Smith Alastair D, Gilchrist Iain D, Hood Bruce, Tassabehji May, Karmiloff-Smith Annette
Department of Experimental Psychology, University of Bristol, 12a Priory Road, Bristol BS8 1TN, UK.
Perception. 2009;38(5):694-701. doi: 10.1068/p6050.
Williams syndrome (WS) is a genetic disorder associated with impairments of spatial cognition. This has primarily been studied in small-scale space, and rarely in large-scale environments. In order to fully characterise the spatial deficits in WS, and also to address claims that the deletion of LIM-kinase 1 (LIMK1) on chromosome 7 is responsible for those deficits, we report an automated large-scale search task for humans that places the participant egocentrically within the search space. Search locations were defined as lights and switches embedded in the floor, and participants attempted to locate a hidden target by pressing the switch at potential locations. We compared individuals with WS to patients with smaller deletions (including LIMK1) in the critical region on chromosome 7. Whilst partial-deletion participants performed efficiently on the task, participants with WS demonstrated inefficient search profiles: their search slopes were steeper and they made significantly more erroneous revisits to previously inspected locations. Our findings indicate that spatial deficits associated with WS also affect large-scale spatial processing and suggest that hemizygous deletion of LIMK1 is not sufficient to account for any of the spatial deficits associated with WS.
威廉姆斯综合征（WS）是一种与空间认知障碍相关的遗传性疾病。此前主要是在小规模空间中对此进行研究，而在大规模环境中的研究则很少。为了全面描述WS患者的空间缺陷，并回应关于7号染色体上LIM激酶1（LIMK1）缺失是导致这些缺陷原因的说法，我们报告了一项针对人类的自动化大规模搜索任务，该任务将参与者以自我为中心置于搜索空间内。搜索位置被定义为嵌入地板的灯和开关，参与者试图通过按下潜在位置的开关来找到隐藏目标。我们将WS患者与7号染色体关键区域存在较小缺失（包括LIMK1）的患者进行了比较。虽然部分缺失的参与者在任务中表现高效，但WS患者的搜索表现不佳：他们的搜索斜率更陡，并且对先前检查过的位置进行错误重访的次数显著更多。我们的研究结果表明，与WS相关的空间缺陷也会影响大规模空间处理，并表明LIMK1的半合子缺失不足以解释与WS相关的任何空间缺陷。
