Dissociation of Measures of Topographical and Non-topographical Cognitive Ability in Older Adults

The relationship between topographical and non-topographical cognitive measures was studied for 25 elderly participants. The topographical measures were the Camden Topographical Recognition Memory Test (CTRMT), a Topographical Mental Rotation Test (TMRT), and a Virtual Pond Maze (VPM). The non-topographical tests were the Montreal Cognitive Assessment (MoCA), the Trail-Making Test-B (TMT-B), and a matching-to-sample Visual Short-Term Memory Test (VSMT). Only the correlation (0.48) between the TMT-B and the TMRT attained significance; the bivariate correlations among the three topographical measures were modest, ranging from 29 to 33, although they did correlate highly with a topographic composite score (0.69-0.78). A factor analysis yielded a further distinction between the topographical and non-topographical measures. Loadings for the three topographical measures on a presumed “topographical” factor ranged from 0.62 to 0.71 but only from 0.17 to 0.23 for the second factor. The MoCA and TMT-B loaded on both factors, while the VSMT measure loaded poorly (-0.03) on the topographical factor but highly (0.89) on the second factor. The results suggest that standard measures of cognitive function may not be optimal for specific assessment of topographical abilities, the best predictor of impending Alzheimer’s dementia.