Relationships between footedness and aging on postural control: Evidence from the Yakumo study.

ABSTRACTThe effects of footedness and aging on postural maintenance function were examined in this study. Using the postural maintenance task, the trajectories of the centre of pressure (COP) were measured with a stabilometer in the lateral and posterior/anterior directions. One hundred and ninety-three right-footers (112 middle-aged: 40-64 years old and 81 old-aged: 65-80 years old) and thirty-two left-footers (14 middle-aged and 18 old-aged) among healthy community members participated in this study. Using the ratio of the COP deviation area sizes for the open- vs. closed-eye conditions as an index, the ratios in the lateral and the posterior/anterior directions were compared in relation to the footedness and the age groups. The results indicated that the left-footers of the older adults group showed a larger COP deviation ratio than that of the middle-aged group, and the left-footers showed a larger deviation ratio in the lateral direction than in the posterior-anterior direction. These findings suggest a weak postural maintenance function of the older adults left footers. As most left-footers are left-handed, health promotion staff should notice that older adults who are left-handers are at a higher risk of falling.

Relation between cognitive and cerebello-thalamo-cortical functions in healthy elderly people: Evidence from the Yakumo Study.

Relations between cognitive and cerebello-thalamo-cortical functions in healthy elderly people (65-75 years old) were examined by longitudinal behavioral data. Based on the individually calculated cognitive decline ratio in D-CAT (digit cancelation test) and in LMT (Logical Memory Test) during the period of 11 years, participants were classified into the Decline and the Maintain groups and group differences in the postural tremor measures (Quotient of Romberg) were compared. Significant group differences were shown in the postural tremor measure in D-CAT that reflects prefrontal function, but it was not the case in LMT. These results strengthened our previous findings that suggest a strong relation between the cerebello-thalamo-cortical function and the prefrontal cortex function using behavioral measures. Findings provide evidence that to strengthen postural function such as physical exercise is effective for slowing cognitive decline with age.

Visual Search Load Effects on Age-Related Cognitive Decline: Evidence From the Yakumo Longitudinal Study.

The validity of Bucur and Madden's (2010) proposal that an age-related decline is particularly pronounced in executive function measures rather than in elementary perceptual speed measures was examined via the Yakumo Study longitudinal database. Their proposal suggests that cognitive load differentially affects cognitive abilities in older adults. To address their proposal, linear regression coefficients of 104 participants were calculated individually for the digit cancellation task 1 (D-CAT1), where participants search for a given single digit, and the D-CAT3, where they search for 3 digits simultaneously. Therefore, it can be conjectured that the D-CAT1 represents primarily elementary perceptual speed and low-visual search load task. whereas the D-CAT3 represents primarily executive function and high-visual search load task. Regression coefficients from age 65 to 75 for the D-CAT3 showed a significantly steeper decline than that for the D-CAT1, and a large number of participants showed this tendency. These results support the proposal by Brcur and Madden (2010) and suggest that the degree of cognitive load affects age-related cognitive decline.

A potential biomarker for fatigue: Oxidative stress and anti-oxidative activity.

We sought to determine whether oxidative stress and anti-oxidative activity could act as biomarkers that discriminate patients with chronic fatigue syndrome (CFS) from healthy volunteers at acute and sub-acute fatigue and resting conditions. We calculated the oxidative stress index (OSI) from reactive oxygen metabolites-derived compounds (d-ROMs) and the biological antioxidant potential (BAP). We determined changes in d-ROMs, BAP, and OSI in acute and sub-acute fatigue in two healthy groups, and compared their values at rest between patients with CFS (diagnosed by Fukuda 1994 criteria) and another group of healthy controls. Following acute fatigue in healthy controls, d-ROMs and OSI increased, and BAP decreased. Although d-ROMs and OSI were significantly higher after sub-acute fatigue, BAP did not decrease. Resting condition yielded higher d-ROMs, higher OSI, and lower BAP in patients with CFS than in healthy volunteers, but lower d-ROMs and OSI when compared with sub-acute controls. BAP values did not significantly differ between patients with CFS and controls in the sub-acute condition. However, values were significantly higher than in the resting condition for controls. Thus, measured of oxidative stress (d-ROMS) and anti-oxidative activity (BAP) might be useful for discriminating acute, sub-acute, and resting fatigue in healthy people from patients with CFS, or for evaluating fatigue levels in healthy people.

[Relations among higher brain function, trust, and gullibility in middle-aged and elderly people].

In this study, we examined the relationships among higher brain function, trust or distrust, and gullibility in middle-aged and elderly people. It has been pointed out that the trust can be regarded the psychological frame of automatic processing in decision-makinig. The participants were 309 rural community dwellers (127-males and 182 females) whose mean age was 64.9 years old (SD = 9.9). The trust scale of Amagai (1997) and the Nagoya University Cognitive Assessment Battery were used to measure sense of trust and higher brain function, respectively. Gullibility was measured by self-report using two items. Correlation analyses showed that higher brain function positively correlated with degree of trust in others and negatively correlated with distrust. However, regression analysis demonstrated that only the relationship between category fluency and distrust was significant. Furthermore, the degree of distrust positively correlated with gullibility.

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.