Broadbent Hannah J, Farran Emily K, Tolmie Andy
Psychology and Human Development, Institute of Education, University of London, UK.
Dev Sci. 2014 Nov;17(6):920-34. doi: 10.1111/desc.12176. Epub 2014 Apr 7.
Recent findings suggest that difficulties on small-scale visuospatial tasks documented in Williams syndrome (WS) also extend to large-scale space. In particular, individuals with WS often present with difficulties in allocentric spatial coding (encoding relationships between items within an environment or array). This study examined the effect of atypical spatial processing in WS on large-scale navigational strategies, using a novel 3D virtual environment. During navigation of recently learnt large-scale space, typically developing (TD) children predominantly rely on the use of a sequential egocentric strategy (recalling the sequence of left-right body turns throughout a route), but become more able to use an allocentric strategy between 5 and 10 years of age. The navigation strategies spontaneously employed by TD children between 5 and 10 years of age and individuals with WS were analysed. The ability to use an allocentric strategy on trials where spatial relational knowledge was required to find the shortest route was also examined. Results showed that, unlike TD children, during spontaneous navigation the WS group did not predominantly employ a sequential egocentric strategy. Instead, individuals with WS followed the path until the correct environmental landmarks were found, suggesting the use of a time-consuming and inefficient view-matching strategy for wayfinding. Individuals with WS also presented with deficits in allocentric spatial coding, demonstrated by difficulties in determining short-cuts when required and difficulties developing a mental representation of the environment layout. This was found even following extensive experience in an environment, suggesting that - unlike in typical development - experience cannot contribute to the development of spatial relational processing in WS. This atypical presentation of both egocentric and allocentric spatial encoding is discussed in relation to specific difficulties on small-scale spatial tasks and known atypical cortical development in WS.
最近的研究结果表明，威廉姆斯综合征（WS）患者在小规模视觉空间任务中出现的困难也延伸到了大规模空间。特别是，患有WS的个体在以客体为中心的空间编码（编码环境或阵列中项目之间的关系）方面常常存在困难。本研究使用一种新颖的3D虚拟环境，考察了WS患者非典型空间处理对大规模导航策略的影响。在最近学习的大规模空间导航过程中，发育正常（TD）的儿童主要依赖于使用顺序自我中心策略（回忆整个路线中左右身体转动的顺序），但在5到10岁之间变得更能使用以客体为中心的策略。分析了5到10岁的TD儿童和WS患者自发采用的导航策略。还考察了在需要空间关系知识来找到最短路线的试验中使用以客体为中心策略的能力。结果表明，与TD儿童不同，在自发导航过程中，WS组并没有主要采用顺序自我中心策略。相反，患有WS的个体沿着路径走，直到找到正确的环境地标，这表明他们在寻路时使用了一种耗时且低效的视图匹配策略。患有WS的个体在以客体为中心的空间编码方面也存在缺陷，这表现为在需要时难以确定捷径以及难以形成环境布局的心理表征。即使在一个环境中有丰富的经验之后，仍发现了这一情况，这表明——与典型发育不同——经验并不能促进WS患者空间关系处理的发展。本文结合小规模空间任务中的特定困难以及WS中已知的非典型皮质发育，讨论了自我中心和以客体为中心空间编码的这种非典型表现。
