Biomedical subjects

C Deruelle

Publications and source records attributed to C Deruelle.

11 recordsLinked to original sources

PubMed2007

[Autism and mental retardation: a study of the early social communication].

OBJECTIVE: To determine developmental communication profiles in young autistic children with mental retardation. METHODS: A group of 19 autistic children (mean age=43 months) were matched with a group of 11 mentally retarded children (mean age=39 months) on mental age (17,6 months). All of these children were without speech (less than 5 words of vocabulary). Communication skills were assessed with the Guidetti-Tourrette scales (ECSP), French adaptation of the Seibert-Hogan scales. RESULTS: Autistic children displayed a much lower score than mentally retarded children in the 3 functions of early social communication (behavior regulation, social interaction and joint attention). The developmental communication profiles was the same in the 2 groups. DISCUSSION: The results showed evidence of distortion in autistic children development: they displayed important deficits in communication skills, in comparison with cognitive skills. Autistic children mainly displayed requesting gestures: they used adults to help them to reach a goal, instead of regarding them as social partners. However, young children who have mental age less than 18 months mainly use the same functions of communication, with or without autistic trouble. CONCLUSIONS: There is a same developmental sequence in communication skills in young children, with or without autistic trouble.

Autistic Disorder↗

PubMed2006

Brief report: recognition of emotional and non-emotional biological motion in individuals with autistic spectrum disorders.

This study aimed to explore the perception of different components of biological movement in individuals with autism and Asperger syndrome. The ability to recognize a person's actions, subjective states, emotions, and objects conveyed by moving point-light displays was assessed in 19 participants with autism and 19 comparable typical control participants. Results showed that the participants with autism were as able as controls to name point-light displays of non-human objects and human actions. In contrast, they were significantly poorer at labeling emotional displays, suggesting that they are specifically impaired in attending to emotional states. Most studies have highlighted an emotional deficit in facial expression perception; our results extend this hypothesized deficit to the perception and interpretation of whole-body biological movements.

Adolescent↗

PubMed2001

Motion and emotion: a novel approach to the study of face processing by young autistic children.

The specificity of facial processing impairment in autistic children, particularly in the domain of emotion, is still debated. The aim of our study was to assess the influence of motion on facial expression recognition in young autistic children. Thirteen autistic children (M age: 69.38 months) were matched for gender and developmental level with a control group of 13 normal children (M age: 40.53 months). They were compared on their ability to match videotaped "still," "dynamic," and "strobe" emotional and nonemotional facial expressions with photographs. Results indicate that children with autism do not perform significantly worse than their controls in any of our experimental conditions. Compared to previous studies showing lower performance in autistic than in control children when presented with static faces, our data suggest that slow dynamic presentations facilitate facial expression recognition by autistic children. This result could be of interest to parents and specialists involved in education and reeducation of these children.

Attention↗

PubMed2000

Perception of partly occluded figures by baboons (Papio papio).

Comparative literature provides conflicting findings whether animals experience amodal completion. Five experiments were conducted to verify if baboons perceive partly occluded objects as complete. The first three experiments used a go/no-go procedure and a video monitor for stimulus presentation. These experiments failed to reveal amodal completion, suggesting that the stimuli were processed as 2-D images rather than 3-D objects. In contrast, completion was demonstrated in a fourth experiment with cardboard stimuli in a two-alternative forced-choice (2AFC) discrimination task presented in a Wisconsin General Test Apparatus. Although in experiment 5 the same 2AFC procedure was used as in experiment 4, completion was absent when the stimuli were shown with a computer graphic system. The results suggest that baboons share with humans the ability for amodal completion, but also underline some procedural factors that might affect the elicitation of this capacity.

Analysis of Variance↗

PubMed2000

Positive and negative compatibility effects.

This paper reports a series of four experiments that established a negative compatibility effect (NCE) by which compatible distractors led to slower and less accurate target performance than did incompatible ones (Experiment 1). This effect is interpreted as an early perceptual effect that delays the attribution of visual attention over the target location in the compatible condition. This view predicted that the NCE should be observed only when attention has to be selectively attributed to the target location. In Experiments 2 and 3, this prediction was tested by manipulating the perceptual load in the display. High perceptual load displays are known to require selective attention (Lavie, 1995). Accordingly, reliable NCEs were observed when high-load displays were used. In contrast, reduced NCEs were found in displays that did not require selective attention. Experiment 4 established that the manifestation of the NCE was influenced by low-level visual cues, such as brightness and contrast. Overall, these experiments indicated that the NCE can be understood as an early perceptual effect, which arises from a conflict between the cues that guide the distribution of attention when the task requires selective attention.

Adolescent↗

PubMed1999

Configural and local processing of faces in children with Williams syndrome.

Three experiments investigated face processing in children with Williams syndrome (WS). In Experiment 1, the ability to discriminate different aspects of faces was compared between WS subjects and a group of children individually matched for chronological age (CA-matches) and another group matched for mental age (MA-matches). In Experiments 2 and 3, the ability to process the local and configural aspects of geometrical patterns and faces was assessed within the same groups of subjects. The results indicated that the WSs' overall performance on face recognition was below that of the CA-matches, but similar to that of the MA-matches. This study revealed in addition that the CA- and MA-matches showed a bias toward a configural mode of face and geometrical shape processing, whereas children with WS did not show any bias. These findings suggest that face processing undergoes an abnormal developmental course in WS.

Adolescent↗

PubMed1997

Processing of global and local visual information and hemispheric specialization in humans (Homo sapiens) and baboons (Papio papio).

Global precedence was examined in 8 baboons and 14 humans using compound stimuli presented in the left visual hemifield (LVF) or the right visual hemifield (RVF). Humans showed a global advantage and global-to-local interference. Baboons showed a local advantage and no interference. For humans and baboons, a LVF advantage appeared for global matching and an unsignificant RVF advantage appeared for local matching. The local advantage in baboons still emerged when the memory load of the task was removed and when the local elements were connected by lines or were adjacent. Moreover, global precedence in humans persisted with unfamiliar forms. Species differences suggest that global precedence is not a universal trait and that this effect in humans does not have a purely perceptual or sensory basis.

Adult↗

PubMed1997

Hemispheric lateralisation and global precedence effects in the processing of visual stimuli by humans and baboons (Papio papio).

This paper examines the effect of global precedence (GPE: Navon, 1977) and its lateralisation from a comparative perspective. Using a divided field matching-to-sample task with compound stimuli, Experiment 1 demonstrated consistent patterns of lateralisation in humans and baboons, corresponding to a right-hemisphere advantage for global processing and a left- but nonsignificant advantage for local processing. Species differences emerged in terms of GPE; humans showed a global precedence effect, and baboons were better for local than for global matching. In Experiment 2, a visual search task was used to assess the origin of species differences in terms of GPE. Humans processed the global structure of the forms pre-attentively, whereas baboons used an attentional search strategy. From this finding, it is argued that lateralisation in Experiment 1 was rooted in early perceptual mechanisms. So far, consistent patterns of lateralisation for global/local processing have been found in baboons, chimpanzees, and humans, suggesting that this phenomenon has a long evolutionary history.

Journal Article↗

PubMed1994

Face recognition in children with early right or left brain damage.

Development of face processing after unilateral brain lesions sustained before one year of age was assessed in children aged between seven and 10 years by various tasks involving face processing. Each child was paired with an age- and IQ-matched control. There were three unilateral right-hemisphere lesions and three unilateral left lesions. The results showed that some of the skills relative to face processing were preserved (or recovered?), whereas other skills were severely impaired; the pattern varied from one child to another. The existence of these dissociations shows that preservation of low-level visual processing together with exposure to the appropriate stimuli for several years is by no means sufficient for face processing skills to develop normally.

Brain Damage, Chronic↗

PubMed1991

Visual field asymmetries for pattern processing are present in infancy. A comment on T. Hatta's study on children's performances.

From a study on 4 to 6 year-old children, Hatta (Hatta, Neuropyschologia 28, 1053-1062, 1990) concludes that (a) a left visual-field advantage develops at age 4 to 5 years in visuo-spatial stimulus recognition, and (b) since both the right visual-field advantage for verbal and the left visual-field advantage for visuo-spatial material develop at the same age, there is no support for the claim that the left and right hemispheres develop differentially. We contest these conclusions on the basis of our own infant studies which have shown a right visual-field advantage in 4 to 9 month-old infants for individual face recognition and more recently, for some aspects of visual patterns.

Child, Preschool↗

PubMed1991

Hemispheric asymmetries in visual pattern processing in infancy.

A right hemisphere advantage was observed in a previous study of 4- to 9-month old infants presented with a face discrimination task (de Schonen & Mathivet, 1990). The present study was designed to investigate pattern processing by the two hemispheres and the interhemispheric communication of this processing. Infants aged 4 to 9 months were tested with divided visual field presentations in one or two discrimination tasks. Under both task conditions, the infants had to discriminate between two patterns in which only two local components differed. Under one condition the components of the patterns were arranged so as to produce a face-like pattern. Under the other condition the same components were arranged into arbitrary patterns that were not "good form" patterns. No performance asymmetry was observed with the arbitrary patterns; whereas, a right hemisphere (RH) disadvantage was observed with the face-like patterns compared with both the RH performances on the arbitary patterns and the left hemisphere (LH) performances on the face-like patterns. These results show that the RH advantage for individual face recognition is not due to a general immaturity or inability of the LH in pattern processing at this period of development, nor to a more specific inability in a local mode of pattern processing. On the other hand, the RH does not completely lack local processing capacity, but is at a disadvantage when this local mode of processing has to be used with face-like (or good form) patterns. The interhemispheric communication of visual discrimination learning was tested by measuring learning transfer between the visual fields. Contrary to de Schonen and Bry's study (1987) on faceness recognition, no data in favor of interhemispheric communication were recorded in the present study.

Attention↗