Automatic Imitation

ERIC Educational Resources Information Center

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"…

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

PubMed

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.

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

PubMed

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.

Imitation as behaviour parsing.

PubMed Central

Byrne, R W

2003-01-01

Non-human great apes appear to be able to acquire elaborate skills partly by imitation, raising the possibility of the transfer of skill by imitation in animals that have only rudimentary mentalizing capacities: in contrast to the frequent assumption that imitation depends on prior understanding of others' intentions. Attempts to understand the apes' behaviour have led to the development of a purely mechanistic model of imitation, the 'behaviour parsing' model, in which the statistical regularities that are inevitable in planned behaviour are used to decipher the organization of another agent's behaviour, and thence to imitate parts of it. Behaviour can thereby be understood statistically in terms of its correlations (circumstances of use, effects on the environment) without understanding of intentions or the everyday physics of cause-and-effect. Thus, imitation of complex, novel behaviour may not require mentalizing, but conversely behaviour parsing may be a necessary preliminary to attributing intention and cause. PMID:12689378

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

PubMed

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.

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

PubMed Central

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. PMID:26441782

Thermal imitators with single directional invisibility

NASA Astrophysics Data System (ADS)

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.

Automatic imitation: A meta-analysis.

PubMed

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).

The Monosyllable Imitation Test for Toddlers: influence of stimulus characteristics on imitation, compliance and diagnostic accuracy.

PubMed

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

2017-01-01

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 for them to imitate. This study presents a new test of elicited imitation-the Monosyllable Imitation Test for Toddlers (MITT)-comprising stimuli of varying characteristics and test features designed to optimize compliance. To investigate whether the stimulus characteristics of neighbourhood density and consonant complexity have independent and/or convergent influences on imitation accuracy; and to examine non-compliance rates and diagnostic accuracy of the MITT and an existing test, the Test of Early Nonword Repetition (TENR) (Stokes and Klee 2009a). Fifty-two toddlers (25-35 months) participated. Twenty-six had typically developing language (TDs) and 26 were defined as late talkers (LTs) based on parent-reported vocabulary. The MITT stimuli were created by manipulating both neighbourhood density (dense or sparse) and consonant complexity (early- or late-developing initial consonant). The MITT was designed to maximize compliance by: (1) using eight monosyllabic stimuli, (2) providing three exposures to stimuli and (3) embedding imitation in a motivating context: a computer animation with reasons for imitation. Stimulus characteristics influenced imitation accuracy in TDs and LTs. For TDs, neighbourhood density had an independent influence, whereas for LTs consonant complexity had an independent influence. These characteristics also had convergent influences. For TDs, stimuli were all equally easy to imitate, except those that were both sparse and contained a late-developing consonant which were harder to imitate. For LTs, stimuli that were both dense and contained an early-developing consonant were easier to imitate than any other

Unintended imitation in nonword repetition.

PubMed

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

2009-12-01

Verbal repetition is conventionally considered to require motor-reproduction of only the phonologically relevant content of a perceived linguistic stimulus, while imitation of incidental acoustic properties of the stimulus is not an explicit part of this task. Exemplar-based theories of speech processing, however, would predict that imitation beyond linguistic reproduction may occur in word repetition. Five experiments were conducted in which verbal audio-motor translations had to be performed under different conditions. Nonwords varying in phonemic content, in vocal pitch (F(0)), and in speaking style (schwa-syllable expression) were presented. We experimentally varied the factors response delay (repetition vs. shadowing), intention-to-repeat (repetition vs. pseudo-naming), and phonological load (repetition vs. transformation). The responses of ten healthy participants were examined for phonemic accuracy and for traces of para-phonological imitation. Two aphasic patients with phonological impairments were also included, to find out if lesions to left anterior or posterior perisylvian cortex interfere with imitation. In the healthy participants, significant imitation of both F(0) and phonetic style was observed, with markedly stronger effects for the latter. Strong imitation was also found in an aphasic patient with a lesion to left anterior perisylvian cortex, whereas almost no imitation occurred in a patient with a lesion to the posterior language area. The degree of unintended imitation was modulated by each of the three independent factors introduced here. The results are discussed on the background of cognitive and neurolinguistic theories of imitation.

The Left, The Better: White-Matter Brain Integrity Predicts Foreign Language Imitation Ability.

PubMed

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.

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

ERIC Educational Resources Information Center

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…

The development of imitation in infancy

PubMed Central

Jones, Susan S.

2009-01-01

An overview of existing data on imitation in infancy suggests that changes in the direction of imitation research are underway. The widely accepted view that newborn infants imitate lacks supporting evidence. Instead, existing data suggest that infants do not imitate others until their second year, and that imitation of different kinds of behaviour emerges at different ages. The evidence is consistent with a dynamic systems account in which the ability to imitate is not an inherited, specialized module, but is instead the emergent product of a system of social, cognitive and motor components, each with its own developmental history. PMID:19620104

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

PubMed

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.

Nonverbal imitation skills in children with specific language delay.

PubMed

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.

Imitation, Awareness, and Folk Linguistic Artifacts

ERIC Educational Resources Information Center

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…

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

PubMed

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.

Mothers Respond Differently to Infants' Familiar versus Non-Familiar Verbal Imitations

ERIC Educational Resources Information Center

Olson, Janet; Masur, Elise Frank

2012-01-01

Mothers' verbal responses to their infants' spontaneous imitations of familiar and non-familiar words during naturally occurring interactions were examined in a longitudinal sample observed at 1 ; 1, 1 ; 5 and 1 ; 9. Maternal responses to both familiar and non-familiar imitations exhibited structural characteristics likely to be facilitative of…

Harms and benefits from social imitation

NASA Astrophysics Data System (ADS)

Slanina, František

2001-10-01

We study the role of imitation within a model of economics with adaptive agents. The basic ingredients are those of the minority game. We add the possibility of local information exchange and imitation of the neighbour's strategy. Imitators should pay a fee to the imitated. Connected groups are formed, which act as if they were single players. Coherent spatial areas of rich and poor agents result, leading to the decrease of local social tensions. Size and stability of these areas depends on the parameters of the model. Global performance measured by the attendance volatility is optimised at certain value of the imitation probability. The social tensions are suppressed for large imitation probability, but due to the price paid by the imitators the requirements of high global effectivity and low social tensions are in conflict, as well as the requirements of low global and low local wealth differences.

Neural systems for preparatory control of imitation.

PubMed

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.

Automatic imitation in a strategic context: players of rock–paper–scissors imitate opponents' gestures†

PubMed Central

Cook, Richard; Bird, Geoffrey; Lünser, Gabriele; Huck, Steffen; Heyes, Cecilia

2012-01-01

A compelling body of evidence indicates that observing a task-irrelevant action makes the execution of that action more likely. However, it remains unclear whether this ‘automatic imitation’ effect is indeed automatic or whether the imitative action is voluntary. The present study tested the automaticity of automatic imitation by asking whether it occurs in a strategic context where it reduces payoffs. Participants were required to play rock–paper–scissors, with the aim of achieving as many wins as possible, while either one or both players were blindfolded. While the frequency of draws in the blind–blind condition was precisely that expected at chance, the frequency of draws in the blind–sighted condition was significantly elevated. Specifically, the execution of either a rock or scissors gesture by the blind player was predictive of an imitative response by the sighted player. That automatic imitation emerges in a context where imitation reduces payoffs accords with its ‘automatic’ description, and implies that these effects are more akin to involuntary than to voluntary actions. These data represent the first evidence of automatic imitation in a strategic context, and challenge the abstraction from physical aspects of social interaction typical in economic and game theory. PMID:21775334

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

ERIC Educational Resources Information Center

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…

Elements of a comprehensive theory of infant imitation.

PubMed

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.

Effect of meaning on apraxic finger imitation deficits.

PubMed

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.

Race modulates neural activity during imitation

PubMed Central

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

Pathological Imitative Behavior and Response Preparation in Schizophrenia.

PubMed

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.

Multipactor Physics, Acceleration, and Breakdown in Dielectric-Loaded Accelerating Structures

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fischer, Richard P.; Gold, Steven H.

2016-07-01

The objective of this 3-year program is to study the physics issues associated with rf acceleration in dielectric-loaded accelerating (DLA) structures, with a focus on the key issue of multipactor loading, which has been found to cause very significant rf power loss in DLA structures whenever the rf pulsewidth exceeds the multipactor risetime (~10 ns). The experiments are carried out in the X-band magnicon laboratory at the Naval Research Laboratory (NRL) in collaboration with Argonne National Laboratory (ANL) and Euclid Techlabs LLC, who develop the test structures with support from the DoE SBIR program. There are two main elements inmore » the research program: (1) high-power tests of DLA structures using the magnicon output (20 MW @11.4 GHz), and (2) tests of electron acceleration in DLA structures using relativistic electrons from a compact X-band accelerator. The work during this period has focused on a study of the use of an axial magnetic field to suppress multipactor in DLA structures, with several new high power tests carried out at NRL, and on preparation of the accelerator for the electron acceleration experiments.« less

Imitation and speech: commonalities within Broca's area.

PubMed

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.

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

NASA Astrophysics Data System (ADS)

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.

The neural basis of the imitation drive.

PubMed

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.

Enculturated Chimpanzees Imitate Rationally

ERIC Educational Resources Information Center

Buttelmann, David; Carpenter, Malinda; Call, Josep; Tomasello, Michael

2007-01-01

Human infants imitate others' actions "rationally": they copy a demonstrator's action when that action is freely chosen, but less when it is forced by some constraint (Gergely, Bekkering & Kiraly, 2002). We investigated whether enculturated chimpanzees (Pan troglodytes) also imitate rationally. Using Gergely and colleagues' (2002) basic procedure,…

Examination of Correlates of Different Imitative Functions in Young Children with Autism Spectrum Disorders

ERIC Educational Resources Information Center

Ingersoll, Brooke; Meyer, Katherine

2011-01-01

Children with autism spectrum disorders (ASD) have difficulties with social-communication skills, including imitation, language, joint attention, and play. This study investigated whether imitation performance in two different contexts (structured-elicited vs. social-interactive) was differentially related to attention-following, social…

Vocal Imitations of Non-Vocal Sounds

PubMed Central

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

The perils of the imitation age.

PubMed

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.

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

ERIC Educational Resources Information Center

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…

Repeated imitation makes human vocalizations more word-like.

PubMed

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).

The neural basis of the imitation drive

PubMed Central

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. PMID:26168793

Phonetic imitation by young children and its developmental changes.

PubMed

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.

Exploring links among imitation, mental development, and temperament

PubMed Central

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. PMID:27840593

Exploring links among imitation, mental development, and temperament.

PubMed

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.

Understanding the mechanisms behind deficits in imitation: do individuals with autism know 'what' to imitate and do they know 'how' to imitate?

PubMed

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 problems in autism are complicated and inconclusive at the present time. There is some evidence for impaired selection, especially implicating poor preferential attention to biological motion and poor ascription of intention to action. There is also some evidence that both transformations of perspectives and mapping of visual to motor information are impaired, characterized as correspondence problems. However, it is not yet clear how poor selection processes contribute to correspondence problems and vice versa. Insight in this interaction may provide a valuable contribution to our understanding of imitation problems in autism. For further research we recommend that tasks should be constrained to target as few mechanisms as possible in given experiments. Copyright © 2012 Elsevier Ltd. All rights reserved.

Learning to Imitate in Infancy

ERIC Educational Resources Information Center

Parton, David A.

1976-01-01

Theories of imitation learning are examined regarding their account of how the infant acquires the ability to emit a response which resembles a response previously exhibited by another. The role of cognition in imitation learning theory is discussed. (BRT)

Imitation, empathy, and mirror neurons.

PubMed

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.

From Imitation to Conversation: The First Dialogues with Human Neonates

ERIC Educational Resources Information Center

Nagy, Emese

2006-01-01

The functional maturity of the newborn infant's brain, the resemblances between neonatal imitation and imitation in adults and the possibly lateralized neonatal imitation suggest that the mirror neuron system may contribute to neonatal imitation. Newborn infants not only imitate but also initiate previously imitated gestures, and are able to…

Verbal Imitation Is Based on Intention Understanding

ERIC Educational Resources Information Center

Over, Harriet; Gattis, Merideth

2010-01-01

Using an elicited imitation paradigm, we investigated whether young children imitate the communicative intentions behind speech. Previous research using elicited imitation has shown that children tend to correct ungrammatical sentences. This finding is usually interpreted as evidence that children, like adults, remember and reproduce the gist of…

The Reciprocity of "Imitative Learning" through Apprenticeship

ERIC Educational Resources Information Center

Chan, Selena

2017-01-01

Humans are proposed to have evolved to learn through observation, imitation and practice or mimesis. In this article, the contribution of imitation, as an important but poorly understood aspect of mimetic learning, is advocated to create affordances for dyadic learning. However, learning through imitation is often perceived with negative…

Mimicry and automatic imitation are not correlated

PubMed Central

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

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

PubMed

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).

Computational approaches to motor learning by imitation.

PubMed Central

Schaal, Stefan; Ijspeert, Auke; Billard, Aude

2003-01-01

Movement imitation requires a complex set of mechanisms that map an observed movement of a teacher onto one's own movement apparatus. Relevant problems include movement recognition, pose estimation, pose tracking, body correspondence, coordinate transformation from external to egocentric space, matching of observed against previously learned movement, resolution of redundant degrees-of-freedom that are unconstrained by the observation, suitable movement representations for imitation, modularization of motor control, etc. All of these topics by themselves are active research problems in computational and neurobiological sciences, such that their combination into a complete imitation system remains a daunting undertaking-indeed, one could argue that we need to understand the complete perception-action loop. As a strategy to untangle the complexity of imitation, this paper will examine imitation purely from a computational point of view, i.e. we will review statistical and mathematical approaches that have been suggested for tackling parts of the imitation problem, and discuss their merits, disadvantages and underlying principles. Given the focus on action recognition of other contributions in this special issue, this paper will primarily emphasize the motor side of imitation, assuming that a perceptual system has already identified important features of a demonstrated movement and created their corresponding spatial information. Based on the formalization of motor control in terms of control policies and their associated performance criteria, useful taxonomies of imitation learning can be generated that clarify different approaches and future research directions. PMID:12689379

Neural correlates of individual differences in manual imitation fidelity

PubMed Central

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

Frequency-dependent oscillatory neural profiles during imitation

PubMed Central

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

Frequency-dependent oscillatory neural profiles during imitation.

PubMed

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.

Perception-action coupling and imitation in autism spectrum disorder.

PubMed

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.

Multiple Imitation Mechanisms in Children

ERIC Educational Resources Information Center

Subiaul, Francys; Anderson, Sarah; Brandt, Janina; Elkins, Jenny

2012-01-01

Four studies using a computerized paradigm investigated whether children's imitation performance is content-specific and to what extent dependent on other cognitive processes such as trial-and-error learning, recall, and observational learning. Experiment 1 showed that 3-year-olds could successfully imitate what we call novel cognitive rules…

Selective and Faithful Imitation at 12 and 15 Months

ERIC Educational Resources Information Center

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,…

Psychological distance reduces literal imitation: Evidence from an imitation-learning paradigm.

PubMed

Hansen, Jochim; Alves, Hans; Trope, Yaacov

2016-03-01

The present experiments tested the hypothesis that observers engage in more literal imitation of a model when the model is psychologically near to (vs. distant from) the observer. Participants learned to fold a dog out of towels by watching a model performing this task. Temporal (Experiment 1) and spatial (Experiment 2) distance from the model were manipulated. As predicted, participants copied more of the model's specific movements when the model was near (vs. distant). Experiment 3 replicated this finding with a paper-folding task, suggesting that distance from a model also affects imitation of less complex tasks. Perceived task difficulty, motivation, and the quality of the end product were not affected by distance. We interpret the findings as reflecting different levels of construal of the model's performance: When the model is psychologically distant, social learners focus more on the model's goal and devise their own means for achieving the goal, and as a result show less literal imitation of the model. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Effects of stimulus response compatibility on covert imitation of vowels.

PubMed

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.

Deferred and immediate imitation in regressive and early onset autism

PubMed Central

Rogers, Sally J.; Young, Gregory S.; Cook, Ian; Giolzetti, Angelo; Ozonoff, Sally

2010-01-01

Deferred imitation has long held a privileged position in early cognitive development, considered an early marker of representational thought with links to language development and symbolic processes. Children with autism have difficulties with several abilities generally thought to be related to deferred imitation: immediate imitation, language, and symbolic play. However, few studies have examined deferred imitation in early autism. The present study examined both deferred, spontaneous imitation and immediate, elicited imitation on a set of carefully matched tasks in 36 young children with autism: 16 with early onset autism, 20 with regressive autism and two contrast groups, younger typically developing children (n = 20) and age matched children with significant developmental delays (n = 21). Analyses of co-variance controlling for differences in verbal mental age revealed significant main effects for task, but no main effect of group and no interaction of task by group. Deferred imitation scores were lower than immediate imitation scores for all groups. Imitation performance was related to overall intellectual functioning for all groups, and there were moderate and significant relations between imitation in the immediate elicited condition and in the spontaneous deferred condition for all groups. Finally, there were no differences between onset subgroups in imitation scores, suggesting that the two share a similar phenotype involving both types of imitation. PMID:18221343

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

PubMed Central

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

2009-01-01

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. PMID:19620112

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

PubMed

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.

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

PubMed

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.

Teaching children generalized imitation skills: a case report.

PubMed

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.

Neural correlates of phonetic convergence and speech imitation.

PubMed

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.

Neural correlates of phonetic convergence and speech imitation

PubMed Central

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. PMID:24062704

Nurturance and Imitation: The Mediating Role of Attraction

ERIC Educational Resources Information Center

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…

The influence of group membership on cross-contextual imitation.

PubMed

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.

Social and strategic imitation: the way to consensus.

PubMed

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

2012-01-01

Humans do not always make rational choices, a fact that experimental economics is putting on solid grounds. The social context plays an important role in determining our actions, and often we imitate friends or acquaintances without any strategic consideration. We explore here the interplay between strategic and social imitative behavior in a coordination problem on a social network. We observe that for interactions on 1D and 2D lattices any amount of social imitation prevents the freezing of the network in domains with different conventions, thus leading to global consensus. For interactions on complex networks, the interplay of social and strategic imitation also drives the system towards global consensus while neither dynamics alone does. We find an optimum value for the combination of imitative behaviors to reach consensus in a minimum time, and two different dynamical regimes to approach it: exponential when social imitation predominates, power-law when strategic considerations prevail.

Contingent imitation increases verbal interaction in children with autism spectrum disorders.

PubMed

Ishizuka, Yuka; Yamamoto, Jun-Ichi

2016-11-01

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 verbal interaction such as vocal imitation, vocalization, and vocal turn-taking via contingent imitation. We used an alternating treatment design composed of the conditions of contingent imitation and control for six children with autism (aged 33-63 months). For contingent imitation condition, adults imitated children's vocalization immediately. For control condition, adults did not imitate but gave a vocal response immediately. Results showed that in contingent imitation condition, all children increased the number of vocal imitations and vocal turn-takings compared with control condition. The number of vocalizations increased in both condition for all children. Overall, it is suggested that all children promote verbal interaction via contingent imitation. © The Author(s) 2016.

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

PubMed

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.

Imitating emotions instead of strategies in spatial games elevates social welfare

NASA Astrophysics Data System (ADS)

Szolnoki, Attila; Xie, Neng-Gang; Wang, Chao; Perc, Matjaž

2011-11-01

The success of imitation as an evolutionary driving force in spatial games has often been questioned, especially for social dilemmas such as the snowdrift game, where the most profitable one may be the mixed phase sustaining both the cooperative and the defective strategy. Here we reexamine this assumption by investigating the evolution of cooperation in spatial social-dilemma games, where, instead of pure strategies, players can adopt emotional profiles of their neighbors. For simplicity, the emotional profile of each player is determined by two pivotal factors only, namely how it behaves towards less and how towards more successful neighbors. We find that imitating emotions such as goodwill and envy instead of pure strategies from the more successful players reestablishes imitation as a tour de force for resolving social dilemmas on structured populations without any additional assumptions or strategic complexity.

Prototyping high-gradient mm-wave accelerating structures

DOE PAGES

Nanni, Emilio A.; Dolgashev, Valery A.; Haase, Andrew; ...

2017-01-01

We present single-cell accelerating structures designed for high-gradient testing at 110 GHz. The purpose of this work is to study the basic physics of ultrahigh vacuum RF breakdown in high-gradient RF accelerators. The accelerating structures are π-mode standing-wave cavities fed with a TM 01 circular waveguide. The structures are fabricated using precision milling out of two metal blocks, and the blocks are joined with diffusion bonding and brazing. The impact of fabrication and joining techniques on the cell geometry and RF performance will be discussed. First prototypes had a measured Q 0 of 2800, approaching the theoretical design value ofmore » 3300. The geometry of these accelerating structures are as close as practical to singlecell standing-wave X-band accelerating structures more than 40 of which were tested at SLAC. This wealth of X-band data will serve as a baseline for these 110 GHz tests. Furthermore, the structures will be powered with short pulses from a MW gyrotron oscillator. RF power of 1 MW may allow an accelerating gradient of 400 MeV/m to be reached.« less

A Cross-Cultural Comparison of Children's Imitative Flexibility

ERIC Educational Resources Information Center

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)…

Imitation in Fragile X Syndrome: Implications for Autism

ERIC Educational Resources Information Center

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…

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

ERIC Educational Resources Information Center

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…

Imitation in Undergraduate Teaching and Learning

ERIC Educational Resources Information Center

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…

Modeling: It's More than Just Imitation

ERIC Educational Resources Information Center

Horner, Sherri L.; Bhattacharyya, Srilata; O'Connor, Evelyn A.

2008-01-01

Anyone who has observed or played with young children probably has noticed how they imitate what they see--their friends, siblings, parents, and teachers; television, movie, and book characters; and sometimes even their family pets. Frequently, this imitation can help children learn appropriate behaviors, attitudes, and thinking patterns.…

The Neural Basis of Vocal Pitch Imitation in Humans.

PubMed

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.

Imitation inhibition in children with Tourette syndrome.

PubMed

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.

Unintended imitation affects success in a competitive game.

PubMed

Naber, Marnix; Vaziri Pashkam, Maryam; Nakayama, Ken

2013-12-10

Imitation typically occurs in social contexts where people interact and have common goals. Here, we show that people are also highly susceptible to imitate each other in a competitive context. Pairs of players performed a competitive and fast-reaching task (a variant of the arcade whac-a-mole game) in which money could be earned if players hit brief-appearing visual targets on a large touchscreen before their opponents. In three separate experiments, we demonstrate that reaction times and movements were highly correlated within pairs of players. Players affected their success by imitating each other, and imitation depended on the visibility of the opponent's behavior. Imitation persisted, despite the competitive and demanding nature of the game, even if this resulted in lower scores and payoffs and even when there was no need to counteract the opponent's actions.

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

ERIC Educational Resources Information Center

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

2017-01-01

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…

Investigating the Relationship between Stable Personality Characteristics and Automatic Imitation

PubMed Central

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. PMID:26079137

Investigating the Relationship between Stable Personality Characteristics and Automatic Imitation.

PubMed

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.

Imitation in Neonatal Chimpanzees ("Pan Troglodytes")

ERIC Educational Resources Information Center

Myowa-Yamakoshi, Masako; Tomonaga, Masaki; Tanaka, Masayuki; Matsuzawa, Tetsuro

2004-01-01

This paper provides evidence for imitative abilities in neonatal chimpanzees ("Pan troglodytes"), our closest relatives. Two chimpanzees were reared from birth by their biological mothers. At less than 7 days of age the chimpanzees could discriminate between, and imitate, human facial gestures (tongue protrusion and mouth opening). By the time…

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

PubMed

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.

Imitation and Innovation: The Dual Engines of Cultural Learning.

PubMed

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.

Performance of motor imitation in children with and without dyspraxia.

PubMed

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.

Children with autism respond differently to spontaneous, elicited and deferred imitation.

PubMed

Heimann, M; Nordqvist, E; Strid, K; Connant Almrot, J; Tjus, T

2016-05-01

Imitation, a key vehicle for both cognitive and social development, is often regarded as more difficult for children with autism spectrum disorders (ASD) than for children with Down syndrome (DS) or typically developing (TD) children. The current study investigates similarities and differences in observed elicited, spontaneous and deferred imitation using both actions with objects and gestures as imitation tasks in these groups. Imitation among 19 children with autism was compared with 20 children with DS and 23 TD children matched for mental and language age. Elicited imitation resulted in significantly lower scores for the ASD group compared with the other two groups, an effect mainly carried by a low level of gesture imitation among ASD children. We observed no differences among the groups for spontaneous imitation. However, children with ASD or DS displayed less deferred imitation than the TD group. Proneness to imitate also differed among groups: only 10 (53%) of the children with autism responded in the elicited imitation condition compared with all children with DS and almost all TD children (87%). These findings add to our understanding of the kind of imitation difficulties children with ASD might have. They also point to the necessity of not equating various imitation measures because these may capture different processes and be differently motivating for children with autism. © 2016 MENCAP and International Association of the Scientific Study of Intellectual and Developmental Disabilities and John Wiley & Sons Ltd.

Being Imitated, Conformity, and Social Influence: An Integrative Review.

ERIC Educational Resources Information Center

Thelen, Mark H.; And Others

1981-01-01

Reviews literature on effects of being imitated and the social influence function of imitation, plus related literature on conformity from social psychology. Considers this research within a number of theoretical contexts, especially within the conceptual framework of effectance motivation. Suggests imitation may facilitate mastery and control of…

An Automated Procedure for Evaluating Song Imitation

PubMed Central

Mandelblat-Cerf, Yael; Fee, Michale S.

2014-01-01

Songbirds have emerged as an excellent model system to understand the neural basis of vocal and motor learning. Like humans, songbirds learn to imitate the vocalizations of their parents or other conspecific “tutors.” Young songbirds learn by comparing their own vocalizations to the memory of their tutor song, slowly improving until over the course of several weeks they can achieve an excellent imitation of the tutor. Because of the slow progression of vocal learning, and the large amounts of singing generated, automated algorithms for quantifying vocal imitation have become increasingly important for studying the mechanisms underlying this process. However, methodologies for quantifying song imitation are complicated by the highly variable songs of either juvenile birds or those that learn poorly because of experimental manipulations. Here we present a method for the evaluation of song imitation that incorporates two innovations: First, an automated procedure for selecting pupil song segments, and, second, a new algorithm, implemented in Matlab, for computing both song acoustic and sequence similarity. We tested our procedure using zebra finch song and determined a set of acoustic features for which the algorithm optimally differentiates between similar and non-similar songs. PMID:24809510

Advanced accelerator and mm-wave structure research at LANL

DOE Office of Scientific and Technical Information (OSTI.GOV)

Simakov, Evgenya Ivanovna

2016-06-22

This document outlines acceleration projects and mm-wave structure research performed at LANL. The motivation for PBG research is described first, with reference to couplers for superconducting accelerators and structures for room-temperature accelerators and W-band TWTs. These topics are then taken up in greater detail: PBG structures and the MIT PBG accelerator; SRF PBG cavities at LANL; X-band PBG cavities at LANL; and W-band PBG TWT at LANL. The presentation concludes by describing other advanced accelerator projects: beam shaping with an Emittance Exchanger, diamond field emitter array cathodes, and additive manufacturing of novel accelerator structures.

Not All That Glitters is Gold: Gold Imitations in History.

PubMed

Karpenko, Vladimír

2007-07-01

When gold became considered as a precious metal for decorative purposes and later for coinage, attempts at producing imitations soon began to appear. There were two motives behind this activity: to make a metal that could pass as gold, and to quite openly imitate this precious metal for people who could not afford true gold. Imitation gold was produced by metallurgists, and later also by alchemists. This paper is about gold imitations that did not contain any precious metal. Gold-like alloys of silver are thus excluded. An attempt is further undertaken to classify into separate groups the various gold imitations that have appeared in different cultures throughout time, with an emphasis on brass as a typical imitation of gold.

The Consequences of Failing to Imitate.

ERIC Educational Resources Information Center

Richman, Charles L.; And Others

This demonstration study examines the affective reactions of infants when they imitate or fail to imitate play behavior modeled by an adult. Subjects were twenty-four 18-month-old and twenty-four 24-month-old male and female infants. Each infant visited the laboratory twice with an inter-session interval of 48 hours. At each session, the infant…

Shadow-Reading: Affordances for Imitation in the Language Classroom

ERIC Educational Resources Information Center

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…

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

PubMed

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.

Auditory perception bias in speech imitation

PubMed Central

Postma-Nilsenová, Marie; Postma, Eric

2013-01-01

In an experimental study, we explored the role of auditory perception bias in vocal pitch imitation. Psychoacoustic tasks involving a missing fundamental indicate that some listeners are attuned to the relationship between all the higher harmonics present in the signal, which supports their perception of the fundamental frequency (the primary acoustic correlate of pitch). Other listeners focus on the lowest harmonic constituents of the complex sound signal which may hamper the perception of the fundamental. These two listener types are referred to as fundamental and spectral listeners, respectively. We hypothesized that the individual differences in speakers' capacity to imitate F0 found in earlier studies, may at least partly be due to the capacity to extract information about F0 from the speech signal. Participants' auditory perception bias was determined with a standard missing fundamental perceptual test. Subsequently, speech data were collected in a shadowing task with two conditions, one with a full speech signal and one with high-pass filtered speech above 300 Hz. The results showed that perception bias toward fundamental frequency was related to the degree of F0 imitation. The effect was stronger in the condition with high-pass filtered speech. The experimental outcomes suggest advantages for fundamental listeners in communicative situations where F0 imitation is used as a behavioral cue. Future research needs to determine to what extent auditory perception bias may be related to other individual properties known to improve imitation, such as phonetic talent. PMID:24204361

Generalized Imitation of Facial Models by Children with Autism

ERIC Educational Resources Information Center

DeQuinzio, Jaime Ann; Townsend, Dawn Buffington; Sturmey, Peter; Poulson, Claire L.

2007-01-01

Imitation is an essential skill in the acquisition of language and communication skills. An initial phase in teaching young children with autism to engage in appropriate affective responding may be to teach the imitation of facial models. Using a multiple baseline across participants design, imitation training (consisting of modeling, prompting,…

A specific deficit of imitation in autism spectrum disorder.

PubMed

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.

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

PubMed

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).

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

PubMed

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.

Enhancing voluntary imitation through attention and motor imagery.

PubMed

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.

Multi-Mode Cavity Accelerator Structure

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jiang, Yong; Hirshfield, Jay Leonard

2016-11-10

This project aimed to develop a prototype for a novel accelerator structure comprising coupled cavities that are tuned to support modes with harmonically-related eigenfrequencies, with the goal of reaching an acceleration gradient >200 MeV/m and a breakdown rate <10 -7/pulse/meter. Phase I involved computations, design, and preliminary engineering of a prototype multi-harmonic cavity accelerator structure; plus tests of a bimodal cavity. A computational procedure was used to design an optimized profile for a bimodal cavity with high shunt impedance and low surface fields to maximize the reduction in temperature rise ΔT. This cavity supports the TM010 mode and its 2ndmore » harmonic TM011 mode. Its fundamental frequency is at 12 GHz, to benchmark against the empirical criteria proposed within the worldwide High Gradient collaboration for X-band copper structures; namely, a surface electric field E sur max< 260 MV/m and pulsed surface heating ΔT max< 56 °K. With optimized geometry, amplitude and relative phase of the two modes, reductions are found in surface pulsed heating, modified Poynting vector, and total RF power—as compared with operation at the same acceleration gradient using only the fundamental mode.« less

Singing proficiency in congenital amusia: imitation helps.

PubMed

Tremblay-Champoux, Alexandra; Dalla Bella, Simone; Phillips-Silver, Jessica; Lebrun, Marie-Andrée; Peretz, Isabelle

2010-09-01

Singing out of tune characterizes congenital amusia. Here, we examine whether an aid to memory improves singing by studying vocal imitation in 11 amusic adults and 11 matched controls. Participants sang a highly familiar melody on the original lyrics and on the syllable /la/ in three conditions. First, they sang the melody from memory. Second, they sang it after hearing a model, and third, they sang in unison with the model. Results show that amusic individuals benefit from singing by imitation, whether singing after the model or in unison with the model. The amusics who were the most impaired in memory benefited most, particularly when singing on the syllable /la/. Nevertheless, singing remains poor on the pitch dimension; rhythm was intact and unaffected by imitation. These results point to memory as a source of impairment in poor singing, and to imitation as a possible aid for poor singers.

Kinematic Measures of Imitation Fidelity in Primary School Children

ERIC Educational Resources Information Center

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…

Infants Show Stability of Goal-Directed Imitation

ERIC Educational Resources Information Center

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…

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

PubMed

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.

The shared neural basis of empathy and facial imitation accuracy.

PubMed

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.

The history of imitation in learning theory: the language acquisition process.

PubMed Central

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 imitation in the history of learning theory, the authors conclude that generalized imitation, as defined and analyzed by operant learning theorists, is a sufficiently robust formulation of learned imitation to facilitate a behavior-analytic account of first-language acquisition. PMID:2230633

Action generation and action perception in imitation: an instance of the ideomotor principle.

PubMed Central

Wohlschläger, Andreas; Gattis, Merideth; Bekkering, Harold

2003-01-01

We review a series of behavioural experiments on imitation in children and adults that test the predictions of a new theory of imitation. Most of the recent theories of imitation assume a direct visual-to-motor mapping between perceived and imitated movements. Based on our findings of systematic errors in imitation, the new theory of goal-directed imitation (GOADI) instead assumes that imitation is guided by cognitively specified goals. According to GOADI, the imitator does not imitate the observed movement as a whole, but rather decomposes it into its separate aspects. These aspects are hierarchically ordered, and the highest aspect becomes the imitator's main goal. Other aspects become sub-goals. In accordance with the ideomotor principle, the main goal activates the motor programme that is most strongly associated with the achievement of that goal. When executed, this motor programme sometimes matches, and sometimes does not, the model's movement. However, the main goal extracted from the model movement is almost always imitated correctly. PMID:12689376

Imitating expressions: emotion-specific neural substrates in facial mimicry.

PubMed

Lee, Tien-Wen; Josephs, Oliver; Dolan, Raymond J; Critchley, Hugo D

2006-09-01

Intentionally adopting a discrete emotional facial expression can modulate the subjective feelings corresponding to that emotion; however, the underlying neural mechanism is poorly understood. We therefore used functional brain imaging (functional magnetic resonance imaging) to examine brain activity during intentional mimicry of emotional and non-emotional facial expressions and relate regional responses to the magnitude of expression-induced facial movement. Eighteen healthy subjects were scanned while imitating video clips depicting three emotional (sad, angry, happy), and two 'ingestive' (chewing and licking) facial expressions. Simultaneously, facial movement was monitored from displacement of fiducial markers (highly reflective dots) on each subject's face. Imitating emotional expressions enhanced activity within right inferior prefrontal cortex. This pattern was absent during passive viewing conditions. Moreover, the magnitude of facial movement during emotion-imitation predicted responses within right insula and motor/premotor cortices. Enhanced activity in ventromedial prefrontal cortex and frontal pole was observed during imitation of anger, in ventromedial prefrontal and rostral anterior cingulate during imitation of sadness and in striatal, amygdala and occipitotemporal during imitation of happiness. Our findings suggest a central role for right inferior frontal gyrus in the intentional imitation of emotional expressions. Further, by entering metrics for facial muscular change into analysis of brain imaging data, we highlight shared and discrete neural substrates supporting affective, action and social consequences of somatomotor emotional expression.

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

PubMed

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.

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

PubMed Central

Heyes, Cecilia

2016-01-01

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. PMID:26644604

Methodological issues in measures of imitative reaction times.

PubMed

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.

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

ERIC Educational Resources Information Center

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…

High gradient tests of metallic mm-wave accelerating structures

DOE PAGES

Dal Forno, Massimo; Dolgashev, Valery; Bowden, Gordon; ...

2017-05-10

This study explores the physics of vacuum rf breakdowns in high gradient mm-wave accelerating structures. We performed a series of experiments with 100 GHz and 200 GHz metallic accelerating structures, at the Facility for Advanced Accelerator Experimental Tests (FACET) at the SLAC National Accelerator Laboratory. This paper presents the experimental results of rf tests of 100 GHz travelling-wave accelerating structures, made of hard copper-silver alloy. The results are compared with pure hard copper structures. The rf fields were excited by the FACET ultra-relativistic electron beam. The accelerating structures have open geometries, 10 cm long, composed of two halves separated bymore » a variable gap. The rf frequency of the fundamental accelerating mode depends on the gap size and can be changed from 90 GHz to 140 GHz. The measured frequency and pulse length are consistent with our simulations. When the beam travels off-axis, a deflecting field is induced in addition to the decelerating longitudinal field. We measured the deflecting forces by observing the displacement of the electron bunch and used this measurement to verify the expected accelerating gradient. We present the first quantitative measurement of rf breakdown rates in 100 GHz copper-silver accelerating structure, which was 10 –3 per pulse, with peak electric field of 0.42 GV/m, an accelerating gradient of 127 MV/m, at a pulse length of 2.3 ns. The goal of our studies is to understand the physics of gradient limitations in order to increase the energy reach of future accelerators.« less

High gradient tests of metallic mm-wave accelerating structures

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dal Forno, Massimo; Dolgashev, Valery; Bowden, Gordon

This study explores the physics of vacuum rf breakdowns in high gradient mm-wave accelerating structures. We performed a series of experiments with 100 GHz and 200 GHz metallic accelerating structures, at the Facility for Advanced Accelerator Experimental Tests (FACET) at the SLAC National Accelerator Laboratory. This paper presents the experimental results of rf tests of 100 GHz travelling-wave accelerating structures, made of hard copper-silver alloy. The results are compared with pure hard copper structures. The rf fields were excited by the FACET ultra-relativistic electron beam. The accelerating structures have open geometries, 10 cm long, composed of two halves separated bymore » a variable gap. The rf frequency of the fundamental accelerating mode depends on the gap size and can be changed from 90 GHz to 140 GHz. The measured frequency and pulse length are consistent with our simulations. When the beam travels off-axis, a deflecting field is induced in addition to the decelerating longitudinal field. We measured the deflecting forces by observing the displacement of the electron bunch and used this measurement to verify the expected accelerating gradient. We present the first quantitative measurement of rf breakdown rates in 100 GHz copper-silver accelerating structure, which was 10 –3 per pulse, with peak electric field of 0.42 GV/m, an accelerating gradient of 127 MV/m, at a pulse length of 2.3 ns. The goal of our studies is to understand the physics of gradient limitations in order to increase the energy reach of future accelerators.« less

Imitation of snack food intake among normal-weight and overweight children.

PubMed

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 < 0.0001]. Moreover, findings suggest that children may display different 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.

Reduced integration and differentiation of the imitation network in autism: A combined functional connectivity magnetic resonance imaging and diffusion-weighted imaging study.

PubMed

Fishman, Inna; Datko, Michael; Cabrera, Yuliana; Carper, Ruth A; Müller, Ralph-Axel

2015-12-01

Converging evidence indicates that brain abnormalities in autism spectrum disorder (ASD) involve atypical network connectivity, but few studies have integrated functional with structural connectivity measures. This multimodal investigation examined functional and structural connectivity of the imitation network in children and adolescents with ASD, and its links with clinical symptoms. Resting state functional magnetic resonance imaging and diffusion-weighted imaging were performed in 35 participants with ASD and 35 typically developing controls, aged 8 to 17 years, matched for age, gender, intelligence quotient, and head motion. Within-network analyses revealed overall reduced functional connectivity (FC) between distributed imitation regions in the ASD group. Whole brain analyses showed that underconnectivity in ASD occurred exclusively in regions belonging to the imitation network, whereas overconnectivity was observed between imitation nodes and extraneous regions. Structurally, reduced fractional anisotropy and increased mean diffusivity were found in white matter tracts directly connecting key imitation regions with atypical FC in ASD. These differences in microstructural organization of white matter correlated with weaker FC and greater ASD symptomatology. Findings demonstrate atypical connectivity of the brain network supporting imitation in ASD, characterized by a highly specific pattern. This pattern of underconnectivity within, but overconnectivity outside the functional network is in contrast with typical development and suggests reduced network integration and differentiation in ASD. Our findings also indicate that atypical connectivity of the imitation network may contribute to ASD clinical symptoms, highlighting the role of this fundamental social cognition ability in the pathophysiology of ASD. © 2015 American Neurological Association.

Are Automatic Imitation and Spatial Compatibility Mediated by Different Processes?

ERIC Educational Resources Information Center

Cooper, Richard P.; Catmur, Caroline; Heyes, Cecilia

2013-01-01

Automatic imitation or "imitative compatibility" is thought to be mediated by the mirror neuron system and to be a laboratory model of the motor mimicry that occurs spontaneously in naturalistic social interaction. Imitative compatibility and spatial compatibility effects are known to depend on different stimulus dimensions--body…

Deferred and Immediate Imitation in Regressive and Early Onset Autism

ERIC Educational Resources Information Center

Rogers, Sally J.; Young, Gregory S.; Cook, Ian; Giolzetti, Angelo; Ozonoff, Sally

2008-01-01

Deferred imitation has long held a privileged position in early cognitive development, considered an early marker of representational thought with links to language development and symbolic processes. Children with autism have difficulties with several abilities generally thought to be related to deferred imitation: immediate imitation, language,…

Time Course Analyses Confirm Independence of Imitative and Spatial Compatibility

ERIC Educational Resources Information Center

Catmur, Caroline; Heyes, Cecilia

2011-01-01

Imitative compatibility, or automatic imitation, has been used as a measure of imitative performance and as a behavioral index of the functioning of the human mirror system (e.g., Brass, Bekkering, Wohlschlager, & Prinz, 2000; Heyes, Bird, Johnson, & Haggard, 2005; Kilner, Paulignan, & Blakemore, 2003). However, the use of imitative…

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

PubMed Central

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. PMID:27833573

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

PubMed

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.

A comparison of between- and within-subjects imitation designs.

PubMed

Kressley, Regina A; Knopf, Monika

2006-12-01

Two experimental methods, which have dominated the study of declarative memory in preverbal children with imitation tasks, namely the deferred imitation and elicited imitation paradigm, differ in the amount of physical contact with test stimuli afforded infants prior to a test for long-term recall. The current study assessed effects of pre- and post-demonstration contact with test stimuli on deferred imitation of novel, single-step unrelated actions with multiple objects by 8(1/2)- and 10(1/2)-month-old infants (N=50). The rate of target action completion after a delay remained consistent at both ages across different conditions of prior contact with test stimuli. This study shows that a within-subjects baseline appraisal is valid within certain experimental parameters and offers a more economical alternative. The results show furthermore that different experimental designs utilized to assess deferred imitation are highly comparable for the first year despite differences in determining baseline.

Imitation and Creativity: Beneficial Effects of Propulsion Strategies and Specificity

ERIC Educational Resources Information Center

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…

Impact of imitation processes on the effectiveness of ring vaccination.

PubMed

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.

Robots Learn to Recognize Individuals from Imitative Encounters with People and Avatars

NASA Astrophysics Data System (ADS)

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.

Preserved imitation in contrast to limited free application of comfortable hand actions in intellectually able young adults with an autism spectrum disorder.

PubMed

Beelen, Caroline; Cuypers, Koen; van Schuerbeeck, Lise; Braeken, Marijke; Ross, Veerle; Jongen, Ellen; Meesen, Raf; Vanvuchelen, Marleen

2017-06-01

Imitation problems are commonly reported in children with an autism spectrum disorder. However, it has not yet been determined whether imitation problems persist into young adulthood. In this study, we investigated imitation skills of 20 intellectually able young adults with autism spectrum disorder relative to 19 age-matched neurotypical adults. For this purpose, we used a bar-transport task, which evokes the application of the end-state comfort principle. Specifically, we examined whether young adults with autism spectrum disorder imitated the means-end structure of a demonstrator's bar-transport action with and without application of the end-state comfort principle (imitation task). In addition, we examined whether participants spontaneously applied the end-state comfort principle during a similar bar-transport task (free execution task). Results revealed that young adults with autism spectrum disorder imitated the means-end structure of observed actions to the same degree as neurotypical adults ( p = 0.428). In contrast, they applied the end-state comfort principle less often during free executed actions ( p = 0.035). Moreover, during these actions, they were slower to place the bar into the penholder ( p = 0.023), which contributed to the reduced efficiency of their performance. Findings suggest that imitation abilities of young adults with autism spectrum disorder are preserved and that observing others' actions might promote more efficient action planning in this population.

Interspecific song imitation by a Prairie Warbler

Treesearch

Bruce E. Byers; Brodie A. Kramer; Michael E. Akresh; David I. King

2013-01-01

Song development in oscine songbirds relies on imitation of adult singers and thus leaves developing birds vulnerable to potentially costly errors caused by imitation of inappropriate models, such as the songs of other species. In May and June 2012, we recorded the songs of a bird that made such an error: a male Prairie Warbler (Setophaga discolor)...

Imitation in Infancy. Cambridge Studies in Cognitive and Perceptual Development.

ERIC Educational Resources Information Center

Nadel, Jacqueline, Ed.; Butterworth, George, Ed.

Modern research has suggested that imitation is a natural mechanism of learning and communication, yet the possibility of imitation in newborn humans has been controversial. This book looks at evidence for innate imitation in babies. The chapters in the first section of the book reassess the Piagetian tradition, especially concerning the relation…

Variable energy constant current accelerator structure

DOEpatents

Anderson, Oscar A.

1990-01-01

A variable energy, constant current ion beam accelerator structure is disclosed comprising an ion source capable of providing the desired ions, a pre-accelerator for establishing an initial energy level, a matching/pumping module having means for focusing means for maintaining the beam current, and at least one main accelerator module for continuing beam focus, with means capable of variably imparting acceleration to the beam so that a constant beam output current is maintained independent of the variable output energy. In a preferred embodiment, quadrupole electrodes are provided in both the matching/pumping module and the one or more accelerator modules, and are formed using four opposing cylinder electrodes which extend parallel to the beam axis and are spaced around the beam at 90.degree. intervals with opposing electrodes maintained at the same potential. Adjacent cylinder electrodes of the quadrupole structure are maintained at different potentials to thereby reshape the cross section of the charged particle beam to an ellipse in cross section at the mid point along each quadrupole electrode unit in the accelerator modules. The beam is maintained in focus by alternating the major axis of the ellipse along the x and y axis respectively at adjacent quadrupoles. In another embodiment, electrostatic ring electrodes may be utilized instead of the quadrupole electrodes.

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

ERIC Educational Resources Information Center

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…

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

PubMed Central

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

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

ERIC Educational Resources Information Center

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…

Robots Learn to Recognize Individuals from Imitative Encounters with People and Avatars

PubMed Central

Boucenna, Sofiane; Cohen, David; Meltzoff, Andrew N.; Gaussier, Philippe; Chetouani, Mohamed

2016-01-01

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. PMID:26844862

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

PubMed

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.

A developmental roadmap for learning by imitation in robots.

PubMed

Lopes, Manuel; Santos-Victor, José

2007-04-01

In this paper, we present a strategy whereby a robot acquires the capability to learn by imitation following a developmental pathway consisting on three levels: 1) sensory-motor coordination; 2) world interaction; and 3) imitation. With these stages, the system is able to learn tasks by imitating human demonstrators. We describe results of the different developmental stages, involving perceptual and motor skills, implemented in our humanoid robot, Baltazar. At each stage, the system's attention is drawn toward different entities: its own body and, later on, objects and people. Our main contributions are the general architecture and the implementation of all the necessary modules until imitation capabilities are eventually acquired by the robot. Also, several other contributions are made at each level: learning of sensory-motor maps for redundant robots, a novel method for learning how to grasp objects, and a framework for learning task description from observation for program-level imitation. Finally, vision is used extensively as the sole sensing modality (sometimes in a simplified setting) avoiding the need for special data-acquisition hardware.

A Bayesian Developmental Approach to Robotic Goal-Based Imitation Learning.

PubMed

Chung, Michael Jae-Yoon; Friesen, Abram L; Fox, Dieter; Meltzoff, Andrew N; Rao, Rajesh P N

2015-01-01

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.

Reinforcement of Infant Vocalizations through Contingent Vocal Imitation

ERIC Educational Resources Information Center

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…

Bend-imitating models of abruptly bent electron waveguides

NASA Astrophysics Data System (ADS)

Vakhnenko, Oleksiy O.

2011-07-01

The fundamentals of bend-imitating approach regarding the one-electron quantum mechanics in abruptly bent ideal electron waveguides are given. In general, the theory allows to model each particular circularlike bend of a continuous quantum wire as some effective multichannel scatterer being pointlike in longitudinal direction. Its scattering ability is determined by the bending angle, mean bending radius, lateral coordinate (or coordinates) in wire cross section, time (or electronic energy), and possibly by the applied magnetic field. In an equivalent formulation, the theory gives rise to rather simple matching rules for the electron wave function and its longitudinal derivative affecting only the straight parts of a wire and thereby permitting to bypass a detailed quantum mechanical consideration of elbow domains. The proposed technique is applicable for the analytical investigation of spectral and transport electronic properties related to the ideal abruptly bent 3D wirelike structures of fixed cross section and is adaptable to the 2D wirelike structures as well as to the wirelike structures subjected to the magnetic field perpendicular to the plane of wire bending. In the framework of bend-imitating approach, the investigation of electron scattering in a singly bent 2D quantum wire and a doubly bent 2D quantum wire with S-like bend has been made and the explicit dependences of transmission and reflection coefficients on geometrical parameters of respective structure as well as on electron energy have been obtained. The total suppression of mixing between the scattering channels of S-like bent quantum wire is predicted.

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

PubMed Central

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

Study on ancient Chinese imitated GE ware by INAA and WDXRF

NASA Astrophysics Data System (ADS)

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.

Advances in high gradient normal conducting accelerator structures

DOE PAGES

Simakov, Evgenya Ivanovna; Dolgashev, Valery A.; Tantawi, Sami G.

2018-03-09

Here, this paper reviews the current state-of-the-art in understanding the phenomena of ultra-high vacuum radio-frequency (rf) breakdown in accelerating structures and the efforts to improve stable operation of the structures at accelerating gradients above 100 MV/m. Numerous studies have been conducted recently with the goal of understanding the dependence of the achievable accelerating gradients and breakdown rates on the frequency of operations, the geometry of the structure, material and method of fabrication, and operational temperature. Tests have been conducted with single standing wave accelerator cells as well as with the multi-cell traveling wave structures. Notable theoretical effort was directed atmore » understanding the physical mechanisms of the rf breakdown and its statistical behavior. Finally, the achievements presented in this paper are the result of the large continuous self-sustaining collaboration of multiple research institutions in the United States and worldwide.« less

Advances in high gradient normal conducting accelerator structures

DOE Office of Scientific and Technical Information (OSTI.GOV)

Simakov, Evgenya Ivanovna; Dolgashev, Valery A.; Tantawi, Sami G.

Here, this paper reviews the current state-of-the-art in understanding the phenomena of ultra-high vacuum radio-frequency (rf) breakdown in accelerating structures and the efforts to improve stable operation of the structures at accelerating gradients above 100 MV/m. Numerous studies have been conducted recently with the goal of understanding the dependence of the achievable accelerating gradients and breakdown rates on the frequency of operations, the geometry of the structure, material and method of fabrication, and operational temperature. Tests have been conducted with single standing wave accelerator cells as well as with the multi-cell traveling wave structures. Notable theoretical effort was directed atmore » understanding the physical mechanisms of the rf breakdown and its statistical behavior. Finally, the achievements presented in this paper are the result of the large continuous self-sustaining collaboration of multiple research institutions in the United States and worldwide.« less

The Impact of Imitation on Vaccination Behavior in Social Contact Networks

PubMed Central

Ndeffo Mbah, Martial L.; Liu, Jingzhou; Bauch, Chris T.; Tekel, Yonas I.; Medlock, Jan; Meyers, Lauren Ancel; Galvani, Alison P.

2012-01-01

Previous game-theoretic studies of vaccination behavior typically have often assumed that populations are homogeneously mixed and that individuals are fully rational. In reality, there is heterogeneity in the number of contacts per individual, and individuals tend to imitate others who appear to have adopted successful strategies. Here, we use network-based mathematical models to study the effects of both imitation behavior and contact heterogeneity on vaccination coverage and disease dynamics. We integrate contact network epidemiological models with a framework for decision-making, within which individuals make their decisions either based purely on payoff maximization or by imitating the vaccination behavior of a social contact. Simulations suggest that when the cost of vaccination is high imitation behavior may decrease vaccination coverage. However, when the cost of vaccination is small relative to that of infection, imitation behavior increases vaccination coverage, but, surprisingly, also increases the magnitude of epidemics through the clustering of non-vaccinators within the network. Thus, imitation behavior may impede the eradication of infectious diseases. Calculations that ignore behavioral clustering caused by imitation may significantly underestimate the levels of vaccination coverage required to attain herd immunity. PMID:22511859

The relationship between attention and deferred imitation in 12-month-old infants.

PubMed

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.

An exploration of imitation recognition in young children with autism spectrum disorders.

PubMed

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.

A Qualitative Analysis of Imitation Performances of Preschoolers with Down Syndrome

ERIC Educational Resources Information Center

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…

An assessment of generalization of imitation in two enculturated orangutans (Pongo pygmaeus).

PubMed

Yunger, Jennifer L; Bjorklund, David F

2004-06-01

Deferred imitation of object-related actions and generalization of imitation to similar but not identical tasks were assessed in two human-reared (enculturated) orangutans (Pongo pygmaeus). Each ape displayed low levels of deferred imitation but did not provide evidence of generalization of imitation. Results suggest that enculturated orangutans may not possess social-cognitive abilities similar to that which enculturated chimpanzees are assumed to possess.

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

PubMed

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.

A Bayesian Developmental Approach to Robotic Goal-Based Imitation Learning

PubMed Central

Chung, Michael Jae-Yoon; Friesen, Abram L.; Fox, Dieter; Meltzoff, Andrew N.; Rao, Rajesh P. N.

2015-01-01

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. PMID:26536366

Methodological Issues in Measures of Imitative Reaction Times

ERIC Educational Resources Information Center

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…

Imitation in Infancy: The Wealth of the Stimulus

ERIC Educational Resources Information Center

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,…

Ritual, Imitation and Education in R. S. Peters

ERIC Educational Resources Information Center

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…

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

PubMed

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.

Imitation of transitive and intransitive actions in healthy individuals.

PubMed

Carmo, Joana C; Rumiati, Raffaella I

2009-04-01

A handful of patients have been described as being impaired in performing transitive gestures, despite being still able to perform intransitive gestures. This impairment need not be explained by assuming different mechanisms; rather, it can be due to transitive actions being more difficult. In this study we tested whether neurologically healthy participants had greater difficulties in imitating transitive actions with respect to intransitive actions. Consistent with the prediction, subjects imitated intransitive better than transitive gestures. The ease of imitation of intransitive actions supports the complexity account of apraxic impairments.

Neural mechanisms of imitation and 'mirror neuron' functioning in autistic spectrum disorder.

PubMed

Williams, Justin H G; Waiter, Gordon D; Gilchrist, Anne; Perrett, David I; Murray, Alison D; Whiten, Andrew

2006-01-01

An association between autistic spectrum disorder and imitative impairment might result from dysfunction in mirror neurons (MNs) that serve to relate observed actions to motor codings. To explore this hypothesis, we employed a functional magnetic resonance imaging (fMRI) protocol previously used to identify the neural substrate of imitation, and human MN function, to compare 16 adolescent males of normal intelligence with autistic spectrum disorder (ASD) and age, sex and IQ matched controls. In the control group, in accord with previous findings, we identified activity attributable to MNs in areas of the right parietal lobe. Activity in this area was less extensive in the ASD group and was absent during non-imitative action execution. Broca's area was minimally active during imitation in controls. Differential patterns of activity during imitation and action observation in ASD and controls were most evident in an area at the right temporo-parietal junction also associated with a 'theory of mind' (ToM) function. ASD participants also failed to show modulation of left amygdala activity during imitation that was evident in the controls. This may have implications for understanding the imitation of emotional stimuli in ASD. Overall, we suggest that ASD is associated with altered patterns of brain activity during imitation, which could stem from poor integration between areas serving visual, motor, proprioceptive and emotional functions. Such poor integration is likely to adversely affect the development of ToM through imitation as well as other aspects of social cognitive function in ASD.

A Qualitative Analysis of Imitation Performances of Preschoolers With Down Syndrome.

PubMed

Vanvuchelen, Marleen

2016-05-01

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 disability of undifferentiated etiology (ID-UND). Imitation performances on the Preschool Imitation and Praxis Scale were videotaped for blind scoring on 30 possible errors. Children with DS made fewer production errors (synkinesias, OR 0.3 [0.1-0.7]), but more conceptual errors (substitution, OR 2.5 [1.6-3.9]) compared to children with ID-UND. This finding is in line with the view of a cognitive phenotype in DS, which is characterized by preserved visuospatial and impaired language abilities.

Accelerated Electron-Beam Formation with a High Capture Coefficient in a Parallel Coupled Accelerating Structure

NASA Astrophysics Data System (ADS)

Chernousov, Yu. D.; Shebolaev, I. V.; Ikryanov, I. M.

2018-01-01

An electron beam with a high (close to 100%) coefficient of electron capture into the regime of acceleration has been obtained in a linear electron accelerator based on a parallel coupled slow-wave structure, electron gun with microwave-controlled injection current, and permanent-magnet beam-focusing system. The high capture coefficient was due to the properties of the accelerating structure, beam-focusing system, and electron-injection system. Main characteristics of the proposed systems are presented.

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

PubMed

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

2013-01-01

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

Influence of action-effect associations acquired by ideomotor learning on imitation.

PubMed

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.

Influence of Action-Effect Associations Acquired by Ideomotor Learning on Imitation

PubMed Central

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

Enactivism and neonatal imitation: conceptual and empirical considerations and clarifications

PubMed Central

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. PMID:25228895

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

PubMed

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.

Variable energy constant current accelerator structure

DOEpatents

Anderson, O.A.

1988-07-13

A variable energy, constant current ion beam accelerator structure is disclosed comprising an ion source capable of providing the desired ions, a pre-accelerator for establishing an initial energy level, a matching/pumping module having means for focusing means for maintaining the beam current, and at least one main accelerator module for continuing beam focus, with means capable of variably imparting acceleration to the beam so that a constant beam output current is maintained independent of the variable output energy. In a preferred embodiment, quadrupole electrodes are provided in both the matching/pumping module and the one or more accelerator modules, and are formed using four opposing cylinder electrodes which extend parallel to the beam axis and are spaced around the beam at 90/degree/ intervals with opposing electrodes maintained at the same potential. 12 figs., 3 tabs.

Observation of Wakefield Suppression in a Photonic-Band-Gap Accelerator Structure

DOE PAGES

Simakov, Evgenya I.; Arsenyev, Sergey A.; Buechler, Cynthia E.; ...

2016-02-10

We report experimental observation of higher order mode (HOM) wakefield suppression in a room-temperature traveling-wave photonic band gap (PBG) accelerating structure at 11.700 GHz. It has been long recognized that PBG structures have potential for reducing long-range wakefields in accelerators. The first ever demonstration of acceleration in a room-temperature PBG structure was conducted in 2005. Since then, the importance of PBG accelerator research has been recognized by many institutions. However, the full experimental characterization of the wakefield spectrum and demonstration of wakefield suppression when the accelerating structure is excited by an electron beam has not been performed to date. Wemore » conducted an experiment at the Argonne Wakefield Accelerator (AWA) test facility and observed wakefields excited by a single high charge electron bunch when it passes through a PBG accelerator structure. Lastly, excellent HOM suppression properties of the PBG accelerator were demonstrated in the beam test.« less

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

ERIC Educational Resources Information Center

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…

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

ERIC Educational Resources Information Center

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…

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

PubMed Central

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

EEG Mu Rhythm and Imitation Impairments in Individuals with Autism Spectrum Disorder

PubMed Central

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

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

PubMed

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.

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

PubMed Central

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. PMID:25767454

Developing an effective IM/IT strategy.

PubMed

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.

On the relationship between collisionless shock structure and energetic particle acceleration

NASA Technical Reports Server (NTRS)

Kennel, C. F.

1983-01-01

Recent experimental research on bow shock structure and theoretical studies of quasi-parallel shock structure and shock acceleration of energetic particles were reviewed, to point out the relationship between structure and particle acceleration. The phenomenological distinction between quasi-parallel and quasi-perpendicular shocks that has emerged from bow shock research; present efforts to extend this work to interplanetary shocks; theories of particle acceleration by shocks; and particle acceleration to shock structures using multiple fluid models were discussed.

Neonatal Imitation: Theory, Experimental Design, and Significance for the Field of Social Cognition.

PubMed

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.

Neonatal Imitation: Theory, Experimental Design, and Significance for the Field of Social Cognition

PubMed Central

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. PMID:28824502

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

PubMed

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.

Voluntary Imitation in Alzheimer’s Disease Patients

PubMed Central

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

Initial investigations into preschoolers' mirror-style versus transposed bodily imitation.

PubMed

Dunphy-Lelii, Sarah

2014-03-01

In typical development, imitation plays a key role in sociocognitive competence. The current study investigated a hypothesised developmental trajectory in face-to-face full body imitation style in 91 preschoolers, as well as a relation between imitation style and theory of mind (ToM). Children's response style to 8 lateralized action prompts was recorded as either "mirror" or "transposed." Overall, mirror-style response increased with age, and was predominant for children and an adult comparison group. Imitation style varied depending on the prompt given, with certain actions showing a side bias regardless of prompt viewed. Mirror-style response was correlated with ToM performance after controlling for language ability, but not after controlling for age. Findings are discussed regarding the hypothesised relation between postural synchrony and larger perspective-taking competence.

Imitation, Sign Language Skill and the Developmental Ease of Language Understanding (D-ELU) Model.

PubMed

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

Imitation, Sign Language Skill and the Developmental Ease of Language Understanding (D-ELU) Model

PubMed Central

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

Cooperation in the Mixed Population Minority Game with Imitation

NASA Astrophysics Data System (ADS)

Quan, Hong-Jun; Wang, Bing-Hong; Hui, Pak-Ming; Luo, Xiao-Shu

2001-09-01

After studying the effects of imitation on the mixed population of adaptive agents with different memories competing in a minority game, we have found that when the pure population lies in a crowded regime, the introduction of imitation can considerably improve cooperation among agents in a money market.

Comprehensive Longitudinal Study Challenges the Existence of Neonatal Imitation in Humans.

PubMed

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.

Imitation and the Social Mind: Autism and Typical Development

ERIC Educational Resources Information Center

Rogers, Sally J., Ed.; Williams, Justin H. G., Ed.

2006-01-01

From earliest infancy, a typically developing child imitates or mirrors the facial expressions, postures and gestures, and emotional behavior of others. Where does this capacity come from, and what function does it serve? What happens when imitation is impaired? Synthesizing cutting-edge research emerging from a range of disciplines, this…

Simulation Studies of the Dielectric Grating as an Accelerating and Focusing Structure

DOE Office of Scientific and Technical Information (OSTI.GOV)

Soong, Ken; Peralta, E.A.; Byer, R.L.

A grating-based design is a promising candidate for a laser-driven dielectric accelerator. Through simulations, we show the merits of a readily fabricated grating structure as an accelerating component. Additionally, we show that with a small design perturbation, the accelerating component can be converted into a focusing structure. The understanding of these two components is critical in the successful development of any complete accelerator. The concept of accelerating electrons with the tremendous electric fields found in lasers has been proposed for decades. However, until recently the realization of such an accelerator was not technologically feasible. Recent advances in the semiconductor industry,more » as well as advances in laser technology, have now made laser-driven dielectric accelerators imminent. The grating-based accelerator is one proposed design for a dielectric laser-driven accelerator. This design, which was introduced by Plettner, consists of a pair of opposing transparent binary gratings, illustrated in Fig. 1. The teeth of the gratings serve as a phase mask, ensuring a phase synchronicity between the electromagnetic field and the moving particles. The current grating accelerator design has the drive laser incident perpendicular to the substrate, which poses a laser-structure alignment complication. The next iteration of grating structure fabrication seeks to monolithically create an array of grating structures by etching the grating's vacuum channel into a fused silica wafer. With this method it is possible to have the drive laser confined to the plane of the wafer, thus ensuring alignment of the laser-and-structure, the two grating halves, and subsequent accelerator components. There has been previous work using 2-dimensional finite difference time domain (2D-FDTD) calculations to evaluate the performance of the grating accelerator structure. However, this work approximates the grating as an infinite structure and does not accurately model a

Imitative Learning of Actions on Objects by Children, Chimpanzees, and Enculturated Chimpanzees.

ERIC Educational Resources Information Center

Tomasello, Michael; And Others

1993-01-01

Compared the abilities of 3 mother-reared and 3 human-raised (enculturated) chimpanzees and 16 human toddlers to imitatively learn novel actions on objects. Found that mother-reared chimpanzees were poorer imitators than both enculturated chimpanzees and human children, who did not differ from one another in imitative learning. On time delay…

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

ERIC Educational Resources Information Center

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…

Phonetic and phonological imitation of intonation in two varieties of Italian

PubMed Central

D’Imperio, Mariapaola; Cavone, Rossana; Petrone, Caterina

2014-01-01

The aim of this study was to test whether both phonetic and phonological representations of intonation can be rapidly modified when imitating utterances belonging to a different regional variety of the same language. Our main hypothesis was that tonal alignment, just as other phonetic features of speech, would be rapidly modified by Italian speakers when imitating pitch accents of a different (Southern) variety of Italian. In particular, we tested whether Bari Italian (BI) speakers would produce later peaks for their native rising L + H* (question pitch accent) in the process of imitating Neapolitan Italian (NI) rising L* + H accents. Also, we tested whether BI speakers are able to modify other phonetic properties (pitch level) as well as phonological characteristics (changes in tonal composition) of the same contour. In a follow-up study, we tested if the reverse was also true, i.e., whether NI speakers would produce earlier peaks within the L* + H accent in the process of imitating the L + H* of BI questions, despite the presence of a contrast between two rising accents in this variety. Our results show that phonetic detail of tonal alignment can be successfully modified by both BI and NI speakers when imitating a model speaker of the other variety. The hypothesis of a selective imitation process preventing alignment modifications in NI was hence not supported. Moreover the effect was significantly stronger for low frequency words. Participants were also able to imitate other phonetic cues, in that they modified global utterance pitch level. Concerning phonological convergence, speakers modified the tonal specification of the edge tones in order to resemble that of the other variety by either suppressing or increasing the presence of a final H%. Hence, our data show that intonation imitation leads to fast modification of both phonetic and phonological intonation representations including detail of tonal alignment and pitch scaling. PMID:25408676

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

PubMed

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.

An Evaluation of Imitation Recognition Abilities in Typically Developing Children and Young Children with Autism Spectrum Disorder.

PubMed

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.

rf breakdown tests of mm-wave metallic accelerating structures

DOE PAGES

Dal Forno, Massimo; Dolgashev, Valery; Bowden, Gordon; ...

2016-01-06

In this study, we explore the physics and frequency-scaling of vacuum rf breakdowns at sub-THz frequencies. We present the experimental results of rf tests performed in metallic mm-wave accelerating structures. These experiments were carried out at the facility for advanced accelerator experimental tests (FACET) at the SLAC National Accelerator Laboratory. The rf fields were excited by the FACET ultrarelativistic electron beam. We compared the performances of metal structures made with copper and stainless steel. The rf frequency of the fundamental accelerating mode, propagating in the structures at the speed of light, varies from 115 to 140 GHz. The traveling wavemore » structures are 0.1 m long and composed of 125 coupled cavities each. We determined the peak electric field and pulse length where the structures were not damaged by rf breakdowns. We calculated the electric and magnetic field correlated with the rf breakdowns using the FACET bunch parameters. The wakefields were calculated by a frequency domain method using periodic eigensolutions. Such a method takes into account wall losses and is applicable to a large variety of geometries. The maximum achieved accelerating gradient is 0.3 GV/m with a peak surface electric field of 1.5 GV/m and a pulse length of about 2.4 ns.« less

Motor Imitation Abilities and Neurological Signs in Autistic Children.

ERIC Educational Resources Information Center

Jones, Vicki; Prior, Margot

1985-01-01

Ten autistic children were compared with 10 chronologically and mentally normal children on two tests of motor imitation and on the Herzig Battery for Non-Focal Neurological Signs. Results indicated that autistic Ss had significant handicaps in the neurodevelopmental area, with very poor performance on motor imitation tasks and a universal and…

Atypical Social Modulation of Imitation in Autism Spectrum Conditions

ERIC Educational Resources Information Center

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…

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

ERIC Educational Resources Information Center

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…

Training Social Cognition: From Imitation to Theory of Mind

ERIC Educational Resources Information Center

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.…

Neural bases of imitation and pantomime in acute stroke patients: distinct streams for praxis.

PubMed

Hoeren, Markus; Kümmerer, Dorothee; Bormann, Tobias; Beume, Lena; Ludwig, Vera M; Vry, Magnus-Sebastian; Mader, Irina; Rijntjes, Michel; Kaller, Christoph P; Weiller, Cornelius

2014-10-01

specifically related to the dorso-dorsal stream, i.e. posterior intraparietal sulcus and superior parietal lobule, were more strongly associated with imitation. Conversely, in contrast to imitation, pantomime deficits were associated with ventro-dorsal regions such as the supramarginal gyrus, as well as brain structures counted to the ventral stream, such as the extreme capsule. Ventral stream involvement was especially clear for content errors which were related to anterior temporal damage. However, movement errors were not consistently associated with a specific lesion location. In summary, our results indicate that imitation mainly relies on the dorso-dorsal stream for visuo-motor conversion and on-line movement control. Conversely, pantomime additionally requires ventro-dorsal and ventral streams for access to stored action engrams and retrieval of tool-action relationships. © The Author (2014). Published by Oxford University Press on behalf of the Guarantors of Brain. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

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

PubMed

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.

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

PubMed

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.

Object words modulate the activity of the mirror neuron system during action imitation.

PubMed

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.

Method for computationally efficient design of dielectric laser accelerator structures

DOE PAGES

Hughes, Tyler; Veronis, Georgios; Wootton, Kent P.; ...

2017-06-22

Here, dielectric microstructures have generated much interest in recent years as a means of accelerating charged particles when powered by solid state lasers. The acceleration gradient (or particle energy gain per unit length) is an important figure of merit. To design structures with high acceleration gradients, we explore the adjoint variable method, a highly efficient technique used to compute the sensitivity of an objective with respect to a large number of parameters. With this formalism, the sensitivity of the acceleration gradient of a dielectric structure with respect to its entire spatial permittivity distribution is calculated by the use of onlymore » two full-field electromagnetic simulations, the original and ‘adjoint’. The adjoint simulation corresponds physically to the reciprocal situation of a point charge moving through the accelerator gap and radiating. Using this formalism, we perform numerical optimizations aimed at maximizing acceleration gradients, which generate fabricable structures of greatly improved performance in comparison to previously examined geometries.« less

Anatomical and spatial matching in imitation: Evidence from left and right brain-damaged patients.

PubMed

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.

Accelerated laboratory weathering of acrylic lens materials

NASA Astrophysics Data System (ADS)

Arndt, Thomas; Richter, Steffen; Kogler, René; Pasierb, Mike; Walby, Christopher

2015-09-01

Flat samples from various poly(methyl methacrylate) (PMMA) formulations were subjected to outdoor weathering in Arizona and Florida, EMMAQUA® accelerated outdoor weathering, and two accelerated laboratory weathering procedures at 3 Sun irradiance which, imitate dry (Arizona) and wet (Florida) conditions. The main mode of degradation is yellowing and not the generation of haze for any weathering procedure within the investigated radiant exposure. Higher UV absorber concentrations lead to smaller changes in optical properties and in the resulting relative concentrator photovoltaic (CPV) module efficiencies. Comparison of sample properties after various weathering procedures reveals that the influence of weathering factors other than radiant exposure depends on the sample as well.

Reafferent copies of imitated actions in the right superior temporal cortex

PubMed Central

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

Imitation dynamics of vaccine decision-making behaviours based on the game theory.

PubMed

Yang, Junyuan; Martcheva, Maia; Chen, Yuming

2016-01-01

Based on game theory, we propose an age-structured model to investigate the imitation dynamics of vaccine uptake. We first obtain the existence and local stability of equilibria. We show that Hopf bifurcation can occur. We also establish the global stability of the boundary equilibria and persistence of the disease. The theoretical results are supported by numerical simulations.

Automatic imitation of pro- and antisocial gestures: Is implicit social behavior censored?

PubMed

Cracco, Emiel; Genschow, Oliver; Radkova, Ina; Brass, Marcel

2018-01-01

According to social reward theories, automatic imitation can be understood as a means to obtain positive social consequences. In line with this view, it has been shown that automatic imitation is modulated by contextual variables that constrain the positive outcomes of imitation. However, this work has largely neglected that many gestures have an inherent pro- or antisocial meaning. As a result of their meaning, antisocial gestures are considered taboo and should not be used in public. In three experiments, we show that automatic imitation of symbolic gestures is modulated by the social intent of these gestures. Experiment 1 (N=37) revealed reduced automatic imitation of antisocial compared with prosocial gestures. Experiment 2 (N=118) and Experiment 3 (N=118) used a social priming procedure to show that this effect was stronger in a prosocial context than in an antisocial context. These findings were supported in a within-study meta-analysis using both frequentist and Bayesian statistics. Together, our results indicate that automatic imitation is regulated by internalized social norms that act as a stop signal when inappropriate actions are triggered. Copyright © 2017 Elsevier B.V. All rights reserved.

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

ERIC Educational Resources Information Center

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…

Development of High-Gradient Dielectric Laser-Driven Particle Accelerator Structures

DOE Office of Scientific and Technical Information (OSTI.GOV)

Byer, Robert L.

2013-11-07

The thrust of Stanford's program is to conduct research on high-gradient dielectric accelerator structures driven with high repetition-rate, tabletop infrared lasers. The close collaboration between Stanford and SLAC (Stanford Linear Accelerator Center) is critical to the success of this project, because it provides a unique environment where prototype dielectric accelerator structures can be rapidly fabricated and tested with a relativistic electron beam.

Motor facilitation during real-time movement imitation in Parkinson's disease: a virtual reality study.

PubMed

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.

Direct and octave-shifted pitch matching during nonword imitations in men, women, and children

PubMed Central

Peter, Beate; Foster, Bronsyn; Haas, Heather; Middleton, Kyle; McKibben, Kiersten

2014-01-01

Summary Objectives 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. To evaluate the role of a history of speech sound disorder (SSD) in the adult participants. Study Design Observational. Methods 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 to that in the targets and in the participants’ non-imitated control word productions. Results 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. Conclusions 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. PMID:25439509

Phonetic imitation from an individual-difference perspective: subjective attitude, personality and "autistic" traits.

PubMed

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.

EH 11n modes E type in the disk and washer accelerating structure

NASA Astrophysics Data System (ADS)

Andreev, V. G.; Belugin, V. M.; Daikovsky, A. G.; Esin, S. K.; Kravchuk, L. V.; Paramonov, V. V.; Ryabov, A. D.

1983-01-01

The disk and washer accelerating structure has a great deal to do with high-beta structures progress. The frequencies and electromagnetic fields for modes, which have a different number of azimuthal variations, are calculated to determined the dispersion properties and other characteristics of parasitic modes in a disc and washer accelerating structure. The main attention was given to the accelerating structure of the linear accelerator of the Institute for Nuclear Research (INR) of the USSR Academy of Sciences. Modification of a structure for PIGMI accelerator (LANL, USA) is considered briefly.

Controlling automatic imitative tendencies: interactions between mirror neuron and cognitive control systems.

PubMed

Cross, Katy A; Torrisi, Salvatore; Reynolds Losin, Elizabeth A; Iacoboni, Marco

2013-12-01

Humans have an automatic tendency to imitate others. Although several regions commonly observed in social tasks have been shown to be involved in imitation control, there is little work exploring how these regions interact with one another. We used fMRI and dynamic causal modeling to identify imitation-specific control mechanisms and examine functional interactions between regions. Participants performed a pre-specified action (lifting their index or middle finger) in response to videos depicting the same two actions (biological cues) or dots moving with similar trajectories (non-biological cues). On congruent trials, the stimulus and response were similar (e.g. index finger response to index finger or left side dot stimulus), while on incongruent trials the stimulus and response were dissimilar (e.g. index finger response to middle finger or right side dot stimulus). Reaction times were slower on incongruent compared to congruent trials for both biological and non-biological stimuli, replicating previous findings that suggest the automatic imitative or spatially compatible (congruent) response must be controlled on incongruent trials. Neural correlates of the congruency effects were different depending on the cue type. The medial prefrontal cortex, anterior cingulate, inferior frontal gyrus pars opercularis (IFGpo) and the left anterior insula were involved specifically in controlling imitation. In addition, the IFGpo was also more active for biological compared to non-biological stimuli, suggesting that the region represents the frontal node of the human mirror neuron system (MNS). Effective connectivity analysis exploring the interactions between these regions, suggests a role for the mPFC and ACC in imitative conflict detection and the anterior insula in conflict resolution processes, which may occur through interactions with the frontal node of the MNS. We suggest an extension of the previous models of imitation control involving interactions between imitation

Imitation and observational learning of hand actions: prefrontal involvement and connectivity.

PubMed

Higuchi, S; Holle, H; Roberts, N; Eickhoff, S B; Vogt, S

2012-01-16

The first aim of this event-related fMRI study was to identify the neural circuits involved in imitation learning. We used a rapid imitation task where participants directly imitated pictures of guitar chords. The results provide clear evidence for the involvement of dorsolateral prefrontal cortex, as well as the fronto-parietal mirror circuit (FPMC) during action imitation when the requirements for working memory are low. Connectivity analyses further indicated a robust connectivity between left prefrontal cortex and the components of the FPMC bilaterally. We conclude that a mechanism of automatic perception-action matching alone is insufficient to account for imitation learning. Rather, the motor representation of an observed, complex action, as provided by the FPMC, only serves as the 'raw material' for higher-order supervisory and monitoring operations associated with the prefrontal cortex. The second aim of this study was to assess whether these neural circuits are also recruited during observational practice (OP, without motor execution), or only during physical practice (PP). Whereas prefrontal cortex was not consistently activated in action observation across all participants, prefrontal activation intensities did predict the behavioural practice effects, thus indicating a crucial role of prefrontal cortex also in OP. In addition, whilst OP and PP produced similar activation intensities in the FPMC when assessed during action observation, during imitative execution, the practice-related activation decreases were significantly more pronounced for PP than for OP. This dissociation indicates a lack of execution-related resources in observationally practised actions. More specifically, we found neural efficiency effects in the right motor cingulate-basal ganglia circuit and the FPMC that were only observed after PP but not after OP. Finally, we confirmed that practice generally induced activation decreases in the FPMC during both action observation and

On the effectiveness of vocal imitations and verbal descriptions of sounds.

PubMed

Lemaitre, Guillaume; Rocchesso, Davide

2014-02-01

Describing unidentified sounds with words is a frustrating task and vocally imitating them is often a convenient way to address the issue. This article reports on a study that compared the effectiveness of vocal imitations and verbalizations to communicate different referent sounds. The stimuli included mechanical and synthesized sounds and were selected on the basis of participants' confidence in identifying the cause of the sounds, ranging from easy-to-identify to unidentifiable sounds. The study used a selection of vocal imitations and verbalizations deemed adequate descriptions of the referent sounds. These descriptions were used in a nine-alternative forced-choice experiment: Participants listened to a description and picked one sound from a list of nine possible referent sounds. Results showed that recognition based on verbalizations was maximally effective when the referent sounds were identifiable. Recognition accuracy with verbalizations dropped when identifiability of the sounds decreased. Conversely, recognition accuracy with vocal imitations did not depend on the identifiability of the referent sounds and was as high as with the best verbalizations. This shows that vocal imitations are an effective means of representing and communicating sounds and suggests that they could be used in a number of applications.

Effects of children's working memory capacity and processing speed on their sentence imitation performance.

PubMed

Poll, Gerard H; Miller, Carol A; Mainela-Arnold, Elina; Adams, Katharine Donnelly; Misra, Maya; Park, Ji Sook

2013-01-01

More limited working memory capacity and slower processing for language and cognitive tasks are characteristics of many children with language difficulties. Individual differences in processing speed have not consistently been found to predict language ability or severity of language impairment. There are conflicting views on whether working memory and processing speed are integrated or separable abilities. To evaluate four models for the relations of individual differences in children's processing speed and working memory capacity in sentence imitation. The models considered whether working memory and processing speed are integrated or separable, as well as the effect of the number of operations required per sentence. The role of working memory as a mediator of the effect of processing speed on sentence imitation was also evaluated. Forty-six children with varied language and reading abilities imitated sentences. Working memory was measured with the Competing Language Processing Task (CLPT), and processing speed was measured with a composite of truth-value judgment and rapid automatized naming tasks. Mixed-effects ordinal regression models evaluated the CLPT and processing speed as predictors of sentence imitation item scores. A single mediator model evaluated working memory as a mediator of the effect of processing speed on sentence imitation total scores. Working memory was a reliable predictor of sentence imitation accuracy, but processing speed predicted sentence imitation only as a component of a processing speed by number of operations interaction. Processing speed predicted working memory capacity, and there was evidence that working memory acted as a mediator of the effect of processing speed on sentence imitation accuracy. The findings support a refined view of working memory and processing speed as separable factors in children's sentence imitation performance. Processing speed does not independently explain sentence imitation accuracy for all sentence

Doing Justice to the Imitation Game

NASA Astrophysics Data System (ADS)

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.

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

PubMed

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.

Effects of movement imitation training in Parkinson's disease: A virtual reality pilot study.

PubMed

Robles-García, Verónica; Corral-Bergantiños, Yoanna; Espinosa, Nelson; García-Sancho, Carlos; Sanmartín, Gabriel; Flores, Julián; Cudeiro, Javier; Arias, Pablo

2016-05-01

Hypometria is a clinical motor sign in Parkinson's disease. Its origin likely emerges from basal ganglia dysfunction, leading to an impaired control of inhibitory intracortical motor circuits. Some neurorehabilitation approaches include movement imitation training; besides the effects of motor practice, there might be a benefit due to observation and imitation of un-altered movement patterns. In this sense, virtual reality facilitates the process by customizing motor-patterns to be observed and imitated. To evaluate the effect of a motor-imitation therapy focused on hypometria in Parkinson's disease using virtual reality. We carried out a randomized controlled pilot-study. Sixteen patients were randomly assigned in experimental and control groups. Groups underwent 4-weeks of training based on finger-tapping with the dominant hand, in which imitation was the differential factor (only the experimental group imitated). We evaluated self-paced movement features and cortico-spinal excitability (recruitment curves and silent periods in both hemispheres) before, immediately after, and two weeks after the training period. Movement amplitude increased significantly after the therapy in the experimental group for the trained and un-trained hands. Motor thresholds and silent periods evaluated with transcranial magnetic stimulation were differently modified by training in the two groups; although the changes in the input-output recruitment were similar. This pilot study suggests that movement imitation therapy enhances the effect of motor practice in patients with Parkinson's disease; imitation-training might be helpful for reducing hypometria in these patients. These results must be clarified in future larger trials. Copyright © 2016 Elsevier Ltd. All rights reserved.

Video stimuli reduce object-directed imitation accuracy: a novel two-person motion-tracking approach.

PubMed

Reader, Arran T; Holmes, Nicholas P

2015-01-01

Imitation is an important form of social behavior, and research has aimed to discover and explain the neural and kinematic aspects of imitation. However, much of this research has featured single participants imitating in response to pre-recorded video stimuli. This is in spite of findings that show reduced neural activation to video vs. real life movement stimuli, particularly in the motor cortex. We investigated the degree to which video stimuli may affect the imitation process using a novel motion tracking paradigm with high spatial and temporal resolution. We recorded 14 positions on the hands, arms, and heads of two individuals in an imitation experiment. One individual freely moved within given parameters (moving balls across a series of pegs) and a second participant imitated. This task was performed with either simple (one ball) or complex (three balls) movement difficulty, and either face-to-face or via a live video projection. After an exploratory analysis, three dependent variables were chosen for examination: 3D grip position, joint angles in the arm, and grip aperture. A cross-correlation and multivariate analysis revealed that object-directed imitation task accuracy (as represented by grip position) was reduced in video compared to face-to-face feedback, and in complex compared to simple difficulty. This was most prevalent in the left-right and forward-back motions, relevant to the imitator sitting face-to-face with the actor or with a live projected video of the same actor. The results suggest that for tasks which require object-directed imitation, video stimuli may not be an ecologically valid way to present task materials. However, no similar effects were found in the joint angle and grip aperture variables, suggesting that there are limits to the influence of video stimuli on imitation. The implications of these results are discussed with regards to previous findings, and with suggestions for future experimentation.

Imitation and Education: A Philosophical Inquiry into Learning by Example

ERIC Educational Resources Information Center

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…

25 CFR 304.1 - Penalties for imitation or unauthorized use.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 25 Indians 2 2010-04-01 2010-04-01 false Penalties for imitation or unauthorized use. 304.1 Section 304.1 Indians INDIAN ARTS AND CRAFTS BOARD, DEPARTMENT OF THE INTERIOR NAVAJO, PUEBLO, AND HOPI SILVER, USE OF GOVERNMENT MARK § 304.1 Penalties for imitation or unauthorized use. The use of Government...

Automatic imitation effects are influenced by experience of synchronous action in children.

PubMed

O'Sullivan, Eoin P; Bijvoet-van den Berg, Simone; Caldwell, Christine A

2018-07-01

By their fourth year of life, children are expert imitators, but it is unclear how this ability develops. One approach suggests that certain types of experience might forge associations between the sensory and motor representations of an action that may facilitate imitation at a later time. Sensorimotor experience of this sort may occur when an infant's action is imitated by a caregiver or when socially synchronous action occurs. This learning approach, therefore, predicts that the strength of sensory-motor associations should depend on the frequency and quality of previous experience. Here, we tested this prediction by examining automatic imitation, that is, the tendency of an action stimulus to facilitate the performance of that action and interfere with the performance of an incompatible action. We required children (aged between 3 years 8 months and 7 years 11 months) to respond to actions performed by an experimenter (e.g., two hands clapping) with both compatible actions (i.e., two hands clapping) and incompatible actions (i.e., two hands waving) at different stages in the experimental procedure. As predicted by a learning account, actions thought to be performed in synchrony (i.e., clapping/waving) produced stronger automatic imitation effects when compared with actions where previous sensorimotor experience is likely to be more limited (e.g., pointing/hand closing). Furthermore, these automatic imitation effects were not found to vary with age, with both compatible and incompatible responses quickening with age. These findings suggest a role for sensorimotor experience in the development of imitative ability. Copyright © 2018 Elsevier Inc. All rights reserved.

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

PubMed

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.

"Imitation of similar beings": social mimesis as an argument in evolutionary theory around 1900.

PubMed

Willer, Stefan

2009-01-01

The article analyzes imitation as both a fascinating and irritating phenomenon in "classical" evolutionary theory. Evolutionists situate imitation on the threshold between the natural and the socio-cultural, hence between the animal and the human. This intermediate position can be regarded as a symptom for the unresolved and maybe unresolvable problem of intentionality and teleology in nature. To elaborate this problem, I examine the ways in which imitation was conceived of by the German Africologist Wilhelm Bleek in his treatise On the Origin of Language and by Charles Darwin in The Descent of Man. Bleek and Darwin share a high esteem of imitation, which they see as the mainspring of human mental capacities, including language. But at the same time, imitation for them is the epitome of a low level of consciousness, embodied in the figures of the idiot, the savage, and the ape. Thus, the problem of similarity comes to the fore: similarity produced by imitation, but also being at the basis of every act of imitation. This problem is further evidenced with a side glance on Darwin's remarks about mimicry in The Origin of Species. The article closes with a literary reading of Franz Kafka's Report to an Academy, in which imitation and similarity represent survival strategies and motivate a strange shift from ape to man.

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

PubMed

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.

Authenticity and Imitation in Translating Exposition: A Corpus-Based Study

ERIC Educational Resources Information Center

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…

Sensitivity to Communicative Relevance Tells Young Children What to Imitate

ERIC Educational Resources Information Center

Southgate, Victoria; Chevallier, Coralie; Csibra, Gergely

2009-01-01

How do children decide which elements of an action demonstration are important to reproduce in the context of an imitation game? We tested whether selective imitation of a demonstrator's actions may be based on the same search for relevance that drives adult interpretation of ostensive communication. Three groups of 18-month-old infants were shown…

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

PubMed Central

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

Associations Between United States Medical Licensing Examination (USMLE) and Internal Medicine In-Training Examination (IM-ITE) Scores

PubMed Central

Zeger, Scott L.; Kolars, Joseph C.

2008-01-01

Background Little is known about the associations of previous standardized examination scores with scores on subsequent standardized examinations used to assess medical knowledge in internal medicine residencies. Objective To examine associations of previous standardized test scores on subsequent standardized test scores. Design Retrospective cohort study. Participants One hundred ninety-five internal medicine residents. Methods Bivariate associations of United States Medical Licensing Examination (USMLE) Steps and Internal Medicine In-Training Examination (IM-ITE) scores were determined. Random effects analysis adjusting for repeated administrations of the IM-ITE and other variables known or hypothesized to affect IM-ITE score allowed for discrimination of associations of individual USMLE Step scores on IM-ITE scores. Results In bivariate associations, USMLE scores explained 17% to 27% of the variance in IME-ITE scores, and previous IM-ITE scores explained 66% of the variance in subsequent IM-ITE scores. Regression coefficients (95% CI) for adjusted associations of each USMLE Step with IM-ITE scores were USMLE-1 0.19 (0.12, 0.27), USMLE-2 0.23 (0.17, 0.30), and USMLE-3 0.19 (0.09, 0.29). Conclusions No single USMLE Step is more strongly associated with IM-ITE scores than the others. Because previous IM-ITE scores are strongly associated with subsequent IM-ITE scores, appropriate modeling, such as random effects methods, should be used to account for previous IM-ITE administrations in studies for which IM-ITE score is an outcome. PMID:18612735

Associations between United States Medical Licensing Examination (USMLE) and Internal Medicine In-Training Examination (IM-ITE) scores.

PubMed

McDonald, Furman S; Zeger, Scott L; Kolars, Joseph C

2008-07-01

Little is known about the associations of previous standardized examination scores with scores on subsequent standardized examinations used to assess medical knowledge in internal medicine residencies. To examine associations of previous standardized test scores on subsequent standardized test scores. Retrospective cohort study. One hundred ninety-five internal medicine residents. Bivariate associations of United States Medical Licensing Examination (USMLE) Steps and Internal Medicine In-Training Examination (IM-ITE) scores were determined. Random effects analysis adjusting for repeated administrations of the IM-ITE and other variables known or hypothesized to affect IM-ITE score allowed for discrimination of associations of individual USMLE Step scores on IM-ITE scores. In bivariate associations, USMLE scores explained 17% to 27% of the variance in IME-ITE scores, and previous IM-ITE scores explained 66% of the variance in subsequent IM-ITE scores. Regression coefficients (95% CI) for adjusted associations of each USMLE Step with IM-ITE scores were USMLE-1 0.19 (0.12, 0.27), USMLE-2 0.23 (0.17, 0.30), and USMLE-3 0.19 (0.09, 0.29). No single USMLE Step is more strongly associated with IM-ITE scores than the others. Because previous IM-ITE scores are strongly associated with subsequent IM-ITE scores, appropriate modeling, such as random effects methods, should be used to account for previous IM-ITE administrations in studies for which IM-ITE score is an outcome.

Rational over-imitation: Preschoolers consider material costs and copy causally irrelevant actions selectively.

PubMed

Keupp, Stefanie; Bancken, Christin; Schillmöller, Jelka; Rakoczy, Hannes; Behne, Tanya

2016-02-01

Children's strong tendency to over-imitate - i.e., to reproduce causally irrelevant actions - presents a well-documented, yet puzzling, phenomenon. On first sight this instrumentally inefficient behavior seems maladaptive and different accounts have been put forward to explain it. Causal accounts claim that children are misled by an adult's demonstration, mistake the superfluous actions as causally necessary, and therefore imitate them. Other accounts emphasize cognitive-motivational aspects underlying over-imitation, e.g. social motivations to affiliate with the model, or to adhere to normative conventions. Since all accounts predict the occurrence of over-imitation under typical conditions, different parameters and circumstances have to be considered to distinguish between them. Thus, we investigated children's over-imitation and their spontaneous verbal reactions to a puppet's behavior, in contexts in which a causally irrelevant action either led to the destruction of a valuable object belonging to the experimenter, or not. In addition, children saw the full action sequence being demonstrated either with an instrumental or a conventional focus. Causal accounts predict no flexibility across these contexts, because over-imitation is said to occur automatically. Normative accounts claim that different normative considerations affect children's behavior and action parsing, and therefore predict different response patterns across conditions. We found that over-imitation was less frequent in costly and instrumental conditions. Children criticized the puppet for omitting irrelevant actions more often in the non-costly condition, but criticized her more often for performing irrelevant actions in the costly condition, often expressing their moral concern. The results support the rational normative action interpretation account of over-imitation. Copyright © 2015 Elsevier B.V. All rights reserved.

Neonatal imitation and an epigenetic account of mirror neuron development.

PubMed

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.

The Role of Elicited Verbal Imitation in Toddlers' Word Learning

ERIC Educational Resources Information Center

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…

25 CFR 141.27 - Trade in imitation Indian crafts prohibited.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 25 Indians 1 2013-04-01 2013-04-01 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 Indian crafts prohibited. No person may...

Strategies for Teaching Children with Autism to Imitate Response Chains Using Video Modeling

ERIC Educational Resources Information Center

Tereshko, Lisa; MacDonald, Rebecca; Ahearn, William H.

2010-01-01

Video modeling has been found to be an effective procedure for teaching a variety of skills to persons with autism, however, some individuals do not learn through video instruction. The purpose of the current investigation was to teach children with autism, who initially did not imitate a video model, to construct three toy structures through the…

Task-dependent and distinct roles of the temporoparietal junction and inferior frontal cortex in the control of imitation.

PubMed

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.

Relations between 18-month-olds' gaze pattern and target action performance: a deferred imitation study with eye tracking.

PubMed

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

Imitation, mirror neurons and autism.

PubMed

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.

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

ERIC Educational Resources Information Center

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…

Task-dependent and distinct roles of the temporoparietal junction and inferior frontal cortex in the control of imitation

PubMed Central

Obhi, Sukhvinder S.; Banissy, Michael J.; Santiesteban, Idalmis; Press, Clare; Catmur, Caroline; Bird, Geoffrey

2015-01-01

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. PMID:25481003

Becoming a high-fidelity - super - imitator: what are the contributions of social and individual learning?

PubMed

Subiaul, Francys; Patterson, Eric M; Schilder, Brian; Renner, Elizabeth; Barr, Rachel

2015-11-01

In contrast to other primates, human children's imitation performance goes from low to high fidelity soon after infancy. Are such changes associated with the development of other forms of learning? We addressed this question by testing 215 children (26-59 months) on two social conditions (imitation, emulation) - involving a demonstration - and two asocial conditions (trial-and-error, recall) - involving individual learning - using two touchscreen tasks. The tasks required responding to either three different pictures in a specific picture order (Cognitive: Airplane→Ball→Cow) or three identical pictures in a specific spatial order (Motor-Spatial: Up→Down→Right). There were age-related improvements across all conditions and imitation, emulation and recall performance were significantly better than trial-and-error learning. Generalized linear models demonstrated that motor-spatial imitation fidelity was associated with age and motor-spatial emulation performance, but cognitive imitation fidelity was only associated with age. While this study provides evidence for multiple imitation mechanisms, the development of one of those mechanisms - motor-spatial imitation - may be bootstrapped by the development of another social learning skill - motor-spatial emulation. Together, these findings provide important clues about the development of imitation, which is arguably a distinctive feature of the human species. © 2014 John Wiley & Sons Ltd.

Memory and representation in young children with Down syndrome: Exploring deferred imitation and object permanence.

PubMed

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.

Video-based intervention for children with autism: towards improved assessment of pre-requisite imitation skills.

PubMed

Rayner, Christopher

2015-04-01

To explore the relationship between responses to imitation assessment and video-based intervention (VBI) in children with autism. Interview- and observation-based imitation assessments were conducted for five boys with autism prior to VBI across three studies. In two of the three studies, the boys' imitative responses to videos with an animated model and a human model were also compared. Participants who were assessed to have strong imitation skills were also those who responded more positively to VBI. No clear differences were reported in the boys' responses to the equivalent videos with the animated model and the human model. The level of imitation skills required for successful VBI is relative to the target behaviour. Revision of existing imitation assessment measures, as well as development and validation of more comprehensive measures is warranted for use in conjunction with VBI.

Rethinking 'rational imitation' in 14-month-old infants: a perceptual distraction approach.

PubMed

Beisert, Miriam; Zmyj, Norbert; Liepelt, Roman; Jung, Franziska; Prinz, Wolfgang; Daum, Moritz M

2012-01-01

In their widely noticed study, Gergely, Bekkering, and Király (2002) showed that 14-month-old infants imitated an unusual action only if the model freely chose to perform this action and not if the choice of the action could be ascribed to external constraints. They attributed this kind of selective imitation to the infants' capacity of understanding the principle of rational action. In the current paper, we present evidence that a simpler approach of perceptual distraction may be more appropriate to explain their results. When we manipulated the saliency of context stimuli in the two original conditions, the results were exactly opposite to what rational imitation predicts. Based on these findings, we reject the claim that the notion of rational action plays a key role in selective imitation in 14-month-olds.

Unintended Imitation in Nonword Repetition

ERIC Educational Resources Information Center

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

2009-01-01

Verbal repetition is conventionally considered to require motor-reproduction of only the phonologically relevant content of a perceived linguistic stimulus, while imitation of incidental acoustic properties of the stimulus is not an explicit part of this task. Exemplar-based theories of speech processing, however, would predict that imitation…

Phonetic Imitation from an Individual-Difference Perspective: Subjective Attitude, Personality and “Autistic” Traits

PubMed Central

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

Do humans ape? Or do apes human? Imitation and intention in humans (Homo sapiens) and other animals.

PubMed

Horowitz, Alexandra C

2003-09-01

A. Whiten, D. M. Custance, J.-C. Gomez, P. Teixidor, and K. A. Bard (1996) tested chimpanzees' (Pan troglodytes) and human children's (Homo sapiens) skills at imitation with a 2-action test on an "artificial fruit." Chimpanzees imitated to a restricted degree; children were more thoroughly imitative. Such results prompted some to assert that the difference in imitation indicates a difference in the subjects' understanding of the intentions of the demonstrator (M. Tomasello, 1996). In this experiment, 37 adult human subjects were tested with the artificial fruit. Far from being perfect imitators, the adults were less imitative than the children. These results cast doubt on the inference from imitative performance to an ability to understand others' intentions. The results also demonstrate how any test of imitation requires a control group and attention to the level of behavioral analysis. Copyright 2003 APA, all rights reserved

Development and Content of Children's Imitation in the Second and Third Years of Life.

ERIC Educational Resources Information Center

Kuczynski, Leon

In order to assess the potential role of imitation in early socialization, a study was conducted to investigate the content and development of children's imitative behavior in the home. Data consisted of incidents of immediate and deferred imitation collected over a 4- to 8-month period by mothers trained in observational recording. Subjects…

Mirroring, Imitation, Identification: The Sense of Self in Relation to the Mother's Internal World

ERIC Educational Resources Information Center

Rhode, Maria

2005-01-01

The phenomenon of neonatal imitation, and the use of mutual imitation by mother and baby in the service of attunement, are considered in relation to psychoanalytic theories of mirroring, imitation and identification. Material from infant observation and from the treatment of two children on the autistic spectrum is discussed in terms of the…

An Rf Focused Interdigital Ion Accelerating Structure

DOE Office of Scientific and Technical Information (OSTI.GOV)

Swenson, D.A.

2003-08-26

An Rf Focused Interdigital (RFI) ion accelerating structure will be described. It represents an effective combination of the Wideroee (or interdigital) linac structure, used for many low frequency, heavy ion applications, and the rf electric quadrupole focusing used in the RFQ and RFD linac structures. As in the RFD linac structure, rf focusing is introduced into the RFI linac structure by configuring the drift tubes as two independent pieces operating at different electrical potentials as determined by the rf fields of the linac structure. Each piece (or electrode) of the RFI drift tube supports two fingers pointed inwards towards themore » opposite end of the drift tube forming a four-finger geometry that produces an rf quadrupole field along the axis of the linac for focusing the beam. However, because of the differences in the rf field configuration along the axis, the scheme for introducing rf focusing into the interdigital linac structure is quite different from that adopted for the RFD linac structure. The RFI linac structure promises to have significant size, efficiency, performance, and cost advantages over existing linac structures for the acceleration of low energy ion beams of all masses (light to heavy). These advantages will be reviewed. A 'cold model' of this new linac structure has been fabricated and the results of rf cavity measurements on this cold model will be presented.« less

Own and Others' Prior Experiences Influence Children's Imitation of Causal Acts.

PubMed

Williamson, Rebecca A; Meltzoff, Andrew N

2011-07-01

Young children learn from others' examples, and they do so selectively. We examine whether the efficacy of prior experiences influences children's imitation. Thirty-six-month-olds had initial experience on a causal learning task either by performing the task themselves or by watching an adult perform it. The nature of the experience was manipulated such that the actor had either an easy or a difficult experience completing the task. Next, a second adult demonstrated an innovative technique for completing it. Children who had a difficult first-person experience, and those who had witnessed another person having difficulty, were significantly more likely to adopt and imitate the adult's innovation than those who had or witnessed an easy experience. Children who observed another were also more likely to imitate than were those who had the initial experience themselves. Imitation is influenced by prior experience, both when it is obtained through one's own hands-on motor manipulation and when it derives from observing the acts of others.

Comparing plant and fungal gravitropism using imitational models based on reiterative computation

NASA Astrophysics Data System (ADS)

Moore, David; Stočkus, Alvidas

Mathematical models which imitate plant gravitropic responses were used to compare plant and fungal gravitropism with kinetic data from the agarics Coprinus cinereus and Flammulina velutipes. Similarities were: bending depends on differential growth; growth of the organ is most intensive just behind the apex; gravitropisms exhibit a substantial time delay. Differences were: the agaric stem apex always returns to the vertical (some plant organs show stable plagiogravitropic growth); curvature compensation occurred in C. cinereus; C. cinereus stems rarely overshot or oscillated around the vertical although data for F. velutipes showed a single overshoot and oscillation. The work focused attention on the need for data on detection-level thresholds, angle-response and acceleration-response relationships in fungi, and the need for detailed observations of gravitropism kinetics in a larger number and wider range of fungi.

Contingent Imitation Increases Verbal Interaction in Children with Autism Spectrum Disorders

ERIC Educational Resources Information Center

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…

Imitative Production of Rising Speech Intonation in Pediatric Cochlear Implant Recipients

ERIC Educational Resources Information Center

Peng, Shu-Chen; Tomblin, J. Bruce; Spencer, Linda J.; Hurtig, Richard R.

2007-01-01

Purpose: This study investigated the acoustic characteristics of pediatric cochlear implant (CI) recipients' imitative production of rising speech intonation, in relation to the perceptual judgments by listeners with normal hearing (NH). Method: Recordings of a yes-no interrogative utterance imitated by 24 prelingually deafened children with a CI…

The Ghost Condition: Imitation Versus Emulation in Young Children's Observational Learning.

ERIC Educational Resources Information Center

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…

Mirror me: Imitative responses in adults with autism.

PubMed

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

2016-02-01

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 disorder participants and 20 healthy controls matched for age, gender and education. Participants performed simple finger-lifting movements in response to (1) biological finger and non-biological dot movement stimuli, (2) acoustic stimuli and (3) combined visual-acoustic stimuli with different contextual (compatible/incompatible) and temporal (simultaneous/asynchronous) relation. Mixed model analyses revealed slower reaction times in autism spectrum disorder. Both groups responded faster to biological compared to non-biological stimuli (Experiment 1) implying intact processing advantage for biological stimuli in autism spectrum disorder. In Experiment 3, both groups had similar 'interference effects' when stimuli were presented simultaneously. However, autism spectrum disorder participants had abnormally slow responses particularly when incompatible stimuli were presented consecutively. Our results suggest imitative control deficits rather than global imitative system impairments. © The Author(s) 2015.

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

ERIC Educational Resources Information Center

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…

The Value of Being Imitated

ERIC Educational Resources Information Center

Parton, David A.; Priefert, Maria J.

1975-01-01

This study examines the possibility that the relational stimulus arising from being imitated serves a reinforcing function. A total of 48 preschool children performed a task in which some neutral stimuli were repeatedly associated either with an adult's matching the subject's behavior or the adult's mismatching the subject's behavior. (Author/GO)

Imitation from 12 to 24 months in autism and typical development: A longitudinal Rasch analysis

PubMed Central

Young, Gregory S.; Rogers, Sally J.; Hutman, Ted; Rozga, Agata; Sigman, Marian; Ozonoff, Sally

2013-01-01

The development of imitation during the second year of life plays an important role in domains of socio-cognitive development such as language and social learning. Deficits in imitation ability in persons with autism spectrum disorder (ASD) have also been repeatedly documented from toddlerhood into adulthood, raising the possibility that early disruptions in imitation contribute to the onset of ASD and the deficits in language and social interaction that define the disorder. This study prospectively examined the development of imitation between 12 and 24 months of age in 154 infants at familial risk for ASD and 78 typically developing infants who were all later assessed at 36 months for ASD or other developmental delays. The study established a developmental measure of imitation ability, and examined group differences over time, using an analytic Rasch measurement model. Results revealed a unidimensional latent construct of imitation and verified a reliable sequence of imitation skills that was invariant over time for all outcome groups. Results also showed that all groups displayed similar significant linear increases in imitation ability between 12 and 24 months and that these increases were related to individual growth in both expressive language and ratings of social engagement, but not fine motor development. The group of children who developed ASD by age 3 years exhibited delayed imitation development compared to the low-risk typical outcome group across all time-points, but were indistinguishable from other high-risk infants who showed other cognitive delays not related to ASD. PMID:21910524

Imitation and Emulation by Dogs Using a Bidirectional Control Procedure

PubMed Central

Miller, Holly C.; Rayburn-Reeves, Rebecca; Zentall, Thomas R.

2009-01-01

A successful procedure for studying imitative behavior in non-humans is the bidirectional control procedure in which observers are exposed to a demonstrator that responds by moving a manipulandum in one of two different directions (e.g., left vs. right). Imitative learning is demonstrated when observers make the response in the direction that they observed it being made. This procedure controls for socially mediated effects (the mere presence of a demonstrator), stimulus enhancement (attention drawn to a manipulandum by its movement), and if an appropriate control is included, emulation (learning how the environment works). Recent research with dogs has found that dogs may not demonstrate imitative learning when the demonstrator is human. In the present research, we found that when odors were controlled for, dogs imitated the direction of a screen push demonstrated by another dog more than in a control condition in which they observed the screen move independently while another dog was present. Furthermore, we found that dogs would match the direction of screen push demonstrated by a human and they were equally likely to match the direction in which the screen moved independently while a human was present. PMID:18977419

Memory and representation in young children with Down syndrome: Exploring deferred imitation and object permanence

PubMed Central

RAST, MECHTHILD; MELTZOFF, ANDREW N.

2013-01-01

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. PMID:25530676

An evolutionary strategy based on partial imitation for solving optimization problems

NASA Astrophysics Data System (ADS)

Javarone, Marco Alberto

2016-12-01

In this work we introduce an evolutionary strategy to solve combinatorial optimization tasks, i.e. problems characterized by a discrete search space. In particular, we focus on the Traveling Salesman Problem (TSP), i.e. a famous problem whose search space grows exponentially, increasing the number of cities, up to becoming NP-hard. The solutions of the TSP can be codified by arrays of cities, and can be evaluated by fitness, computed according to a cost function (e.g. the length of a path). Our method is based on the evolution of an agent population by means of an imitative mechanism, we define 'partial imitation'. In particular, agents receive a random solution and then, interacting among themselves, may imitate the solutions of agents with a higher fitness. Since the imitation mechanism is only partial, agents copy only one entry (randomly chosen) of another array (i.e. solution). In doing so, the population converges towards a shared solution, behaving like a spin system undergoing a cooling process, i.e. driven towards an ordered phase. We highlight that the adopted 'partial imitation' mechanism allows the population to generate solutions over time, before reaching the final equilibrium. Results of numerical simulations show that our method is able to find, in a finite time, both optimal and suboptimal solutions, depending on the size of the considered search space.

Imitation Pedagogy and Ethical Indoctrination.

ERIC Educational Resources Information Center

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…

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

PubMed

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.

Principles for Designing Mathematical Tasks That Enhance Imitative and Creative Reasoning

ERIC Educational Resources Information Center

Lithner, Johan

2017-01-01

The design research programme learning by imitative and creative reasoning (LICR) studies whether, how and why tasks and teaching that enhance creative reasoning lead to a more productive struggle and more efficient learning than the common but inefficient task designs based on imitating given solution procedures. The purpose of this paper is to…

The Importance of Distinguishing "Propensity" versus "Ability" to Imitate in ASD Research and Early Detection

ERIC Educational Resources Information Center

Vivanti, Giacomo

2015-01-01

Imitation abnormalities are often documented in young children with Autism Spectrum Disorder (ASD), however the relevance of imitation to early development and early detection of ASD remains unclear. Recent studies that investigated whether imitation at 12 months distinguishes children who will subsequently receive an ASD diagnosis from other…

Do as I … Did! Long-term memory of imitative actions in dogs (Canis familiaris).

PubMed

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.

Social learning by imitation in a reptile (Pogona vitticeps).

PubMed

Kis, Anna; Huber, Ludwig; Wilkinson, Anna

2015-01-01

The ability to learn through imitation is thought to be the basis of cultural transmission and was long considered a distinctive characteristic of humans. There is now evidence that both mammals and birds are capable of imitation. However, nothing is known about these abilities in the third amniotic class-reptiles. Here, we use a bidirectional control procedure to show that a reptile species, the bearded dragon (Pogona vitticeps), is capable of social learning that cannot be explained by simple mechanisms such as local enhancement or goal emulation. Subjects in the experimental group opened a trap door to the side that had been demonstrated, while subjects in the ghost control group, who observed the door move without the intervention of a conspecific, were unsuccessful. This, together with differences in behaviour between experimental and control groups, provides compelling evidence that reptiles possess cognitive abilities that are comparable to those observed in mammals and birds and suggests that learning by imitation is likely to be based on ancient mechanisms.

The Fuzzy Set Called 'Imitations.'

ERIC Educational Resources Information Center

Moerk, Ernst L.

This investigation addresses problems of defining verbal imitation, and suggests solutions by analyzing verbal interactions between two children and their mothers. Children were between 18 and 35 months old, with a mean length of utterance between 1.4 and 4.2 morphemes. Analyses focus upon the uses these children made of maternal models; 10…

The mirror neuron system as revealed through neonatal imitation: presence from birth, predictive power and evidence of plasticity.

PubMed

Simpson, Elizabeth A; Murray, Lynne; Paukner, Annika; Ferrari, Pier F

2014-01-01

There is strong evidence that neonates imitate previously unseen behaviours. These behaviours are predominantly used in social interactions, demonstrating neonates' ability and motivation to engage with others. Research on neonatal imitation can provide a wealth of information about the early mirror neuron system (MNS), namely its functional characteristics, its plasticity from birth and its relation to skills later in development. Although numerous studies document the existence of neonatal imitation in the laboratory, little is known about its natural occurrence during parent-infant interactions and its plasticity as a consequence of experience. We review these critical aspects of imitation, which we argue are necessary for understanding the early action-perception system. We address common criticisms and misunderstandings about neonatal imitation and discuss methodological differences among studies. Recent work reveals that individual differences in neonatal imitation positively correlate with later social, cognitive and motor development. We propose that such variation in neonatal imitation could reflect important individual differences of the MNS. Although postnatal experience is not necessary for imitation, we present evidence that neonatal imitation is influenced by experience in the first week of life.

The mimetic transition: a simulation study of the evolution of learning by imitation.

PubMed

Higgs, P G

2000-07-07

Culturally transmitted ideas or memes must have had a large effect on the survival and fecundity of early humans. Those with better techniques of obtaining food and making tools, clothing and shelters would have had a substantial advantage. It has been proposed that memes can explain why our species has an unusually large brain and high cognitive ability: the brain evolved because of selection for the ability to imitate. This article presents an evolutionary model of a population in which culturally transmitted memes can have both positive and negative effects on the fitness of individuals. It is found that genes for increased imitative ability are selectively favoured. The model predicts that imitative ability increases slowly until a mimetic transition occurs where memes become able to spread like an epidemic. At this point there is a dramatic increase in the imitative ability, the number of memes known per individual and the mean fitness of the population. Selection for increased imitative ability is able to overcome substantial selection against increased brain size in some cases.

The mimetic transition: a simulation study of the evolution of learning by imitation.

PubMed Central

Higgs, P G

2000-01-01

Culturally transmitted ideas or memes must have had a large effect on the survival and fecundity of early humans. Those with better techniques of obtaining food and making tools, clothing and shelters would have had a substantial advantage. It has been proposed that memes can explain why our species has an unusually large brain and high cognitive ability: the brain evolved because of selection for the ability to imitate. This article presents an evolutionary model of a population in which culturally transmitted memes can have both positive and negative effects on the fitness of individuals. It is found that genes for increased imitative ability are selectively favoured. The model predicts that imitative ability increases slowly until a mimetic transition occurs where memes become able to spread like an epidemic. At this point there is a dramatic increase in the imitative ability, the number of memes known per individual and the mean fitness of the population. Selection for increased imitative ability is able to overcome substantial selection against increased brain size in some cases. PMID:10972132

Imitation of body postures and hand movements in children with specific language impairment.

PubMed

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 years 3 months to 6 years 7 months of age). Five tests were used to examine imitation and its underlying cognitive and motor skills such as kinesthesia, working memory, and gross motor coordination. It was hypothesized that children with SLI show a weakness in imitation of body postures and that this deficit is not equally influenced by the underlying cognitive and motor skills. There was a group effect in each cognitive and motor task, but only gross motor coordination proved to be a strong predictor of imitation in children with SLI. In contrast, hand movement imitation was strongly predicted by performance in the Kinesthesia task in typically developing children. Thus, the findings show not only that children with SLI performed more poorly on the imitation tasks than their typically developing peers but also that the groups' performances showed qualitative differences. The results of the current study provide additional support to the view that the weaknesses in children with SLI are not limited to the verbal domain.

A Mozart is not a Pavarotti: singers outperform instrumentalists on foreign accent imitation.

PubMed

Christiner, Markus; Reiterer, Susanne Maria

2015-01-01

Recent findings have shown that people with higher musical aptitude were also better in oral language imitation tasks. However, whether singing capacity and instrument playing contribute differently to the imitation of speech has been ignored so far. Research has just recently started to understand that instrumentalists develop quite distinct skills when compared to vocalists. In the same vein the role of the vocal motor system in language acquisition processes has poorly been investigated as most investigations (neurobiological and behavioral) favor to examine speech perception. We set out to test whether the vocal motor system can influence an ability to learn, produce and perceive new languages by contrasting instrumentalists and vocalists. Therefore, we investigated 96 participants, 27 instrumentalists, 33 vocalists and 36 non-musicians/non-singers. They were tested for their abilities to imitate foreign speech: unknown language (Hindi), second language (English) and their musical aptitude. Results revealed that both instrumentalists and vocalists have a higher ability to imitate unintelligible speech and foreign accents than non-musicians/non-singers. Within the musician group, vocalists outperformed instrumentalists significantly. First, adaptive plasticity for speech imitation is not reliant on audition alone but also on vocal-motor induced processes. Second, vocal flexibility of singers goes together with higher speech imitation aptitude. Third, vocal motor training, as of singers, may speed up foreign language acquisition processes.

A Mozart is not a Pavarotti: singers outperform instrumentalists on foreign accent imitation

PubMed Central

Christiner, Markus; Reiterer, Susanne Maria

2015-01-01

Recent findings have shown that people with higher musical aptitude were also better in oral language imitation tasks. However, whether singing capacity and instrument playing contribute differently to the imitation of speech has been ignored so far. Research has just recently started to understand that instrumentalists develop quite distinct skills when compared to vocalists. In the same vein the role of the vocal motor system in language acquisition processes has poorly been investigated as most investigations (neurobiological and behavioral) favor to examine speech perception. We set out to test whether the vocal motor system can influence an ability to learn, produce and perceive new languages by contrasting instrumentalists and vocalists. Therefore, we investigated 96 participants, 27 instrumentalists, 33 vocalists and 36 non-musicians/non-singers. They were tested for their abilities to imitate foreign speech: unknown language (Hindi), second language (English) and their musical aptitude. Results revealed that both instrumentalists and vocalists have a higher ability to imitate unintelligible speech and foreign accents than non-musicians/non-singers. Within the musician group, vocalists outperformed instrumentalists significantly. Conclusion: First, adaptive plasticity for speech imitation is not reliant on audition alone but also on vocal-motor induced processes. Second, vocal flexibility of singers goes together with higher speech imitation aptitude. Third, vocal motor training, as of singers, may speed up foreign language acquisition processes. PMID:26379537

Sentence imitation as a marker of SLI in Czech: disproportionate impairment of verbs and clitics.

PubMed

Smolík, Filip; Vávru, Petra

2014-06-01

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. 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 digit span and nonword repetition tasks. Sentence imitations were scored for accuracy and error types. A separate count of inaccuracies for individual part-of-speech categories was performed. Children with SLI had substantially more inaccurate imitations than the control groups. The differences in the memory measures could not account for the differences between children with SLI and the control groups in imitation accuracy, even though they accounted for the differences between the language-matched and age-matched control groups. The proportion of grammatical errors was larger in children with SLI than in the control groups. The categories that were most affected in imitations of children with SLI were verbs and clitics. Sentence imitation is a sensitive marker of SLI. Verbs and clitics are the most vulnerable categories in Czech SLI. The pattern of errors suggests that impaired syntactic representations are the most likely source of difficulties in children with SLI.

What drives young children to over-imitate? Investigating the effects of age, context, action type, and transitivity.

PubMed

Clay, Zanna; Over, Harriet; Tennie, Claudio

2018-02-01

Imitation underlies many traits thought to characterize our species, which includes the transmission and acquisition of language, material culture, norms, rituals, and conventions. From early childhood, humans show an intriguing willingness to imitate behaviors, even those that have no obvious function. This phenomenon, known as "over-imitation," is thought to explain some of the key differences between human cultures as compared with those of nonhuman animals. Here, we used a single integrative paradigm to simultaneously investigate several key factors proposed to shape children's over-imitation: age, context, transitivity, and action type. We compared typically developing children aged 4-6years in a task involving actions verbally framed as being instrumental, normative, or communicative in function. Within these contexts, we explored whether children were more likely to over-imitate transitive versus intransitive actions and manual versus body part actions. Results showed an interaction between age and context; as children got older, they were more likely to imitate within a normative context, whereas younger children were more likely to imitate in instrumental contexts. Younger children were more likely to imitate transitive actions (actions on objects) than intransitive actions compared with older children. Our results show that children are highly sensitive to even minimal cues to perceived context and flexibly adapt their imitation accordingly. As they get older, children's imitation appears to become less object bound, less focused on instrumental outcomes, and more sensitive to normative cues. This shift is consistent with the proposal that over-imitation becomes increasingly social in its function as children move through childhood and beyond. Copyright © 2017 Elsevier Inc. All rights reserved.

It's Not What You Know, It's Who You Know: Older Siblings Facilitate Imitation during Infancy.

ERIC Educational Resources Information Center

Barr, Rachel; Hayne, Harlene

2003-01-01

Investigated effects of older siblings on imitation by 12-, 15-, and 18-month-olds. Found that all age groups acquired one to two new behaviors per day through imitation. Older infants imitated more multi-step sequences and substituted more objects during reenactment than younger. Compared to infants without siblings, infants with siblings…

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

ERIC Educational Resources Information Center

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…

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

ERIC Educational Resources Information Center

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…

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

ERIC Educational Resources Information Center

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…

Innovation, imitation, and problem-solving in a networked group.

PubMed

Wisdom, Thomas N; Goldstone, Robert L

2011-04-01

We implemented a problem-solving task in which groups of participants simultaneously played a simple innovation game in a complex problem space, with score feedback provided after each of a number of rounds. Each participant in a group was allowed to view and imitate the guesses of others during the game. The results showed the use of social learning strategies previously studied in other species, and demonstrated benefits of social learning and nonlinear effects of group size on strategy and performance. Rather than simply encouraging conformity, groups provided information to each individual about the distribution of useful innovations in the problem space. Imitation facilitated innovation rather than displacing it, because the former allowed good solutions to be propagated and preserved for further cumulative innovations in the group. Participants generally improved their solutions through the use of fairly conservative strategies, such as changing only a small portion of one's solution at a time, and tending to imitate solutions similar to one's own. Changes in these strategies over time had the effect of making solutions increasingly entrenched, both at individual and group levels. These results showed evidence of nonlinear dynamics in the decentralization of innovation, the emergence of group phenomena from complex interactions of individual efforts, stigmergy in the use of social information, and dynamic tradeoffs between exploration and exploitation of solutions. These results also support the idea that innovation and creativity can be recognized at the group level even when group members are generally cautious and imitative.

Hemispheric specialisation for imitation of hand-head positions and finger configurations: a controlled study in patients with complete callosotomy.

PubMed

Lausberg, Hedda; Cruz, Robyn Flaum

2004-01-01

Several studies of patients with unilateral brain damage and a patient with spontaneous callosal disconnection [Journal of Neurology, Neurosurgery, and Psychiatry 61 (1996) 176; Neuropsychologia 37 (1999) 559; Neuropsychologia 39 (2001) 1432] suggest that the imitation of positions of the hand relative to the head is a strongly lateralised left hemispheric function. In contrast, the imitation of finger configurations draws on resources of both hemispheres with a predominance of the right hemisphere. While these findings suggest a specific pattern of imitation impairment in split-brain patients, thus far, no imitation deficits have been reported in split-brain patients. Three patients with complete callosotomy and two control groups, four patients with partial callosotomy and 10 healthy subjects, imitated hand-head positions and finger configurations with non-lateralised and tachistoscopic stimulus presentation. In addition, the influence of visual control on the imitation performance was examined. One split-brain patient showed the predicted dissociation as she had severe right hemispheric deficit in imitating hand-head positions, while finger configuration imitation was preserved. The other two split-brain patients had no impairment in hand-head position imitation. Withdrawal of visual control significantly deteriorated imitation of finger configurations in the split-brain group, but not in the controls, demonstrating that the split-brain patients relied heavily on visual control as a compensatory strategy indicating an imitation deficit in the separate hemispheres. The findings question the previously held belief that in split-brain patients both hemispheres are perfectly capable of imitating gestures and that imitation is not dependent on hemispherically specialised functions.

The mirror neuron system as revealed through neonatal imitation: presence from birth, predictive power and evidence of plasticity

PubMed Central

Simpson, Elizabeth A.; Murray, Lynne; Paukner, Annika; Ferrari, Pier F.

2014-01-01

There is strong evidence that neonates imitate previously unseen behaviours. These behaviours are predominantly used in social interactions, demonstrating neonates' ability and motivation to engage with others. Research on neonatal imitation can provide a wealth of information about the early mirror neuron system (MNS), namely its functional characteristics, its plasticity from birth and its relation to skills later in development. Although numerous studies document the existence of neonatal imitation in the laboratory, little is known about its natural occurrence during parent–infant interactions and its plasticity as a consequence of experience. We review these critical aspects of imitation, which we argue are necessary for understanding the early action–perception system. We address common criticisms and misunderstandings about neonatal imitation and discuss methodological differences among studies. Recent work reveals that individual differences in neonatal imitation positively correlate with later social, cognitive and motor development. We propose that such variation in neonatal imitation could reflect important individual differences of the MNS. Although postnatal experience is not necessary for imitation, we present evidence that neonatal imitation is influenced by experience in the first week of life. PMID:24778381

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

PubMed Central

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

Effects of Model Characterization on Preschool Children's Evaluative, Imitative and Nonimitative Responses.

ERIC Educational Resources Information Center

Whitman, Thomas L.; Taub, Susan Ilene

This study examined the effects of differentially characterizing a model as "good", "bad", or "neutral" on preschool children's subsequent evaluation and imitation of the model. The model's aggressive and motor behaviors were more frequently imitated than were his non-aggressive and verbal behaviors. Instructions influenced the Ss' evaluation of…

[An investigation of the imitation skills in children with autism spectrum disorder and their association with receptive-expressive language development].

PubMed

Turan, Figen; Ökçün Akçamuş, Meral Çilem

2013-01-01

This study aimed to compare imitation skills in children with autism spectrum disorder, and age-matched typically developing children and children with developmental delay, as well as to examine the association between imitation skills, and receptive and expressive language development in children with autism spectrum disorder. Imitation skills in children with autism spectrum disorder (n=18), and age-matched children with developmental delay (n=15) and typically developing children (n= 16) were assessed using the Motor Imitation Scale and Imitation Battery, and the differences in mean imitation scores between the groups were examined. Receptive language and expressive language development in the children with autism spectrum disorder were assessed using the Turkish Communicative Development Inventory (TCDI), and their association with imitation scores was explored. The children with autism spectrum disorder had significantly lower imitation scores than the children with developmental delay and typically developing children; however, there wasn't a significant difference in imitation scores between the children with developmental delay and typically developing children. A significant association between imitation scores, and receptive and expressive language development was observed in the children with autism spectrum disorder. The present findings indicate that deficient imitation skills are a distinctive feature of children with autism spectrum disorder and that imitation skills play a crucial role in children's language development.

Song and speech: examining the link between singing talent and speech imitation ability.

PubMed

Christiner, Markus; Reiterer, Susanne M

2013-01-01

In previous research on speech imitation, musicality, and an ability to sing were isolated as the strongest indicators of good pronunciation skills in foreign languages. We, therefore, wanted to take a closer look at the nature of the ability to sing, which shares a common ground with the ability to imitate speech. This study focuses on whether good singing performance predicts good speech imitation. Forty-one singers of different levels of proficiency were selected for the study and their ability to sing, to imitate speech, their musical talent and working memory were tested. Results indicated that singing performance is a better indicator of the ability to imitate speech than the playing of a musical instrument. A multiple regression revealed that 64% of the speech imitation score variance could be explained by working memory together with educational background and singing performance. A second multiple regression showed that 66% of the speech imitation variance of completely unintelligible and unfamiliar language stimuli (Hindi) could be explained by working memory together with a singer's sense of rhythm and quality of voice. This supports the idea that both vocal behaviors have a common grounding in terms of vocal and motor flexibility, ontogenetic and phylogenetic development, neural orchestration and auditory memory with singing fitting better into the category of "speech" on the productive level and "music" on the acoustic level. As a result, good singers benefit from vocal and motor flexibility, productively and cognitively, in three ways. (1) Motor flexibility and the ability to sing improve language and musical function. (2) Good singers retain a certain plasticity and are open to new and unusual sound combinations during adulthood both perceptually and productively. (3) The ability to sing improves the memory span of the auditory working memory.

Song and speech: examining the link between singing talent and speech imitation ability

PubMed Central

Christiner, Markus; Reiterer, Susanne M.

2013-01-01

In previous research on speech imitation, musicality, and an ability to sing were isolated as the strongest indicators of good pronunciation skills in foreign languages. We, therefore, wanted to take a closer look at the nature of the ability to sing, which shares a common ground with the ability to imitate speech. This study focuses on whether good singing performance predicts good speech imitation. Forty-one singers of different levels of proficiency were selected for the study and their ability to sing, to imitate speech, their musical talent and working memory were tested. Results indicated that singing performance is a better indicator of the ability to imitate speech than the playing of a musical instrument. A multiple regression revealed that 64% of the speech imitation score variance could be explained by working memory together with educational background and singing performance. A second multiple regression showed that 66% of the speech imitation variance of completely unintelligible and unfamiliar language stimuli (Hindi) could be explained by working memory together with a singer's sense of rhythm and quality of voice. This supports the idea that both vocal behaviors have a common grounding in terms of vocal and motor flexibility, ontogenetic and phylogenetic development, neural orchestration and auditory memory with singing fitting better into the category of “speech” on the productive level and “music” on the acoustic level. As a result, good singers benefit from vocal and motor flexibility, productively and cognitively, in three ways. (1) Motor flexibility and the ability to sing improve language and musical function. (2) Good singers retain a certain plasticity and are open to new and unusual sound combinations during adulthood both perceptually and productively. (3) The ability to sing improves the memory span of the auditory working memory. PMID:24319438

The role of accent imitation in sensorimotor integration during processing of intelligible speech

PubMed Central

Adank, Patti; Rueschemeyer, Shirley-Ann; Bekkering, Harold

2013-01-01

Recent theories on how listeners maintain perceptual invariance despite variation in the speech signal allocate a prominent role to imitation mechanisms. Notably, these simulation accounts propose that motor mechanisms support perception of ambiguous or noisy signals. Indeed, imitation of ambiguous signals, e.g., accented speech, has been found to aid effective speech comprehension. Here, we explored the possibility that imitation in speech benefits perception by increasing activation in speech perception and production areas. Participants rated the intelligibility of sentences spoken in an unfamiliar accent of Dutch in a functional Magnetic Resonance Imaging experiment. Next, participants in one group repeated the sentences in their own accent, while a second group vocally imitated the accent. Finally, both groups rated the intelligibility of accented sentences in a post-test. The neuroimaging results showed an interaction between type of training and pre- and post-test sessions in left Inferior Frontal Gyrus, Supplementary Motor Area, and left Superior Temporal Sulcus. Although alternative explanations such as task engagement and fatigue need to be considered as well, the results suggest that imitation may aid effective speech comprehension by supporting sensorimotor integration. PMID:24109447

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

PubMed

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.

Testing the arousal hypothesis of neonatal imitation in infant rhesus macaques

PubMed Central

Pedersen, Eric J.; Simpson, Elizabeth A.

2017-01-01

Neonatal imitation is the matching of (often facial) gestures by newborn infants. Some studies suggest that performance of facial gestures is due to general arousal, which may produce false positives on neonatal imitation assessments. Here we examine whether arousal is linked to facial gesturing in newborn infant rhesus macaques (Macaca mulatta). We tested 163 infants in a neonatal imitation paradigm in their first postnatal week and analyzed their lipsmacking gestures (a rapid opening and closing of the mouth), tongue protrusion gestures, and yawn responses (a measure of arousal). Arousal increased during dynamic stimulus presentation compared to the static baseline across all conditions, and arousal was higher in the facial gestures conditions than the nonsocial control condition. However, even after controlling for arousal, we found a condition-specific increase in facial gestures in infants who matched lipsmacking and tongue protrusion gestures. Thus, we found no support for the arousal hypothesis. Consistent with reports in human newborns, imitators’ propensity to match facial gestures is based on abilities that go beyond mere arousal. We discuss optimal testing conditions to minimize potentially confounding effects of arousal on measurements of neonatal imitation. PMID:28617816

Effects of Vicarious Consequences and Model and Experimenter Sex on Imitative Behavior in First-Grade Children

ERIC Educational Resources Information Center

Garrett, Candace S.; Cunningham, Donald J.

1974-01-01

Results indicate that reward and ignore conditions were not different but both yielded higher imitative scores than the punishment condition; same-sex models yielded higher imitation scores than opposite-sex models; lowest imitation scores were obtained by children exposed to a male experimenter and a female model. (Author/BJG)

Ultra-High Accelerating Gradients in Radio-Frequency Cryogenic Copper Structures

NASA Astrophysics Data System (ADS)

Cahill, Alexander David

Normal conducting radio-frequency (rf) particle accelerators have many applications, including colliders for high energy physics, high-intensity synchrotron light sources, non-destructive testing for security, and medical radiation therapy. In these applications, the accelerating gradient is an important parameter. Specifically for high energy physics, increasing the accelerating gradient extends the potential energy reach and is viewed as a way to mitigate their considerable cost. Furthermore, a gradient increase will enable for more compact and thus accessible free electron lasers (FELs). The major factor limiting larger accelerating gradients is vacuum rf breakdown. Basic physics of this phenomenon has been extensively studied over the last few decades. During which, the occurrence of rf breakdowns was shown to be probabilistic, and can be characterized by a breakdown rate. The current consensus is that vacuum rf breakdowns are caused by movements of crystal defects induced by periodic mechanical stress. The stress may be caused by pulsed surface heating and large electric fields. A compelling piece of evidence that supports this hypothesis is that accelerating structures constructed from harder materials exhibit larger accelerating gradients for similar breakdown rates. One possible method to increase sustained electric fields in copper cavities is to cool them to temperatures below 77 K, where the rf surface resistance and coefficient of thermal expansion decrease, while the yield strength (which correlates with hardness) and thermal conductivity increase. These changes in material properties at low temperature increases metal hardness and decreases the mechanical stress from exposure to rf electromagnetic fields. To test the validity of the improvement in breakdown rate, experiments were conducted with cryogenic accelerating cavities in the Accelerator Structure Test Area (ASTA) at SLAC National Accelerator Laboratory. A short 11.4 GHz standing wave

The role of consensus and culture in children's imitation of inefficient actions.

PubMed

DiYanni, Cara J; Corriveau, Kathleen H; Kurkul, Katelyn; Nasrini, Jad; Nini, Deniela

2015-09-01

A significant body of work has demonstrated children's imitative abilities when learning novel actions. Although some research has examined the role of cultural background in children's imitation of inefficient actions, to our knowledge no research has explored how culture and conformity interact when engaging in imitation. In Study 1, 87 Caucasian American and Chinese American preschoolers were presented with either one model or three models performing an inefficient action. Whereas there were no cultural differences in imitation in the Single Model condition, Chinese Americans were significantly more likely to copy the model's preference for an inefficient tool in the Consensus condition. Children's tool choice was associated with their justification for their choice as well as their memory for the model's action. Study 2 explored the impact of immigration status on the cultural differences in children's tool choice by including 16 first-generation Caucasian American children. When comparing the findings with the rates from Study 1, both groups of Caucasian American preschoolers imitated at rates significantly lower than the Chinese American preschoolers. We suggest that the tool choices of Caucasian American children relate to a tendency to engage in a perceptually driven mode of learning, whereas the choices of the Chinese American children reflect a greater likelihood to use a socially driven mode. Copyright © 2015 Elsevier Inc. All rights reserved.

Are you a good mimic? Neuro-acoustic signatures for speech imitation ability

PubMed Central

Reiterer, Susanne M.; Hu, Xiaochen; Sumathi, T. A.; Singh, Nandini C.

2013-01-01

We investigated individual differences in speech imitation ability in late bilinguals using a neuro-acoustic approach. One hundred and thirty-eight German-English bilinguals matched on various behavioral measures were tested for “speech imitation ability” in a foreign language, Hindi, and categorized into “high” and “low ability” groups. Brain activations and speech recordings were obtained from 26 participants from the two extreme groups as they performed a functional neuroimaging experiment which required them to “imitate” sentences in three conditions: (A) German, (B) English, and (C) German with fake English accent. We used recently developed novel acoustic analysis, namely the “articulation space” as a metric to compare speech imitation abilities of the two groups. Across all three conditions, direct comparisons between the two groups, revealed brain activations (FWE corrected, p < 0.05) that were more widespread with significantly higher peak activity in the left supramarginal gyrus and postcentral areas for the low ability group. The high ability group, on the other hand showed significantly larger articulation space in all three conditions. In addition, articulation space also correlated positively with imitation ability (Pearson's r = 0.7, p < 0.01). Our results suggest that an expanded articulation space for high ability individuals allows access to a larger repertoire of sounds, thereby providing skilled imitators greater flexibility in pronunciation and language learning. PMID:24155739

Deep imitation learning for 3D navigation tasks.

PubMed

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.

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

ERIC Educational Resources Information Center

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…

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

PubMed

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.

What imitation tells us about social cognition: a rapprochement between developmental psychology and cognitive neuroscience.

PubMed Central

Meltzoff, Andrew N; Decety, Jean

2003-01-01

Both developmental and neurophysiological research suggest a common coding between perceived and generated actions. This shared representational network is innately wired in humans. We review psychological evidence concerning the imitative behaviour of newborn human infants. We suggest that the mechanisms involved in infant imitation provide the foundation for understanding that others are 'like me' and underlie the development of theory of mind and empathy for others. We also analyse functional neuroimaging studies that explore the neurophysiological substrate of imitation in adults. We marshal evidence that imitation recruits not only shared neural representations between the self and the other but also cortical regions in the parietal cortex that are crucial for distinguishing between the perspective of self and other. Imitation is doubly revealing: it is used by infants to learn about adults, and by scientists to understand the organization and functioning of the brain. PMID:12689375

Conditional imitation might promote cooperation under high temptations to defect

NASA Astrophysics Data System (ADS)

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.

Child implant users' imitation of happy- and sad-sounding speech

PubMed Central

Wang, David J.; Trehub, Sandra E.; Volkova, Anna; van Lieshout, Pascal

2013-01-01

Cochlear implants have enabled many congenitally or prelingually deaf children to acquire their native language and communicate successfully on the basis of electrical rather than acoustic input. Nevertheless, degraded spectral input provided by the device reduces the ability to perceive emotion in speech. We compared the vocal imitations of 5- to 7-year-old deaf children who were highly successful bilateral implant users with those of a control sample of children who had normal hearing. First, the children imitated several happy and sad sentences produced by a child model. When adults in Experiment 1 rated the similarity of imitated to model utterances, ratings were significantly higher for the hearing children. Both hearing and deaf children produced poorer imitations of happy than sad utterances because of difficulty matching the greater pitch modulation of the happy versions. When adults in Experiment 2 rated electronically filtered versions of the utterances, which obscured the verbal content, ratings of happy and sad utterances were significantly differentiated for deaf as well as hearing children. The ratings of deaf children, however, were significantly less differentiated. Although deaf children's utterances exhibited culturally typical pitch modulation, their pitch modulation was reduced relative to that of hearing children. One practical implication is that therapeutic interventions for deaf children could expand their focus on suprasegmental aspects of speech perception and production, especially intonation patterns. PMID:23801976

[Neurodynamic Bases of Imitation Learning and Episodic Memory].

PubMed

Tsukerman, V D

2016-01-01

In this review, three essentially important processes in development of cognitive behavior are considered: knowledge of a spatial environment by means of physical activity, coding and a call of an existential context of episodic memory and imitation learning based on the mirror neural mechanism. The data show that the parietal and frontal system of learning by imitation, allows the developing organism to seize skills of management and motive synergies in perisomatic space, to understand intentions and the purposes of observed actions of other individuals. At the same time a widely distributed parietal and frontal and entorhinal-hippocampal system mediates spatial knowledge and the solution of the navigation tasks important for creation of an existential context of episodic memory.

Neuroprosthetic Decoder Training as Imitation Learning.

PubMed

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.

Neuroprosthetic Decoder Training as Imitation Learning

PubMed Central

Merel, Josh; Paninski, Liam; Cunningham, John P.

2016-01-01

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. PMID:27191387

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

PubMed

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.

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

PubMed

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.

Teaching the Imitation and Spontaneous Use of Descriptive Gestures in Young Children with Autism Using a Naturalistic Behavioral Intervention

ERIC Educational Resources Information Center

Ingersoll, Brooke; Lewis, Elizabeth; Kroman, Emily

2007-01-01

Children with autism exhibit deficits in the imitation and spontaneous use of descriptive gestures. Reciprocal Imitation Training (RIT), a naturalistic imitation intervention, has been shown to increase object imitation skills in young children with autism. A single-subject, multiple-baseline design across five young children with autism was used…

An Invitation to Imitation

DTIC Science & Technology

2015-03-15

Super Mario Bros, 2010b. URL http://www.youtube.com/watch?v=anOI0xZ3kGM. S. Ross and J. A. Bagnell. Efficient reductions for imitation learning. In...learning to drive a car in a video game by performing a direct mapping from screen shots to steering angles. Figure 4 illustrates the classic super - an...same distribution and thus the super - vised learning assumption of independent and identically distributed (i.i.d.) data is badly violated. A natural

Imitative and best response behaviors in a nonlinear Cournotian setting

NASA Astrophysics Data System (ADS)

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.

The Effects of Reciprocal Imitation on Teacher-Student Relationships and Student Learning Outcomes

ERIC Educational Resources Information Center

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.…

A systems level analysis of the mirror neuron hypothesis and imitation impairments in autism spectrum disorders.

PubMed

Kana, Rajesh K; Wadsworth, Heather M; Travers, Brittany G

2011-01-01

Although several studies suggest an imitation deficit as a key feature of autism, questions have been raised about the consistency of this finding and about the component skills involved in imitation. The primary aim of this review is to examine the uneven profile of imitation deficits found in autism in the context of the mirror neuron system (MNS) dysfunction hypothesis. We use the cortical underconnectivity framework (Just et al., 2004) to examine the coordination of brain areas that orchestrate the communication between the component skills underlying imitation. A comprehensive account of imitation deficit in autism should take into account the regions that are at the core of the MNS (e.g., IFG and IPL) and related regions that feed into the MNS (e.g., STS, Cerebellum) in their functioning and in their coordination. Our findings suggest that the MNS may be associated with mediating familiarity, attention, self-other matching, and social relevance, which may be vital in characterizing the imitation deficits in autism. Such an analysis may have greater clinical and therapeutic value. Published by Elsevier Ltd.

Motion Recognition and Modifying Motion Generation for Imitation Robot Based on Motion Knowledge Formation

NASA Astrophysics Data System (ADS)

Okuzawa, Yuki; Kato, Shohei; Kanoh, Masayoshi; Itoh, Hidenori

A knowledge-based approach to imitation learning of motion generation for humanoid robots and an imitative motion generation system based on motion knowledge learning and modification are described. The system has three parts: recognizing, learning, and modifying parts. The first part recognizes an instructed motion distinguishing it from the motion knowledge database by the continuous hidden markov model. When the motion is recognized as being unfamiliar, the second part learns it using locally weighted regression and acquires a knowledge of the motion. When a robot recognizes the instructed motion as familiar or judges that its acquired knowledge is applicable to the motion generation, the third part imitates the instructed motion by modifying a learned motion. This paper reports some performance results: the motion imitation of several radio gymnastics motions.

The Development of Rational Imitation in 9- and 12-Month-Old Infants

ERIC Educational Resources Information Center

Zmyj, Norbert; Daum, Moritz M.; Aschersleben, Gisa

2009-01-01

Studies on rational imitation have provided evidence for the fact that infants as young as 12 months of age engage in rational imitation. However, the developmental onset of this ability is unclear. In this study, we investigated whether 9- and 12-month-olds detect voluntary and implicit as well as nonvoluntary and explicit constraints in the head…

Elicited Imitation in Children and Adults with Autism: Is There a Deficit?

ERIC Educational Resources Information Center

Beadle-Brown, Julie D.; Whiten, Andrew

2004-01-01

Rogers and Pennington (1991) proposed that an early deficit in imitation, together with a cascade of developmental disorders in emotion sharing and theory of mind, could be important in understanding autism, but the research on deficits in imitation is not conclusive. Using a Do-As-I-Do procedure, the present study tested the existence of a…

Teaching Caregivers to Implement Video Modeling Imitation Training via iPad for Their Children with Autism

ERIC Educational Resources Information Center

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…

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

ERIC Educational Resources Information Center

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…

Fabrication and Characterization of Woodpile Structures for Direct Laser Acceleration

DOE Office of Scientific and Technical Information (OSTI.GOV)

McGuinness, C.; Colby, E.; England, R.J.

2010-08-26

An eight and nine layer three dimensional photonic crystal with a defect designed specifically for accelerator applications has been fabricated. The structures were fabricated using a combination of nanofabrication techniques, including low pressure chemical vapor deposition, optical lithography, and chemical mechanical polishing. Limits imposed by the optical lithography set the minimum feature size to 400 nm, corresponding to a structure with a bandgap centered at 4.26 {micro}m. Reflection spectroscopy reveal a peak in reflectivity about the predicted region, and good agreement with simulation is shown. The eight and nine layer structures will be aligned and bonded together to form themore » complete seventeen layer woodpile accelerator structure.« less

Comparative Cognition: Action Imitation Using Episodic Memory.

PubMed

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.

Imitative Production of Rising Speech Intonation in Pediatric Cochlear Implant Recipients

PubMed Central

Peng, Shu-Chen; Tomblin, J. Bruce; Spencer, Linda J.; Hurtig, Richard R.

2011-01-01

Purpose This study investigated the acoustic characteristics of pediatric cochlear implant (CI) recipients' imitative production of rising speech intonation, in relation to the perceptual judgments by listeners with normal hearing (NH). Method Recordings of a yes–no interrogative utterance imitated by 24 prelingually deafened children with a CI were extracted from annual evaluation sessions. These utterances were perceptually judged by adult NH listeners in regard with intonation contour type (non-rise, partial-rise, or full-rise) and contour appropriateness (on a 5-point scale). Fundamental frequency, intensity, and duration properties of each utterance were also acoustically analyzed. Results Adult NH listeners' judgments of intonation contour type and contour appropriateness for each CI participant 's utterances were highly positively correlated. The pediatric CI recipients did not consistently use appropriate intonation contours when imitating a yes–no question. Acoustic properties of speech intonation produced by these individuals were discernible among utterances of different intonation contour types according to NH listeners' perceptual judgments. Conclusions These findings delineated the perceptual and acoustic characteristics of speech intonation imitated by prelingually deafened children and young adults with a CI. Future studies should address whether the degraded signals these individuals perceive via a CI contribute to their difficulties with speech intonation production. PMID:17905907

Changes in Frontoparietotemporal Connectivity following Do-As-I-Do Imitation Training in Chimpanzees ( Pan troglodytes).

PubMed

Pope, Sarah M; Taglialatela, Jared P; Skiba, Sara A; Hopkins, William D

2018-03-01

Human imitation is supported by an underlying "mirror system" principally composed of inferior frontal, inferior parietal, and superior temporal cortical regions. Across primate species, differences in frontoparietotemporal connectivity have been hypothesized to explain phylogenetic variation in imitative abilities. However, if and to what extent these regions are involved in imitation in nonhuman primates is unknown. We hypothesized that "Do As I Do" (DAID) imitation training would enhance white matter integrity within and between frontoparietotemporal regions. To this end, four captive chimpanzees ( Pan troglodytes) were trained to reproduce 23 demonstrated actions, and four age-/sex-matched controls were trained to produce basic husbandry behaviors in response to manual cues. Diffusion tensor images were acquired before and after 600 min of training over an average of 112 days. Bilateral and asymmetrical changes in frontoparietotemporal white matter integrity were compared between DAID trained subjects and controls. We found that imitation trained subjects exhibited leftward shifts in both mean fractional anisotropy and tract strength asymmetry measures in brain regions within the mirror system. This is the first report of training-induced changes in white matter integrity in chimpanzees and suggests that frontoparietotemporal connectivity, particularly in the left hemisphere, may have facilitated the emergence of increasingly complex imitation learning abilities.

Conditioning exercises in ski jumping: biomechanical relationship of squat jumps, imitation jumps, and hill jumps.

PubMed

Lorenzetti, Silvio; Ammann, Fabian; Windmüller, Sabrina; Häberle, Ramona; Müller, Sören; Gross, Micah; Plüss, Michael; Plüss, Stefan; Schödler, Berni; Hübner, Klaus

2017-11-22

As hill jumps are very time-consuming, ski jumping athletes often perform various imitation jumps during training. The performed jumps should be similar to hill jumps, but a direct comparison of the kinetic and kinematic parameters has not been performed yet. Therefore, this study aimed to correlate 11 common parameters during hill jumps (Oberstdorf Germany), squat jumps (wearing indoor shoes), and various imitation jumps (rolling 4°, rolling flat, static; jumping equipment or indoor shoes) on a custom-built instrumented vehicle with a catch by the coach. During the performed jumps, force and video data of the take-off of 10 athletes were measured. The imitation and squat jumps were then ranked. The main difference between the hill jumps and the imitation and squat jumps is the higher maximal force loading rate during the hill jumps. Imitation jumps performed on a rolling platform, on flat ground were the most similar to hill jumps in terms of the force-time, and leg joint kinematic properties. Thus, non-hill jumps with a technical focus should be performed from a rolling platform with a flat inrun with normal indoor shoes or jumping equipment, and high normal force loading rates should be the main focus of imitation training.

Nature of Motor Imitation Problems in School-Aged Boys with Autism: A Motor or a Cognitive Problem?

ERIC Educational Resources Information Center

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

2007-01-01

This case-control study explores the underlying mechanisms of imitation problems in boys with autism by manipulating imitation task variables and by correlating imitation performance with competence on general motor tests (Movement Assessment Battery for Children and Peabody Developmental Motor Scales). Fifty-five boys participated in this study:…

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

PubMed

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.

Infant and adult visual attention during an imitation demonstration

PubMed Central

Taylor, Gemma; Herbert, Jane S

2014-01-01

Deferred imitation tasks have shown that manipulations at encoding can enhance infant learning and memory performance within an age, suggesting that brain maturation alone cannot fully account for all developmental changes in early memory abilities. The present study investigated whether changes in the focus of attention during learning might contribute to improving memory abilities during infancy. Infants aged 6, 9, and 12 months, and an adult comparison group, watched a video of a puppet imitation demonstration while visual behavior was recorded on an eye tracker. Overall, infants spent less time attending to the video than adults, and distributed their gaze more equally across the demonstrator and puppet stimulus. In contrast, adults directed their gaze primarily to the puppet. When infants were tested for their behavioral recall of the target actions, “imitators” were shown to have increased attention to the person and decreased attention to the background compared to “non-imitators.” These results suggest that attention during learning is related to memory outcome and that changes in attention may be one mechanism by which manipulations to the learning event may enhance infant recall memory. © 2013 The Authors. Developmental Psychobiology published by Wiley Periodicals, Inc. PMID:24037972

Acquisition of automatic imitation is sensitive to sensorimotor contingency.

PubMed

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.

Choosing order of operations to accelerate strip structure analysis in parameter range

NASA Astrophysics Data System (ADS)

Kuksenko, S. P.; Akhunov, R. R.; Gazizov, T. R.

2018-05-01

The paper considers the issue of using iteration methods in solving the sequence of linear algebraic systems obtained in quasistatic analysis of strip structures with the method of moments. Using the analysis of 4 strip structures, the authors have proved that additional acceleration (up to 2.21 times) of the iterative process can be obtained during the process of solving linear systems repeatedly by means of choosing a proper order of operations and a preconditioner. The obtained results can be used to accelerate the process of computer-aided design of various strip structures. The choice of the order of operations to accelerate the process is quite simple, universal and could be used not only for strip structure analysis but also for a wide range of computational problems.

Laboratory studies of imitation/field studies of tradition: towards a synthesis in animal social learning.

PubMed

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.

Mental steps: Differential activation of internal pacemakers in motor imagery and in mental imitation of gait.

PubMed

Sacheli, Lucia Maria; Zapparoli, Laura; De Santis, Carlo; Preti, Matteo; Pelosi, Catia; Ursino, Nicola; Zerbi, Alberto; Banfi, Giuseppe; Paulesu, Eraldo

2017-10-01

Gait imagery and gait observation can boost the recovery of locomotion dysfunctions; yet, a neurologically justified rationale for their clinical application is lacking as much as a direct comparison of their neural correlates. Using functional magnetic resonance imaging, we measured the neural correlates of explicit motor imagery of gait during observation of in-motion videos shot in a park with a steady cam (Virtual Walking task). In a 2 × 2 factorial design, we assessed the modulatory effect of gait observation and of foot movement execution on the neural correlates of the Virtual Walking task: in half of the trials, the participants were asked to mentally imitate a human model shown while walking along the same route (mental imitation condition); moreover, for half of all the trials, the participants also performed rhythmic ankle dorsiflexion as a proxy for stepping movements. We found that, beyond the areas associated with the execution of lower limb movements (the paracentral lobule, the supplementary motor area, and the cerebellum), gait imagery also recruited dorsal premotor and posterior parietal areas known to contribute to the adaptation of walking patterns to environmental cues. When compared with mental imitation, motor imagery recruited a more extensive network, including a brainstem area compatible with the human mesencephalic locomotor region (MLR). Reduced activation of the MLR in mental imitation indicates that this more visually guided task poses less demand on subcortical structures crucial for internally generated gait patterns. This finding may explain why patients with subcortical degeneration benefit from rehabilitation protocols based on gait observation. Hum Brain Mapp 38:5195-5216, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Deliberately generated and imitated facial expressions of emotions in people with eating disorders.

PubMed

Dapelo, Marcela Marin; Bodas, Sergio; Morris, Robin; Tchanturia, Kate

2016-02-01

People with eating disorders have difficulties in socio emotional functioning that could contribute to maintaining the functional consequences of the disorder. This study aimed to explore the ability to deliberately generate (i.e., pose) and imitate facial expressions of emotions in women with anorexia (AN) and bulimia nervosa (BN), compared to healthy controls (HC). One hundred and three participants (36 AN, 25 BN, and 42 HC) were asked to pose and imitate facial expressions of anger, disgust, fear, happiness, and sadness. Their facial expressions were recorded and coded. Participants with eating disorders (both AN and BN) were less accurate than HC when posing facial expressions of emotions. Participants with AN were less accurate compared to HC imitating facial expressions, whilst BN participants had a middle range performance. All results remained significant after controlling for anxiety, depression and autistic features. The relatively small number of BN participants recruited for this study. The study findings suggest that people with eating disorders, particularly those with AN, have difficulties posing and imitating facial expressions of emotions. These difficulties could have an impact in social communication and social functioning. This is the first study to investigate the ability to pose and imitate facial expressions of emotions in people with eating disorders, and the findings suggest this area should be further explored in future studies. Copyright © 2015. Published by Elsevier B.V.

Studies on the S-band bunching system with the Hybrid Bunching-accelerating Structure

NASA Astrophysics Data System (ADS)

Pei, Shi-Lun; Gao, Bin

2018-04-01

Generally, a standard bunching system is composed of a standing-wave (SW) pre-buncher (PB), a traveling-wave (TW) buncher (B) and a standard accelerating structure. In the industrial area, the bunching system is usually simplified by eliminating the PB and integrating the B and the standard accelerating structure together to form a β-varied accelerating structure. The beam capturing efficiency for this kind of simplified system is often worse than that for the standard one. The hybrid buncher (HB) has been proved to be a successful attempt to reduce the cost but preserve the beam quality as much as possible. Here we propose to exclusively simplify the standard bunching system by integrating the PB, the B and the standard accelerating structure together to form a Hybrid Bunching-accelerating Structure (HBaS). Compared to the standard bunching system, the one based on the HBaS is more compact, and the cost is lowered to the largest extent. With almost the same beam transportation efficiency (∼70%) from the electron gun to the linac exit, the peak-to-peak (p-to-p) beam energy spread and the 1 σ emittance of the linac with the HBaS are ∼20% and ∼60% bigger than those of the linac based on the split PB/B/standard accelerating structure system. Nonetheless, the proposed HBaS can be widely applied in the industrial linacs to greatly increase the beam capturing efficiency without fairly increasing the construction cost.

Don’t Try This at Home: Toddlers’ Imitation of New Skills from People on Video

PubMed Central

Strouse, Gabrielle A.; Troseth, Georgene L.

2008-01-01

Imitation of people on educational television is a potential way for very young children to learn new skills. Although toddlers in previous studies exhibited a “video deficit” in learning, 24-month-olds in Study 1 successfully reproduced behaviors modeled by a person who was on video as well as they did those modeled by a person who was present in the room (even after a 24-hour delay). Neither displaced filming context nor cuts between actions affected toddler’s imitation from video. Shortening the demonstration in Study 2 affected imitation in the video condition but not in the live condition. In Study 3, 24-month-olds who viewed the original, longer videos on their family TV (with which they had a viewing history) imitated significantly less than those who viewed the videos on the lab monitor. Imitation of a live modeler was the same across settings (home or lab). Implications for toddlers’ judgments of reliable information sources and for the design of educational television programs are discussed. PMID:18675431

Summary of the Normal-Conducting Accelerating Structures for LEDA and APT

NASA Astrophysics Data System (ADS)

Schneider, J. David

1998-04-01

The accelerator production of tritium (APT) plant requires a continuous (100% duty-factor), 100-mA, 1000--1700-MeV proton beam. Superconducting structures will accelerate protons above about 200 MeV, but room-temperature, normal-conducting (NC) copper structures will be used for lower energies. We will assemble the front 11-MeV portion of this NC accelerator as the low-energy demonstration accelerator (LEDA). This presentation will cover the demonstated operation of the proton injector, the design, fabrication, and tuning status of the 6.7-MeV RFQ, and the design features of the CCDTL (coupled-cavity drift-tube linac) that will accelerate protons to 100 MeV, before use of a conventional CCL (coupled-cavity linac). Several innovative features result in improved performance, ease of use, and improved reliabiltiy. The75-keV injector features a microwave ion source, dual-solenoid transport, and has no electronics at high potential. Its demonstrated high efficiency (less than 800 Watts), excellent proton fraction (>90%), high current (>110 mA), and reliability make it attractive for several other high-current applications. The 6.7-MeV, 350-MHz RFQ is an 8-meter-long, brazed-copper structure with hundreds of cooling channels that carry away the 1.3 MW of waste heat. During beam operation, only the cooling-water temperature is adjustable to maintain structure resonance. LEDA's 700-MHz CCDTL structure is new, combining features of the conventional DTL and CCL structures. All focus magnets are external to the copper accelerating cavities, each of which contains either one or two drift tubes. A `hot model' will validate fabrication, cooling, tuning, and coupling techniques. The LEDA facility is being upgraded with 15 MW of power and cooling utiliites, to support seven 1-MW cw RF systems needed to power all structures. The first few of these 1.3 MW 350-MHz systems are operational, and extensive testing was completed on the critical RF windows. Updates will be given on the

Children's Faithfulness in Imitating Language Use Varies Cross-culturally, Contingent on Prior Experience

ERIC Educational Resources Information Center

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…

A new compact structure for a high intensity low-energy heavy-ion accelerator

NASA Astrophysics Data System (ADS)

Wang, Zhi-Jun; He, Yuan; A. Kolomiets, A.; Liu, Shu-Hui; Du, Xiao-Nan; Jia, Huan; Li, Chao; Wang, Wang-Sheng; Chen, Xi-Meng

2013-12-01

A new compact accelerating structure named Hybrid RFQ is proposed to accelerate a high-intensity low-energy heavy ion beam in HISCL (High Intensive heavy ion SuperConducting Linear accelerator), which is an injector of HIAF (Heavy Ion Advanced Research Facility). It is combined by an alternative series of acceleration gaps and RFQ sections. The proposed structure has a high accelerating ability compared with a conventional RFQ and is more compact than traditional DTLs. A Hybrid RFQ is designed to accelerate 238U34+ from 0.38 MeV/u to 1.33 MeV/u. The operation frequency is described to be 81.25 MHz at CW (continuous wave) mode. The design beam current is 1.0 mA. The results of beam dynamics and RF simulation of the Hybrid RFQ show that the structure has a good performance at the energy range for ion acceleration. The emittance growth is less than 5% in both directions and the RF power is less than 150 kW. In this paper, the results of beam dynamics and RF simulation of the Hybrid RFQ are presented.

Cultural differences in the imitation and transmission of inefficient actions.

PubMed

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.

The Relation between Contingency Preference and Imitation in 6-8-Month-Old Infants

ERIC Educational Resources Information Center

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…

On Quantizing Ride Comfort and Allowable Accelerations

DTIC Science & Technology

1976-07-01

UnImited and approved for Public release. ,.Io. 7 D5Xt4WX.AX..JL.1.X.1LJ -’a~ft IF I.,, I. ’W No 1 -0.U /cM Report) MAR 3 19M0 III. SUPPLEMENTARY NOTES...vehicle’s habitability for a given tive. This is for three main reasons: acceleration-time history. These indices are: Mankind is very variable, and even an...though the limits may not be entirely "correct" in an absolute sense,.e ~utIY* review the l~steryof an analogousawL I Hey~ f .,B 7 -tisom e To better

Imitation of novel conspecific and human speech sounds in the killer whale (Orcinus orca).

PubMed

Abramson, José Z; Hernández-Lloreda, Mª Victoria; García, Lino; Colmenares, Fernando; Aboitiz, Francisco; Call, Josep

2018-01-31

Vocal imitation is a hallmark of human spoken language, which, along with other advanced cognitive skills, has fuelled the evolution of human culture. Comparative evidence has revealed that although the ability to copy sounds from conspecifics is mostly uniquely human among primates, a few distantly related taxa of birds and mammals have also independently evolved this capacity. Remarkably, field observations of killer whales have documented the existence of group-differentiated vocal dialects that are often referred to as traditions or cultures and are hypothesized to be acquired non-genetically. Here we use a do-as-I-do paradigm to study the abilities of a killer whale to imitate novel sounds uttered by conspecific (vocal imitative learning) and human models (vocal mimicry). We found that the subject made recognizable copies of all familiar and novel conspecific and human sounds tested and did so relatively quickly (most during the first 10 trials and three in the first attempt). Our results lend support to the hypothesis that the vocal variants observed in natural populations of this species can be socially learned by imitation. The capacity for vocal imitation shown in this study may scaffold the natural vocal traditions of killer whales in the wild. © 2018 The Author(s).

Flow acceleration structure of Aurelia aurita: implications on propulsion

NASA Astrophysics Data System (ADS)

Kim, Jin-Tae; Piper, Matthew; Chamorro, Leonardo P.

2017-11-01

The jetting and paddling mechanisms used by Aurelia aurita jellyfish allows for one of the most efficient propulsion among other metazoans. Characterization of the induced flow acceleration is critical to uncover distinctive patterns. We found four acceleration structures using 3D measurements of body and flow dynamics in Lagrangian frame of reference. Two intense structures occur near the bell margin and are generated by paddling; the other two around the center of the jellyfish and half magnitude are a result of jetting. Their interaction leads to the maximum flow velocity in the middle of the relaxation, where relatively straight flow trajectories occur. The jellyfish achieves an efficient relaxation by generating flow deceleration with minor body deceleration.

The change of amyloplasts structure and composition of storage starch in potato minitubers during imitated microgravity

NASA Astrophysics Data System (ADS)

Nedukha, O. M.; Kordyum, E. L.; Martyn, G. M.; Schnyukova, E. I.

Potato was designated for food production in the controlled ecological life-support system CELSS because its tubers as it is known contain starch and significant protein content and are edible food after the long-term storage We used the cultivation of potato miniplants under influence of long-term horizontal clinorotation 2 rev min which imitated microgravity as a model for the technology of potato food production in the CELSS The aim of our work was to determine content and composition storage starch as well as amyloplast ultrastructure of storage parenchyma cells in potato minitubers formed under long-term to 6 weeks slow horizontal clinorotation 2 rpm Minitubers developed from axillary buds of potato miniplants growing in the aseptic stationary conditions and under clinorotation Methods of scanning and transmission electron microscopy were used for the study of surface and ultrastructure of amyloplasts the biochemical method by Hovenkamp-Hermelink et al 1988 - for study of starch composition Some differences were observed in amyloplast structure under clinorotation namely increased volume of starch grains in plastid decreased stroma volume changed structure of envelope membranes in comparison with the stationary control Besides an appearance of fraction of gigantic amyloplasts in central layers of parenchyma was observed under clinorotation after 4 weeks of growth The total starch content increased and reached to 219 5 - 4 1 mg g FW at 6 weeks of clinorotation it was 167 5 - 5 6 mg g FW in the control minitubers A ratio of

Low Fidelity Imitation of Atypical Biological Kinematics in Autism Spectrum Disorders Is Modulated by Self-Generated Selective Attention.

PubMed

Hayes, Spencer J; Andrew, Matthew; Elliott, Digby; Gowen, Emma; Bennett, Simon J

2016-02-01

We examined whether adults with autism had difficulty imitating atypical biological kinematics. To reduce the impact that higher-order processes have on imitation we used a non-human agent model to control social attention, and removed end-state target goals in half of the trials to minimise goal-directed attention. Findings showed that only neurotypical adults imitated atypical biological kinematics. Adults with autism did, however, become significantly more accurate at imitating movement time. This confirmed they engaged in the task, and that sensorimotor adaptation was self-regulated. The attentional bias to movement time suggests the attenuation in imitating kinematics might be a compensatory strategy due to deficits in lower-level visuomotor processes associated with self-other mapping, or selective attention modulated the processes that represent biological kinematics.

Object-directed imitation in autism spectrum disorder is differentially influenced by motoric task complexity, but not social contextual cues.

PubMed

Chetcuti, Lacey; Hudry, Kristelle; Grant, Megan; Vivanti, Giacomo

2017-11-01

We examined the role of social motivation and motor execution factors in object-directed imitation difficulties in autism spectrum disorder. A series of to-be-imitated actions was presented to 35 children with autism spectrum disorder and 20 typically developing children on an Apple ® iPad ® by a socially responsive or aloof model, under conditions of low and high motor demand. There were no differences in imitation performance (i.e. the number of actions reproduced within a fixed sequence), for either group, in response to a model who acted socially responsive or aloof. Children with autism spectrum disorder imitated the high motor demand task more poorly than the low motor demand task, while imitation performance for typically developing children was equivalent across the low and high motor demand conditions. Furthermore, imitative performance in the autism spectrum disorder group was unrelated to social reciprocity, though positively associated with fine motor coordination. These results suggest that difficulties in object-directed imitation in autism spectrum disorder are the result of motor execution difficulties, not reduced social motivation.

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

PubMed

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.

Critical brain regions for tool-related and imitative actions: a componential analysis

PubMed Central

Shapiro, Allison D.; Coslett, H. Branch

2014-01-01

Numerous functional neuroimaging studies suggest that widespread bilateral parietal, temporal, and frontal regions are involved in tool-related and pantomimed gesture performance, but the role of these regions in specific aspects of gestural tasks remains unclear. In the largest prospective study of apraxia-related lesions to date, we performed voxel-based lesion–symptom mapping with data from 71 left hemisphere stroke participants to assess the critical neural substrates of three types of actions: gestures produced in response to viewed tools, imitation of tool-specific gestures demonstrated by the examiner, and imitation of meaningless gestures. Thus, two of the three gesture types were tool-related, and two of the three were imitative, enabling pairwise comparisons designed to highlight commonalities and differences. Gestures were scored separately for postural (hand/arm positioning) and kinematic (amplitude/timing) accuracy. Lesioned voxels in the left posterior temporal gyrus were significantly associated with lower scores on the posture component for both of the tool-related gesture tasks. Poor performance on the kinematic component of all three gesture tasks was significantly associated with lesions in left inferior parietal and frontal regions. These data enable us to propose a componential neuroanatomic model of action that delineates the specific components required for different gestural action tasks. Thus, visual posture information and kinematic capacities are differentially critical to the three types of actions studied here: the kinematic aspect is particularly critical for imitation of meaningless movement, capacity for tool-action posture representations are particularly necessary for pantomimed gestures to the sight of tools, and both capacities inform imitation of tool-related movements. These distinctions enable us to advance traditional accounts of apraxia. PMID:24776969

Body odors promote automatic imitation in autism.

PubMed

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.

Vocal Tract Images Reveal Neural Representations of Sensorimotor Transformation During Speech Imitation

PubMed Central

Carey, Daniel; Miquel, Marc E.; Evans, Bronwen G.; Adank, Patti; McGettigan, Carolyn

2017-01-01

Abstract Imitating speech necessitates the transformation from sensory targets to vocal tract motor output, yet little is known about the representational basis of this process in the human brain. Here, we address this question by using real-time MR imaging (rtMRI) of the vocal tract and functional MRI (fMRI) of the brain in a speech imitation paradigm. Participants trained on imitating a native vowel and a similar nonnative vowel that required lip rounding. Later, participants imitated these vowels and an untrained vowel pair during separate fMRI and rtMRI runs. Univariate fMRI analyses revealed that regions including left inferior frontal gyrus were more active during sensorimotor transformation (ST) and production of nonnative vowels, compared with native vowels; further, ST for nonnative vowels activated somatomotor cortex bilaterally, compared with ST of native vowels. Using test representational similarity analysis (RSA) models constructed from participants’ vocal tract images and from stimulus formant distances, we found that RSA searchlight analyses of fMRI data showed either type of model could be represented in somatomotor, temporal, cerebellar, and hippocampal neural activation patterns during ST. We thus provide the first evidence of widespread and robust cortical and subcortical neural representation of vocal tract and/or formant parameters, during prearticulatory ST. PMID:28334401

The influence of ambient speech on adult speech productions through unintentional imitation.

PubMed

Delvaux, Véronique; Soquet, Alain

2007-01-01

This paper deals with the influence of ambient speech on individual speech productions. A methodological framework is defined to gather the experimental data necessary to feed computer models simulating self-organisation in phonological systems. Two experiments were carried out. Experiment 1 was run on French native speakers from two regiolects of Belgium: two from Liège and two from Brussels. When exposed to the way of speaking of the other regiolect via loudspeakers, the speakers of one regiolect produced vowels that were significantly different from their typical realisations, and significantly closer to the way of speaking specific of the other regiolect. Experiment 2 achieved a replication of the results for 8 Mons speakers hearing a Liège speaker. A significant part of the imitative effect remained up to 10 min after the end of the exposure to the other regiolect productions. As a whole, the results suggest that: (i) imitation occurs automatically and unintentionally, (ii) the modified realisations leave a memory trace, in which case the mechanism may be better defined as 'mimesis' than as 'imitation'. The potential effects of multiple imitative speech interactions on sound change are discussed in this paper, as well as the implications for a general theory of phonetic implementation and phonetic representation.

Brief Report: Imitation of Object-Directed Acts in Young Children with Autism Spectrum Disorders

ERIC Educational Resources Information Center

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…

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

PubMed

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).

Deferred imitation in 18-month-olds from two cultural contexts: the case of Cameroonian Nso farmer and German-middle class infants.

PubMed

Borchert, Sonja; Lamm, Bettina; Graf, Frauke; Knopf, Monika

2013-12-01

Imitative learning has been described in naturalistic studies for different cultures, but lab-based research studying imitative learning across different cultural contexts is almost missing. Therefore, imitative learning was assessed with 18-month-old German middle-class and Cameroonian Nso farmer infants - representing two highly different eco-cultural contexts associated with different cultural models, the psychological autonomy and the hierarchical relatedness - by using the deferred imitation paradigm. Study 1 revealed that the infants from both cultural contexts performed a higher number of target actions in the deferred imitation than in the baseline phase. Moreover, it was found that German middle-class infants showed a higher mean imitation rate as they performed more target actions in the deferred imitation phase compared with Cameroonian Nso farmer infants. It was speculated that the opportunity to manipulate the test objects directly after the demonstration of the target actions could enhance the mean deferred imitation rate of the Cameroonian Nso farmer infants which was confirmed in Study 2. Possible explanations for the differences in the amount of imitated target actions of German middle-class and Cameroonian Nso farmer infants are discussed considering the object-related, dyadic setting of the imitation paradigm with respect to the different learning contexts underlying the different cultural models of learning. Copyright © 2013 Elsevier Inc. All rights reserved.

Learning of spatial relationships between observed and imitated actions allows invariant inverse computation in the frontal mirror neuron system.

PubMed

Oh, Hyuk; Gentili, Rodolphe J; Reggia, James A; Contreras-Vidal, José L

2011-01-01

It has been suggested that the human mirror neuron system can facilitate learning by imitation through coupling of observation and action execution. During imitation of observed actions, the functional relationship between and within the inferior frontal cortex, the posterior parietal cortex, and the superior temporal sulcus can be modeled within the internal model framework. The proposed biologically plausible mirror neuron system model extends currently available models by explicitly modeling the intraparietal sulcus and the superior parietal lobule in implementing the function of a frame of reference transformation during imitation. Moreover, the model posits the ventral premotor cortex as performing an inverse computation. The simulations reveal that: i) the transformation system can learn and represent the changes in extrinsic to intrinsic coordinates when an imitator observes a demonstrator; ii) the inverse model of the imitator's frontal mirror neuron system can be trained to provide the motor plans for the imitated actions.

The Robot in the Crib: A Developmental Analysis of Imitation Skills in Infants and Robots

ERIC Educational Resources Information Center

Demiris, Yiannis; Meltzoff, Andrew

2008-01-01

Interesting systems, whether biological or artificial, develop. Starting from some initial conditions, they respond to environmental changes, and continuously improve their capabilities. Developmental psychologists have dedicated significant effort to studying the developmental progression of infant imitation skills, because imitation underlies…

Effects of Context and Facial Expression on Imitation Tasks in Preschool Children with Autism

ERIC Educational Resources Information Center

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…

Do Imitation Problems Reflect a Core Characteristic in Autism? Evidence from a Literature Review

ERIC Educational Resources Information Center

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…

Interindividual Differences in Neonatal Imitation and the Development of Action Chains in Rhesus Macaques

ERIC Educational Resources Information Center

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…

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

NASA Astrophysics Data System (ADS)

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.

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

PubMed

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.

High-Power Testing of 11.424-GHz Dielectric-Loaded Accelerating Structures

NASA Astrophysics Data System (ADS)

Gold, Steven; Gai, Wei

2001-10-01

Argonne National Laboratory has previously described the design, construction, and bench testing of an X-band traveling-wave accelerating structure loaded with a permittivity=20 dielectric (P. Zou et al., Rev. Sci. Instrum. 71, 2301, 2000.). We describe a new program to build a test accelerator using this structure. The accelerator will be powered by the high-power 11.424-GHz radiation from the magnicon facility at the Naval Research Laboratory ( O.A. Nezhevenko et al., Proc. PAC 2001, in press). The magnicon is expected to provide up to 30 MW from each of two WR-90 output waveguide arms in pulses of up to 1 microsecond duration, permitting tests up to a gradient of 40 MV/m. Still higher power pulses (100-500 MW) may be available at the output of an active pulse compressor driven by the magnicon ( A.L. Vikharev et al., Proc. 9th Workshop on Advanced Accelerator Concepts.).

Laser Wakefield Acceleration: Structural and Dynamic Studies. Final Technical Report ER40954

DOE Office of Scientific and Technical Information (OSTI.GOV)

Downer, Michael C.

2014-04-30

Particle accelerators enable scientists to study the fundamental structure of the universe, but have become the largest and most expensive of scientific instruments. In this project, we advanced the science and technology of laser-plasma accelerators, which are thousands of times smaller and less expensive than their conventional counterparts. In a laser-plasma accelerator, a powerful laser pulse exerts light pressure on an ionized gas, or plasma, thereby driving an electron density wave, which resembles the wake behind a boat. Electrostatic fields within this plasma wake reach tens of billions of volts per meter, fields far stronger than ordinary non-plasma matter (suchmore » as the matter that a conventional accelerator is made of) can withstand. Under the right conditions, stray electrons from the surrounding plasma become trapped within these “wake-fields”, surf them, and acquire energy much faster than is possible in a conventional accelerator. Laser-plasma accelerators thus might herald a new generation of compact, low-cost accelerators for future particle physics, x-ray and medical research. In this project, we made two major advances in the science of laser-plasma accelerators. The first of these was to accelerate electrons beyond 1 gigaelectronvolt (1 GeV) for the first time. In experimental results reported in Nature Communications in 2013, about 1 billion electrons were captured from a tenuous plasma (about 1/100 of atmosphere density) and accelerated to 2 GeV within about one inch, while maintaining less than 5% energy spread, and spreading out less than ½ milliradian (i.e. ½ millimeter per meter of travel). Low energy spread and high beam collimation are important for applications of accelerators as coherent x-ray sources or particle colliders. This advance was made possible by exploiting unique properties of the Texas Petawatt Laser, a powerful laser at the University of Texas at Austin that produces pulses of 150 femtoseconds (1 femtosecond

Using multi-level Bayesian lesion-symptom mapping to probe the body-part-specificity of gesture imitation skills.

PubMed

Achilles, Elisabeth I S; Weiss, Peter H; Fink, Gereon R; Binder, Ellen; Price, Cathy J; Hope, Thomas M H

2017-11-01

Past attempts to identify the neural substrates of hand and finger imitation skills in the left hemisphere of the brain have yielded inconsistent results. Here, we analyse those associations in a large sample of 257 left hemisphere stroke patients. By introducing novel Bayesian methods, we characterise lesion symptom associations at three levels: the voxel-level, the single-region level (using anatomically defined regions), and the region-pair level. The results are inconsistent across those three levels and we argue that each level of analysis makes assumptions which constrain the results it can produce. Regardless of the inconsistencies across levels, and contrary to past studies which implicated differential neural substrates for hand and finger imitation, we find no consistent voxels or regions, where damage affects one imitation skill and not the other, at any of the three analysis levels. Our novel Bayesian approach indicates that any apparent differences appear to be driven by an increased sensitivity of hand imitation skills to lesions that also impair finger imitation. In our analyses, the results of the highest level of analysis (region-pairs) emphasise a role of the primary somatosensory and motor cortices, and the occipital lobe in imitation. We argue that this emphasis supports an account of both imitation tasks based on direct sensor-motor connections, which throws doubt on past accounts which imply the need for an intermediate (e.g. body-part-coding) system of representation. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.

Is It Rational to Assume that Infants Imitate Rationally? A Theoretical Analysis and Critique

ERIC Educational Resources Information Center

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…

Learning an Embodied Visual Language: Four Imitation Strategies Available to Sign Learners

PubMed Central

Shield, Aaron; Meier, Richard P.

2018-01-01

The parts of the body that are used to produce and perceive signed languages (the hands, face, and visual system) differ from those used to produce and perceive spoken languages (the vocal tract and auditory system). In this paper we address two factors that have important consequences for sign language acquisition. First, there are three types of lexical signs: one-handed, two-handed symmetrical, and two-handed asymmetrical. Natural variation in hand dominance in the population leads to varied input to children learning sign. Children must learn that signs are not specified for the right or left hand but for dominant and non-dominant. Second, we posit that children have at least four imitation strategies available for imitating signs: anatomical (Activate the same muscles as the sign model), which could lead learners to inappropriately use their non-dominant hand; mirroring (Produce a mirror image of the modeled sign), which could lead learners to produce lateral movement reversal errors or to use the non-dominant hand; visual matching (Reproduce what you see from your perspective), which could lead learners to produce inward–outward movement and palm orientation reversals; and reversing (Reproduce what the sign model would see from his/her perspective). This last strategy is the only one that always yields correct phonological forms in signed languages. To test our hypotheses, we turn to evidence from typical and atypical hearing and deaf children as well as from typical adults; the data come from studies of both sign acquisition and gesture imitation. Specifically, we posit that all children initially use a visual matching strategy but typical children switch to a mirroring strategy sometime in the second year of life; typical adults tend to use a mirroring strategy in learning signs and imitating gestures. By contrast, children and adults with autism spectrum disorder (ASD) appear to use the visual matching strategy well into childhood or even adulthood

Imitate or innovate? Children's innovation is influenced by the efficacy of observed behaviour.

PubMed

Carr, Kayleigh; Kendal, Rachel L; Flynn, Emma G

2015-09-01

This study investigated the age at which children judge it futile to imitate unreliable information, in the form of a visibly ineffective demonstrated solution, and deviate to produce novel solutions ('innovations'). Children aged 4-9 years were presented with a novel puzzle box, the Multiple-Methods Box (MMB), which offered multiple innovation opportunities to extract a reward using different tools, access points and exits. 209 children were assigned to conditions in which eight social demonstrations of a reward retrieval method were provided; each condition differed incrementally in terms of the method's efficacy (0%, 25%, 75%, and 100% success at extracting the reward). An additional 47 children were assigned to a no-demonstration control condition. Innovative reward extractions from the MMB increased with decreasing efficacy of the demonstrated method. However, imitation remained a widely used strategy irrespective of the efficacy of the method being reproduced (90% of children produced at least one imitative attempt, and imitated on an average of 4.9 out of 8 attempt trials). Children were more likely to innovate in relation to the tool than exit, even though the latter would have been more effective. Overall, innovation was rare: only 12.4% of children innovated by discovering at least one novel reward exit. Children's prioritisation of social information is consistent with theories of cultural evolution indicating imitation is a prepotent response following observation of behaviour, and that innovation is a rarity; so much so, that even maladaptive behaviour is copied. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.

Kinematics and Kinetics of Squats, Drop Jumps and Imitation Jumps of Ski Jumpers

PubMed Central

Pauli, Carole A.; Keller, Melanie; Ammann, Fabian; Hübner, Klaus; Lindorfer, Julia; Taylor, William R.

2016-01-01

Abstract Pauli, CA, Keller, M, Ammann, F, Hübner, K, Lindorfer, J, Taylor, WR, and Lorenzetti, S. Kinematics and kinetics of squats, drop jumps and imitation jumps of ski jumpers. J Strength Cond Res 30(3): 643–652, 2016—Squats, drop jumps, and imitation jumps are commonly used training exercises in ski jumping to enhance maximum force, explosive force, and sport-specific skills. The purpose of this study was to evaluate the kinetics and kinematics of training exercises in ski jumping and to find objective parameters in training exercises that most correlate with the competition performance of ski jumpers. To this end, barbell squats, drop jumps, and imitation jumps were measured in a laboratory environment for 10 elite ski jumpers. Force and motion data were captured, and the influence of maximum vertical force, force difference, vertical take-off velocity, knee moments, knee joint power, and a knee valgus/varus index was evaluated and correlated with their season jump performance. The results indicate that, especially for the imitation jumps, a good correlation exists between the vertical take-off velocity and the personal jump performance on the hill (R = 0.718). Importantly, however, the more the athletes tended toward a valgus knee alignment during the measured movements, the worse their performance (R = 0.729 imitation jumps; R = 0.685 squats). Although an evaluation of the athletes' lower limb alignment during competitive jumping on the hill is still required, these preliminary data suggest that performance training should additionally concentrate on improving knee alignment to increase ski jumping performance. PMID:26418370

The mirror neuron system is more active during complementary compared with imitative action.

PubMed

Newman-Norlund, Roger D; van Schie, Hein T; van Zuijlen, Alexander M J; Bekkering, Harold

2007-07-01

We assessed the role of the human mirror neuron system (MNS) in complementary actions using functional magnetic resonance imaging while participants prepared to execute imitative or complementary actions. The BOLD signal in the right inferior frontal gyrus and bilateral inferior parietal lobes was greater during preparation of complementary than during imitative actions, suggesting that the MNS may be essential in dynamically coupling action observation to action execution.

Critical brain regions for tool-related and imitative actions: a componential analysis.

PubMed

Buxbaum, Laurel J; Shapiro, Allison D; Coslett, H Branch

2014-07-01

Numerous functional neuroimaging studies suggest that widespread bilateral parietal, temporal, and frontal regions are involved in tool-related and pantomimed gesture performance, but the role of these regions in specific aspects of gestural tasks remains unclear. In the largest prospective study of apraxia-related lesions to date, we performed voxel-based lesion-symptom mapping with data from 71 left hemisphere stroke participants to assess the critical neural substrates of three types of actions: gestures produced in response to viewed tools, imitation of tool-specific gestures demonstrated by the examiner, and imitation of meaningless gestures. Thus, two of the three gesture types were tool-related, and two of the three were imitative, enabling pairwise comparisons designed to highlight commonalities and differences. Gestures were scored separately for postural (hand/arm positioning) and kinematic (amplitude/timing) accuracy. Lesioned voxels in the left posterior temporal gyrus were significantly associated with lower scores on the posture component for both of the tool-related gesture tasks. Poor performance on the kinematic component of all three gesture tasks was significantly associated with lesions in left inferior parietal and frontal regions. These data enable us to propose a componential neuroanatomic model of action that delineates the specific components required for different gestural action tasks. Thus, visual posture information and kinematic capacities are differentially critical to the three types of actions studied here: the kinematic aspect is particularly critical for imitation of meaningless movement, capacity for tool-action posture representations are particularly necessary for pantomimed gestures to the sight of tools, and both capacities inform imitation of tool-related movements. These distinctions enable us to advance traditional accounts of apraxia. © The Author (2014). Published by Oxford University Press on behalf of the Guarantors

A compact linear accelerator based on a scalable microelectromechanical-system RF-structure

NASA Astrophysics Data System (ADS)

Persaud, A.; Ji, Q.; Feinberg, E.; Seidl, P. A.; Waldron, W. L.; Schenkel, T.; Lal, A.; Vinayakumar, K. B.; Ardanuc, S.; Hammer, D. A.

2017-06-01

A new approach for a compact radio-frequency (RF) accelerator structure is presented. The new accelerator architecture is based on the Multiple Electrostatic Quadrupole Array Linear Accelerator (MEQALAC) structure that was first developed in the 1980s. The MEQALAC utilized RF resonators producing the accelerating fields and providing for higher beam currents through parallel beamlets focused using arrays of electrostatic quadrupoles (ESQs). While the early work obtained ESQs with lateral dimensions on the order of a few centimeters, using a printed circuit board (PCB), we reduce the characteristic dimension to the millimeter regime, while massively scaling up the potential number of parallel beamlets. Using Microelectromechanical systems scalable fabrication approaches, we are working on further reducing the characteristic dimension to the sub-millimeter regime. The technology is based on RF-acceleration components and ESQs implemented in the PCB or silicon wafers where each beamlet passes through beam apertures in the wafer. The complete accelerator is then assembled by stacking these wafers. This approach has the potential for fast and inexpensive batch fabrication of the components and flexibility in system design for application specific beam energies and currents. For prototyping the accelerator architecture, the components have been fabricated using the PCB. In this paper, we present proof of concept results of the principal components using the PCB: RF acceleration and ESQ focusing. Ongoing developments on implementing components in silicon and scaling of the accelerator technology to high currents and beam energies are discussed.

A compact linear accelerator based on a scalable microelectromechanical-system RF-structure.

PubMed

Persaud, A; Ji, Q; Feinberg, E; Seidl, P A; Waldron, W L; Schenkel, T; Lal, A; Vinayakumar, K B; Ardanuc, S; Hammer, D A

2017-06-01

A new approach for a compact radio-frequency (RF) accelerator structure is presented. The new accelerator architecture is based on the Multiple Electrostatic Quadrupole Array Linear Accelerator (MEQALAC) structure that was first developed in the 1980s. The MEQALAC utilized RF resonators producing the accelerating fields and providing for higher beam currents through parallel beamlets focused using arrays of electrostatic quadrupoles (ESQs). While the early work obtained ESQs with lateral dimensions on the order of a few centimeters, using a printed circuit board (PCB), we reduce the characteristic dimension to the millimeter regime, while massively scaling up the potential number of parallel beamlets. Using Microelectromechanical systems scalable fabrication approaches, we are working on further reducing the characteristic dimension to the sub-millimeter regime. The technology is based on RF-acceleration components and ESQs implemented in the PCB or silicon wafers where each beamlet passes through beam apertures in the wafer. The complete accelerator is then assembled by stacking these wafers. This approach has the potential for fast and inexpensive batch fabrication of the components and flexibility in system design for application specific beam energies and currents. For prototyping the accelerator architecture, the components have been fabricated using the PCB. In this paper, we present proof of concept results of the principal components using the PCB: RF acceleration and ESQ focusing. Ongoing developments on implementing components in silicon and scaling of the accelerator technology to high currents and beam energies are discussed.

Impaired imitation of gestures in mild dementia: comparison of dementia with Lewy bodies, Alzheimer's disease and vascular dementia.

PubMed

Nagahama, Yasuhiro; Okina, Tomoko; Suzuki, Norio

2015-11-01

To examine whether imitation of gestures provided useful information to diagnose early dementia in elderly patients. Imitation of finger and hand gestures was evaluated in patients with mild dementia; 74 patients had dementia with Lewy bodies (DLB), 100 with Alzheimer's disease (AD) and 52 with subcortical vascular dementia (SVaD). Significantly, more patients with DLB (32.4%) compared with patients with AD (5%) or SVaD (11.5%) had an impaired ability to imitate finger gestures bilaterally. Also, significantly, more patients with DLB (36.5%) compared with patients with AD (5%) or SVaD (15.4%) had lower mean scores of both hands. In contrast, impairment of the imitation of bimanual gestures was comparable among the three patient groups (DLB 50%, AD 42%, SVaD 42.3%). Our study revealed that imitation of bimanual gestures was impaired non-specifically in about half of the patients with mild dementia, whereas imitation of finger gestures was significantly more impaired in patients with early DLB than in those with AD or SVaD. Although the sensitivity was not high, the imitation tasks may provide additional information for diagnosis of mild dementia, especially for DLB. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Two sympatric species of passerine birds imitate the same raptor calls in alarm contexts

NASA Astrophysics Data System (ADS)

Ratnayake, Chaminda P.; Goodale, Eben; Kotagama, Sarath W.

2010-01-01

While some avian mimics appear to select sounds randomly, other species preferentially imitate sounds such as predator calls that are associated with danger. Previous work has shown that the Greater Racket-tailed Drongo ( Dicrurus paradiseus) incorporates predator calls and heterospecific alarm calls into its own species-typical alarm vocalizations. Here, we show that another passerine species, the Sri Lanka Magpie ( Urocissa ornata), which inhabits the same Sri Lankan rainforest, imitates three of the same predator calls that drongos do. For two of these call types, there is evidence that magpies also use them in alarm contexts. Our results support the hypothesis that imitated predator calls can serve as signals of alarm to multiple species.

Applying machine learning to identify autistic adults using imitation: An exploratory study.

PubMed

Li, Baihua; Sharma, Arjun; Meng, James; Purushwalkam, Senthil; Gowen, Emma

2017-01-01

Autism spectrum condition (ASC) is primarily diagnosed by behavioural symptoms including social, sensory and motor aspects. Although stereotyped, repetitive motor movements are considered during diagnosis, quantitative measures that identify kinematic characteristics in the movement patterns of autistic individuals are poorly studied, preventing advances in understanding the aetiology of motor impairment, or whether a wider range of motor characteristics could be used for diagnosis. The aim of this study was to investigate whether data-driven machine learning based methods could be used to address some fundamental problems with regard to identifying discriminative test conditions and kinematic parameters to classify between ASC and neurotypical controls. Data was based on a previous task where 16 ASC participants and 14 age, IQ matched controls observed then imitated a series of hand movements. 40 kinematic parameters extracted from eight imitation conditions were analysed using machine learning based methods. Two optimal imitation conditions and nine most significant kinematic parameters were identified and compared with some standard attribute evaluators. To our knowledge, this is the first attempt to apply machine learning to kinematic movement parameters measured during imitation of hand movements to investigate the identification of ASC. Although based on a small sample, the work demonstrates the feasibility of applying machine learning methods to analyse high-dimensional data and suggest the potential of machine learning for identifying kinematic biomarkers that could contribute to the diagnostic classification of autism.

Vocal Tract Images Reveal Neural Representations of Sensorimotor Transformation During Speech Imitation.

PubMed

Carey, Daniel; Miquel, Marc E; Evans, Bronwen G; Adank, Patti; McGettigan, Carolyn

2017-05-01

Imitating speech necessitates the transformation from sensory targets to vocal tract motor output, yet little is known about the representational basis of this process in the human brain. Here, we address this question by using real-time MR imaging (rtMRI) of the vocal tract and functional MRI (fMRI) of the brain in a speech imitation paradigm. Participants trained on imitating a native vowel and a similar nonnative vowel that required lip rounding. Later, participants imitated these vowels and an untrained vowel pair during separate fMRI and rtMRI runs. Univariate fMRI analyses revealed that regions including left inferior frontal gyrus were more active during sensorimotor transformation (ST) and production of nonnative vowels, compared with native vowels; further, ST for nonnative vowels activated somatomotor cortex bilaterally, compared with ST of native vowels. Using test representational similarity analysis (RSA) models constructed from participants' vocal tract images and from stimulus formant distances, we found that RSA searchlight analyses of fMRI data showed either type of model could be represented in somatomotor, temporal, cerebellar, and hippocampal neural activation patterns during ST. We thus provide the first evidence of widespread and robust cortical and subcortical neural representation of vocal tract and/or formant parameters, during prearticulatory ST. © The Author 2017. Published by Oxford University Press.

[Acute skin infections and their imitators in children : A photo quiz].

PubMed

Theiler, M; Schwieger-Briel, A; Weibel, L

2017-10-01

Skin infections account for 40% of emergency visits in pediatric dermatology. It is important to promptly recognize skin infections with potential complications and initiate treatment. However some characteristic skin findings may imitate skin infections and are often misdiagnosed. To illustrate frequent pediatric skin infections and pitfalls in view of imitators and differential diagnoses. A photo quiz is presented with the discussion of a selection of acute pediatric skin infections in comparison to their infectious or noninfectious differential diagnoses. The following infectious skin conditions and imitators are described and clinical clues for differentiation highlighted: eczema herpeticum and bacterial superinfection of atopic dermatitis; exanthematous hand, foot and mouth disease and varicella infection; erythema chronicum multilocularis and anular urticaria; Gianotti-Crosti syndrome and Gianotti-Crosti-like reaction; bacterial folliculitis of the scalp and kerion celsi and eosinophilic pustular folliculitis of the scalp; cutaneous Leishmaniasis and idiopathic facial aseptic granuloma; allergic and bacterial lymphangitis; bullous impetigo contagiosa and nonaccidental scalding. Careful anamnesis and skin examination with attention to the here illustrated differential diagnoses are essential to avoid pitfalls in the evaluation of acute pediatric skin infections.

Sharp plasma pinnacle structure based on shockwave for an improved laser wakefield accelerator

NASA Astrophysics Data System (ADS)

Fang, Ming; Zhang, Zhijun; Wang, Wentao; Liu, Jiansheng; Li, Ruxin

2018-07-01

We created a sharp plasma pinnacle structure for localized electron injection and controlled acceleration in a laser wakefield accelerator. The formation of this shockwave-based pinnacle structure was investigated using aerodynamic theory. Details and scaling laws for the shockwave angle, shock position, shock width, and density ratio were experimentally and theoretically presented. Such work is crucial to yielding an expected plasma density distribution in a laser–plasma experiment but has had little discussion in the literature. Compared with the commonly used shock downramp structure, the particle-in-cell simulations demonstrated that the e beam injected in the created pinnacle structure could be accelerated to higher energy with much smaller root-mean-square relative energy spread. Moreover, this study indicated that the beam charge and transverse emittance can be tuned by the shock angle.

Repetitive transcranial magnetic stimulation reveals a role for the left inferior parietal lobule in matching observed kinematics during imitation.

PubMed

Reader, Arran T; Royce, Ben P; Marsh, Jade E; Chivers, Katy-Jayne; Holmes, Nicholas P

2018-04-01

Apraxia (a disorder of complex movement) suggests that the left inferior parietal lobule (IPL) plays a role in kinematic or spatial aspects of imitation, which may be particularly important for meaningless (i.e. unfamiliar intransitive) actions. Mirror neuron theories indicate that the IPL is part of a frontoparietal system that can support imitation by linking observed and stored actions through visuomotor matching, and have less to say about different subregions of the left IPL, or how different types of action (i.e. meaningful or meaningless) are processed for imitation. We used repetitive transcranial magnetic stimulation (rTMS) to bridge this gap and better understand the roles of the left supramarginal gyrus (SMG) and left angular gyrus (AG) in imitation. We also examined whether these areas are differentially involved in meaningful and meaningless action imitation. We applied rTMS over the left SMG, over the left AG or during a no-rTMS baseline condition, and then asked participants to imitate a confederate's actions whilst the arm and hand movements of both individuals were motion-tracked. rTMS over both the left SMG and the left AG reduced the velocity of participants' finger movements relative to the actor during imitation of finger gestures, regardless of action meaning. Our results support recent claims in apraxia and confirm a role for the left IPL in kinematic processing during gesture imitation, regardless of action meaning. © 2018 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

Evaluating the impact of investments in information technology on structural inertia in health organizations.

PubMed

Bewley, Lee W

2010-01-01

Structural inertia is the overall capacity of an organization to adapt within a market environment. This paper reviews the impact of healthcare investments in information management/information technology (IM/IT) on the strategic management concept of structural inertia. Research indicates that healthcare executives should consider the relative state of structural inertia for their firms and match them with potential IM/IT solutions. Additionally, organizations should favorably consider IM/IT solutions that are comparatively less complex.

Social Intervention for Adolescents with Autism and Significant Intellectual Disability: Initial Efficacyof Reciprocal Imitation Training

ERIC Educational Resources Information Center

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…

Imitation and action understanding in autistic spectrum disorders: how valid is the hypothesis of a deficit in the mirror neuron system?

PubMed

Hamilton, Antonia F de C; Brindley, Rachel M; Frith, Uta

2007-04-09

The motor mirror neuron system supports imitation and goal understanding in typical adults. Recently, it has been proposed that a deficit in this mirror neuron system might contribute to poor imitation performance in children with autistic spectrum disorders (ASD) and might be a cause of poor social abilities in these children. We aimed to test this hypothesis by examining the performance of 25 children with ASD and 31 typical children of the same verbal mental age on four action representation tasks and a theory of mind battery. Both typical and autistic children had the same tendency to imitate an adult's goals, to imitate in a mirror fashion and to imitate grasps in a motor planning task. Children with ASD showed superior performance on a gesture recognition task. These imitation and gesture recognition tasks all rely on the mirror neuron system in typical adults, but performance was not impaired in children with ASD. In contrast, the ASD group were impaired on the theory of mind tasks. These results provide clear evidence against a general imitation impairment and a global mirror neuron system deficit in children with autism. We suggest this data can best be understood in terms of multiple brain systems for different types of imitation and action understanding, and that the ability to understand and imitate the goals of hand actions is intact in children with ASD.

See What I See, Do as I Do: Promoting Joint Attention and Imitation in Preschoolers with Autism Spectrum Disorder

ERIC Educational Resources Information Center

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…

Associative sequence learning: the role of experience in the development of imitation and the mirror system

PubMed Central

Catmur, Caroline; Walsh, Vincent; Heyes, Cecilia

2009-01-01

A core requirement for imitation is a capacity to solve the correspondence problem; to map observed onto executed actions, even when observation and execution yield sensory inputs in different modalities and coordinate frames. Until recently, it was assumed that the human capacity to solve the correspondence problem is innate. However, it is now becoming apparent that, as predicted by the associative sequence learning model, experience, and especially sensorimotor experience, plays a critical role in the development of imitation. We review evidence from studies of non-human animals, children and adults, focusing on research in cognitive neuroscience that uses training and naturally occurring variations in expertise to examine the role of experience in the formation of the mirror system. The relevance of this research depends on the widely held assumption that the mirror system plays a causal role in generating imitative behaviour. We also report original data supporting this assumption. These data show that theta-burst transcranial magnetic stimulation of the inferior frontal gyrus, a classical mirror system area, disrupts automatic imitation of finger movements. We discuss the implications of the evidence reviewed for the evolution, development and intentional control of imitation. PMID:19620108

Superficial Dorsal Vein Rupture Imitating Penile Fracture

PubMed Central

Topsakal, Medih; Kavukcu, Ender; Karadeniz, Tahir

2011-01-01

Dorsal vein rupture of the penis is a rare condition, and few cases have been reported in the literature. Herein we report a 41-year-old man who presented with mildly painful and acute swollen penis, which initially imitated a penile fracture but was surgically explored and shown to be a superficial dorsal vein rupture. PMID:21556219

Exploring the Relationship between Gestural Recognition and Imitation: Evidence of Dyspraxia in Autism Spectrum Disorders

ERIC Educational Resources Information Center

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…

A compact linear accelerator based on a scalable microelectromechanical-system RF-structure

DOE PAGES

Persaud, A.; Ji, Q.; Feinberg, E.; ...

2017-06-08

Here, a new approach for a compact radio-frequency (RF) accelerator structure is presented. The new accelerator architecture is based on the Multiple Electrostatic Quadrupole Array Linear Accelerator (MEQALAC) structure that was first developed in the 1980s. The MEQALAC utilized RF resonators producing the accelerating fields and providing for higher beam currents through parallel beamlets focused using arrays of electrostatic quadrupoles (ESQs). While the early work obtained ESQs with lateral dimensions on the order of a few centimeters, using a printed circuit board (PCB), we reduce the characteristic dimension to the millimeter regime, while massively scaling up the potential number ofmore » parallel beamlets. Using Microelectromechanical systems scalable fabrication approaches, we are working on further red ucing the characteristic dimension to the sub-millimeter regime. The technology is based on RF-acceleration components and ESQs implemented in the PCB or silicon wafers where each beamlet passes through beam apertures in the wafer. The complete accelerator is then assembled by stacking these wafers. This approach has the potential for fast and inexpensive batch fabrication of the components and flexibility in system design for application specific beam energies and currents. For prototyping the accelerator architecture, the components have been fabricated using the PCB. In this paper, we present proof of concept results of the principal components using the PCB: RF acceleration and ESQ focusing. Finally, ongoing developments on implementing components in silicon and scaling of the accelerator technology to high currents and beam energies are discussed.« less

The Organizational Culture and Structure of Accelerated Schools.

ERIC Educational Resources Information Center

Steaffens, Susan; McCarthy, Jane; Putney, LeAnn; Steinhoff, Carl

This paper describes the organizational culture and structure of five accelerated schools in the Clark County School District in Nevada, focusing on the similarities and differences among these schools. The cultural aspects of the schools under comparison included the guiding principles, the central values, and the learning philosophy, whereas the…

Observation of multipactor suppression in a dielectric-loaded accelerating structure using an applied axial magnetic field

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jing, C.; Konecny, R.; Antipov, S.

2013-11-18

Efforts by a number of institutions to develop a Dielectric-Loaded Accelerating (DLA) structure capable of supporting high gradient acceleration when driven by an external radio frequency source have been ongoing over the past decade. Single surface resonant multipactor has been previously identified as one of the major limitations on the practical application of DLA structures in electron accelerators. In this paper, we report the results of an experiment that demonstrated suppression of multipactor growth in an X-band DLA structure through the use of an applied axial magnetic field. This represents an advance toward the practical use of DLA structures inmore » many accelerator applications.« less

Is the Good-Imitator-Poor-Talker Profile Syndrome-Specific in Down Syndrome?: Evidence from Standardised Imitation and Language Measures

ERIC Educational Resources Information Center

Vanvuchelen, M.; Feys, H.; De Weerdt, W.

2011-01-01

The emergence of the Down syndrome (DS) behavioural phenotype during early development may be of great importance for early intervention. The main goal of this study was to investigate the good-imitator-poor-talker developmental profile in DS at preschool age. Twenty children with Down syndrome (DS; mean nonverbal mental age NMA 1 y10 m) and 15…

Mirror Me: Imitative Responses in Adults with Autism

ERIC Educational Resources Information Center

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…

Gestural Imitation and Limb Apraxia in Corticobasal Degeneration

ERIC Educational Resources Information Center

Salter, Jennifer E.; Roy, Eric A.; Black, Sandra E.; Joshi, Anish; Almeida, Quincy

2004-01-01

Limb apraxia is a common symptom of corticobasal degeneration (CBD). While previous research has shown that individuals with CBD have difficulty imitating transitive (tool-use actions) and intransitive non-representational gestures (nonsense actions), intransitive representational gestures (actions without a tool) have not been examined. In the…

Male More than Female Infants Imitate Propulsive Motion

ERIC Educational Resources Information Center

Benenson, Joyce F.; Tennyson, Robert; Wrangham, Richard W.

2011-01-01

Few experimental studies investigate the mechanisms by which young children develop sex-typed activity preferences. Gender self-labeling followed by selective imitation of same-sex models currently is considered a primary socialization mechanism. Research with prenatally androgenized girls and non-human primates also suggests an innate male…

Dynamic Assessment of Elicited Imitation: A Case Analysis of an Advanced L2 English Speaker

ERIC Educational Resources Information Center

van Compernolle, Rémi A.; Zhang, Haomin

2014-01-01

The focus of this paper is on the design, administration, and scoring of a dynamically administered elicited imitation test of L2 English morphology. Drawing on Vygotskian sociocultural psychology, particularly the concepts of zone of proximal development and dynamic assessment, we argue that support provided during the elicited imitation test…

Imitation from 12 to 24 Months in Autism and Typical Development: A Longitudinal Rasch Analysis

ERIC Educational Resources Information Center

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…

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

ERIC Educational Resources Information Center

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…

Causal knowledge and imitation/emulation switching in chimpanzees (Pan troglodytes) and children (Homo sapiens).

PubMed

Horner, Victoria; Whiten, Andrew

2005-07-01

This study explored whether the tendency of chimpanzees and children to use emulation or imitation to solve a tool-using task was a response to the availability of causal information. Young wild-born chimpanzees from an African sanctuary and 3- to 4-year-old children observed a human demonstrator use a tool to retrieve a reward from a puzzle-box. The demonstration involved both causally relevant and irrelevant actions, and the box was presented in each of two conditions: opaque and clear. In the opaque condition, causal information about the effect of the tool inside the box was not available, and hence it was impossible to differentiate between the relevant and irrelevant parts of the demonstration. However, in the clear condition causal information was available, and subjects could potentially determine which actions were necessary. When chimpanzees were presented with the opaque box, they reproduced both the relevant and irrelevant actions, thus imitating the overall structure of the task. When the box was presented in the clear condition they instead ignored the irrelevant actions in favour of a more efficient, emulative technique. These results suggest that emulation is the favoured strategy of chimpanzees when sufficient causal information is available. However, if such information is not available, chimpanzees are prone to employ a more comprehensive copy of an observed action. In contrast to the chimpanzees, children employed imitation to solve the task in both conditions, at the expense of efficiency. We suggest that the difference in performance of chimpanzees and children may be due to a greater susceptibility of children to cultural conventions, perhaps combined with a differential focus on the results, actions and goals of the demonstrator.

CPU-GPU hybrid accelerating the Zuker algorithm for RNA secondary structure prediction applications.

PubMed

Lei, Guoqing; Dou, Yong; Wan, Wen; Xia, Fei; Li, Rongchun; Ma, Meng; Zou, Dan

2012-01-01

Prediction of ribonucleic acid (RNA) secondary structure remains one of the most important research areas in bioinformatics. The Zuker algorithm is one of the most popular methods of free energy minimization for RNA secondary structure prediction. Thus far, few studies have been reported on the acceleration of the Zuker algorithm on general-purpose processors or on extra accelerators such as Field Programmable Gate-Array (FPGA) and Graphics Processing Units (GPU). To the best of our knowledge, no implementation combines both CPU and extra accelerators, such as GPUs, to accelerate the Zuker algorithm applications. In this paper, a CPU-GPU hybrid computing system that accelerates Zuker algorithm applications for RNA secondary structure prediction is proposed. The computing tasks are allocated between CPU and GPU for parallel cooperate execution. Performance differences between the CPU and the GPU in the task-allocation scheme are considered to obtain workload balance. To improve the hybrid system performance, the Zuker algorithm is optimally implemented with special methods for CPU and GPU architecture. Speedup of 15.93× over optimized multi-core SIMD CPU implementation and performance advantage of 16% over optimized GPU implementation are shown in the experimental results. More than 14% of the sequences are executed on CPU in the hybrid system. The system combining CPU and GPU to accelerate the Zuker algorithm is proven to be promising and can be applied to other bioinformatics applications.

Becoming a High-Fidelity--"Super"--Imitator: What Are the Contributions of Social and Individual Learning?

ERIC Educational Resources Information Center

Subiaul, Francys; Patterson, Eric M.; Schilder, Brian; Renner, Elizabeth; Barr, Rachel

2015-01-01

In contrast to other primates, human children's imitation performance goes from low to high fidelity soon after infancy. Are such changes associated with the development of other forms of learning? We addressed this question by testing 215 children (26-59 months) on two social conditions (imitation, emulation)--involving a demonstration--and two…

rf breakdown measurements in electron beam driven 200 GHz copper and copper-silver accelerating structures

DOE PAGES

Dal Forno, Massimo; Dolgashev, Valery; Bowden, Gordon; ...

2016-11-30

This study explores the physics of vacuum rf breakdowns in subterahertz high-gradient traveling-wave accelerating structures. We present the experimental results of rf tests of 200 GHz metallic accelerating structures, made of copper and copper-silver. These experiments were carried out at the Facility for Advanced Accelerator Experimental Tests (FACET) at the SLAC National Accelerator Laboratory. The rf fields were excited by the FACET ultrarelativistic electron beam. The traveling-wave structure is an open geometry, 10 cm long, composed of two halves separated by a gap. The rf frequency of the fundamental accelerating mode depends on the gap size and can be changedmore » from 160 to 235 GHz. When the beam travels off axis, a deflecting field is induced in addition to the longitudinal field. We measure the deflecting forces by observing the displacement of the electron bunch and use this measurement to verify the expected accelerating gradient. Furthermore, we present the first quantitative measurement of rf breakdown rates in 200 GHz metallic accelerating structures. The breakdown rate of the copper structure is 10 –2 per pulse, with a peak surface electric field of 500 MV/m and a rf pulse length of 0.3 ns, which at a relatively large gap of 1.5 mm, or one wavelength, corresponds to an accelerating gradient of 56 MV/m. For the same breakdown rate, the copper-silver structure has a peak electric field of 320 MV/m at a pulse length of 0.5 ns. For a gap of 1.1 mm, or 0.74 wavelengths, this corresponds to an accelerating gradient of 50 MV/m.« less

What Infant Memory Tells Us about Infantile Amnesia: Long-Term Recall and Deferred Imitation

PubMed Central

Meltzoff, Andrew N.

2013-01-01

Long-term recall memory was assessed using a nonverbal method requiring subjects to reenact a past event from memory (deferred imitation). A large sample of infants (N = 192), evenly divided between 14- and 16-months old, was tested across two experiments. A delay of 2 months was used in Experiment 1 and a delay of 4 months in Experiment 2. In both experiments two treatment groups were used, In one treatment group, motor practice (immediate imitation) was allowed before the delay was imposed; in the other group, subjects were prevented from motor practice before the delay. Age-matched control groups were used lo assess the spontaneous production of the target acts in the absence of exposure to the model in both experiments. The results demonstrated significant deferred imitation for both treatment groups at both delay intervals, and moreover showed that infants retained and imitated multiple acts. These findings suggest that infants have a nonverbal declarative memory system that supports the recall of past events across long-term delays. The implications of these findings for the multiple memory system debate in cognitive science and neuroscience and for theories of infantile amnesia are considered. PMID:7622990

The portrait of a medieval alchemist with symbols of elements imitating creation.

PubMed

Mahdihassan, S

1988-07-01

This paper depicts e paraphernalia of an alchemist who believed in imitating creation and generating a soul thereby. The magic wands of creation are a compass and a triangular carpenter's square. They can produce the dual natured soul Ruh or Spirit symbolized as Cock and Nafs of "the soul" as snake: The real creative energy by nature is ultrasonic energy, characterizing the word of command of the creator. Ultrasonic energy can be produced by fiddle which is depicted also as such a producer. Thus all the elements necessary to imitate creation have been depicted here.

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

PubMed Central

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

Micro structure processing on plastics by accelerated hydrogen molecular ions

NASA Astrophysics Data System (ADS)

Hayashi, H.; Hayakawa, S.; Nishikawa, H.

2017-08-01

A proton has 1836 times the mass of an electron and is the lightest nucleus to be used for accelerator in material modification. We can setup accelerator with the lowest acceleration voltage. It is preferable characteristics of Proton Beam Writer (PBW) for industrial applications. On the contrary ;proton; has the lowest charge among all nuclei and the potential impact to material is lowest. The object of this research is to improve productivity of the PBW for industry application focusing on hydrogen molecular ions. These ions are generated in the same ion source by ionizing hydrogen molecule. There is no specific ion source requested and it is suitable for industrial use. We demonstrated three dimensional (3D) multilevel micro structures on polyester base FPC (Flexible Printed Circuits) using proton, H2+ and H3+. The reactivity of hydrogen molecular ions is much higher than that of proton and coincident with the level of expectation. We can apply this result to make micro devices of 3D multilevel structures on FPC.

Sentence Imitation as a Marker of SLI in Czech: Disproportionate Impairment of Verbs and Clitics

ERIC Educational Resources Information Center

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…

Cervical deciduosis imitating dysplasia.

PubMed

van Diepen, Diederik Anthony; Hellebrekers, Bart; van Haaften, Anne-Marie; Natté, Remco

2015-09-22

Ectopic cervical deciduosis is generally an accidental finding during pregnancy, and usually presents without any symptoms or need for therapeutic intervention. However, it can sometimes imitate dysplasia or carcinoma. We report a case of a 34-year-old G2P0, with a history of cervical dysplasia, presenting at 11 weeks of gestation, with vaginal blood loss. During examination, lesions mimicking dysplasia were found on the cervix. Histological examination reported cervical deciduosis. Deciduosis is a benign change during pregnancy and will resolve spontaneously. With the increasing use of cytology and colposcopy, the reported incidence is growing. When it is hard to differentiate between dysplasia and deciduosis, histological confirmation should be considered. 2015 BMJ Publishing Group Ltd.

Cervical deciduosis imitating dysplasia

PubMed Central

van Diepen, Diederik Anthony; Hellebrekers, Bart; van Haaften, Anne-Marie; Natté, Remco

2015-01-01

Ectopic cervical deciduosis is generally an accidental finding during pregnancy, and usually presents without any symptoms or need for therapeutic intervention. However, it can sometimes imitate dysplasia or carcinoma. We report a case of a 34-year-old G2P0, with a history of cervical dysplasia, presenting at 11 weeks of gestation, with vaginal blood loss. During examination, lesions mimicking dysplasia were found on the cervix. Histological examination reported cervical deciduosis. Deciduosis is a benign change during pregnancy and will resolve spontaneously. With the increasing use of cytology and colposcopy, the reported incidence is growing. When it is hard to differentiate between dysplasia and deciduosis, histological confirmation should be considered. PMID:26396123

Vocal learning beyond imitation: mechanisms of adaptive vocal development in songbirds and human infants

PubMed Central

Tchernichovski, Ofer; Marcus, Gary

2014-01-01

Studies of vocal learning in songbirds typically focus on the acquisition of sensory templates for song imitation and on the consequent process of matching song production to templates. However, functional vocal development also requires the capacity to adaptively diverge from sensory templates, and to flexibly assemble vocal units. Examples of adaptive divergence include the corrective imitation of abnormal songs, and the decreased tendency to copy overabundant syllables. Such frequency-dependent effects might mirror tradeoffs between the assimilation of group identity (culture) while establishing individual and flexibly expressive songs. Intriguingly, although the requirements for vocal plasticity vary across songbirds, and more so between birdsong and language, the capacity to flexibly assemble vocal sounds develops in a similar, stepwise manner across species. Therefore, universal features of vocal learning go well beyond the capacity to imitate. PMID:25005823

Discrimination and Imitation of Facial Expressions by Neonates.

ERIC Educational Resources Information Center

Field, Tiffany

Findings of a series of studies on individual differences and maturational changes in expressivity at the neonatal stage and during early infancy are reported. Research results indicate that newborns are able to discriminate and imitate the basic emotional expressions: happy, sad, and surprised. Results show widened infant lips when the happy…

Children Selectively Trust Individuals Who Have Imitated Them

ERIC Educational Resources Information Center

Over, Harriet; Carpenter, Malinda; Spears, Russell; Gattis, Merideth

2013-01-01

We investigated the influence of being imitated on children's subsequent trust. Five- to six-year-olds interacted with one experimenter who mimicked their choices and another experimenter who made different choices. Children were then presented with two tests. In a preference test, the experimenters offered conflicting preferences for the contents…

"Goals" Are Not an Integral Component of Imitation

ERIC Educational Resources Information Center

Leighton, Jane; Bird, Geoffrey; Heyes, Cecilia

2010-01-01

Several theories suggest that actions are coded for imitation in terms of mentalistic goals, or inferences about the actor's intentions, and that these goals solve the "correspondence problem" by allowing sensory input to be translated into matching motor output. We tested this intention reading hypothesis against general process accounts of…

Kinematics and Kinetics of Squats, Drop Jumps and Imitation Jumps of Ski Jumpers.

PubMed

Pauli, Carole A; Keller, Melanie; Ammann, Fabian; Hübner, Klaus; Lindorfer, Julia; Taylor, William R; Lorenzetti, Silvio

2016-03-01

Squats, drop jumps, and imitation jumps are commonly used training exercises in ski jumping to enhance maximum force, explosive force, and sport-specific skills. The purpose of this study was to evaluate the kinetics and kinematics of training exercises in ski jumping and to find objective parameters in training exercises that most correlate with the competition performance of ski jumpers. To this end, barbell squats, drop jumps, and imitation jumps were measured in a laboratory environment for 10 elite ski jumpers. Force and motion data were captured, and the influence of maximum vertical force, force difference, vertical take-off velocity, knee moments, knee joint power, and a knee valgus/varus index was evaluated and correlated with their season jump performance. The results indicate that, especially for the imitation jumps, a good correlation exists between the vertical take-off velocity and the personal jump performance on the hill (R = 0.718). Importantly, however, the more the athletes tended toward a valgus knee alignment during the measured movements, the worse their performance (R = 0.729 imitation jumps; R = 0.685 squats). Although an evaluation of the athletes' lower limb alignment during competitive jumping on the hill is still required, these preliminary data suggest that performance training should additionally concentrate on improving knee alignment to increase ski jumping performance.

Prefrontal involvement in imitation learning of hand actions: effects of practice and expertise.

PubMed

Vogt, Stefan; Buccino, Giovanni; Wohlschläger, Afra M; Canessa, Nicola; Shah, N Jon; Zilles, Karl; Eickhoff, Simon B; Freund, Hans-Joachim; Rizzolatti, Giacomo; Fink, Gereon R

2007-10-01

In this event-related fMRI study, we demonstrate the effects of a single session of practising configural hand actions (guitar chords) on cortical activations during observation, motor preparation and imitative execution. During the observation of non-practised actions, the mirror neuron system (MNS), consisting of inferior parietal and ventral premotor areas, was more strongly activated than for the practised actions. This finding indicates a strong role of the MNS in the early stages of imitation learning. In addition, the left dorsolateral prefrontal cortex (DLPFC) was selectively involved during observation and motor preparation of the non-practised chords. This finding confirms Buccino et al.'s [Buccino, G., Vogt, S., Ritzl, A., Fink, G.R., Zilles, K., Freund, H.-J., Rizzolatti, G., 2004a. Neural circuits underlying imitation learning of hand actions: an event-related fMRI study. Neuron 42, 323-334] model of imitation learning: for actions that are not yet part of the observer's motor repertoire, DLPFC engages in operations of selection and combination of existing, elementary representations in the MNS. The pattern of prefrontal activations further supports Shallice's [Shallice, T., 2004. The fractionation of supervisory control. In: Gazzaniga, M.S. (Ed.), The Cognitive Neurosciences, Third edition. MIT Press, Cambridge, MA, pp. 943-956] proposal of a dominant role of the left DLPFC in modulating lower level systems and of a dominant role of the right DLPFC in monitoring operations.

Calculation of structural dynamic forces and stresses using mode acceleration

NASA Technical Reports Server (NTRS)

Blelloch, Paul

1989-01-01

While the standard mode acceleration formulation in structural dynamics has often been interpreted to suggest that the reason for improved convergence obtainable is that the dynamic correction factor is divided by the modal frequencies-squared, an alternative formulation is presented which clearly indicates that the only difference between mode acceleration and mode displacement data recovery is the addition of a static correction term. Attention is given to the advantages in numerical implementation associated with this alternative, as well as to an illustrative example.

CPU-GPU hybrid accelerating the Zuker algorithm for RNA secondary structure prediction applications

PubMed Central

2012-01-01

Background Prediction of ribonucleic acid (RNA) secondary structure remains one of the most important research areas in bioinformatics. The Zuker algorithm is one of the most popular methods of free energy minimization for RNA secondary structure prediction. Thus far, few studies have been reported on the acceleration of the Zuker algorithm on general-purpose processors or on extra accelerators such as Field Programmable Gate-Array (FPGA) and Graphics Processing Units (GPU). To the best of our knowledge, no implementation combines both CPU and extra accelerators, such as GPUs, to accelerate the Zuker algorithm applications. Results In this paper, a CPU-GPU hybrid computing system that accelerates Zuker algorithm applications for RNA secondary structure prediction is proposed. The computing tasks are allocated between CPU and GPU for parallel cooperate execution. Performance differences between the CPU and the GPU in the task-allocation scheme are considered to obtain workload balance. To improve the hybrid system performance, the Zuker algorithm is optimally implemented with special methods for CPU and GPU architecture. Conclusions Speedup of 15.93× over optimized multi-core SIMD CPU implementation and performance advantage of 16% over optimized GPU implementation are shown in the experimental results. More than 14% of the sequences are executed on CPU in the hybrid system. The system combining CPU and GPU to accelerate the Zuker algorithm is proven to be promising and can be applied to other bioinformatics applications. PMID:22369626

Accelerating atomic structure search with cluster regularization

NASA Astrophysics Data System (ADS)

Sørensen, K. H.; Jørgensen, M. S.; Bruix, A.; Hammer, B.

2018-06-01

We present a method for accelerating the global structure optimization of atomic compounds. The method is demonstrated to speed up the finding of the anatase TiO2(001)-(1 × 4) surface reconstruction within a density functional tight-binding theory framework using an evolutionary algorithm. As a key element of the method, we use unsupervised machine learning techniques to categorize atoms present in a diverse set of partially disordered surface structures into clusters of atoms having similar local atomic environments. Analysis of more than 1000 different structures shows that the total energy of the structures correlates with the summed distances of the atomic environments to their respective cluster centers in feature space, where the sum runs over all atoms in each structure. Our method is formulated as a gradient based minimization of this summed cluster distance for a given structure and alternates with a standard gradient based energy minimization. While the latter minimization ensures local relaxation within a given energy basin, the former enables escapes from meta-stable basins and hence increases the overall performance of the global optimization.

Functional lateralization of temporoparietal junction - imitation inhibition, visual perspective-taking and theory of mind.

PubMed

Santiesteban, Idalmis; Banissy, Michael J; Catmur, Caroline; Bird, Geoffrey

2015-10-01

Although neuroimaging studies have consistently identified the temporoparietal junction (TPJ) as a key brain region involved in social cognition, the literature is far from consistent with respect to lateralization of function. For example, during theory-of-mind tasks bilateral TPJ activation is found in some studies but only right hemisphere activation in others. Visual perspective-taking and imitation inhibition, which have been argued to recruit the same socio-cognitive processes as theory of mind, are associated with unilateral activation of either left TPJ (perspective taking) or right TPJ (imitation inhibition). The present study investigated the functional lateralization of TPJ involvement in the above three socio-cognitive abilities using transcranial direct current stimulation. Three groups of healthy adults received anodal stimulation over right TPJ, left TPJ or the occipital cortex prior to performing three tasks (imitation inhibition, visual perspective-taking and theory of mind). In contrast to the extant neuroimaging literature, our results suggest bilateral TPJ involvement in imitation inhibition and visual perspective-taking, while no effect of anodal stimulation was observed on theory of mind. The discrepancy between these findings and those obtained using neuroimaging highlight the efficacy of neurostimulation as a complementary methodological tool in cognitive neuroscience. © 2015 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

THE PORTRAIT OF A MEDIEVAL ALCHEMIST WITH SYMBOLS OF ELEMENTS IMITATING CREATION

PubMed Central

Mahdihassan, S.

1988-01-01

This paper depicts e paraphernalia of an alchemist who believed in imitating creation and generating a soul thereby. The magic wands of creation are a compass and a triangular carpenter's square. They can produce the dual natured soul Ruh or Spirit symbolized as Cock and Nafs of “the soul” as snake: The real creative energy by nature is ultrasonic energy, characterizing the word of command of the creator. Ultrasonic energy can be produced by fiddle which is depicted also as such a producer. Thus all the elements necessary to imitate creation have been depicted here. PMID:22557629

Effects of Bundle Type and Substitution with Spent Laying Hen Surimi on Quality Characteristics of Imitation Crabsticks.

PubMed

Jin, Sang-Keun; Choi, Jung-Seok; Kim, Gap-Don

2017-01-01

The purpose of this study was to evaluate the effects of bundle type (BT) and substitution with spent laying hen (SH) surimi on quality characteristics of imitation crabsticks made from Alaska Pollack (AP) during 6 wk of cold storage. Diagonally bundled samples had poorer gel characteristics and more lipid oxidation when compared with straight bundled ones ( p <0.05). The color of diagonally bundled imitation crabsticks deteriorated with storage time ( p <0.01). However, BT did not affect sensory characteristics ( p >0.05). SH substitution had an effect on most quality characteristics of imitation crabsticks; darker and poorer gel characteristics were observed and its effect on sensory evaluation was seen at the initial storage. Thus, BT and SH substitution can be considered to have a slight effect on eating quality of imitation crabsticks, despite their negative effects on color, gel characteristics, and lipid oxidation.

Mirror neurons and imitation: a computationally guided review.

PubMed

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.

Atypical biological motion kinematics are represented by complementary lower-level and top-down processes during imitation learning.

PubMed

Hayes, Spencer J; Dutoy, Chris A; Elliott, Digby; Gowen, Emma; Bennett, Simon J

2016-01-01

Learning a novel movement requires a new set of kinematics to be represented by the sensorimotor system. This is often accomplished through imitation learning where lower-level sensorimotor processes are suggested to represent the biological motion kinematics associated with an observed movement. Top-down factors have the potential to influence this process based on the social context, attention and salience, and the goal of the movement. In order to further examine the potential interaction between lower-level and top-down processes in imitation learning, the aim of this study was to systematically control the mediating effects during an imitation of biological motion protocol. In this protocol, we used non-human agent models that displayed different novel atypical biological motion kinematics, as well as a control model that displayed constant velocity. Importantly the three models had the same movement amplitude and movement time. Also, the motion kinematics were displayed in the presence, or absence, of end-state-targets. Kinematic analyses showed atypical biological motion kinematics were imitated, and that this performance was different from the constant velocity control condition. Although the imitation of atypical biological motion kinematics was not modulated by the end-state-targets, movement time was more accurate in the absence, compared to the presence, of an end-state-target. The fact that end-state targets modulated movement time accuracy, but not biological motion kinematics, indicates imitation learning involves top-down attentional, and lower-level sensorimotor systems, which operate as complementary processes mediated by the environmental context. Copyright © 2015 Elsevier B.V. All rights reserved.

Plastic changes following imitation-based speech and language therapy for aphasia: a high-density sleep EEG study.

PubMed

Sarasso, Simone; Määttä, Sara; Ferrarelli, Fabio; Poryazova, Rositsa; Tononi, Giulio; Small, Steven L

2014-02-01

BACKGROUND OBJECTIVE: measurement of plastic brain changes induced by a novel rehabilitative approach is a key requirement for validating its biological rationale linking the potential therapeutic gains to the changes in brain physiology. Based on an emerging notion linking cortical plastic changes to EEG sleep slow-wave activity (SWA) regulation, we aimed to assess the acute plastic changes induced by an imitation-based speech therapy in individuals with aphasia by comparing sleep SWA changes before and after therapy. A total of 13 left-hemispheric stroke patients underwent language assessment with the Western Aphasia Battery (WAB) before and after 2 consecutive high-density (hd) EEG sleep recordings interleaved by a daytime session of imitation-based speech therapy (Intensive Mouth Imitation and Talking for Aphasia Therapeutic Effects [IMITATE]). This protocol is thought to stimulate bilateral connections between the inferior parietal lobule and the ventral premotor areas. A single exposure to IMITATE resulted in increases in local EEG SWA during subsequent sleep over the same regions predicted by the therapeutic rationale, particularly over the right hemisphere (unaffected by the lesion). Furthermore, changes in SWA over the left-precentral areas predicted changes in WAB repetition scores in our group, supporting the role of perilesional areas in predicting positive functional responses. Our results suggest that SWA changes occurring in brain areas activated during imitation-based aphasia therapy may reflect the acute plastic changes induced by this intervention. Further testing will be needed to evaluate SWA as a non-invasive assessment of changes induced by the therapy and as a predictor of positive long-term clinical outcome.

The role of imitation in the observed heterogeneity in EEG mu rhythm in autism and typical development.

PubMed

Bernier, Raphael; Aaronson, Benjamin; McPartland, James

2013-06-01

Dysfunction in an execution/observation matching system, or mirror neuron system, has been proposed to contribute to the social deficits observed in Autism Spectrum Disorder (ASD). Atypical activity in this system, as reflected in attenuation of the EEG mu rhythm, has been demonstrated in several studies; however, normative patterns of activity have been evident in other ASD samples. The current study sought to investigate this poorly understood heterogeneity in social perceptual brain function in ASD. EEG mu rhythm was recorded in a well-characterized sample of 19 children with ASD (mean age=6.4; 1 female) and 19 age-matched typically developing peers (mean age=6.9; 2 females) during execution and observation of goal-directed hand actions. Children were assessed on variables theoretically related to mirror neuron system function (MNS), such as ASD symptoms and imitation ability. Results indicated that MNS activity was associated with facial imitation ability, but not hand imitation ability, in children with ASD and typically developing individuals. Groups were comparable in terms of average MNS activity during both action observation and execution, but, in both groups, a subset of children showed absent or significantly reduced MNS activity during observation of action in conjunction with greater difficulty in imitation. These results emphasize the relationship between EEG indices of MNS function and imitative skill and suggest that dysfunction of the MNS is related to imitation ability in both clinical and typical populations, rather than representing a core deficit or universal impairment in ASD. Copyright © 2013 Elsevier Inc. All rights reserved.

Altered Brain Activation During Action Imitation and Observation in Schizophrenia: A Translational Approach to Investigating Social Dysfunction in Schizophrenia

PubMed Central

Thakkar, Katharine N.; Peterman, Joel S.; Park, Sohee

2015-01-01

Objective Social impairments are a key feature of schizophrenia, but their underlying mechanisms are poorly understood. Imitation, a process through which we understand the minds of others, involves the so-called mirror neuron system, a network comprising the inferior parietal lobe, inferior frontal gyrus, and posterior superior temporal sulcus. The authors examined mirror neuron system function in schizophrenia. Method Sixteen medicated schizophrenia patients and 16 healthy comparison subjects performed an action imitation/ observation task during functional MRI. Participants saw a video of a moving hand or spatial cue and were instructed to either execute finger movements associated with the stimulus or simply observe. Activation in the mirror neuron system was measured during imitative versus nonimitative actions and observation of a moving hand versus a moving spatial cue. These contrasts were compared across groups. Results Activation in the mirror neuron system was less specific for imitation in schizophrenia. Relative to healthy subjects, patients had reduced activity in the posterior superior temporal sulcus during imitation and greater activity in the posterior superior temporal sulcus and inferior parietal lobe during nonimitative action. Patients also showed reduced activity in these regions during action observation. Mirror neuron system activation was related to symptom severity and social functioning in patients and to schizotypal syndrome in comparison subjects. Conclusions Given the role of the inferior parietal lobe and posterior superior temporal sulcus in imitation and social cognition, impaired imitative ability in schizophrenia may stem from faulty perception of biological motion and transformations from perception to action. These findings extend our understanding of social dysfunction in schizophrenia. PMID:24626638