One of the overriding hopes of the Down syndrome (DS) research community is to arrive at a better understanding of how trisomy 21 affects brain development and function, and that doing so will improve quality of life and independence for people with DS. In searching for the underlying causes of intellectual disability in DS, researchers and clinicians have studied how changes to genes and cells may relate to motor and cognitive function. Thus far, alterations in many areas of the central nervous system have been found and it is now known that, beginning before birth, different changes occur in different areas over the course of life. Because of these spatial and temporal variations, multiple approaches for addressing motor and cognitive function must be considered.