Abstract
Handedness difference in the age-related cognitive decline was examined. Participants were healthy middle aged left-handed (n = 22, 10 men and 12 women) and right-handed (22 men and 56 women). Digit cancellation performance decline ratios were calculated by the longitudinal Digit Cancellation Test data with an interval of 10 years. Performance decline ratios were compared for handedness and sex concerning to D-CAT1 (1-digit cancellation condition) and D-CAT3 (3-digits cancellation condition) performances. The results indicated first that the performance decline ratio in the left-handed was significantly larger than that in the right-handed both in D-CAT1 and D-CAT3, suggestive of low aging tolerance of executive function in left-handed people. Moreover, there was a significant sex difference such that men demonstrated a larger decline in D-CAT3, which demands more considerable cognitive resources, compared to D-CAT1, whereas this was not observed in women. Possible executive function mechanisms during aging were discussed in relation to handedness and sex.