Abstract
Experiments with the number selection task were executed to investigate effects of aging and time of testing. A trial of the task was constructed with 2 numbers of different sizes, and the instruction to which a participant responded to select the LARGER number ("SIZE" for physically larger one, or "NUM" for numerically larger one). Young and older adults in Tokyo (N=83) and Toronto (N=136) participated experiments, answering 48 consecutive trials on computer with touch-panel display. The correct ratio showed only effects of aging, with no effects of time of testing. In contrast, averages of reaction time showed interaction of two factors, indicating only older adults exhibited time of testing effects. In addition, reaction time of each item was affected by Task switching, instruction, and Congruent/Incongruent differently between with Japanese and Canadian participants. Performance of these cognitive controls will be discussed with various factors.
