The purpose of this study was to clarify the diurnal and seasonal variations in TAF.
The subjects were 5 healthy men aged 30-37 years old. The measurements of TAF were carried out from a.m. 5°30′ to p.m. 9°30′ at intervals of 4 hours and in this study, the examinee aimed at the target of the Takakura's apparatus for 15 minutes continuously in each time. TAF-L and -D were computed from the standardized curve and the coefficient of variation was computed from TAF-L and -D. The duration of concentration maintenance, which is the total duration of aiming level better than 2.5 in the standardized curve, was measured.
The experiments were made in July and in February on the same subjects.
The following results were obtained;
1) As the diurnal variation, it was observed that the mean regulatory range in the feed back system concerning with the target aiming became rough at 1°30′ p.m., but the relative reliability to exhibition of the feed back oscillation on this range became high.
2) As the seasonal variation, it was certain that the mean regulatory rane in the feed back system concerning with the target-aiming became more rough in summer than in winter, and that the hypofunction in the feed back system was remarkable on the afternoon in summer according to the observation of the duration held above the TAF-L of 2.5.