Junko Hatta

Developmental trajectories of verbal and visuospatial abilities in healthy older adults: Comparison of the hemisphere asymmetry reduction in older adults model and the right hemi-ageing model

Two models of cognitive ageing, the hemisphere asymmetry reduction in older adults (HAROLD) model and the right hemi-ageing model, were compared based upon the verbal memory and visuospatial task performance of 338 elderly participants. Comparison of the developmental trajectories for four age groups (50s, 60s, 70s and 80s) supported the HAROLD model, but not the right hemi-ageing model. Performance differences between the verbal memory and visuospatial tasks in the earlier age groups decreased in the later age groups. There was a sex difference in the cognitive-decline trajectories for verbal and visuospatial task performance after the 50s.

Sex Difference in Cognitive Aging for Letter Fluency and Semantic Fluency

This study examined the sex difference in cognitive aging for verbal abilities. To examine developmental changes on Letter Fluency (LFT) and Semantic Fluency (SFT) tests, healthy 224 women and 139 men over 40 years old participated in this study. The results showed that performance of both sex in the 40’s and 50’s remained at the same level, but the performance declining for the LFT and the SFT after the 70’s were not parallel. For the LFT, men showed a steep decline from 50’s to 70’s, whereas women showed a gradual decline from 50’s to 80’s. For the SFT, men showed a sharp decline from 50’s to 70’s and remained at a similar level after the 70’s, whereas women did not show a steep performance decline from their 50’s to 70’s and their performance level in 70’s was the same as in 80’s.

Developmental Changes of Prefrontal Cortex and Cerebro-Cerebellar Functioning in Older Adults: Evidence from Stabilometer and Cognitive Tests

The relation between cognitive and postural functioning was examined as developmental changes among healthy older adults. The 339 participants (207 women and 132 men) of four age groups (50’s, 60’s, 70’s, and 80’s) were given the Digit Cancellation Test (D-CAT) for the assessment of prefrontal cortex related cognitive functioning, and the Logical Memory Test for the assessment of fronto-parietal cortex related cognitive functioning. The postural functioning of the participants was measured by a stabilometer for the assessment of cerebro-cerebellar related motor functioning. The results showed that the developmental changes in performances for non-automatic intentional cognitive and automatic motor postural functioning were not parallel. Cognitive functioning did not show clear sex difference while motor postural functioning showed robust sex difference. Largely, cognitive functioning DCAT and Logical Memory Test showed gradual performance decrease 23-48% for each age group from 50’s to 80’s while robust motor postural functioning performance decreased approximately 60% from 70’s to 80’s in men and approximately 65% from 60’s to 70’s in women. Based upon these findings, characteristics of age-related changes in cerebro-cerebellar brain systems in middle aged and older healthy people are discussed.