Perceptual speed or executive function in aging

In relation to BP-related effects on cognitive changes in elderly people, Bucur and Madden (2010) proposed that age-related effects associate more closely with complex abilities such as executive function than with elementary perceptual speed. In this study, the validity of their proposal was examined using Yakumo study longitudinal data. From the database, linear regression coefficients (slope) in D-CAT (digit cancelation test) results from 65 to 75 years old were calculated. In this study, data of participants who had been assessed D-CAT at least 4 times for 11 years period were analyzed. Participants were assigned into two groups (sustain group whose mean regression coefficient was more than -0.05 in the D-CAT1 condition, and decline group whose mean regression coefficient was less than -0.05 in the D-CAT1 condition). Comparisons of mean regression coefficients in the D-CAT1 and the D-CAT3 conditions showed that the declining slope in D-CAT3 was significantly more prominent than that of in D-CAT1 in the sustain group. Number of participants who showed more prominent decline slope in D-CAT3 than in D-CAT1 was significantly large. The results for the decline group showed no clear difference in regression coefficients between the D-CAT1 and the D-CAT3. These results support the proposal by Bucur and Madden (2010) that cognitive aging affects more frontal lobe-dependent aspects of measures, and then the decline becomes more pronounced in the D-CAT3 than in the D-CAT1.