Soichi Ando

CENTRAL AND PERIPHERAL VISUAL REACTION TIME OF SOCCER PLAYERS AND NONATHLETES

Visual Reaction Time (RT) was measured by presenting three different sizes of stimulus to the central and peripheral fields of vision in 6 soccer players and 6 nonathletes. An electromyogram was recorded from the flexor digitorum superficialis muscle of the responding forearm. Peripheral visual RT was longer in comparison to central visual RT due to an increment in Premotor Time. The soccer players showed shorter Premotor Times during central and peripheral visual RT tasks than nonathletes, suggesting that the soccer players are better able to respond quickly to a stimulus presented to peripheral as well as central positions.

Practice Effects on Reaction Time for Peripheral and Central Visual Fields

The present study examined whether EMG-RT (KT) for a key press to stimulus in peripheral and central visual fields decreases with practice. 16 male students were divided into two groups, one practicing using peripheral vision, the other practicing using central vision. Before and after practice, RT was measured for peripheral and central visual fields. Each group practiced three blocks of 25 trials five days a week for three weeks. RT for peripheral and central visual fields decreased with practice. Practice effects on RT for the peripheral visual field extended to RT for the central visual field, and vice versa. It is suggested that the transfer may reflect the decrease in the central nervous systems processing time in common between two RT tasks.

Increase in reaction time for the peripheral visual field during exercise above the ventilatory threshold.

The purpose of the present study was to determine whether reaction time (RT) for the peripheral visual field increases at exercise intensity above the ventilatory threshold (VT) during incremental exercise and to examine the relationship between aerobic capacity and the extent of increase in the RT. Nine healthy subjects performed a simple manual RT task for the peripheral visual field at rest, during exercise on a cycle ergometer, and immediately after exercise. After warm-up exercise, the subjects cycled at 40xa0W for 3xa0min, increasing by 40xa0W every 3xa0min until 240xa0W in a step-wise manner. During incremental exercise, RT measurements were performed 1xa0min and 30xa0s after the start of every increase in workload. The RT for the peripheral visual field significantly increased at exercise intensity above VT, as compared with at rest. The increase in the RT, which was calculated by subtracting the RT at rest from the RT at 240xa0W, negatively correlated with maximal oxygen uptake

Retention of Practice Effects on Simple Reaction Time for Peripheral and Central Visual Fields

left( {dot V{text{O}_{2 max}}} right)

Attention Can Be Oriented to Intermediate Locations within the Large Area of the Visual Field

for each subject (r=−0.73, P<0.05). It is likely that high aerobic capacity attenuates the increase in the RT for the peripheral visual field during exhaustive exercise.

Effects of strenuous exercise on visual perception are independent of visual resolution

Bioelectrical impedance analysis (BIA) is an affordable, non-invasive, easy-to-operate, and fast alternative method to assess body composition. However, BIA tends to overestimate the percent body fat (%BF) in lean elderly and underestimate %BF in obese elderly people. This study examined whether proximal electrode placement eliminates this problem. Forty-two elderly men and women (64–96xa0years) who had a wide range of BMI [22.4xa0±xa03.3xa0kg/m2 (meanxa0±xa0SD), range 16.8–33.9xa0kg/m2] and %BF (11.3–44.8%) participated in this study. Using 2H and 18O dilutions as the criterion for measuring total body water (TBW), we compared various BIA electrode placements; wrist-to-ankle, arm-to-arm, leg-to-leg, elbow-to-knee, five- and nine-segment models, and the combination of distal (wrists or ankles) and proximal (elbows or knees) electrodes. TBW was most strongly correlated with the square height divided by the impedance between the knees and elbows (H2/Zproximal; rxa0=xa00.965, Pxa0<xa00.001). In the wrist-to-ankle, arm-to-arm, leg-to-leg, and five-segment models, we observed systematic errors associated with %BF (Pxa0<xa00.05). After including the impedance ratio of the proximal to distal segments (P/D) as an independent variable, none of the BIA methods examined showed any systematic bias against %BF. In addition, all methods were able to estimate TBW more accurately (e.g., in the wrist-to-ankle model, from R2xa0=xa00.90, SEExa0=xa01.69xa0kg to R2xa0=xa00.94, SEExa0=xa01.30xa0kg). The results suggest that BIA using distal electrodes alone tends to overestimate TBW in obese and underestimate TBW in lean subjects, while proximal electrodes improve the accuracy of body composition measurements.

Vegetation and Climate of the Summit Zone of Mount Kinabalu in Relation to the Walker Circulation

Previous researchers reported that EMG Reaction Time (RT) for a key press in peripheral and central visual fields decreases with practice. The practice effects on the RT for peripheral visual field transferred to the RT for the central visual field, and vice versa. The present study investigated whether practice effects on the RT for peripheral and central visual fields and the corresponding transfer effects lasted 3 wk. or not. 16 male subjects were divided into two groups, one practicing using peripheral vision, the other practicing using central vision. Each group practiced RT tasks for 3 wk. 3 wk. after practice terminated, the practice effects and the transfer effects were maintained as a significant decrease in RT was found over the 3-wk. retention interval, suggesting that once the neural correlates of responding quickly are improved, the improved performances are remarkably stable for at least 3 wk.

Development of SSR markers for the tropical alpine tree species Leptospermum recurvum (Myrtaceae) on Mount Kinabalu in Borneo

The purpose of this study was to test if increased oxygen availability affected simple reaction time (RT) to peripheral visual stimuli during exercise. Twelve male participants performed RT tasks at rest, during cycling with three different workloads (100, 150, and 200xa0W), and after exercise. We fractionated RT into Premotor time and Motor time. Under normoxia, Premotor time significantly increased during exercise at 200xa0W (meanxa0±xa0SD, 224.7xa0±xa034.8xa0ms) relative to that at rest (213.3xa0±xa034.1xa0ms) (Pxa0<xa00.05). In contrast, we found no difference in Premotor time between at rest (214.0xa0±xa027.0xa0ms) and at 200xa0W (213.0xa0±xa021.6xa0ms) under hyperoxia. Furthermore, Premotor time significantly decreased at 150xa0W (201.3xa0±xa022.4xa0ms) relative to that at rest under hyperoxia (Pxa0<xa00.05). These results suggest that increased oxygen availability during exercise has beneficial effects on perceptual performance.