Visuospatial working memory in Turner's syndrome

Turner's syndrome is a genetic disorder, specific to women, in which one of the X chromosomes is partially or completely deleted. This syndrome is ass ociated with physical features such as short stature or failure in primary and secondary sexual development, together with a specific pattern of cogni tive functions. It has been suggested that women affected by Turner's syndr ome perform poorly in tasks measuring visuospatial abilities and have a ver bal IQ significantly higher than performance IQ. Although this result hits received strong empirical support, the nature of the visuospatial deficit i s still unclear. Recent studies on visuospatial processes have highlighted that the underlying cognitive structure is more complex than previously sug gested and several dissociations have been reported (e.g., visual vs spatia l, sequential vs simultaneous, or passive vs active processes). In thr pres ent study we analyze in detail the characteristics of the visuospatial defi cit associated with Turner's syndrome by presenting four young women with a comprehensive battery of tasks designed to tap all aspects of visuospatial working memory. Results confirm that Turner's syndrome is associated with a general visuospatial working memory deficit, but the pattern of performan ce of different cases can be different, with ii greater emphasis on active visuospatial processes, and on either sequential or simultaneous spatial pr ocesses. (C) 2001 Academic Press.