Down Syndrome in Neurobiological Perspective: An Emphasis on Spatial Cognition

Explored the role of the hippocampus in impaired spatial representational abilities in persons with Down syndrome (DS). Mental retardation from DS usually arises as a result of the triplication (trisomy) of chromosome 21. Presumably, deficient neural development has a detrimental impact on adaptive and intellectual functioning. It is hypothesized that the ability to represent objects and events in the environment is a prerequisite skill for knowledge acquisition. Neurobiological, neuropsychological, and behavioral evidence indicates that individuals with DS have impaired spatial representational abilities. Although the responsible neural loci are difficult to pinpoint, it is argued that the hippocampus may be implicated. in addition, diffuse language lateralization is likely to be a contributor to poor visuospatial performance. Task analyses that take into account attentional and behavioral requirements could aid neuropsychological test administration and interpretation.