Social approach in pre-school children with Williams syndrome: the role of the face.

BACKGROUND: Indiscriminate social approach behaviour is a salient aspect of the Williams syndrome (WS) behavioural phenotype. The present study examines approach behaviour in pre-schoolers with WS and evaluates the role of the face in WS social approach behaviour. METHOD: Ten pre-schoolers with WS (aged 3-6 years) and two groups of typically developing children, matched to the WS group on chronological or mental age, participated in an observed play session. The play session incorporated social and non-social components including two components that assessed approach behaviour towards strangers; one in which the stranger's face could be seen and one in which the stranger's face was covered. RESULTS: In response to the non-social aspects of the play session, the WS group behaved similarly to both control groups. In contrast, the pre-schoolers with WS were significantly more willing than either control group to engage with a stranger, even when the stranger's face could not be seen. CONCLUSION: The findings challenge the hypothesis that an unusual attraction to the face directly motivates social approach behaviour in individuals with WS.

Peripheral sensory stimulation and the release of transmitter amino acids in vivo from specific regions of cerebral cortex.

The effects of sensory stimulation on the release of amino acids from sensori-motor and visual cortices have been studied using a superfusion technique. Electrical stimulation of the brachial plexus contra-lateral to the superfusion cannula increased significantly the release of glutamate and glutamine from the sensori-motor cortex of anesthetized rats. No clear effect was observed with the other amino acids. Stimulation of the ipsi-lateral plexus had no effect on glutamate and glutamine release. In unanesthetized animals, stimulation of the contra-lateral brachial plexus raised the levels of all the amino acids in sensori-motor cortex superfusate. Weak photic stimulation of the eyes of dark-adapted rats increased glutamate release from the visual cortex but caused no significant change in the release of other amino acids. All evoked increases in amino acid release were reversible at the cessation of the stimuli.