Down syndrome (DS) and Williams syndrome (WS) are neurodevelopmental disorders with distinct genetic origins. In our laboratory, we have undertaken a long-term project to characterize the real-world spatial capacities of individuals with DS, WS, and typically-developing children of similar mental age.
The reasons for characterizing allocentric spatial memory processes in DS and WS are manifold: allocentric spatial memories are critical for the construction of cognitive maps, which are essential for developing independence and autonomy in individuals with intellectual disability; allocentric spatial memories are a fundamental component of episodic memory, and thus may serve as a proxy for assessing episodic memory function, especially in individuals with impaired language function; and finally, although allocentric spatial memory is one of the hallmark cognitive processes studied in mouse models of WS and DS, its impairment in humans with WS and DS has not been unequivocally demonstrated.
One of our first studies described the allocentric spatial capacities of individuals with DS, noting both impairments and preservation of function. Our second study not only documented severe allocentric spatial memory deficits in individuals with WS, but also showed that these deficits are accompanied by facilitated spatial response learning.
We currently have on-going investigations to describe the ability of individuals with DS or WS to use self-generated movements (path integration) to construct egocentric and allocentric representations of their environment.