Imitation Abilities Research Articles

Automatic Facial Expression Learning Method Based on Humanoid Robot XIN-REN

The ability of a humanoid robot to display human-like facial expressions is crucial to the natural human–computer interaction. To fulfill this requirement for an imitative humanoid robot, XIN-REN, an automatic facial expression learning method is proposed. In this method, first, a forward kinematics model, which is designed to reflect nonlinear mapping relationships between servo displacement vectors and corresponding expression shape vectors, is converted into a linear relationships between the mechanical energy of servo displacements and the potential energy of feature points, based on the energy conservation principle. Second, an improved inverse kinematics model is established under the constraints of instantaneous similarity and movement smoothness. Finally, online expression learning is employed to determine the optimal servo displacements for transferring the facial expressions of a human performer to the robot. To illustrate the performance of the proposed method, we conduct evaluation experiments on the forward kinematics model and the inverse kinematics model, based on the data collected from the robot's random states as well as fixed procedures by animators. Further, we evaluate the facial imitation ability with different values of the weighting factor, according to three sequential indicators (space-similarity, time-similarity, and movement smoothness). Experimental results indicate that the deviations in mean shape and position do not exceed 6 pixels and 3 pixels, respectively, and the average servo displacement deviation does not exceed 0.8%. Compared with other related studies, the proposed method maintains better space–time similarity with the performer, besides ensuring smoother trajectory for multiframe sequential imitation.

Social and Communication Skills Predict Imitation Abilities in Children with Autism

This study examined whether social and communicative skills would predict the ability to imitate conventional-interactive gestures (e.g., HAND WAVING for saying goodbye) in children with autism spectrum disorders (ASD). Twenty 6- to 11-year-old Chinese-speaking children with ASD participated. Their social and communicative skills were assessed based on their caregivers’ ratings on their social and communication impairments and the observation of their gesture production in spontaneous interactions with the caregivers three months prior to the administration of the gesture imitation task. After controlling for gesture recognition and visual-motor coordination skills, the results of the partial correlation analyses have shown that there was significant association among the number of conventional-interactive gestures imitated accurately, the caregivers’ ratings, and the number of conventional-interactive gestures produced during interactions. Four regression analyses were thus conducted. We found the severity of social and communication impairments predicted the imitation of communicative gestures, with such relation mediated by the production of conventional-interactive gestures during the interactions. Overall, the results suggest that social and communication skills may play a causal role in imitation abilities in children with autism.

Explicit imitation and working memory

Much research a has been conducted in regards to implicit imitation, that is, phonetic imitation that occurs largely without a speaker’s knowledge. However, explicit imitation, which occurs intentionally, has received far less attention. While it is observed that individuals vary in explicit imitative abilities, i.e., some individuals’ speech shift more towards a given target voice than others, the factors that contribute to these differences have yet to be identified. The current study investigates individual differences in explicit imitation by exploring the correlation between explicit imitation and working memory, the memory involved in short term conscious processing. Subjects participated in a baseline word reading task as well as an imitation task which involved repeating the same words aloud after hearing prerecorded stimuli from a Texan speaker. Additionally, subjects completed a reading Span task in order to measure working memory capacity and determine the effect of working memory on degree of explicit phonetic imitation. The degree of proportional phonetic shift towards the target speaker was correlated with Span scores in order to determine what link exists between explicit imitation and working memory on the level of the individual.

Instrumental Jazz Improvisation Development

The purpose of this exploratory study was to examine the role aural imitation ability, jazz theory knowledge, and personal background variables play in the development of jazz improvisation achievement. Participants ( N = 70) included 26 high school and 44 college instrumentalists with varying degrees of jazz improvisation experience. Data were collected using four researcher-designed instruments: (a) Participant Improvisation Experience Survey (PIES), (b) Improvisation Achievement Performance Measure (IAPM), (c) Aural Imitation Measure (AIM), and (d) the Jazz Theory Measure (JTM). Results indicate that aural imitation ability and technical facility are fundamental skills supporting jazz improvisation achievement. Other contributing factors include improvisation experience, jazz experience, practicing improvisation, perceived self-confidence, self-assessment, and jazz theory knowledge. Further analysis of results led to improvisation being viewed from a developmental perspective and achievement levels being distinguished on a developmental continuum (i.e., novice, intermediate, advanced) based on performance evaluations within musical categories (i.e., rhythm/time feel, harmony, melody/rhythmic development, style, expressivity, and creativity).

Imitation: Not in Our Genes

A powerful longitudinal study has failed to find any evidence that newborn babies can imitate facial gestures, hand movements or vocalisations. After 40 years of uncertainty, these findings indicate that humans learn to imitate; this capacity is not inborn.

Vocal matching in interactions between mothers and their normal-hearing and hearing-impaired twins

Vocal matching, the ability to imitate phonetic properties of speech, was examined in interactions between mothers and their normal-hearing (NH) and hearing-impaired twins who used hearing aids (HAs) or a cochlear implant (CI). Vocalizations of three mother-twin triads were recorded in three sessions over 12 months. In one triad, the twins were 15.8 months old and NH. In another triad, the twins were 11.8 months; one was NH while the other had HAs. In the third triad, both twins were 14.8 months; one was NH while the other had a CI. A vocal match was defined as an instance of perceptual and acoustic similarity between adjacent maternal and infant utterances in relation to pitch height and contour, utterance duration, rhythm, or vowels and consonants. Reciprocal vocal matching occurred in 28% to 38% of infant vocalizations across triads. At session three, CI and HA infants’ reciprocal vocal matches increased compared to two previous sessions and to those of NH siblings; reciprocal vocal matches in the NH dyad decreased over time. The results suggest that vocal matching is a part of linguistic interactions between mothers and their NH and HI infants and that pediatric hearing loss affects mothers’ and infants’ imitative abilities.

Voluntary Imitation in Alzheimer's Disease Patients.

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.

Language is a girlie thing, isn't it? A psycholinguistic exploration of the L2 gender gap

ABSTRACTNotwithstanding a surge of novel insights into the male/female variable on human behaviour and cognitive functions, the gender factor is still far from being well understood. Pursuing an interdisciplinary approach, informed by neuroscientific research, this study used linguistic and psychological measures to investigate gender differences in the realm of foreign language (L2) proficiency of late learners. The performance of 64 subjects (32 females), matched for age, education and linguistic background, was analysed regarding gender and personality/motivation differences. Results revealed a gender gap in two domains of L2 expertise and cast doubt on the idea of a general female language advantage: male subjects outperformed their female counterparts in phonetic speech imitation ability (pronunciation). An advantage of the women could be found for grammar learning. Results fit the current line of neurolinguistic research on the neural substrates of language. The study revealed that an open-minded, extravert and motivated personality is beneficial to language learning. A conscious and persistent approach can be favourable for grammar learning. We suggest that foreign language teaching should accommodate more to male/female differences and take into account effects of personality and motivation differences.

Do as I do, not as I say: Actions speak louder than words in preschoolers learning from others

To date, no research has examined children’s imitative abilities in the context of learning self-regulatory strategies from adults—especially when there is a conflict between communicative intent and later behavior. A sample of 84 4- and 5-year-olds performed a delay-of-gratification task after observing an adult perform the same task. Across four between-participants conditions, the model either did or did not state her intention to complete the task (positive vs. negative communication), modeled self-regulatory strategies, and then either did or did not complete the task successfully (positive vs. negative outcome). Children in the positive outcome conditions were more likely to imitate the novel strategies and successfully wait in both familiar and unfamiliar self-regulation tasks irrespective of the model’s communicated intent. We discuss implications for practice and interventions.

Using psychodrama to relieve social barriers in an autistic child: A case study and literature review

ObjectiveTo review and update the evidence for the effect of psychodrama for children with autism, and evaluate the effect of psychodrama on an autistic child with severe social barriers, using the theory of mind and psychodrama methodology as the analytical frameworks. MethodsA 5 year-old boy, the research object, was diagnosed as severe autism using behavior observation and autism screening tools, with an DSM-Ⅵcriteria. Autism symptom severity was usually measured by Childhood Autism Rating Scale (CARS) and Autism Behavior Checklist (ABC) in research of autism. In this study, the autistic boy accepted psychodrama training and was measured with CARS before and after the entire training program. The ABC was adopted to evaluate him after each intervention program. Meanwhile the entire training process was recorded. The evaluation criterion consists of four aspects including eye contact, following instructions, focusing attention and imitation ability. Finally, all live records and changes presented in volume tables were analyzed. ResultsThe patient's social barriers were relieved at the end of the third month of the training program. The CARS data shows a shift from the severe to moderate level of autism. ConclusionsIt was possible for autistic children to relieve social barriers by implementing psychodrama training, then to improve the social cognitive ability and enhance the social function of the autistic children. These results provided basic Clinical implications for exploring a new intervention technique to reduce autistic symptom severity.

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

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.

Effects of IP Protection on Export of Knowledge-Intensive Business Services US and EU Evidence.

We investigate the impact of intellectual property protection on exports of services (with a special attention to knowledge-intensive business services) from the US to the EU (27 countries) and rest of the world (36 countries) in 2000-2010. We separately assessed EU member countries because the EU and the US are currently negotiating the TTIP agreement leading to the creation of the largest free trade area. EU15 and US altogether account for about two thirds of global KIBS exports, which makes them the most important players in international turnover in these services.We construct a gravity model of bilateral trade flows that includes standard dependent variables, measuring the “economic masses” of countries and economic distance between them. In our model we built a specific variable: the threat of imitation. It is a dummy variable expressing the level of IPR protection (measured by Ginarte and Park Index) and imitation abilities (with human capital index as a proxy) in the importing country. We investigate empirically the occurrence of market size effects (Maskus, Penubarti 1995), as the theory does not provide definite answer whether more stringent IP regulations increase or decrease trade.

A kinematic study on (un)intentional imitation in bottlenose dolphins.

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

Identification of neuromotor deficits common to autism spectrum disorder and attention deficit/hyperactivity disorder, and imitation deficits specific to autism spectrum disorder.

Deficits in motor and imitation abilities are a core finding in autism spectrum disorders (ASD), but impaired motor functions are also found in attention deficit/hyperactivity disorder (ADHD). Given recent theorising about potential aetiological overlap between the two disorders, the present study aimed to assess difficulties in motor performance and imitation of facial movements and meaningless gestures in a sample of 24 ADHD patients, 22 patients with ASD, and 20 typically developing children, matched for age (6-13 years) and similar in IQ (>80). Furthermore, we explored the impact of comorbid ADHD symptoms on motor and imitation performance in the ASD sample and the interrelationships between the two groups of variables in the clinical groups separately. The results show motor dysfunction was common to both disorders, but imitation deficits were specific to ASD. Together with the pattern of interrelated motor and imitation abilities, which we found exclusively in the ASD group, our findings suggest complex phenotypic, and possibly aetiological, relationships between the two neurodevelopmental conditions.

Sensorized graspable devices for the study of motor imitation in infants.

Researches regarding neonatal imitation are of great clinical interest since they can provide evidences of an innate mechanism underlying action understanding; the study can be led through the analysis of infants' spontaneous movements, like grasping, that are recognized as markers of neural activity. To this aim, a portable and non-intrusive device has been designed and developed to measure infants' grasping during the presentation of specific visual stimuli. The device is composed of two soft handles with embedded pressure sensors. During trials action observation should produce an increase of the measured pressure exerted by the infant's hand, according to the imitation-based paradigm of the defined clinical protocol. The final prototype has been tested within a pilot study and it has been proved to be suitable for monitoring infants' imitation abilities, meeting all the clinical specifications in terms of size, weight, safety and sensitivity. Preliminary acquired results are a starting point to clarify mechanisms related to imitation and sensorimotor system growth. The present methodology could be employed to boosts investigation on the development of mirror neurons in infants.

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

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.

On drawing a line through the spectrogram: how do we understand deficits of vocal pitch imitation?

In recent years there has been a remarkable increase in research focusing on deficits of pitch production in singing. A critical concern has been the identification of “poor pitch singers,” which we refer to more generally as individuals having a “vocal pitch imitation deficit.” The present paper includes a critical assessment of the assumption that vocal pitch imitation abilities can be treated as a dichotomy. Though this practice may be useful for data analysis and may be necessary within educational practice, we argue that this approach is complicated by a series of problems. Moreover, we argue that a more informative (and less problematic) approach comes from analyzing vocal pitch imitation abilities on a continuum, referred to as effect magnitude regression, and offer examples concerning how researchers may analyze data using this approach. We also argue that the understanding of this deficit may be better served by focusing on the effects of experimental manipulations on different individuals, rather than attempt to treat values of individual measures, and isolated tasks, as absolute measures of ability.

The Music Perception Performance of Children with and without Dyslexia in Taiwan

Some Western studies have suggested a strong relation between musical discrimination abilities and reading-related skills. Music processing abilities and reading-related skills were evaluated for typically developing children and children with dyslexia. The results showed that pitch discrimination abilities of Chinese dyslexic children are not different from those of typically developing children. However, the former have poorer rhythm imitation abilities. Thus, in Chinese reading there is a strong relation between rhythm and reading acquisition, which is consistent with the research results on alphabetic languages. On the other hand, a significant correlation existed between the rhythm imitation ability and performance on the onset deletion test for all participants, which suggested that there was a close relation between the function of organizing the distinctive features in appropriate rhythmic pattern and the segmental phonological processing deficits of dyslexic children.

Phonological processing in Mandarin speakers with congenital amusia.

Although there is an emerging consensus that both musical and linguistic pitch processing can be problematic for individuals with a developmental disorder termed congenital amusia, the nature of such a pitch-processing deficit, especially that demonstrated in a speech setting, remains unclear. Therefore, this study tested the performance of native Mandarin speakers, both with and without amusia, on discrimination and imitation tasks for Cantonese level tones, aiming to shed light on this issue. Results suggest that the impact of the phonological deficit, coupled with that of the domain-general pitch deficit, could provide a more comprehensive interpretation of Mandarin amusics' speech impairment. Specifically, when there was a high demand for pitch sensitivity, as in fine-grained pitch discriminations, the operation of the pitch-processing deficit played the more predominant role in modulating amusics' speech performance. But when the demand was low, as in discriminating naturally produced Cantonese level tones, the impact of the phonological deficit was more pronounced compared to that of the pitch-processing deficit. However, despite their perceptual deficits, Mandarin amusics' imitation abilities were comparable to controls'. Such selective impairment in tonal perception suggests that the phonological deficit more severely implicates amusics' input pathways.

Neighborhood linguistic diversity predicts infants’ social learning

Infants’ direct interactions with caregivers have been shown to powerfully influence social and cognitive development. In contrast, little is known about the cognitive influence of social contexts beyond the infant’s immediate interactions with others, for example, the communities in which infants live. The current study addressed this issue by asking whether neighborhood linguistic diversity predicts infants’ propensity to learn from diverse social partners. Data were taken from a series of experiments in which 19-month-old infants from monolingual, English-speaking homes were tested in paradigms that assessed their tendency to imitate the actions of an adult who spoke either English or Spanish. Infants who lived in more linguistically diverse neighborhoods imitated more of the Spanish speaker’s actions. This relation was observed in two separate datasets and found to be independent from variation in infants’ general imitative abilities, age, median family income and population density. These results provide novel evidence suggesting that infants’ social learning is predicted by the diversity of the communities in which they live.