Heterogeneity in motion perception deficits in developmental disorders: evidence from Autism and Williams Syndrome

Certain deficits in visual motion sensitivity can be assessed via traditional motion coherence tasks where the subject is prompted to detect a percentage of coherent motion embedded in a background of random moving dots. This technique has enabled researchers to infer a deficit in visual motion coherence detection in people with Autism Spectrum Disorder (ASD) and Williams Syndrome (WS) which has been suggested to account for a deficit in function of the dorsal stream in these two groups. It is possible, that not only motion coherence, but several different visual motion deficits coexist. Moreover, a different pattern of low level motion detection deficits might underlie each of these developmental disorders. Here we investigate six different aspects of motion detection sensitivity in ASD and WS with the aim to verify if different deficit patterns might be generalized to each clinical group. Nine children with ASD, 10 children with WS and 96 Typically Developing (TD) children participated in this study. Six Random Dot Kinematogram tasks were used. Withingroup score patterns were very heterogeneous across tasks for both clinical groups. However, participants with ASD showed consistent deficits in a ‘Single Mobile’task and participants with WS showed consistent deficits in a ‘Motion Coherence’task. The data are discussed in terms of the dissociations found in the motion detection deficit patterns, possibly related with complex co-morbid visual-attention disorders.Certos déficits na percepção visual do movimento podem ser detectados através das tradicionais tarefas de detecção de coerência do movimento. Neste tipo de tarefas é necessário detectar uma percentagem de movimento coerente embutido num fundo constituído por pontos luminosos com movimento aleatório. Esta técnica permitiu inferir um déficit na detecção visual do movimento coerente em pessoas com Perturbações do Espectro do Autismo (PEA) e com Síndrome de Williams (SW). Este déficit foi sugerido como estando na base de uma perturbação na função do sistema dorsal nestes dois grupos clínicos. É possível que outros déficits na percepção visual do movimento coexistam com o déficit na detecção da coerência do movimento. Além disto, cada uma destas perturbações do desenvolvimento poderá apresentar um padrão específico de déficits na detecção visual do movimento. Nós investigámos seis aspectos diferentes da sensibilidade ao movimento na PEA e na SW com o objectivo de verificar se um conjunto particular de déficits poderia ser generalizado a cada grupo clínico. Participaram neste estudo: nove crianças com PEA, 10 crianças com SW e 96 crianças com desenvolvimento Típico. Foram usados seis cinematogramas de pontos aleatórios. Aqui mostramos que os padrões de déficits são muito heterogéneos dentro de cada grupo clínico. No entanto, os participantes com PEA mostraram déficits consistentes numa tarefa de ‘Movimento Singular’ e os participantes com SW mostraram déficits consistentes numa tarefa de ‘Coerência do Movimento’. Os resultados são discutidos em termos das dissociações encontradas nos padrões de déficits na detecção do movimento, possivelmente relacionadas com déficits complexos associados de atenção visual

Narrowing Perceptual Sensitivity to the Native Language in Infancy: Exogenous Influences on Developmental Timing

The infancy literature situates the perceptual narrowing of speech sounds at around 10 months of age, but little is known about the mechanisms that influence individual differences in this developmental milestone. We hypothesized that such differences might in part be explained by characteristics of mother-child interaction. Infant sensitivity to syllables from their native tongue was compared longitudinally to sensitivity to non-native phonemes, at 6 months and again at 10 months. We replicated previous findings that at the group level, both 6- and 10- month-olds were able to discriminate contrasts in their native language, but only 6-month-olds succeeded in discriminating contrasts in the non-native language. However, when discrimination was assessed for separate groups on the basis of mother-child interaction—a ‘high contingency group’ and a ‘moderate contingency’ group—the vast majority of infants in both groups showed the expected developmental pattern by 10 months, but only infants in the ‘high contingency’ group showed early specialization for their native phonemes by failing to discriminate non-native contrasts at 6-months. The findings suggest that the quality of mother-child interaction is one of the exogenous factors influencing the timing of infant specialization for speech processing

Motion Perception and Social Cognition in Autism: Speed Selective Impairments in Socio-Conceptual Processing?

Aim: Research on Autism Spectrum Disorders (ASD) has mainly focused on the study of social behavioral deficits (e.g. imitation, eye gaze, play, etc.). These studies have emphasized the high-level impairments that lead to abnormal social interaction in ASD. However, as important as the study of social behavior in ASD, is research on lower-level processes that might contribute to the emergence and development of the atypical social behaviors that characterize this condition. Perceptual differences constitute one such factor. Here, we aim to investigate the possible influence of specific visual motion perception deficits in conceptual processing.Materials and Methods: We compared the performance of children with ASD, with that of children with moderate to severe learning disorders (MLD) or typical development (TD) on a series of computerized tasks. These tasks assessed motion detection in non-social and socially embedded backgrounds or contexts.Results: The results provide evidence for speed-selective impairments in processing socially embedded targets in ASD.Conclusions: Based on these findings, we suggest that low-level perceptual deficits might play an important role in the development of social impairments

The rehabilitation of face recognition impairments: A critical review and future directions

While much research has investigated the neural and cognitive characteristics of face recognition impairments (prosopagnosia), much less work has examined their rehabilitation. In this paper, we present a critical analysis of the studies that have attempted to improve face-processing skills in acquired and developmental prosopagnosia, and place them in the context of the wider neurorehabilitation literature. First, we examine whether neuroplasticity within the typical face-processing system varies across the lifespan, in order to examine whether timing of intervention may be crucial. Second, we examine reports of interventions in acquired prosopagnosia, where training in compensatory strategies has had some success. Third, we examine reports of interventions in developmental prosopagnosia, where compensatory training in children and remedial training in adults have both been successful. However, the gains are somewhat limited-compensatory strategies have resulted in labored recognition techniques and limited generalization to untrained faces, and remedial techniques require longer periods of training and result in limited maintenance of gains. Critically, intervention suitability and outcome in both forms of the condition likely depends on a complex interaction of factors, including prosopagnosia severity, the precise functional locus of the impairment, and individual differences such as age. Finally, we discuss future directions in the rehabilitation of prosopagnosia, and the possibility of boosting the effects of cognitive training programmes by simultaneous administration of oxytocin or non-invasive brain stimulation. We conclude that future work using more systematic methods and larger participant groups is clearly required, and in the case of developmental prosopagnosia, there is an urgent need to develop early detection and remediation tools for children, in order to optimize intervention outcome. © 2014 Bate and Bennetts

The Faces in Infant-Perspective Scenes Change over the First Year of Life

Mature face perception has its origins in the face experiences of infants. However, little is known about the basic statistics of faces in early visual environments. We used head cameras to capture and analyze over 72,000 infant-perspective scenes from 22 infants aged 1-11 months as they engaged in daily activities. The frequency of faces in these scenes declined markedly with age: for the youngest infants, faces were present 15 minutes in every waking hour but only 5 minutes for the oldest infants. In general, the available faces were well characterized by three properties: (1) they belonged to relatively few individuals; (2) they were close and visually large; and (3) they presented views showing both eyes. These three properties most strongly characterized the face corpora of our youngest infants and constitute environmental constraints on the early development of the visual system

The two-process theory of face processing: modifications based on two decades of data from infants and adults

Johnson and Morton (1991) used Gabriel Horn’s work on the filial imprinting model to inspire a two-process theory of the development of face processing in humans. In this paper we review evidence accrued over the past two decades from infants and adults, and from other primates, that informs this two-process model. While work with newborns and infants has been broadly consistent with predictions from the model, further refinements and questions have been raised. With regard to adults, we discuss more recent evidence on the extension of the model to eye contact detection, and to subcortical face processing, reviewing functional imaging and patient studies. We conclude with discussion of outstanding caveats and future directions of research in this field

Étude de différents modes d'indexation dans la mémoire verbale

Two attempts are reported to give evidence for indexing of features in long term memory. During an incidental learning task subjects were presented with words ; one task emphasized the paradigmatic features of the words, while the other task emphasized the phonic features of the words presented. Two kinds of recognition test were given two hours later. The results show that the features emphasized during incidental learning are utilized in recall and that these features are organized. These results are considered as supporting the hypothesis that indexing is an organized process resulting from coding of the perceived features of the events.Au cours d'un apprentissage incidentel de noms communs, les sujets sont incités à tenir compte soit de l'aspect paradigmatique, soit de l'aspect phonique de ces mots. Deux sortes de test de reconnaissance à choix ont lieu deux heures plus tard. Les résultats de ces deux expériences montrent que les caractéristiques (paradigmatique et phonique) utilisées lors de l'apprentissage sont réutilisées dans le processus de rappel et qu'il existe une organisation dans l'utilisation de ces caractéristiques. Ces faits sont considérés comme étant en faveur de l'hypothèse que l'indexation en mémoire à long terme se fait par le codage des caractéristiques des événements perçus et qu'il existe une organisation entre les diverses indexations. tiques (paradigmatique et phonique) utilisées lors de l'apprentissage sont réutilisées dans le processus de rappel et qu'il existe une organisation dans l'utilisation de ces caractéristiques. Ces faits sont considérés comme étant en faveur de l'hypothèse que l'indexation en mémoire à long terme se fait par le codage des caractéristiques des événements perçus et qu'il existe une organisation entre les diverses indexations.de Schonen S. Étude de différents modes d'indexation dans la mémoire verbale. In: L'année psychologique. 1968 vol. 68, n°2. pp. 373-389

Déficit mnésique d'origine organique et niveaux d'organisation des tâches à mémoriser

Two groups of patients, with frontal, temporal, parietal and 3rd vent. lesions, have been investigated. The experience was designed to test the importance of increasing levels of organization of 4 tasks in short-term and long term memory. Two modalities of learning have been chosen : one group of subjects was presented with each task only once for a fixed duration while the other group was allowed to carry on the learning until criterion was reached (one fautless recall). Recall tests were carried out 24 hours later for both groups. Results show that for the patients we have studied, forgetting is inversely related to the organization level of tasks, irrespective to learning modalities. duration while the other group was allowed to carry on the learning until criterion was reached (one fautless recall). Recall tests were carried out 24 hours later for both groups. Results show that for the patients we have studied, forgetting is inversely related to the organization level of tasks, irrespective to learning modalities.Deux groupes de sujets atteints de lésions cérébrales frontales, temporales, pariétales et du 3e ventricule ont participé à une expérience destinée à étudier le rôle de 4 niveaux croissants d'organisation de matériel dans l'évocation immédiate et différée. Deux modalités d'apprentissage ont été utilisées. Pour un groupe de sujets, le temps et le nombre de présentations des quatre matériels étaient fixés d'avance ; l'autre groupe de sujets faisait un apprentissage de chacun des matériels jusqu'au critère d'une répétition exacte. Vingt-quatre heures plus tard avait lieu un test de rappel différé pour chacune des épreuves. Ce test de rappel se faisait de la même manière pour les deux groupes de sujets. Les sujets expérimentaux sont classés en fonction de leurs résultats en évocation immédiate et différée par rapport à ceux des groupes contrôle correspondants. Les résultats montrent qu'avec les deux techniques d'apprentissage on retrouve en rappel différé la même hiérarchie des performances que celles observées en rappel immédiat. Cette hiérarchie correspond à celle des niveaux d'organisation des tâches proposées : moins une tâche est organisée, moins elle est susceptible d'être évoquée à long terme, même si elle a fait l'objet d'un apprentissage jusqu'au critère d'une répétition parfaite la veille. Ces résultats semblent en faveur de l'idée que la recherche dans le stock mnésique suivrait un processus analogue à celui de l'enregistrement.de Schonen S. Déficit mnésique d'origine organique et niveaux d'organisation des tâches à mémoriser. In: L'année psychologique. 1968 vol. 68, n°1. pp. 97-114

Le développement de la connaissance des visages : modularité, apprentissage et pré-organisation

The development of facial recognition : modularity, learning and preorganisation. One of the fundamental questions for the cognitive neuroscience of development is to understand which properties of the human brain, which neuronal organisations make possible the development of cognitive competence (language, memory, creation of works of art, knowledge systems, beliefs, hopes etc). What properties of the human brain lead the infant to develop human cognitive capacities ? These questions must be posed at all levels in the study of the brain, from genetics to behaviour. Studies bearing on the cognitive activities of the brain are a necessary approach to cerebral functioning in order to understand how the activity of a neural network constitutes what we call thought, mental states, actions, etc. Questions concerning the development of language, visuo-spatial abilities, reasoning, etc have been studied experimentally for a longer time than questions concerning the development of social behaviour, the affect and the emotions, representations of self and others, which, because they are more difficult to approach and to control experimentally, have until recently been restricted to a clinical approach, often psychoanalytical, of pathological cases, without recourse to an experimental approach to normal development.Quelles propriétés du cerveau humain conduisent l''enfant à développer des compétences cognitives humaines (langage, mémoire, réalisation d’oeuvres d''art, systèmes de connaissances, sciences, croyances, interactions avec autrui et ses représentations mentales, ses croyances, ses espoirs, etc.) ? Les questions relatives au développement des conduites sociales, des aspects émotionnels et affectifs, des représentations de soi et d’autrui, sont plus difficiles à aborder et contrôler expérimentalement que les questions relatives au développement du langage, des habiletés visuospatiales, du raisonnement, etc ; elles ont été traitées pendant longtemps par une approche essentiellement clinique de cas pathologiques, sans recours à une approche expérimentale du développement normal.De Schonen Scania. Le développement de la connaissance des visages : modularité, apprentissage et pré-organisation . In: Intellectica. Revue de l'Association pour la Recherche Cognitive, n°34, 2002/1. Débats actuels sur la cognition chez le bébé. pp. 77-97