger children's snack intake. However, the influence of others on food intake is a complex process that might be explained by different theoretical perspectives.

  1. Anatomical and spatial matching in imitation: Evidence from left and right brain-damaged patients.

    Science.gov (United States)

    Mengotti, Paola; Ripamonti, Enrico; Pesavento, Valentina; Rumiati, Raffaella Ida

    2015-12-01

    Imitation is a sensorimotor process whereby the visual information present in the model's movement has to be coupled with the activation of the motor system in the observer. This also implies that greater the similarity between the seen and the produced movement, the easier it will be to execute the movement, a process also known as ideomotor compatibility. Two components can influence the degree of similarity between two movements: the anatomical and the spatial component. The anatomical component is present when the model and imitator move the same body part (e.g., the right hand) while the spatial component is present when the movement of the model and that of the imitator occur at the same spatial position. Imitation can be achieved by relying on both components, but typically the model's and imitator's movements are matched either anatomically or spatially. The aim of this study was to ascertain the contribution of the left and right hemisphere to the imitation accomplished either with anatomical or spatial matching (or with both). Patients with unilateral left and right brain damage performed an ideomotor task and a gesture imitation task. Lesions in the left and right hemispheres gave rise to different performance deficits. Patients with lesions in the left hemisphere showed impaired imitation when anatomical matching was required, and patients with lesions in the right hemisphere showed impaired imitation when spatial matching was required. Lesion analysis further revealed a differential involvement of left and right hemispheric regions, such as the parietal opercula, in supporting imitation in the ideomotor task. Similarly, gesture imitation seemed to rely on different regions in the left and right hemisphere, such as parietal regions in the left hemisphere and premotor, somatosensory and subcortical regions in the right hemisphere. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. Dissipative quantum mechanics: The generalization of the canonical quantization and von Neumann equation

    International Nuclear Information System (INIS)

    Tarasov, V.E.

    1994-07-01

    Sedov variational principle, which is the generalization of the least actional principle for the dissipative processes is used to generalize the canonical quantization and von Neumann equation for dissipative systems (particles and strings). (author). 66 refs, 1 fig

  3. On a testable unification of electromagnetics, general relativity, and quantum mechanics

    International Nuclear Information System (INIS)

    Bearden, T.E.; Rosenthal, W.

    1991-01-01

    Unrecognized for what it was, in 1903-1904 E.T. Whittaker (W) published a fundamental, engineerable theory of electogravitation (EG) in two profound papers. The first (W-1903) demonstrated a hidden bidirectional EM wave structure in the scalar potential of vacuum, and showed how to produce a standing scalar EM potential wave -- the same wave discovered experimentally four years earlier by Nikola Tesla. W-1903 is a hidden variable theory that shows how to determinsitically curve the local and/or distant spacetime using EM. W-1904 shows that all force field EM can be replaced by interferometry of two scalar potentials, anticipating the Aharonov-Bohm effect by 55 years and extending it to the engineerable macroscopic world. W-1903 shows how to turn EM into G-potential, curve local and/or distant spacetime, and directly engineer the virtual particle flux of vacuum. W-1904 shows how to turn G-potential and curvature of spacetime back into force-field EM, even at a distance. The papers implement Sahkarov's 1968 statement that gravitation is not a fundamental field of nature, gut a conglomerate of other fields. Separately applied to electromagnetic (EM), quantum mechanics (QM), and general relativity (GR), an extended superset of each results. The three supersets are Whittaker-unified, so that a testable, engineerable, unified field theory is generated. EM, QM, and GR each contained a fundamental error that blocked unification, and these three errors are explain. The Schroedinger potential can also be structured and altered, indicating the direct engineering of physical quantum change. Recently Ignatovich has pointed out this hidden bidirectional EM wave structure in the Schroedinger potential, without referencing Whittaker's 1903 discovery of the basic effect

  4. Effect of Gamma Radiation on Quality of Imitation Crab Meat

    International Nuclear Information System (INIS)

    Charoen, Saovapong; Sajjabut, Surasak

    2007-08-01

    Full text: Irradiation at 0.5, 1.0 and 1.5 kGy of some commercial imitation crab meats with non-vacuum packaging reduced the total viable count by 1-2 log cycles, while coliform and Staphylococcus aureus were eliminated by 1.5 kGy gamma radiation. Although TBA number of 1 and 1.5 kGy irradiated samples increased significantly, but the sensory evaluation did not show any significant differences compared with the controls. Radiation dosage of 1.5 kGy appeared to be sufficient for improving bacterial quality and eliminating coliform and Staphylococcus aureus

  5. The random signal generator of imitated nuclear radiation pulse

    International Nuclear Information System (INIS)

    Li Dongcang; Yang Lei; Yuan Shulin; Yang Yinghui; Zang Fujia

    2007-01-01

    Based in pseudo-random uniformity number, it produces random numbers of Gaussian distribution and exponential distribution by arithmetic. The hardware is the single-chip microcomputer of 89C51. Program language makes use of Keil C. The output pulse amplitude is Gaussian distribution, exponential distribution or uniformity distribution. Likewise, it has two mode or upwards two. The time alternation of output pulse is both periodic and exponential distribution. The generator has achieved output control of multi-mode distribution, imitated random characteristic of nuclear pulse in amplitude and in time. (authors)

  6. The trouble with memes : Inference versus imitation in cultural creation.

    Science.gov (United States)

    Atran, S

    2001-12-01

    Memes are hypothetical cultural units passed on by imitation; although nonbiological, they undergo Darwinian selection like genes. Cognitive study of multimodular human minds undermines memetics: unlike in genetic replication, high-fidelity transmission of cultural information is the exception, not the rule. Constant, rapid "mutation" of information during communication generates endlessly varied creations that nevertheless adhere to modular input conditions. The sort of cultural information most susceptible to modular processing is that most readily acquired by children, most easily transmitted across individuals, most apt to survive within a culture, most likely to recur in different cultures, and most disposed to cultural variation and elaboration.

  7. A general contact mechanical formulation of multilayered structures and its application to deconvolute thickness/mechanical properties of glue used in surface force apparatus.

    Science.gov (United States)

    Math, Souvik; Horn, Roger; Jayaram, Vikram; Biswas, Sanjay Kumar

    2007-04-15

    Currently data obtained from surface force apparatus experiments are convoluted with the mechanical response of glue of unknown thickness, used to bond mica sheets to the substrates. This paper describes a formulation to precisely deconvolute out the forces between the mica sheets by determining the thickness of glue, knowing the mechanical properties of the glue. The formulation consists of a general solution based on the noniterative Hankel transform of the Laplace equation. The generality is achieved by treating all the layers except the one in contact as an effective lumped system consisting of a set of springs in series, where each spring represents a layer. The solution is validated by nanoindentation of trilayer systems consisting of layers with widely diverse mechanical properties, some differing from each other by three orders of magnitude. SFA experiments are done with carefully metered slabs of glue. The proposed method is validated by comparing the actual glue thicknesses with those determined using the present analysis.

  8. The Ghost Condition: Imitation Versus Emulation in Young Children's Observational Learning.

    Science.gov (United States)

    Thompson, Doreen E.; Russell, James

    2004-01-01

    Although observational learning by children may occur through imitating a modeler's actions, it can also occur through learning about an object's dynamic affordances- a process that M. Tomasello (1996) calls "emulation." The relative contributions of imitation and emulation within observational learning were examined in a study with 14- to…

  9. The Relation between Contingency Preference and Imitation in 6-8-Month-Old Infants

    Science.gov (United States)

    Klein-Radukic, Sarah; Zmyj, Norbert

    2016-01-01

    Detecting self-generated actions and imitating other-generated actions are important abilities in order to interact with others. The relationship between these domains was investigated in 6-8-month-old infants. In a contingency-preference task, infants observed their own legs on a real-time and a delayed video display. In an imitation task, the…

  10. Do Imitation Problems Reflect a Core Characteristic in Autism? Evidence from a Literature Review

    Science.gov (United States)

    Vanvuchelen, Marleen; Roeyers, Herbert; De Weerdt, Willy

    2011-01-01

    Although imitation problems have been associated with autism for many years, the issue if these problems are a core deficit in autism remains subject of debate. In this review article, the question if autism imitation problems fulfil the criteria of uniqueness, specificity, universality, persistency, precedence and broadness is explored and…

  11. Exploring the Relationship between Gestural Recognition and Imitation: Evidence of Dyspraxia in Autism Spectrum Disorders

    Science.gov (United States)

    Ham, Heidi Stieglitz; Bartolo, Angela; Corley, Martin; Rajendran, Gnanathusharan; Szabo, Aniko; Swanson, Sara

    2011-01-01

    In this study, the relationship between gesture recognition and imitation was explored. Nineteen individuals with Autism Spectrum Disorder (ASD) were compared to a control group of 23 typically developing children on their ability to imitate and recognize three gesture types (transitive, intransitive, and pantomimes). The ASD group performed more…

  12. Authenticity and Imitation in Translating Exposition: A Corpus-Based Study

    Science.gov (United States)

    Elmgrab, Ramadan Ahmed

    2015-01-01

    Many Western scholars such as Dryden show little interest in imitations, and express their preference for translations, i.e. paraphrases that are faithful to the sense of the source text. However, they consider imitations as a viable category of translation. It is the degree of freedom, or departure from the original, that differentiates a…

  13. Social Intervention for Adolescents with Autism and Significant Intellectual Disability: Initial Efficacyof Reciprocal Imitation Training

    Science.gov (United States)

    Ingersoll, Brooke; Walton, Katherine; Carlsen, Danielle; Hamlin, Theresa

    2013-01-01

    Individuals with autism have difficulty with social skills across the lifespan. Few social interventions have been examined for older individuals with autism who also have significant intellectual disabilities (ID). Previous research suggests that reciprocal imitation training (RIT) improves imitation and social engagement in young children with…

  14. Imitation from 12 to 24 Months in Autism and Typical Development: A Longitudinal Rasch Analysis

    Science.gov (United States)

    Young, Gregory S.; Rogers, Sally J.; Hutman, Ted; Rozga, Agata; Sigman, Marian; Ozonoff, Sally

    2011-01-01

    The development of imitation during the second year of life plays an important role in domains of sociocognitive development such as language and social learning. Deficits in imitation ability in persons with autism spectrum disorder (ASD) from toddlerhood into adulthood have also been repeatedly documented, raising the possibility that early…

  15. Reproductive isolation related to mimetic divergence in the poison frog Ranitomeya imitator

    DEFF Research Database (Denmark)

    Twomey, Evan; Vestergaard, Jacob Schack; Summers, Kyle

    2014-01-01

    study the Peruvian poison frog Ranitomeya imitator, a species that has undergone a mimetic radiation into four distinct morphs. Using a combination of colour–pattern analysis, landscape genetics and mate-choice experiments, we show that a mimetic shift in R. imitator is associated with a narrow...

  16. Study on ancient Chinese imitated GE ware by INAA and WDXRF

    International Nuclear Information System (INIS)

    Xie Guoxi; Feng Songlin; Feng Xiangqian; Wang Yanqing; Zhu Jihao; Yan Lingtong; Li Yongqiang; Han Hongye

    2007-01-01

    Imitated GE ware was one of the most famous products of Jingdezhen porcelain field in Ming dynasty (AD 1368-1644). The exterior features of its body and glaze are very marvelous. Black foot, purple mouth and crazing glaze are the main features of imitated GE ware. Until now, the key conditions of resulting these features are not clearly identified. In order to find the critical elements for firing these features, instrumental neutron activation analysis (INAA) and wavelength-dispersive X-ray fluorescence (WDXRF) were used to determine the element abundance patterns of imitated GE ware body and glaze. The experimental data was compared with that of imitated Longquan celadon and of Longquan celadon. The analytical results indicated that Fe, Ti and Na were the critical elements. The body of imitated GE ware which contains high Fe and Ti are the basic conditions of firing its black body, black foot and purple mouth. The glaze of imitated GE ware which contains high Na is the main condition of producing its crazing glaze. Na is the critical element which enlarges the difference in expansion coefficients between the glaze and body of imitated GE ware. Furthermore, Zijin soil was added into kaolin to make the body rich in Fe and Ti. And something which was rich in Na was used to produce crazing glaze in the manufacturing process of imitated GE ware

  17. The Left, The Better: White-Matter Brain Integrity Predicts Foreign Language Imitation Ability.

    Science.gov (United States)

    Vaquero, Lucía; Rodríguez-Fornells, Antoni; Reiterer, Susanne M

    2017-08-01

    Speech imitation is crucial for language acquisition and second-language learning. Interestingly, large individual differences regarding the ability in imitating foreign-language sounds have been observed. The origin of this interindividual diversity remains unknown, although it might be partially explained by structural predispositions. Here we correlated white-matter structural properties of the arcuate fasciculus (AF) with the performance of 52 German-speakers in a Hindi sentence- and word-imitation task. First, a manual reconstruction was performed, permitting us to extract the mean values along the three branches of the AF. We found that a larger lateralization of the AF volume toward the left hemisphere predicted the performance of our participants in the imitation task. Second, an automatic reconstruction was carried out, allowing us to localize the specific region within the AF that exhibited the largest correlation with foreign language imitation. Results of this reconstruction also showed a left lateralization trend: greater fractional anisotropy values in the anterior half of the left AF correlated with the performance in the Hindi-imitation task. From the best of our knowledge, this is the first time that foreign language imitation aptitude is tested using a more ecological imitation task and correlated with DTI tractography, using both a manual and an automatic method. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  18. Sentence Imitation as a Marker of SLI in Czech: Disproportionate Impairment of Verbs and Clitics

    Science.gov (United States)

    Smolík, Filip; Vávru, Petra

    2014-01-01

    Purpose: The authors examined sentence imitation as a potential clinical marker of specific language impairment (SLI) in Czech and its use to identify grammatical markers of SLI. Method: Children with SLI and the age-and language-matched control groups (total N = 57) were presented with a sentence imitation task, a receptive vocabulary task, and…

  19. The Effects of Reciprocal Imitation on Teacher-Student Relationships and Student Learning Outcomes

    Science.gov (United States)

    Zhou, Jiangyuan

    2012-01-01

    Neuroscientific and developmental psychological research in imitation has yielded important insights into building teacher-student relationships and enhancing students' learning. This study investigated the effects of reciprocal imitation on teacher-student relationships and students' learning outcomes in one-on-one teacher-student interactions.…

  20. Contingent Imitation Increases Verbal Interaction in Children with Autism Spectrum Disorders

    Science.gov (United States)

    Ishizuka, Yuka; Yamamoto, Jun-ichi

    2016-01-01

    Several studies have suggested that contingent adult imitation increase nonverbal communication, such as attention and proximity to adults, in children with autism spectrum disorders. However, few studies have shown the effect of contingent imitation on verbal communication. This study examined whether children with autism were able to promote…

  1. Interindividual Differences in Neonatal Imitation and the Development of Action Chains in Rhesus Macaques

    Science.gov (United States)

    Ferrari, Pier Francesco; Paukner, Annika; Ruggiero, Angela; Darcey, Lisa; Unbehagen, Sarah; Suomi, Stephen J.

    2009-01-01

    The capacity to imitate facial gestures is highly variable in rhesus macaques and this variability may be related to differences in specific neurobehavioral patterns of development. This study evaluated the differential neonatal imitative response of 41 macaques in relation to the development of sensory, motor, and cognitive skills throughout the…

  2. Screening suspected counterfeit Viagra and imitations of Viagra with near-infrared spectroscopy.

    NARCIS (Netherlands)

    Vredenbregt, M J; Blok-Tip, L; Hoogerbrugge, Ronald; Barends, D M; Kaste, D de

    2006-01-01

    We describe a near-infrared spectroscopy (NIRS) method for fast-screening Viagra tablets, counterfeit Viagra tablets, and imitations of Viagra. The method can (1) check the homogeneity of a batch; (2) distinguish counterfeits and imitations from authentic Viagra; (3) screen for the presence of

  3. Children's Faithfulness in Imitating Language Use Varies Cross-culturally, Contingent on Prior Experience

    Science.gov (United States)

    Klinger, Jörn; Mayor, Julien; Bannard, Colin

    2016-01-01

    Despite its recognized importance for cultural transmission, little is known about the role imitation plays in language learning. Three experiments examine how rates of imitation vary as a function of qualitative differences in the way language is used in a small indigenous community in Oaxaca, Mexico and three Western comparison groups. Data from…

  4. Out-of-category brand imitation : Product categorization determines copycat evaluation

    NARCIS (Netherlands)

    van Horen, F.; Pieters, Rik

    2017-01-01

    Copycat brands imitate the trade dress of other brands, such as their brand name, logo, and packaging design. Copycats typically operate in the core product category of the imitated brand under the assumption that such “in-category imitation” is most effective. In contrast, four experiments

  5. Brief Report: Imitation of Object-Directed Acts in Young Children with Autism Spectrum Disorders

    Science.gov (United States)

    Gonsiorowski, Anna; Williamson, Rebecca A.; Robins, Diana L.

    2016-01-01

    Children with autism spectrum disorders (ASD) imitate less than typically developing (TD) children; however, the specific features and causes of this deficit are still unclear. The current study investigates the role of joint engagement, specifically children's visual attention to demonstrations, in an object-directed imitation task. This sample…

  6. Is It Rational to Assume that Infants Imitate Rationally? A Theoretical Analysis and Critique

    Science.gov (United States)

    Paulus, Markus

    2012-01-01

    It has been suggested that preverbal infants evaluate the efficiency of others' actions (by applying a "principle of rational action") and that they imitate others' actions rationally. The present contribution presents a conceptual analysis of the claim that preverbal infants imitate rationally. It shows that this ability rests on at least three…

  7. Immediate and Deferred Imitation in Fourteen- and Twenty-Four-Month-Old Infants.

    Science.gov (United States)

    Meltzoff, Andrew N.

    1985-01-01

    A laboratory procedure was developed for assessing imitation in the second year of life. Results demonstrate that 14- and 24-month-olds can imitate a simple action with an unfamiliar object, both immediately and after a 24-hour delay. Implications for research design and theory of infant memory are discussed. (RH)

  8. What Infant Memory Tells Us about Infantile Amnesia: Long-Term Recall and Deferred Imitation.

    Science.gov (United States)

    Meltzoff, Andrew N.

    1995-01-01

    Long-term recall memory was assessed in 14- and 16 month-olds using a nonverbal method requiring subjects to reenact a past event from memory. The results demonstrated significant deferred imitation after delays of two and four months, and that the toddlers retained and imitated multiple acts. (MDM)

  9. Robots Learn to Recognize Individuals from Imitative Encounters with People and Avatars

    Science.gov (United States)

    Boucenna, Sofiane; Cohen, David; Meltzoff, Andrew N.; Gaussier, Philippe; Chetouani, Mohamed

    2016-02-01

    Prior to language, human infants are prolific imitators. Developmental science grounds infant imitation in the neural coding of actions, and highlights the use of imitation for learning from and about people. Here, we used computational modeling and a robot implementation to explore the functional value of action imitation. We report 3 experiments using a mutual imitation task between robots, adults, typically developing children, and children with Autism Spectrum Disorder. We show that a particular learning architecture - specifically one combining artificial neural nets for (i) extraction of visual features, (ii) the robot’s motor internal state, (iii) posture recognition, and (iv) novelty detection - is able to learn from an interactive experience involving mutual imitation. This mutual imitation experience allowed the robot to recognize the interactive agent in a subsequent encounter. These experiments using robots as tools for modeling human cognitive development, based on developmental theory, confirm the promise of developmental robotics. Additionally, findings illustrate how person recognition may emerge through imitative experience, intercorporeal mapping, and statistical learning.

  10. Effects of reputational sanctions on the competitive imitation of design innovations

    NARCIS (Netherlands)

    Gemser, G.; Wijnberg, N.M.

    2001-01-01

    This study examines whether and under what conditions reputational sanctions are a strong deterrent to imitative firm behaviour. Results indicate that reputational sanctions can be an effective barrier to imitation, in particular when firms perceive a reputation for innovation to be a factor in

  11. Study on ancient Chinese imitated GE ware by INAA and WDXRF

    Science.gov (United States)

    Xie, Guoxi; Feng, Songlin; Feng, Xiangqian; Wang, Yanqing; Zhu, Jihao; Yan, Lingtong; Li, Yongqiang; Han, Hongye

    2007-11-01

    Imitated GE ware was one of the most famous products of Jingdezhen porcelain field in Ming dynasty (AD 1368-1644). The exterior features of its body and glaze are very marvelous. Black foot, purple mouth and crazing glaze are the main features of imitated GE ware. Until now, the key conditions of resulting these features are not clearly identified. In order to find the critical elements for firing these features, instrumental neutron activation analysis (INAA) and wavelength-dispersive X-ray fluorescence (WDXRF) were used to determine the element abundance patterns of imitated GE ware body and glaze. The experimental data was compared with that of imitated Longquan celadon and of Longquan celadon. The analytical results indicated that Fe, Ti and Na were the critical elements. The body of imitated GE ware which contains high Fe and Ti are the basic conditions of firing its black body, black foot and purple mouth. The glaze of imitated GE ware which contains high Na is the main condition of producing its crazing glaze. Na is the critical element which enlarges the difference in expansion coefficients between the glaze and body of imitated GE ware. Furthermore, Zijin soil was added into kaolin to make the body rich in Fe and Ti. And something which was rich in Na was used to produce crazing glaze in the manufacturing process of imitated GE ware.

  12. Study on ancient Chinese imitated GE ware by INAA and WDXRF

    Energy Technology Data Exchange (ETDEWEB)

    Xie Guoxi [Institute of High Energy Physics, Chinese Academy of Sciences, 19 Yu Quan Lu, Beijing 100049 (China); Graduated University of Chinese Academy of Sciences, Beijing 100049 (China); Feng Songlin [Institute of High Energy Physics, Chinese Academy of Sciences, 19 Yu Quan Lu, Beijing 100049 (China)], E-mail: fengsl@ihep.ac.cn; Feng Xiangqian; Wang Yanqing; Zhu Jihao; Yan Lingtong [Institute of High Energy Physics, Chinese Academy of Sciences, 19 Yu Quan Lu, Beijing 100049 (China); Li Yongqiang; Han Hongye [Beijing Institute of Cultural Relics, Beijing 100009 (China)

    2007-11-15

    Imitated GE ware was one of the most famous products of Jingdezhen porcelain field in Ming dynasty (AD 1368-1644). The exterior features of its body and glaze are very marvelous. Black foot, purple mouth and crazing glaze are the main features of imitated GE ware. Until now, the key conditions of resulting these features are not clearly identified. In order to find the critical elements for firing these features, instrumental neutron activation analysis (INAA) and wavelength-dispersive X-ray fluorescence (WDXRF) were used to determine the element abundance patterns of imitated GE ware body and glaze. The experimental data was compared with that of imitated Longquan celadon and of Longquan celadon. The analytical results indicated that Fe, Ti and Na were the critical elements. The body of imitated GE ware which contains high Fe and Ti are the basic conditions of firing its black body, black foot and purple mouth. The glaze of imitated GE ware which contains high Na is the main condition of producing its crazing glaze. Na is the critical element which enlarges the difference in expansion coefficients between the glaze and body of imitated GE ware. Furthermore, Zijin soil was added into kaolin to make the body rich in Fe and Ti. And something which was rich in Na was used to produce crazing glaze in the manufacturing process of imitated GE ware.

  13. Effects of Context and Facial Expression on Imitation Tasks in Preschool Children with Autism

    Science.gov (United States)

    Markodimitraki, Maria; Kypriotaki, Maria; Ampartzaki, Maria; Manolitsis, George

    2013-01-01

    The present study explored the effect of the context in which an imitation act occurs (elicited/spontaneous) and the experimenter's facial expression (neutral or smiling) during the imitation task with young children with autism and typically developing children. The participants were 10 typically developing children and 10 children with autism…

  14. Musical experience and Mandarin tone discrimination and imitation

    Science.gov (United States)

    Gottfried, Terry L.; Staby, Ann M.; Ziemer, Christine J.

    2004-05-01

    Previous work [T. L. Gottfried and D. Riester, J. Acoust. Soc. Am. 108, 2604 (2000)] showed that native speakers of American English with musical training performed better than nonmusicians when identifying the four distinctive tones of Mandarin Chinese (high-level, mid-rising, low-dipping, high-falling). Accuracy for both groups was relatively low since listeners were not trained on the phonemic contrasts. Current research compares musicians and nonmusicians on discrimination and imitation of unfamiliar tones. Listeners were presented with two different Mandarin words that had either the same or different tones; listeners indicated whether the tones were same or different. Thus, they were required to determine a categorical match (same or different tone), rather than an auditory match. All listeners had significantly more difficulty discriminating between mid-rising and low-dipping tones than with other contrasts. Listeners with more musical training showed significantly greater accuracy in their discrimination. Likewise, musicians' spoken imitations of Mandarin tones (model tokens presented by a native speaker) were rated as significantly more native-like than those of nonmusicians. These findings suggest that musicians may have abilities or training that facilitate their perception and production of Mandarin tones. However, further research is needed to determine whether this advantage transfers to language learning situations.

  15. Mirror neurons and imitation: a computationally guided review.

    Science.gov (United States)

    Oztop, Erhan; Kawato, Mitsuo; Arbib, Michael

    2006-04-01

    Neurophysiology reveals the properties of individual mirror neurons in the macaque while brain imaging reveals the presence of 'mirror systems' (not individual neurons) in the human. Current conceptual models attribute high level functions such as action understanding, imitation, and language to mirror neurons. However, only the first of these three functions is well-developed in monkeys. We thus distinguish current opinions (conceptual models) on mirror neuron function from more detailed computational models. We assess the strengths and weaknesses of current computational models in addressing the data and speculations on mirror neurons (macaque) and mirror systems (human). In particular, our mirror neuron system (MNS), mental state inference (MSI) and modular selection and identification for control (MOSAIC) models are analyzed in more detail. Conceptual models often overlook the computational requirements for posited functions, while too many computational models adopt the erroneous hypothesis that mirror neurons are interchangeable with imitation ability. Our meta-analysis underlines the gap between conceptual and computational models and points out the research effort required from both sides to reduce this gap.

  16. Generalization of Abel's mechanical problem: The extended isochronicity condition and the superposition principle

    Energy Technology Data Exchange (ETDEWEB)

    Kinugawa, Tohru, E-mail: kinugawa@phoenix.kobe-u.ac.jp [Institute for Promotion of Higher Education, Kobe University, Kobe 657-8501 (Japan)

    2014-02-15

    This paper presents a simple but nontrivial generalization of Abel's mechanical problem, based on the extended isochronicity condition and the superposition principle. There are two primary aims. The first one is to reveal the linear relation between the transit-time T and the travel-length X hidden behind the isochronicity problem that is usually discussed in terms of the nonlinear equation of motion (d{sup 2}X)/(dt{sup 2}) +(dU)/(dX) =0 with U(X) being an unknown potential. Second, the isochronicity condition is extended for the possible Abel-transform approach to designing the isochronous trajectories of charged particles in spectrometers and/or accelerators for time-resolving experiments. Our approach is based on the integral formula for the oscillatory motion by Landau and Lifshitz [Mechanics (Pergamon, Oxford, 1976), pp. 27–29]. The same formula is used to treat the non-periodic motion that is driven by U(X). Specifically, this unknown potential is determined by the (linear) Abel transform X(U) ∝ A[T(E)], where X(U) is the inverse function of U(X), A=(1/√(π))∫{sub 0}{sup E}dU/√(E−U) is the so-called Abel operator, and T(E) is the prescribed transit-time for a particle with energy E to spend in the region of interest. Based on this Abel-transform approach, we have introduced the extended isochronicity condition: typically, τ = T{sub A}(E) + T{sub N}(E) where τ is a constant period, T{sub A}(E) is the transit-time in the Abel type [A-type] region spanning X > 0 and T{sub N}(E) is that in the Non-Abel type [N-type] region covering X < 0. As for the A-type region in X > 0, the unknown inverse function X{sub A}(U) is determined from T{sub A}(E) via the Abel-transform relation X{sub A}(U) ∝ A[T{sub A}(E)]. In contrast, the N-type region in X < 0 does not ensure this linear relation: the region is covered with a predetermined potential U{sub N}(X) of some arbitrary choice, not necessarily obeying the Abel-transform relation. In

  17. Relations between 18-month-olds' gaze pattern and target action performance: a deferred imitation study with eye tracking.

    Science.gov (United States)

    Óturai, Gabriella; Kolling, Thorsten; Knopf, Monika

    2013-12-01

    Deferred imitation studies are used to assess infants' declarative memory performance. These studies have found that deferred imitation performance improves with age, which is usually attributed to advancing memory capabilities. Imitation studies, however, are also used to assess infants' action understanding. In this second research program it has been observed that infants around the age of one year imitate selectively, i.e., they imitate certain kinds of target actions and omit others. In contrast to this, two-year-olds usually imitate the model's exact actions. 18-month-olds imitate more exactly than one-year-olds, but more selectively than two-year-olds, a fact which makes this age group especially interesting, since the processes underlying selective vs. exact imitation are largely debated. The question, for example, if selective attention to certain kinds of target actions accounts for preferential imitation of these actions in young infants is still open. Additionally, relations between memory capabilities and selective imitation processes, as well as their role in shaping 18-month-olds' neither completely selective, nor completely exact imitation have not been thoroughly investigated yet. The present study, therefore, assessed 18-month-olds' gaze toward two types of actions (functional vs. arbitrary target actions) and the model's face during target action demonstration, as well as infants' deferred imitation performance. Although infants' fixation times to functional target actions were not longer than to arbitrary target actions, they imitated the functional target actions more frequently than the arbitrary ones. This suggests that selective imitation does not rely on selective gaze toward functional target actions during the demonstration phase. In addition, a post hoc analysis of interindividual differences suggested that infants' attention to the model's social-communicative cues might play an important role in exact imitation, meaning the imitation

  18. Sensory predictions during action support perception of imitative reactions across suprasecond delays.

    Science.gov (United States)

    Yon, Daniel; Press, Clare

    2018-04-01

    Perception during action is optimized by sensory predictions about the likely consequences of our movements. Influential theories in social cognition propose that we use the same predictions during interaction, supporting perception of similar reactions in our social partners. However, while our own action outcomes typically occur at short, predictable delays after movement execution, the reactions of others occur at longer, variable delays in the order of seconds. To examine whether we use sensorimotor predictions to support perception of imitative reactions, we therefore investigated the temporal profile of sensory prediction during action in two psychophysical experiments. We took advantage of an influence of prediction on apparent intensity, whereby predicted visual stimuli appear brighter (more intense). Participants performed actions (e.g., index finger lift) and rated the brightness of observed outcomes congruent (index finger lift) or incongruent (middle finger lift) with their movements. Observed action outcomes could occur immediately after execution, or at longer delays likely reflective of those in natural social interaction (1800 or 3600 ms). Consistent with the previous literature, Experiment 1 revealed that congruent action outcomes were rated as brighter than incongruent outcomes. Importantly, this facilitatory perceptual effect was found irrespective of whether outcomes occurred immediately or at delay. Experiment 2 replicated this finding and demonstrated that it was not the result of response bias. These findings therefore suggest that visual predictions generated during action are sufficiently general across time to support our perception of imitative reactions in others, likely generating a range of benefits during social interaction. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Imitation of the sequential structure of actions by chimpanzees (Pan troglodytes).

    Science.gov (United States)

    Whiten, A

    1998-09-01

    Imitation was studied experimentally by allowing chimpanzees (Pan troglodytes) to observe alternative patterns of actions for opening a specially designed "artificial fruit." Like problematic foods primates deal with naturally, with the test fruit several defenses had to be removed to gain access to an edible core, but the sequential order and method of defense removal could be systematically varied. Each subject repeatedly observed 1 of 2 alternative techniques for removing each defense and 1 of 2 alternative sequential patterns of defense removal. Imitation of sequential organization emerged after repeated cycles of demonstration and attempts at opening the fruit. Imitation in chimpanzees may thus have some power to produce cultural convergence, counter to the supposition that individual learning processes corrupt copied actions. Imitation of sequential organization was accompanied by imitation of some aspects of the techniques that made up the sequence.

  20. Vocal Imitation in Parrots Allows Addressing of Specific Individuals in a Dynamic Communication Network

    DEFF Research Database (Denmark)

    Balsby, T.J.S.; Momberg, J.V.; Dabelsteen, T.

    2012-01-01

    €“fronted conures live in fission-fusion flocks where they encounter many different individuals every day, and it is possible that their vocal imitation ability is a flexible means to address a specific individual within a flock. We tested this via playback to short-term captive wild conures. Test birds were placed...... together in pairs in outdoor aviaries to form simple flocks. To simulate imitation of a specific individual these pairs received playback of contact calls that primarily imitate one of the two birds. Overall, individuals that received simulated vocal imitations of its calls responded more frequently...... and faster than the other individual. This suggests that orange-fronted conures can use imitations of contact calls to address specific individuals of a flock. In the discussion we argue that the fission-fusion flock dynamics of many parrot species has been an important factor in evolving conures´ and other...

  1. Do as I … Did! Long-term memory of imitative actions in dogs (Canis familiaris).

    Science.gov (United States)

    Fugazza, Claudia; Pogány, Ákos; Miklósi, Ádám

    2016-03-01

    This study demonstrates long-term declarative memory of imitative actions in a non-human animal species. We tested 12 pet dogs for their ability to imitate human actions after retention intervals ranging from 1 to 24 h. For comparison, another 12 dogs were tested for the same actions without delay between demonstration and recall. Our test consisted of a modified version of the Do as I Do paradigm, combined with the two-action procedure to control for non-imitative processes. Imitative performance of dogs remained consistently high independent of increasing retention intervals, supporting the idea that dogs are able to retain mental representations of human actions for an extended period of time. The ability to imitate after such delays supports the use of long-term declarative memory.

  2. Teaching Caregivers to Implement Video Modeling Imitation Training via iPad for Their Children with Autism

    Science.gov (United States)

    Cardon, Teresa A.

    2012-01-01

    Children with autism fail to imitate from an early age and this lack of imitation is a salient diagnostic marker for the disorder. For children with Autism Spectrum Disorder (ASD), increased imitation skills appear to be related to increased skill development in a variety of areas. Video modeling was recently validated as a technique to support…

  3. See What I See, Do as I Do: Promoting Joint Attention and Imitation in Preschoolers with Autism Spectrum Disorder

    Science.gov (United States)

    Warreyn, Petra; Roeyers, Herbert

    2014-01-01

    Since imitation and joint attention are both important abilities for young children and since children with autism spectrum disorder show a range of problems in these domains, imitation and joint attention are important targets for intervention. In this study, we examined the possibility of promoting imitation and joint attention by means of a…

  4. An exploration of imitation recognition in young children with autism spectrum disorders.

    Science.gov (United States)

    Berger, Natalie I; Ingersoll, Brooke

    2013-10-01

    The ability to recognize when one is being imitated has been hypothesized to be an important developmental process related to the emergence of more advanced social-cognitive skills. While a series of behaviors indicating progressively more mature imitation recognition (IR) skills has been assessed in typically developing children, empirical work with children with autism spectrum disorders (ASDs) has largely focused on basic social responses to an imitative adult (e.g. increases in eye contact). Limited work has explored more mature IR behaviors in this population. This study compared the degree to which children with ASD engage in different behaviors thought to be indicative of IR during a naturalistic imitation task and the relationship between different types of IR behaviors and social-cognitive skills (i.e. imitation, language, social reciprocity, and joint attention). Thirty children with ASD were administered standardized measures of cognitive level, language, joint attention, social reciprocity, and imitation. IR behaviors were observed during periods of contingent imitation by an adult. Participants engaged more frequently in less mature (e.g. looking at the experimenter's toy or face) than more mature IR behaviors (e.g. testing the experimenter's intent to imitate). After controlling for developmental level, social reciprocity, object imitation, and gesture imitation were positively correlated with more mature IR. These findings suggest that the development of more mature IR skills is related to the development of other social-cognitive skills in children with ASD and provide additional empirical support for reports of more mature IR observed in this population. , Inc. © 2013 International Society for Autism Research, Wiley Periodicals, Inc.

  5. Motor facilitation during real-time movement imitation in Parkinson's disease: a virtual reality study.

    Science.gov (United States)

    Robles-García, Verónica; Arias, Pablo; Sanmartín, Gabriel; Espinosa, Nelson; Flores, Julian; Grieve, Kenneth L; Cudeiro, Javier

    2013-12-01

    Impaired temporal stability and poor motor unit recruitment are key impairments in Parkinsonian motor control during a whole spectrum of rhythmic movements, from simple finger tapping to gait. Therapies based on imitation can be designed for patients with motor impairments and virtual-reality (VR) offers a new perspective. Motor actions are known to depend upon the dopaminergic system, whose involvement in imitation is unknown. We sought to understand this role and the underlying possibilities for motor rehabilitation, by observing the execution of different motor-patterns during imitation in a VR environment in subjects with and without dopaminergic deficits. 10 OFF-dose idiopathic Parkinson's Disease patients (PD), 9 age-matched and 9 young-subjects participated. Subjects performed finger-tapping at their "comfort" and "slow-comfort" rates, while immersed in VR presenting their "avatar" in 1st person perspective. Imitation was evaluated by asking subjects to replicate finger-tapping patterns different to their natural one. The finger-pattern presented matched their comfort and comfort-slow rates, but without a pause on the table (continuously moving). Patients were able to adapt their finger-tapping correctly, showing that in comparison with the control groups, the dopaminergic deficiency of PD did not impair imitation. During imitation the magnitude of EMG increased and the temporal variability of movement decreased. PD-patients have unaltered ability to imitate instructed motor-patterns, suggesting that a fully-functional dopaminergic system is not essential for such imitation. It should be further investigated if imitation training over a period of time induces positive off-line motor adaptations with transfer to non-imitation tasks. Copyright © 2013 Elsevier Ltd. All rights reserved.

  6. Generalized Airy functions for use in one-dimensional quantum mechanical problems

    Science.gov (United States)

    Eaves, J. O.

    1972-01-01

    The solution of the one dimensional, time independent, Schroedinger equation in which the energy minus the potential varies as the nth power of the distance is obtained from proper linear combinations of Bessel functions. The linear combinations called generalized Airy functions, reduce to the usual Airy functions Ai(x) and Bi(x) when n equals 1 and have the same type of simple asymptotic behavior. Expressions for the generalized Airy functions which can be evaluated by the method of generalized Gaussian quadrature are obtained.

  7. Carbon capture in vehicles : a review of general support, available mechanisms, and consumer-acceptance issues.

    Science.gov (United States)

    2012-05-01

    This survey of the feasibility of introducing carbon capture and storage (CCS) into light vehicles : started by reviewing the level of international support for CCS in general. While there have been : encouraging signs that CCS is gaining acceptance ...

  8. Protective mechanical ventilation during general anesthesia for open abdominal surgery improves postoperative pulmonary function

    NARCIS (Netherlands)

    Severgnini, Paolo; Selmo, Gabriele; Lanza, Christian; Chiesa, Alessandro; Frigerio, Alice; Bacuzzi, Alessandro; Dionigi, Gianlorenzo; Novario, Raffaele; Gregoretti, Cesare; de Abreu, Marcelo Gama; Schultz, Marcus J.; Jaber, Samir; Futier, Emmanuel; Chiaranda, Maurizio; Pelosi, Paolo

    2013-01-01

    The impact of intraoperative ventilation on postoperative pulmonary complications is not defined. The authors aimed at determining the effectiveness of protective mechanical ventilation during open abdominal surgery on a modified Clinical Pulmonary Infection Score as primary outcome and

  9. Behavioral pattern separation and its link to the neural mechanisms of fear generalization.

    Science.gov (United States)

    Lange, Iris; Goossens, Liesbet; Michielse, Stijn; Bakker, Jindra; Lissek, Shmuel; Papalini, Silvia; Verhagen, Simone; Leibold, Nicole; Marcelis, Machteld; Wichers, Marieke; Lieverse, Ritsaert; van Os, Jim; van Amelsvoort, Therese; Schruers, Koen

    2017-11-01

    Fear generalization is a prominent feature of anxiety disorders and post-traumatic stress disorder (PTSD). It is defined as enhanced fear responding to a stimulus that bears similarities, but is not identical to a threatening stimulus. Pattern separation, a hippocampal-dependent process, is critical for stimulus discrimination; it transforms similar experiences or events into non-overlapping representations. This study is the first in humans to investigate the extent to which fear generalization relies on behavioral pattern separation abilities. Participants (N = 46) completed a behavioral task taxing pattern separation, and a neuroimaging fear conditioning and generalization paradigm. Results show an association between lower behavioral pattern separation performance and increased generalization in shock expectancy scores, but not in fear ratings. Furthermore, lower behavioral pattern separation was associated with diminished recruitment of the subcallosal cortex during presentation of generalization stimuli. This region showed functional connectivity with the orbitofrontal cortex and ventromedial prefrontal cortex. Together, the data provide novel experimental evidence that pattern separation is related to generalization of threat expectancies, and reduced fear inhibition processes in frontal regions. Deficient pattern separation may be critical in overgeneralization and therefore may contribute to the pathophysiology of anxiety disorders and PTSD. © The Author (2017). Published by Oxford University Press.

  10. A general reaction mechanism for carbapenem hydrolysis by mononuclear and binuclear metallo-β-lactamases.

    Science.gov (United States)

    Lisa, María-Natalia; Palacios, Antonela R; Aitha, Mahesh; González, Mariano M; Moreno, Diego M; Crowder, Michael W; Bonomo, Robert A; Spencer, James; Tierney, David L; Llarrull, Leticia I; Vila, Alejandro J

    2017-09-14

    Carbapenem-resistant Enterobacteriaceae threaten human health, since carbapenems are last resort drugs for infections by such organisms. Metallo-β-lactamases (MβLs) are the main mechanism of resistance against carbapenems. Clinically approved inhibitors of MBLs are currently unavailable as design has been limited by the incomplete knowledge of their mechanism. Here, we report a biochemical and biophysical study of carbapenem hydrolysis by the B1 enzymes NDM-1 and BcII in the bi-Zn(II) form, the mono-Zn(II) B2 Sfh-I and the mono-Zn(II) B3 GOB-18. These MβLs hydrolyse carbapenems via a similar mechanism, with accumulation of the same anionic intermediates. We characterize the Michaelis complex formed by mono-Zn(II) enzymes, and we identify all intermediate species, enabling us to propose a chemical mechanism for mono and binuclear MβLs. This common mechanism open avenues for rationally designed inhibitors of all MβLs, notwithstanding the profound differences between these enzymes' active site structure, β-lactam specificity and metal content.Carbapenem-resistant bacteria pose a major health threat by expressing metallo-β-lactamases (MβLs), enzymes able to hydrolyse these life-saving drugs. Here the authors use biophysical and computational methods and show that different MβLs share the same reaction mechanism, suggesting new strategies for drug design.

  11. Research 0n Incentive Mechanism of General Contractor and Subcontractors Dynamic Alliance in Construction Project Based on Team Cooperation

    Science.gov (United States)

    Yin, Honglian; Sun, Aihua; Liu, Quanru; Chen, Zhiyi

    2018-03-01

    It is the key of motivating sub-contractors working hard and mutual cooperation, ensuring implementation overall goal of the project that to design rational incentive mechanism for general contractor. Based on the principal-agency theory, the subcontractor efforts is divided into two parts, one for individual efforts, another helping other subcontractors, team Cooperation incentive models of multiple subcontractors are set up, incentive schemes and intensities are also given. The results show that the general contractor may provide individual and team motivation incentives when subcontractors working independently, not affecting each other in time and space; otherwise, the general contractor may only provide individual incentive to entice teams collaboration between subcontractors and helping each other. The conclusions can provide a reference for the subcontract design of general and sub-contractor dynamic alliances.

  12. Impact of melting heat transfer and nonlinear radiative heat flux mechanisms for the generalized Burgers fluids

    Directory of Open Access Journals (Sweden)

    Waqar Azeem Khan

    Full Text Available The present paper deals with the analysis of melting heat and mass transfer characteristics in the stagnation point flow of an incompressible generalized Burgers fluid over a stretching sheet in the presence of non-linear radiative heat flux. A uniform magnetic field is applied normal to the flow direction. The governing equations in dimensional form are reduced to a system of dimensionless expressions by implementation of suitable similarity transformations. The resulting dimensionless problem governing the generalized Burgers is solved analytically by using the homotopy analysis method (HAM. The effects of different flow parameters like the ratio parameter, magnetic parameter, Prandtl number, melting parameter, radiation parameter, temperature ratio parameter and Schmidt number on the velocity, heat and mass transfer characteristics are computed and presented graphically. Moreover, useful discussions in detail are carried out with the help of plotted graphs and tables. Keywords: Generalized Burgers fluid, Non-linear radiative flow, Magnetic field, Melting heat transfer

  13. Chapter 1. General information about uranium. 1.5. Mechanical properties

    International Nuclear Information System (INIS)

    Khakimov, N.; Nazarov, Kh.M.; Mirsaidov, I.U.

    2012-01-01

    Full text: The mechanical properties of uranium depend on its purity, and which mechanical and thermal regimes are used for reprocessing. The average elasticity module value for cast uranium is 20.5•10"-"2 mega newton/m"2 (20.9•10"-"3 kilogram-force/mm"2), strength limit during tension at room temperature is 372–470 mega newton/m"2 (38–48 kilogram-force/mm"2), strength is increased after hardening from β - and γ - phases; and average rigidity by Brinell 19.6–21.6•10"2 mega newton/m"2 (200–220 kilogram-force/mm"2). Exposure by neutron flux (which occurs in nuclear reactors) changes the physical and mechanical properties of uranium: creeping develops and brittleness increases, goods deformation is observed, which forces the operator to use uranium in nuclear reactors as different uranium alloys.

  14. Exploring Spontaneous Imitation in Infancy: A Three Generation Inter-Familial Study

    Directory of Open Access Journals (Sweden)

    Theano Kokkinaki

    2013-05-01

    Full Text Available With the aim to advance our understanding regarding the role of the extended family interactional context for early mother-infant communication, we compared spontaneous early imitative exchanges in dyadic interactions between mothers and infants (Group 1, N = 26 who had no frequent contact with maternal grandmothers, to imitations in two familial subgroups (Group 2, N = 48: (a dyadic interactions of infants with their mothers, and (b with their grandmothers–persons who had frequent contact with the infant. Spontaneous dyadic interactions of infants with their mothers and grandmothers were video-recorded at home from the 2nd to the 10th month of their life. Both comparisons provided evidence of similar frequency of imitative exchanges and developmental trajectories of infant imitations, but also differences in the structure of imitation, the kinds of imitated behaviors and the temporal patterns of imitative components. In the frame of the theory of Innate Intersubjectivity, we assume that differential early family interaction may be related to variations in three fundamental dimensions of infant-significant other communication: “kinematics” (temporal patterns, “physiognomics” (spatial patterns or forms and “energetics” (force or effort. These variations may affect the child’s ability for regulation and negotiation of interpersonal challenges within and outside the family context.

  15. Memory and representation in young children with Down syndrome: Exploring deferred imitation and object permanence.

    Science.gov (United States)

    Rast, Mechthild; Meltzoff, Andrew N

    1995-01-01

    Deferred imitation and object permanence (OP) were tested in 48 young children with Down syndrome (DS), ranging from 20 to 43 months of age. Deferred imitation and high-level OP (invisible displacements) have long been held to be synchronous developments during sensory-motor "Stage 6" (18-24 months of age in unimpaired children). The results of the current study demonstrate deferred imitation in young children with DS, showing they can learn novel behaviors from observation and retain multiple models in memory. This is the first demonstration of deferred imitation in young children with DS. The average OP level passed in this sample was A-not-B, a task passed at 8-12 months of age in normally developing infants. Analyses showed that individual children who failed high-level OP (invisible displacements) could still perform deferred imitation. This indicates that deferred imitation and OP invisible displacements are not synchronous developments in children with DS. This asynchrony is compatible with new data from unimpaired children suggesting that deferred imitation and high-level OP entail separate and distinctive kinds of memory and representation.

  16. The relationship between attention and deferred imitation in 12-month-old infants.

    Science.gov (United States)

    Zmyj, Norbert; Schölmerich, Axel; Daum, Moritz M

    2017-08-01

    Imitation is a frequent behavior in the first years of life, and serves both a social function (e.g., to interact with others) and a cognitive function (e.g., to learn a new skill). Infants differ in their temperament, and temperament might be related to the dominance of one function of imitation. In this study, we investigated whether temperament and deferred imitation are related in 12-month-old infants. Temperament was measured via the Infant Behavior Questionnaire Revised (IBQ-R) and parts of the Laboratory Temperament Assessment Battery (Lab-TAB). Deferred imitation was measured via the Frankfurt Imitation Test for 12-month-olds (FIT-12). Regression analyses revealed that the duration of orienting (IBQ-R) and the latency of the first look away in the Task Orientation task (Lab-TAB) predicted the infants' imitation score. These results suggest that attention-related processes may play a major role when infants start to imitate. Copyright © 2017 Elsevier Inc. All rights reserved.

  17. Comprehensive Longitudinal Study Challenges the Existence of Neonatal Imitation in Humans.

    Science.gov (United States)

    Oostenbroek, Janine; Suddendorf, Thomas; Nielsen, Mark; Redshaw, Jonathan; Kennedy-Costantini, Siobhan; Davis, Jacqueline; Clark, Sally; Slaughter, Virginia

    2016-05-23

    Human children copy others' actions with high fidelity, supporting early cultural learning and assisting in the development and maintenance of behavioral traditions [1]. Imitation has long been assumed to occur from birth [2-4], with influential theories (e.g., [5-7]) placing an innate imitation module at the foundation of social cognition (potentially underpinned by a mirror neuron system [8, 9]). Yet, the very phenomenon of neonatal imitation has remained controversial. Empirical support is mixed and interpretations are varied [10-16], potentially because previous investigations have relied heavily on cross-sectional designs with relatively small samples and with limited controls [17, 18]. Here, we report surprising results from the most comprehensive longitudinal study of neonatal imitation to date. We presented infants (n = 106) with nine social and two non-social models and scored their responses at 1, 3, 6, and 9 weeks of age. Longitudinal analyses indicated that the infants did not imitate any of the models, as they were just as likely to produce the gestures in response to control models as they were to matching models. Previous positive findings were replicated in limited cross-sections of the data, but the overall analyses confirmed these findings to be mere artifacts of restricted comparison conditions. Our results undermine the idea of an innate imitation module and suggest that earlier studies reporting neonatal imitation were methodologically limited. Copyright © 2016 Elsevier Ltd. All rights reserved.

  18. Phonetic imitation from an individual-difference perspective: subjective attitude, personality and "autistic" traits.

    Science.gov (United States)

    Yu, Alan C L; Abrego-Collier, Carissa; Sonderegger, Morgan

    2013-01-01

    Numerous studies have documented the phenomenon of phonetic imitation: the process by which the production patterns of an individual become more similar on some phonetic or acoustic dimension to those of her interlocutor. Though social factors have been suggested as a motivator for imitation, few studies has established a tight connection between language-external factors and a speaker's likelihood to imitate. The present study investigated the phenomenon of phonetic imitation using a within-subject design embedded in an individual-differences framework. Participants were administered a phonetic imitation task, which included two speech production tasks separated by a perceptual learning task, and a battery of measures assessing traits associated with Autism-Spectrum Condition, working memory, and personality. To examine the effects of subjective attitude on phonetic imitation, participants were randomly assigned to four experimental conditions, where the perceived sexual orientation of the narrator (homosexual vs. heterosexual) and the outcome (positive vs. negative) of the story depicted in the exposure materials differed. The extent of phonetic imitation by an individual is significantly modulated by the story outcome, as well as by the participant's subjective attitude toward the model talker, the participant's personality trait of openness and the autistic-like trait associated with attention switching.

  19. Phonetic imitation from an individual-difference perspective: subjective attitude, personality and "autistic" traits.

    Directory of Open Access Journals (Sweden)

    Alan C L Yu

    Full Text Available Numerous studies have documented the phenomenon of phonetic imitation: the process by which the production patterns of an individual become more similar on some phonetic or acoustic dimension to those of her interlocutor. Though social factors have been suggested as a motivator for imitation, few studies has established a tight connection between language-external factors and a speaker's likelihood to imitate. The present study investigated the phenomenon of phonetic imitation using a within-subject design embedded in an individual-differences framework. Participants were administered a phonetic imitation task, which included two speech production tasks separated by a perceptual learning task, and a battery of measures assessing traits associated with Autism-Spectrum Condition, working memory, and personality. To examine the effects of subjective attitude on phonetic imitation, participants were randomly assigned to four experimental conditions, where the perceived sexual orientation of the narrator (homosexual vs. heterosexual and the outcome (positive vs. negative of the story depicted in the exposure materials differed. The extent of phonetic imitation by an individual is significantly modulated by the story outcome, as well as by the participant's subjective attitude toward the model talker, the participant's personality trait of openness and the autistic-like trait associated with attention switching.

  20. Phonetic Imitation from an Individual-Difference Perspective: Subjective Attitude, Personality and “Autistic” Traits

    Science.gov (United States)

    Yu, Alan C. L.; Abrego-Collier, Carissa; Sonderegger, Morgan

    2013-01-01

    Numerous studies have documented the phenomenon of phonetic imitation: the process by which the production patterns of an individual become more similar on some phonetic or acoustic dimension to those of her interlocutor. Though social factors have been suggested as a motivator for imitation, few studies has established a tight connection between language-external factors and a speaker’s likelihood to imitate. The present study investigated the phenomenon of phonetic imitation using a within-subject design embedded in an individual-differences framework. Participants were administered a phonetic imitation task, which included two speech production tasks separated by a perceptual learning task, and a battery of measures assessing traits associated with Autism-Spectrum Condition, working memory, and personality. To examine the effects of subjective attitude on phonetic imitation, participants were randomly assigned to four experimental conditions, where the perceived sexual orientation of the narrator (homosexual vs. heterosexual) and the outcome (positive vs. negative) of the story depicted in the exposure materials differed. The extent of phonetic imitation by an individual is significantly modulated by the story outcome, as well as by the participant’s subjective attitude toward the model talker, the participant’s personality trait of openness and the autistic-like trait associated with attention switching. PMID:24098665

  1. A Bayesian Developmental Approach to Robotic Goal-Based Imitation Learning.

    Directory of Open Access Journals (Sweden)

    Michael Jae-Yoon Chung

    Full Text Available A fundamental challenge in robotics today is building robots that can learn new skills by observing humans and imitating human actions. We propose a new Bayesian approach to robotic learning by imitation inspired by the developmental hypothesis that children use self-experience to bootstrap the process of intention recognition and goal-based imitation. Our approach allows an autonomous agent to: (i learn probabilistic models of actions through self-discovery and experience, (ii utilize these learned models for inferring the goals of human actions, and (iii perform goal-based imitation for robotic learning and human-robot collaboration. Such an approach allows a robot to leverage its increasing repertoire of learned behaviors to interpret increasingly complex human actions and use the inferred goals for imitation, even when the robot has very different actuators from humans. We demonstrate our approach using two different scenarios: (i a simulated robot that learns human-like gaze following behavior, and (ii a robot that learns to imitate human actions in a tabletop organization task. In both cases, the agent learns a probabilistic model of its own actions, and uses this model for goal inference and goal-based imitation. We also show that the robotic agent can use its probabilistic model to seek human assistance when it recognizes that its inferred actions are too uncertain, risky, or impossible to perform, thereby opening the door to human-robot collaboration.

  2. EEG Mu Rhythm and Imitation Impairments in Individuals with Autism Spectrum Disorder

    Science.gov (United States)

    Bernier, R.; Dawson, G.; Webb, S.; Murias, M.

    2009-01-01

    Imitation ability has consistently been shown to be impaired in individuals with autism. A dysfunctional execution/observation matching system has been proposed to account for this impairment. The EEG mu rhythm is believed to reflect an underlying execution/observation matching system. This study investigated evidence of differential mu rhythm attenuation during the observation, execution, and imitation of movements and examined its relation to behaviorally assessed imitation abilities. Fourteen high-functioning adults with autism spectrum disorder (ASD) and 15 IQ- and age-matched typical adults participated. On the behavioral imitation task, adults with ASD demonstrated significantly poorer performance compared to typical adults in all domains of imitation ability. On the EEG task, both groups demonstrated significant attenuation of the mu rhythm when executing an action. However, when observing movement, the individuals with ASD showed significantly reduced attenuation of the mu wave. Behaviorally assessed imitation skills were correlated with degree of mu wave attenuation during observation of movement. These findings suggest that there is execution/observation matching system dysfunction in individuals with autism and that this matching system is related to degree of impairment in imitation abilities. PMID:17451856

  3. Object words modulate the activity of the mirror neuron system during action imitation.

    Science.gov (United States)

    Wu, Haiyan; Tang, Honghong; Ge, Yue; Yang, Suyong; Mai, Xiaoqin; Luo, Yue-Jia; Liu, Chao

    2017-11-01

    Although research has demonstrated that the mirror neuron system (MNS) plays a crucial role in both action imitation and action-related semantic processing, whether action-related words can inversely modulate the MNS activity remains unclear. Here, three types of task-irrelevant words (body parts, verbs, and manufactured objects) were presented to examine the modulation effect of these words on the MNS activity during action observation and imitation. Twenty-two participants were recruited for the fMRI scanning and remaining data from 19 subjects were reported here. Brain activity results showed that word types elicited different modulation effects over nodes of the MNS (i.e., the right inferior frontal gyrus, premotor cortex, inferior parietal lobule, and STS), especially during the imitation stage. Compared with other word conditions, action imitation following manufactured objects words induced stronger activation in these brain regions during the imitation stage. These results were consistent in both task-dependent and -independent ROI analysis. Our findings thus provide evidence for the unique effect of object words on the MNS during imitation of action, which may also confirm the key role of goal inference in action imitation.

  4. Challenges in adapting imitation and reinforcement learning to compliant robots

    Directory of Open Access Journals (Sweden)

    Calinon Sylvain

    2011-12-01

    Full Text Available There is an exponential increase of the range of tasks that robots are forecasted to accomplish. (Reprogramming these robots becomes a critical issue for their commercialization and for their applications to real-world scenarios in which users without expertise in robotics wish to adapt the robot to their needs. This paper addresses the problem of designing userfriendly human-robot interfaces to transfer skills in a fast and efficient manner. This paper presents recent work conducted at the Learning and Interaction group at ADVR-IIT, ranging from skill acquisition through kinesthetic teaching to self-refinement strategies initiated from demonstrations. Our group started to explore the use of imitation and exploration strategies that can take advantage of the compliant capabilities of recent robot hardware and control architectures.

  5. Media influenced imitative hanging: a report from West Bengal.

    Science.gov (United States)

    Chowdhury, A N; Brahma, A; Banerjee, S; Biswas, M K

    2007-01-01

    Media influences behaviour, especially of the young children and adolescents in various ways. The present study examined the media coverage of a judicial hanging and its immediate social effect. In a qualitative study the media coverage of a case of a judicial hanging was thoroughly discussed and the media influence, for over a period of ten weeks of the incident, in terms of suicide and copying of hanging among children, was collected and analysed. Eighteen cases were reported as an aftermath of this hanging: 1 suicide and 17 imitative hanging in children with 5 deaths. This report calls for attention that media should be cautious and responsible in presenting the news items that have potential social impact.

  6. Motion Imitation and Recognition using Parametric Hidden Markov Models

    DEFF Research Database (Denmark)

    Herzog, Dennis; Ude, Ales; Krüger, Volker

    2008-01-01

    ) are important. Only together they convey the whole meaning of an action. Similarly, to imitate a movement, the robot needs to select the proper action and parameterize it, e.g., by the relative position of the object that needs to be grasped. We propose to utilize parametric hidden Markov models (PHMMs), which...... extend the classical HMMs by introducing a joint parameterization of the observation densities, to simultaneously solve the problems of action recognition, parameterization of the observed actions, and action synthesis. The proposed approach was fully implemented on a humanoid robot HOAP-3. To evaluate...... the approach, we focused on reaching and pointing actions. Even though the movements are very similar in appearance, our approach is able to distinguish the two movement types and discover the parameterization, and is thus enabling both, action recognition and action synthesis. Through parameterization we...

  7. Beyond rational imitation: learning arbitrary means actions from communicative demonstrations.

    Science.gov (United States)

    Király, Ildikó; Csibra, Gergely; Gergely, György

    2013-10-01

    The principle of rationality has been invoked to explain that infants expect agents to perform the most efficient means action to attain a goal. It has also been demonstrated that infants take into account the efficiency of observed actions to achieve a goal outcome when deciding whether to reenact a specific behavior or not. It is puzzling, however, that they also tend to imitate an apparently suboptimal unfamiliar action even when they can bring about the same outcome more efficiently by applying a more rational action alternative available to them. We propose that this apparently paradoxical behavior is explained by infants' interpretation of action demonstrations as communicative manifestations of novel and culturally relevant means actions to be acquired, and we present empirical evidence supporting this proposal. In Experiment 1, we found that 14-month-olds reenacted novel arbitrary means actions only following a communicative demonstration. Experiment 2 showed that infants' inclination to reproduce communicatively manifested novel actions is restricted to behaviors they can construe as goal-directed instrumental acts. The study also provides evidence that infants' reenactment of the demonstrated novel actions reflects epistemic motives rather than purely social motives. We argue that ostensive communication enables infants to represent the teleological structure of novel actions even when the causal relations between means and end are cognitively opaque and apparently violate the efficiency expectation derived from the principle of rationality. This new account of imitative learning of novel means shows how the teleological stance and natural pedagogy--two separate cognitive adaptations to interpret instrumental versus communicative actions--are integrated as a system for learning socially constituted instrumental knowledge in humans. Copyright © 2013 Elsevier Inc. All rights reserved.

  8. Rethinking conformity and imitation: divergence, convergence, and social understanding

    Directory of Open Access Journals (Sweden)

    Bert eHodges

    2014-07-01

    Full Text Available Social and developmental psychologists have stressed the pervasiveness and strength of humans’ tendencies to conform and to imitate, and social anthropologists have argued that these tendencies are crucial to the formation of cultures. Research from four domains is reviewed and elaborated to show that divergence is also pervasive and potent, and is interwoven with convergence in a complex set of dynamics that is often unnoticed or minimized. First, classic research in social conformity is reinterpreted in terms of truth, trust, and social solidarity, revealing that dissent is its most salient feature. Second, recent studies of children’s use of testimony to guide action reveal a surprisingly sophisticated balance of trust and prudence, and a concern for truth and charity. Third, new experiments indicate that people diverge from others even under conditions where conformity seems assured. Fourth, current studies of imitation provide strong evidence that children are both selective and faithful in who, what, and why they follow others. All of the evidence reviewed points toward children and adults as being engaged, embodied partners with others, motivated to learn and understand the world, others, and themselves in ways that go beyond goals and rules, prediction and control. Even young children act as if they are in a dialogical relationship with others and the world, rather than acting as if they are solo explorers or blind followers. Overall, the evidence supports the hypothesis that social understanding cannot be reduced to convergence or divergence, but includes ongoing activities that seek greater comprehensiveness and complexity in the ability to act and interact effectively, appropriately, and with integrity.

  9. Rethinking conformity and imitation: divergence, convergence, and social understanding.

    Science.gov (United States)

    Hodges, Bert H

    2014-01-01

    Social and developmental psychologists have stressed the pervasiveness and strength of humans' tendencies to conform and to imitate, and social anthropologists have argued that these tendencies are crucial to the formation of cultures. Research from four domains is reviewed and elaborated to show that divergence is also pervasive and potent, and it is interwoven with convergence in a complex set of dynamics that is often unnoticed or minimized. First, classic research in social conformity is reinterpreted in terms of truth, trust, and social solidarity, revealing that dissent is its most salient feature. Second, recent studies of children's use of testimony to guide action reveal a surprisingly sophisticated balance of trust and prudence, and a concern for truth and charity. Third, new experiments indicate that people diverge from others even under conditions where conformity seems assured. Fourth, current studies of imitation provide strong evidence that children are both selective and faithful in who, what, and why they follow others. All of the evidence reviewed points toward children and adults as being engaged, embodied partners with others, motivated to learn and understand the world, others, and themselves in ways that go beyond goals and rules, prediction and control. Even young children act as if they are in a dialogical relationship with others and the world, rather than acting as if they are solo explorers or blind followers. Overall, the evidence supports the hypothesis that social understanding cannot be reduced to convergence or divergence, but includes ongoing activities that seek greater comprehensiveness and complexity in the ability to act and interact effectively, appropriately, and with integrity.

  10. Influence of Action-Effect Associations Acquired by Ideomotor Learning on Imitation

    Science.gov (United States)

    Bunlon, Frédérique; Marshall, Peter J.; Quandt, Lorna C.; Bouquet, Cedric A.

    2015-01-01

    According to the ideomotor theory, actions are represented in terms of their perceptual effects, offering a solution for the correspondence problem of imitation (how to translate the observed action into a corresponding motor output). This effect-based coding of action is assumed to be acquired through action-effect learning. Accordingly, performing an action leads to the integration of the perceptual codes of the action effects with the motor commands that brought them about. While ideomotor theory is invoked to account for imitation, the influence of action-effect learning on imitative behavior remains unexplored. In two experiments, imitative performance was measured in a reaction time task following a phase of action-effect acquisition. During action-effect acquisition, participants freely executed a finger movement (index or little finger lifting), and then observed a similar (compatible learning) or a different (incompatible learning) movement. In Experiment 1, finger movements of left and right hands were presented as action-effects during acquisition. In Experiment 2, only right-hand finger movements were presented during action-effect acquisition and in the imitation task the observed hands were oriented orthogonally to participants’ hands in order to avoid spatial congruency effects. Experiments 1 and 2 showed that imitative performance was improved after compatible learning, compared to incompatible learning. In Experiment 2, although action-effect learning involved perception of finger movements of right hand only, imitative capabilities of right- and left-hand finger movements were equally affected. These results indicate that an observed movement stimulus processed as the effect of an action can later prime execution of that action, confirming the ideomotor approach to imitation. We further discuss these findings in relation to previous studies of action-effect learning and in the framework of current ideomotor approaches to imitation. PMID:25793755

  11. Direct and octave-shifted pitch matching during nonword imitations in men, women, and children.

    Science.gov (United States)

    Peter, Beate; Foster, Bronsyn; Haas, Heather; Middleton, Kyle; McKibben, Kiersten

    2015-03-01

    To evaluate whether children, women, and men match the speaker's fundamental frequency (F0) during nonword imitation directly when the target F0 is within the responders' vocal ranges and at octave-shifted levels when the target is outside their vocal ranges, and to evaluate the role of a history of speech sound disorder (SSD) in the adult participants. Observational. Nonword sets spoken by a man and a woman were imitated by 14 men, 21 women, and 19 children. Approximately half of the adults and two-thirds of the children had a history of SSD. F0 in the imitations was compared with that in the targets and in the participants' nonimitated control word productions. When the target F0 was within the responders' vocal ranges, the imitations approximated the target F0. Men imitating a woman's voice approximated F0 levels one octave below the target F0. Children imitating a man's voice approximated F0 levels one octave above the target F0. Women imitating a man's voice approximated the target F0 at a ratio of 1.5 known as the perfect fifth in music. A history of SSD did not influence the results. This study replicates previous findings showing that target F0 was a salient aspect of the stimuli that was imitated along with the targets' segmental and prosodic components without explicit prompting. It is the first to show F0 convergence not only directly but also at relevant target/imitation intervals including the octave interval. Copyright © 2015 The Voice Foundation. Published by Elsevier Inc. All rights reserved.

  12. The dynamics of general developmental mechanisms : From Piaget and Vygotsky to dynamic systems models

    NARCIS (Netherlands)

    van Geert, P

    Dynamic systems theory conceives of development as a self-organizational process. Both complexity and order emerge as a product of elementary principles of interaction between components involved in the developmental process. This article presents a dynamic systems model based on a general dual

  13. Selective Short-Term Memory Deficits Arise from Impaired Domain-General Semantic Control Mechanisms

    Science.gov (United States)

    Hoffman, Paul; Jefferies, Elizabeth; Ehsan, Sheeba; Hopper, Samantha; Lambon Ralph, Matthew A.

    2009-01-01

    Semantic short-term memory (STM) patients have a reduced ability to retain semantic information over brief delays but perform well on other semantic tasks; this pattern suggests damage to a dedicated buffer for semantic information. Alternatively, these difficulties may arise from mild disruption to domain-general semantic processes that have…

  14. Midlatitude Forcing Mechanisms for Glacier Mass Balance Investigated Using General Circulation Models

    NARCIS (Netherlands)

    Reichert, B.K.; Bengtsson, L.; Oerlemans, J.

    2001-01-01

    A process-oriented modeling approach is applied in order to simulate glacier mass balance for individual glaciers using statistically downscaled general circulation models (GCMs). Glacier-specific seasonal sensitivity characteristics based on a mass balance model of intermediate complexity are used

  15. Generalization of the Activated Complex Theory of Reaction Rates. II. Classical Mechanical Treatment

    Science.gov (United States)

    Marcus, R. A.

    1964-01-01

    In its usual classical form activated complex theory assumes a particular expression for the kinetic energy of the reacting system -- one associated with a rectilinear motion along the reaction coordinate. The derivation of the rate expression given in the present paper is based on the general kinetic energy expression.

  16. Generalization of the Peierls-Bogolyubov inequality by means of a quantum-mechanical variational principle

    International Nuclear Information System (INIS)

    Soldatov, A.V.

    2000-01-01

    The Peierls-Bogolyubov inequality was generalized and a set of inequalities was derived instead, so that every subsequent inequality in this set approximates the quality in question with better precision than the preceding one. These inequalities lead to a sequence of improving upper bounds to the free energy of a quantum system if this system allows representation in terms of coherent states [ru

  17. The general mechanisms of Cu cluster formation in the processes of ...

    Indian Academy of Sciences (India)

    Sci., Vol. 38, No. 3, June 2015, pp. 701–706. c Indian Academy of Sciences. ... This work represents the basic mechanisms of cluster formation from the gas phase that has been ... required, or in catalytic reactions, where the main factor of effectiveness is the .... ature of liquid nitrogen (77 K), which is used in real exper-.

  18. A cross-cultural comparison of the development of the social smile: a longitudinal study of maternal and infant imitation in 6- and 12-week-old infants.

    Science.gov (United States)

    Wörmann, Viktoriya; Holodynski, Manfred; Kärtner, Joscha; Keller, Heidi

    2012-06-01

    Social smiling is universally regarded as being an infant's first facial expression of pleasure. Underlying co-constructivist emotion theories are the assumptions that the emergence of social smiling is bound to experiences of face-to-face interactions with caregivers and the impact of two developmental mechanisms--maternal and infant imitation. We analyzed mother-infant interactions from two different socio-cultural contexts and hypothesized that cross-cultural differences in face-to-face interactions determine the occurrence of both of these mechanisms and of the frequency of social smiling by 12-week-old infants. Twenty mother-infant dyads from a socio-cultural community with many face-to-face interactions (German families, Münster) were compared with 24 mother-infant dyads from a socio-cultural community with few such interactions (rural Nso families, Cameroon) when the infants were aged 6 and 12 weeks. When infants were 6 weeks old, mothers and their infants from both cultural communities smiled at each other for similar (albeit very short) amounts of time and used imitated each other's smiling similarly rarely. In contrast, when infants were 12 weeks old, mothers and their infants from Münster smiled at and imitated each other more often than did Nso mothers and their infants. Copyright © 2012 Elsevier Inc. All rights reserved.

  19. Selection, integration, and conflict monitoring; assessing the nature and generality of prefrontal cognitive control mechanisms.

    Science.gov (United States)

    Badre, David; Wagner, Anthony D

    2004-02-05

    Prefrontal cortex (PFC) supports flexible behavior by mediating cognitive control, though the elemental forms of control supported by PFC remain a central debate. Dorsolateral PFC (DLPFC) is thought to guide response selection under conditions of response conflict or, alternatively, may refresh recently active representations within working memory. Lateral frontopolar cortex (FPC) may also adjudicate response conflict, though others propose that FPC supports higher order control processes such as subgoaling and integration. Anterior cingulate cortex (ACC) is hypothesized to upregulate response selection by detecting response conflict; it remains unclear whether ACC functions generalize beyond monitoring response conflict. The present fMRI experiment directly tested these competing theories regarding the functional roles of DLPFC, FPC, and ACC. Results reveal dissociable control processes in PFC, with mid-DLPFC selectively mediating resolution of response conflict and FPC further mediating subgoaling/integration. ACC demonstrated a broad sensitivity to control demands, suggesting a generalized role in modulating cognitive control.

  20. Approaching the Shockley-Queisser limit: General assessment of the main limiting mechanisms in photovoltaic cells

    International Nuclear Information System (INIS)

    Vossier, Alexis; Gualdi, Federico; Dollet, Alain; Ares, Richard; Aimez, Vincent

    2015-01-01

    In principle, the upper efficiency limit of any solar cell technology can be determined using the detailed-balance limit formalism. However, “real” solar cells show efficiencies which are always below this theoretical value due to several limiting mechanisms. We study the ability of a solar cell architecture to approach its own theoretical limit, using a novel index introduced in this work, and the amplitude with which the different limiting mechanisms affect the cell efficiency is scrutinized as a function of the electronic gap and the illumination level to which the cell is submitted. The implications for future generations of solar cells aiming at an improved conversion of the solar spectrum are also addressed

  1. Pure states of general quantum-mechanical systems as Kaehler bundles

    International Nuclear Information System (INIS)

    Abbati, M.C.; Cirelli, R.; Lanzavecchia, P.; Mania, A.

    1984-01-01

    Pure states of general quantum systems in the Csup(*)-algebraic approach are endowed with a structure both of Kaehler manifold and of projective bundle with uniformity on the total space. The former structure gives a geometric interpretation of transition probabilities and Wigner theorem. The latter is a finer structure which determines Csup(*)-algebras up to sup(*)-isomorphisms. Pure states of Csup(*)-algebras with continuous trace among projective bundles with uniformity are characterized

  2. Water, Resilience and the Law: From General Concepts and Governance Design Principles to Actionable Mechanisms

    Science.gov (United States)

    Hill Clarvis, M.; Allan, A.; Hannah, D. M.

    2013-12-01

    Climate change has significant ramifications for water law and governance, yet, there is strong evidence that legal regulations have often failed to protect environments or promote sustainable development. Scholars have increasingly suggested that the preservation and restoration paradigms of legislation and regulation are no longer adequate for climate change related challenges in complex and cross-scale social-ecological systems. This is namely due to past assumptions of stationarity, uniformitarianism and the perception of ecosystem change as predictable and reversible. This paper reviews the literature on law and resilience and then presents and discusses a set of practical examples of legal mechanisms from the water resources management sector, identified according to a set of guiding principles from the literature on adaptive capacity, adaptive governance as well as adaptive and integrated water resources management. It then assesses the aptness of these different measures according to scientific evidence of increased uncertainty and changing ecological baselines. A review of the best practice examples demonstrates that there are a number of best practice examples attempting to integrate adaptive elements of flexibility, iterativity, connectivity and subsidiarity into a variety of legislative mechanisms, suggesting that there is not as significant a tension between resilience and the law as many scholars have suggested. However, while many of the mechanisms may indeed be suitable for addressing challenges relating to current levels of change and uncertainty, analysis across a broader range of uncertainty highlights challenges relating to more irreversible changes associated with greater levels of warming. Furthermore the paper identifies a set of pre-requisites that are fundamental to the successful implementation of such mechanisms, namely monitoring and data sharing, financial and technical capacity, particularly in nations that are most at risk with the

  3. The Biology of Atherosclerosis: General Paradigms and Distinct Pathogenic Mechanisms Among HIV-Infected Patients

    OpenAIRE

    Lo, Janet; Plutzky, Jorge

    2012-01-01

    Complications of atherosclerosis, including myocardial infarction and stroke, are the leading cause of death and disability worldwide. Recent data strongly implicate cardiovascular death as a contributor to mortality among patients with human immunodeficiency virus (HIV) infection, with evidence suggesting increased incidence of atherosclerosis among these patients. Therefore, greater understanding of atherosclerotic mechanisms and how these responses may be similar or distinct in HIV-infecte...

  4. A general mechanism for intracellular toxicity of metal-containing nanoparticles

    KAUST Repository

    Sabella, Stefania

    2014-04-09

    The assessment of the risks exerted by nanoparticles is a key challenge for academic, industrial, and regulatory communities worldwide. Experimental evidence points towards significant toxicity for a range of nanoparticles both in vitro and in vivo. Worldwide efforts aim at uncovering the underlying mechanisms for this toxicity. Here, we show that the intracellular ion release elicited by the acidic conditions of the lysosomal cellular compartment-where particles are abundantly internalized-is responsible for the cascading events associated with nanoparticles-induced intracellular toxicity. We call this mechanism a "lysosome-enhanced Trojan horse effect" since, in the case of nanoparticles, the protective cellular machinery designed to degrade foreign objects is actually responsible for their toxicity. To test our hypothesis, we compare the toxicity of similar gold particles whose main difference is in the internalization pathways. We show that particles known to pass directly through cell membranes become more toxic when modified so as to be mostly internalized by endocytosis. Furthermore, using experiments with chelating and lysosomotropic agents, we found that the toxicity mechanism for different metal containing NPs (such as metallic, metal oxide, and semiconductor NPs) is mainly associated with the release of the corresponding toxic ions. Finally, we show that particles unable to release toxic ions (such as stably coated NPs, or diamond and silica NPs) are not harmful to intracellular environments. The Royal Society of Chemistry 2014.

  5. A general mechanism for intracellular toxicity of metal-containing nanoparticles

    KAUST Repository

    Sabella, Stefania; Carney, Randy P.; Brunetti, Virgilio; Malvindi, Maria Ada; Al-Juffali, Noura; Vecchio, Giuseppe; Janes, Sam M.; Bakr, Osman; Cingolani, Roberto; Stellacci, Francesco; Pompa, Pier Paolo

    2014-01-01

    The assessment of the risks exerted by nanoparticles is a key challenge for academic, industrial, and regulatory communities worldwide. Experimental evidence points towards significant toxicity for a range of nanoparticles both in vitro and in vivo. Worldwide efforts aim at uncovering the underlying mechanisms for this toxicity. Here, we show that the intracellular ion release elicited by the acidic conditions of the lysosomal cellular compartment-where particles are abundantly internalized-is responsible for the cascading events associated with nanoparticles-induced intracellular toxicity. We call this mechanism a "lysosome-enhanced Trojan horse effect" since, in the case of nanoparticles, the protective cellular machinery designed to degrade foreign objects is actually responsible for their toxicity. To test our hypothesis, we compare the toxicity of similar gold particles whose main difference is in the internalization pathways. We show that particles known to pass directly through cell membranes become more toxic when modified so as to be mostly internalized by endocytosis. Furthermore, using experiments with chelating and lysosomotropic agents, we found that the toxicity mechanism for different metal containing NPs (such as metallic, metal oxide, and semiconductor NPs) is mainly associated with the release of the corresponding toxic ions. Finally, we show that particles unable to release toxic ions (such as stably coated NPs, or diamond and silica NPs) are not harmful to intracellular environments. The Royal Society of Chemistry 2014.

  6. Crystallographic studies with xenon and nitrous oxide provide evidence for protein-dependent processes in the mechanisms of general anesthesia.

    Science.gov (United States)

    Abraini, Jacques H; Marassio, Guillaume; David, Helene N; Vallone, Beatrice; Prangé, Thierry; Colloc'h, Nathalie

    2014-11-01

    The mechanisms by which general anesthetics, including xenon and nitrous oxide, act are only beginning to be discovered. However, structural approaches revealed weak but specific protein-gas interactions. To improve knowledge, we performed x-ray crystallography studies under xenon and nitrous oxide pressure in a series of 10 binding sites within four proteins. Whatever the pressure, we show (1) hydrophobicity of the gas binding sites has a screening effect on xenon and nitrous oxide binding, with a threshold value of 83% beyond which and below which xenon and nitrous oxide, respectively, binds to their sites preferentially compared to each other; (2) xenon and nitrous oxide occupancies are significantly correlated respectively to the product and the ratio of hydrophobicity by volume, indicating that hydrophobicity and volume are binding parameters that complement and oppose each other's effects; and (3) the ratio of occupancy of xenon to nitrous oxide is significantly correlated to hydrophobicity of their binding sites. These data demonstrate that xenon and nitrous oxide obey different binding mechanisms, a finding that argues against all unitary hypotheses of narcosis and anesthesia, and indicate that the Meyer-Overton rule of a high correlation between anesthetic potency and solubility in lipids of general anesthetics is often overinterpreted. This study provides evidence that the mechanisms of gas binding to proteins and therefore of general anesthesia should be considered as the result of a fully reversible interaction between a drug ligand and a receptor as this occurs in classical pharmacology.

  7. A general mechanism for intracellular toxicity of metal-containing nanoparticles

    Science.gov (United States)

    Sabella, Stefania; Carney, Randy P.; Brunetti, Virgilio; Malvindi, Maria Ada; Al-Juffali, Noura; Vecchio, Giuseppe; Janes, Sam M.; Bakr, Osman M.; Cingolani, Roberto; Stellacci, Francesco; Pompa, Pier Paolo

    2014-05-01

    The assessment of the risks exerted by nanoparticles is a key challenge for academic, industrial, and regulatory communities worldwide. Experimental evidence points towards significant toxicity for a range of nanoparticles both in vitro and in vivo. Worldwide efforts aim at uncovering the underlying mechanisms for this toxicity. Here, we show that the intracellular ion release elicited by the acidic conditions of the lysosomal cellular compartment - where particles are abundantly internalized - is responsible for the cascading events associated with nanoparticles-induced intracellular toxicity. We call this mechanism a ``lysosome-enhanced Trojan horse effect'' since, in the case of nanoparticles, the protective cellular machinery designed to degrade foreign objects is actually responsible for their toxicity. To test our hypothesis, we compare the toxicity of similar gold particles whose main difference is in the internalization pathways. We show that particles known to pass directly through cell membranes become more toxic when modified so as to be mostly internalized by endocytosis. Furthermore, using experiments with chelating and lysosomotropic agents, we found that the toxicity mechanism for different metal containing NPs (such as metallic, metal oxide, and semiconductor NPs) is mainly associated with the release of the corresponding toxic ions. Finally, we show that particles unable to release toxic ions (such as stably coated NPs, or diamond and silica NPs) are not harmful to intracellular environments.The assessment of the risks exerted by nanoparticles is a key challenge for academic, industrial, and regulatory communities worldwide. Experimental evidence points towards significant toxicity for a range of nanoparticles both in vitro and in vivo. Worldwide efforts aim at uncovering the underlying mechanisms for this toxicity. Here, we show that the intracellular ion release elicited by the acidic conditions of the lysosomal cellular compartment - where

  8. The biology of atherosclerosis: general paradigms and distinct pathogenic mechanisms among HIV-infected patients.

    Science.gov (United States)

    Lo, Janet; Plutzky, Jorge

    2012-06-01

    Complications of atherosclerosis, including myocardial infarction and stroke, are the leading cause of death and disability worldwide. Recent data strongly implicate cardiovascular death as a contributor to mortality among patients with human immunodeficiency virus (HIV) infection, with evidence suggesting increased incidence of atherosclerosis among these patients. Therefore, greater understanding of atherosclerotic mechanisms and how these responses may be similar or distinct in HIV-infected patients is needed. Key concepts in atherosclerosis are reviewed, including the evidence that inflammation and abnormal metabolism are major drivers of atherosclerosis, and connected to the current literature regarding atherosclerosis in the context of HIV.

  9. Molecular Mechanisms of Diabetic Retinopathy, General Preventive Strategies, and Novel Therapeutic Targets

    Science.gov (United States)

    Safi, Sher Zaman; Kumar, Selva; Ismail, Ikram Shah Bin

    2014-01-01

    The growing number of people with diabetes worldwide suggests that diabetic retinopathy (DR) and diabetic macular edema (DME) will continue to be sight threatening factors. The pathogenesis of diabetic retinopathy is a widespread cause of visual impairment in the world and a range of hyperglycemia-linked pathways have been implicated in the initiation and progression of this condition. Despite understanding the polyol pathway flux, activation of protein kinase C (KPC) isoforms, increased hexosamine pathway flux, and increased advanced glycation end-product (AGE) formation, pathogenic mechanisms underlying diabetes induced vision loss are not fully understood. The purpose of this paper is to review molecular mechanisms that regulate cell survival and apoptosis of retinal cells and discuss new and exciting therapeutic targets with comparison to the old and inefficient preventive strategies. This review highlights the recent advancements in understanding hyperglycemia-induced biochemical and molecular alterations, systemic metabolic factors, and aberrant activation of signaling cascades that ultimately lead to activation of a number of transcription factors causing functional and structural damage to retinal cells. It also reviews the established interventions and emerging molecular targets to avert diabetic retinopathy and its associated risk factors. PMID:25105142

  10. Recent developments in counterfeits and imitations of Viagra, Cialis and Levitra. A 2005-2006 update

    NARCIS (Netherlands)

    Venhuis BJ; Barends DM; Zwaagstra ME; Kaste D de; Douane Laboratorium; KCF

    2007-01-01

    A strong trend is observed towards increasingly professional counterfeits and imitations of Viagra, Cialis and Levitra, with regard to the appearance of tablets, capsules and packaging. The professional presentation will deceive potential consumers into assuming these products are legal, efficacious

  11. Laboratory studies of imitation/field studies of tradition: towards a synthesis in animal social learning.

    Science.gov (United States)

    Galef, Bennett G

    2015-03-01

    Here I discuss: (1) historical precedents that have resulted in comparative psychologists accepting the two-action method as the "gold standard" in laboratory investigations of imitation learning, (2) evidence suggesting that the two-action procedure may not be adequate to answer questions concerning the role of imitation in the development of traditional behaviors of animals living in natural habitat, and (3) an alternative approach to the laboratory study of imitation that might increase the relevance of laboratory studies of imitation to the work of behavioral ecologists/primatologists interested in animal traditions and their relationship to human cumulative culture. This article is part of a Special Issue entitled: Tribute to Tom Zentall. Copyright © 2014 Elsevier B.V. All rights reserved.

  12. The Gesture Imitation in Alzheimer's Disease Dementia and Amnestic Mild Cognitive Impairment.

    Science.gov (United States)

    Li, Xudong; Jia, Shuhong; Zhou, Zhi; Hou, Chunlei; Zheng, Wenjing; Rong, Pei; Jiao, Jinsong

    2016-07-14

    Alzheimer's disease dementia (ADD) has become an important health problem in the world. Visuospatial deficits are considered to be an early symptom besides memory disorder. The gesture imitation test was devised to detect ADD and amnestic mild cognitive impairment (aMCI). A total of 117 patients with ADD, 118 with aMCI, and 95 normal controls were included in this study. All participants were administered our gesture imitation test, the Mini-Mental State Examination (MMSE), the Montreal Cognitive Assessment (MoCA), the Clock Drawing Test (CDT), and the Clinical Dementia Rating Scale (CDR). Patients with ADD performed worse than normal controls on global scores and had a lower success rate on every item (p imitation test scores were positively correlated with the MMSE (r = 0.637, p imitation test is an easy, rapid tool for detecting ADD, and is suitable for the patients suspected of mild ADD and aMCI in outpatient clinics.

  13. Preserved Imitation of Known Gestures in Children with High-Functioning Autism

    Science.gov (United States)

    Carmo, Joana C.; Rumiati, Raffaella I.; Siugzdaite, Roma; Brambilla, Paolo

    2013-01-01

    It has been suggested that children with autism are particularly deficient at imitating novel gestures or gestures without goals. In the present study, we asked high-functioning autistic children and age-matched typically developing children to imitate several types of gestures that could be either already known or novel to them. Known gestures either conveyed a communicative meaning (i.e., intransitive) or involved the use of objects (i.e., transitive). We observed a significant interaction between gesture type and group of participants, with children with autism performing known gestures better than novel gestures. However, imitation of intransitive and transitive gestures did not differ across groups. These findings are discussed in light of a dual-route model for action imitation. PMID:24062956

  14. Statistical imitation system using relational interest points and Gaussian mixture models

    CSIR Research Space (South Africa)

    Claassens, J

    2009-11-01

    Full Text Available The author proposes an imitation system that uses relational interest points (RIPs) and Gaussian mixture models (GMMs) to characterize a behaviour. The system's structure is inspired by the Robot Programming by Demonstration (RDP) paradigm...

  15. Imitative Modeling as a Theoretical Base for Instructing Language-Disordered Children

    Science.gov (United States)

    Courtright, John A.; Courtright, Illene C.

    1976-01-01

    A modification of A. Bandura's social learning theory (imitative modeling) was employed as a theoretical base for language instruction with eight language disordered children (5 to 10 years old). (Author/SBH)

  16. Investigation of migration an actinide imitator (Ce) in synthesis glass ceramics with a nuclear microscope

    International Nuclear Information System (INIS)

    Bondarenko, V.N.; Goncharov, A.V.; Odejchuk, M.A.; Pistryak, V.M.; Pilipenko, A.V.; Sank, S.Yu.; Sukhostaeva, V.I.; Shevstiev, A.P.

    2005-01-01

    Full text: The generally accepted conception of radioactive waste (RAW) safe disposal, so-called 'multibarrier strategy', assumes construction of several protective barriers in a geologic burial. One of these barriers is is a durable corrosion-resistant container of RAW. The glass ceramics (syntetic alumina silicate) is considered as promising material for such containers. An important parameter for long term reduction of behavior for such materials is rate of radionuclide emanation from the container. As an element whose migration in solids is analogous as that of actinide, one generally uses Cerium. For investigation of transuranium element migration Ce is used as an analogue. Accordingly, CeO 2 may serve as an imitator of transuranium oxides. In the present work Ce migration in glass ceramics has been investigated with a nuclear microprobe which is more sensitive instrument than an electron microscope. The glass ceramic material was prepared from mixture of materials powders (70 % mas. of red granite and 30% mas. of kaolin) by sintering under pressure. The hot pressing was conducted at 1050 deg. temperature and 40 MPa pressure. The endurance time continued 15 min. Manufactured alumina silicate samples were in the form of a pellet. The material density was 2.5-2.7 g/cm 3 . Pellets of imitator substance were made of CeO 2 powder by the same method. After polishing, aluminosilicate and imitator pellets were pressed together and annealed in the temperature range from 600 to 750 deg. C in vacuum during 10 hours. As a result of annealing, Ce penetration occurred thought the interface into the depth of the alumina silicate pellet. After that the pellets were separated, and the alumina silicate pellet was cleaved in the direction transversal to the former interface. The surface of cleavage of alumina silicate pellet was studied with a nuclear microprobe. For measurement of Ce diffusion distribution in alumina silicate samples we applied a nuclear microprobe on the basis

  17. The general theory of the mechanical, electromagnetic and thermodynamic properties of black holes

    International Nuclear Information System (INIS)

    Carter, B.

    1979-01-01

    The introductory section includes a brief account of the basic mathematical concept of a black hole in a general dynamical context. This is followed by a more detailed examination of the properties of the horizon with particular reference to situations in which the black hole is allowed to tend asymptotically towards a stationary final equilibrium state. A more specialized description is then provided of the properties of the horizon in an exactly stationary state. Quasi-stationary states are next considered. The mass of a black hole is discussed. The final section summarizes the results that provide the justification for the belief that a stationary, asymptotically flat black hole state is fully determined by its mass and angular momentum when external matter and fields are absent, or by its mass, angular momentum, and electric charge if electromagnetic fields are allowed for. (U.K.)

  18. Adsorbate-induced lifting of substrate relaxation is a general mechanism governing titania surface chemistry.

    Science.gov (United States)

    Silber, David; Kowalski, Piotr M; Traeger, Franziska; Buchholz, Maria; Bebensee, Fabian; Meyer, Bernd; Wöll, Christof

    2016-09-30

    Under ambient conditions, almost all metals are coated by an oxide. These coatings, the result of a chemical reaction, are not passive. Many of them bind, activate and modify adsorbed molecules, processes that are exploited, for example, in heterogeneous catalysis and photochemistry. Here we report an effect of general importance that governs the bonding, structure formation and dissociation of molecules on oxidic substrates. For a specific example, methanol adsorbed on the rutile TiO 2 (110) single crystal surface, we demonstrate by using a combination of experimental and theoretical techniques that strongly bonding adsorbates can lift surface relaxations beyond their adsorption site, which leads to a significant substrate-mediated interaction between adsorbates. The result is a complex superstructure consisting of pairs of methanol molecules and unoccupied adsorption sites. Infrared spectroscopy reveals that the paired methanol molecules remain intact and do not deprotonate on the defect-free terraces of the rutile TiO 2 (110) surface.

  19. Effect of initial bulk density on high-solids anaerobic digestion of MSW: General mechanism.

    Science.gov (United States)

    Caicedo, Luis M; Wang, Hongtao; Lu, Wenjing; De Clercq, Djavan; Liu, Yanjun; Xu, Sai; Ni, Zhe

    2017-06-01

    Initial bulk density (IBD) is an important variable in anaerobic digestion since it defines and optimizes the treatment capacity of a system. This study reveals the mechanism on how IBD might affect anaerobic digestion of waste. Four different IBD values: D 1 (500-700kgm -3 ), D 2 (900-1000kgm -3 ), D 3 (1100-1200kgm -3 ) and D 4 (1200-1400kgm -3 ) were set and tested over a period of 90days in simulated landfill reactors. The main variables affected by the IBD are the methane generation, saturation degree, extraction of organic matter, and the total population of methanogens. The study identified that IBD >1000kgm -3 may have significant effect on methane generation, either prolonging the lag time or completely inhibiting the process. This study provides a new understanding of the anaerobic digestion process in saturated high-solids systems. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. A general approach for controlling transcription and probing epigenetic mechanisms: application to the CD4 locus.

    Science.gov (United States)

    Wan, Mimi; Kaundal, Ravinder; Huang, Haichang; Zhao, Jiugang; Yang, Xiaojun; Chaiyachati, Barbara H; Li, Sicong; Chi, Tian

    2013-01-15

    Synthetic regulatory proteins such as tetracycline (tet)-controlled transcription factors are potentially useful for repression as well as ectopic activation of endogenous genes and also for probing their regulatory mechanisms, which would offer a versatile genetic tool advantageous over conventional gene targeting methods. In this study, we provide evidence supporting this concept using Cd4 as a model. CD4 is expressed in double-positive and CD4 cells but irreversibly silenced in CD8 cells. The silencing is mediated by heterochromatin established during CD8 lineage development via transient action of the Cd4 silencer; once established, the heterochromatin becomes self-perpetuating independently of the Cd4 silencer. Using a tet-sensitive Cd4 allele harboring a removable Cd4 silencer, we found that a tet-controlled repressor recapitulated the phenotype of Cd4-deficient mice, inhibited Cd4 expression in a reversible and dose-dependent manner, and could surprisingly replace the Cd4 silencer to induce irreversible Cd4 silencing in CD8 cells, thus suggesting the Cd4 silencer is not the (only) determinant of heterochromatin formation. In contrast, a tet-controlled activator reversibly disrupted Cd4 silencing in CD8 cells. The Cd4 silencer impeded this disruption but was not essential for its reversal, which revealed a continuous role of the silencer in mature CD8 cells while exposing a remarkable intrinsic self-regenerative ability of heterochromatin after forced disruption. These data demonstrate an effective approach for gene manipulation and provide insights into the epigenetic Cd4 regulatory mechanisms that are otherwise difficult to obtain.