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Melanie Palomares, Barbara Landau, Howard Egeth; Abnormal spatial integration in Williams Syndrome is distance-dependent. Journal of Vision 2005;5(8):298. doi: 10.1167/5.8.298.
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© ARVO (1962-2015); The Authors (2016-present)
The cognitive profile of Williams Syndrome (WS), a genetic disorder, exhibits a profound weakness in visuospatial abilities and a relative strength in language. Evidence from visuomotor tasks such as drawing and block construction suggests that WS individuals may be impaired in integrating information over space (see Bellugi et al., 1999; Hoffman et al., 2003). We characterized how WS individuals integrate spatial information by measuring positional acuity thresholds. We asked people with WS, normal children and normal adults to judge the position of a target square relative to two flanking squares. We found three notable results: 1) Positional thresholds normally decrease with age, and reach mature levels after 8–9 years old. 2) Doubling the flanker distance from 3 deg to 6 deg doubled positional acuity thresholds in normal adults, 8–9 year olds and 5–6 year olds, while it increased 6 times in WS participants. 3) For flankers at 3 deg, WS participants have thresholds better than 8–9 year olds. For flankers at 6 deg, WS people have thresholds worse than 3–4 year olds. These data suggest that WS people may be good at integrating proximal information, but may be impaired in integrating distal information perhaps reflecting abnormal parietal lobe functions.
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