Abstract
People with Williams syndrome (WS), a rare genetic disorder, have an unusual profile of strengths and weaknesses in visual processing, with impaired visuospatial functions and apparently spared face and object recognition. To determine whether this striking profile is reflected in working memory differences, we compared memory for exact location versus recognition of individual objects in WS. The same stimuli — either faces or houses — were used in both the Location and Identity Conditions. A black and white photo appeared (.5 s) in one of 24 locations on a computer monitor. After a 2 second delay, a second photo appeared (.5 s). In the Location Condition, subjects judged whether the second photo was in the same location as the first; in the Identity Condition, they judged whether it was the same individual face or house. A control condition examined memory for location with the faces phase-scrambled (i.e., mottled gray squares) to ensure that the objects themselves didn't distract subjects from making accurate location judgements. Fourteen participants with WS, ages 10 to 38, were compared to 14 normally developing children, ages 4 to 8, matched to the WS group on mental age (Kaufman Brief Intelligence Test). A 2 (Group: WS vs. Control) × 2 (Condition: Location vs. Identity) × 2 (Stimuli: Faces vs. Houses) Repeated Measures ANOVA revealed a trend for performance in the WS group to be poorer than the control group across all conditions. Planned comparisons contrasted the WS and control groups on each of the 5 conditions. These analyses found that the WS group performed worse than the mental age matched controls on all conditions except the Face Identity Condition. The impairment included the House Identity Condition. However, recognizing houses may require more spatial processing than does recognizing faces, and so studies using other objects are required. People with WS seem to have a general working memory deficit, but memory for faces is relatively spared.
Supported by NICHD F32 HD42346 to KOD, NSF grants 0117744, BCS 01-17475, MRI 9977628 and March of Dimes Grant 12-01-0087 to BL and JEH