Comprehension of spatial language terms in Williams syndrome: evidence for an interaction between domains of strength and weakness.

Individuals with Williams syndrome show an unusual neuropsychological profile, with relatively strong language abilities and impoverished visual and spatial abilities. Two studies are reported that examine the interaction between these two domains in Williams syndrome by assessing individuals' comprehension of spoken language with a spatial component. In a first study, the Test for Reception of Grammar (Bishop, 1983) was given to 32 individuals with Williams syndrome and to controls matched individually for total number of errors on the task. Individuals with Williams syndrome had particular problems when asked to comprehend sentences containing spatial prepositions, making significantly more errors on these items than control groups. A second study examined in more detail comprehension of sentences with spatial and non-spatial components, comparing the performance of 15 individuals with Williams syndrome and control groups matched for vocabulary ability. Individuals with Williams syndrome again showed impaired comprehension of spoken spatial terms. In contrast, they were unimpaired in comprehending utterances without a spatial component, with the exception of descriptions testing comprehension of non-spatial comparatives (lighter than and darker than). These results suggest that the spatial difficulties experienced by individuals with Williams syndrome may constrain language comprehension in certain circumstances. They also shed light on the ways in which spatial cognition may interact with language comprehension more generally.