Williams syndrome (WS) is a rare genetic syndrome. As with all rare syndromes, obtaining adequately powered sample sizes is a challenge. Here we present legacy data from seven UK labs, enabling the characterisation of cross-sectional and longitudinal developmental trajectories of verbal and non-verbal development in the largest sample of…

The size of an individual's phonological similarity effect for visually presented material is assumed to reflect his or her ability to recode, and by implication rehearse, information in verbal short-term memory. Many studies have shown that under these conditions, the size of this effect interacts with age, tending to be nonsignificant in…

Studies of inner speech use in ASD have produced conflicting results. Lidstone et al., J "Autism Dev Disord" (2009) hypothesised that Cognitive Profile (i.e., "discrepancy" between non-verbal and verbal abilities) is a predictor of inner speech use amongst children with ASD. They suggested other, contradictory results might be explained in terms…

Individuals with Williams syndrome (WS) display poor visuo-spatial cognition relative to verbal abilities. Furthermore, whilst perceptual abilities are delayed, visuo-spatial construction abilities are comparatively even weaker, and are characterised by a local bias. We investigated whether this differentiation in visuo-spatial abilities can be…

Non-word repetition, in which participants hear and repeat unfamiliar verbal stimuli, is thought to provide a particularly sensitive measure of verbal short-term memory capacity. However, performance on this task can also be constrained by hearing and speech production skills, and by an individuals' linguistic knowledge. This study examined real…