The emergence of spatial rotation deficits in dementia and normal aging.

The mental rotation required in the Road Map Test of Direction Sense (the "Road Map Test"; J. Money, 1976; J. Money, D. Alexander, & H. T. Walker, 1965) has been thought to be impaired as a function of age, but not dementia. However, spatial rotation in dementia has not been investigated in reference to spatial coordinate systems. Patients with dementia (Alzheimer's and ischemic vascular dementias) and elderly control participants were administered the Road Map Test. The authors analyzed whether the geocentric or egocentric coordinate system determined rotation of Road Map Test turns and predicted impairment in dementia patients. They found equivalent impairment in both types of dementia, greater angulation effect in the geocentric system in patients relative to normal controls, and no egocentric effect. Results also suggest early emergence of spatial rotation deficit in dementia. Spatial rotation is most often associated with working memory, which predicts the correlations found.