Biomedical subjects

Shingo Oda

Publications and source records attributed to Shingo Oda.

8 recordsLinked to original sources

PubMed2006

Tapping speed asymmetry in drummers for single-hand tapping with a stick.

The purpose of this study was to investigate tapping speed asymmetry in 13 right-handed drummers and 13 right-handed nondrummers. The participants executed single-hand tapping with a stick as fast as possible for 10 sec. with the left and right hand. There was no significant difference in the tapping speed of the right hand between the drummers and the nondrummers, whereas in the left hand, the drummers tapped significantly faster than the nondrummers. Drummers showed less tapping speed asymmetry than nondrummers. These results suggest that the tapping speed of the nonpreferred hand progressed nearly to the level of the preferred hand through daily drum training.

Acceleration↗

PubMed2005

Effect of joint angle on mechanomyographic amplitude during unfused and fused tetani in the human biceps brachii muscle.

The influence of muscle length-dependent changes in contractile properties on the mechanomyogram (MMG) was investigated during evoked contractions of the biceps brachii muscle. The biceps of nine healthy subjects was stimulated by single twitches, unfused (10 Hz), and fused (30 Hz) frequencies at elbow joint angles of 75, 90, 105, 120, 135, and 150 degrees. During evoked contractions, the longitudinal movement was estimated by the fluctuation of torque signal, and the lateral movement was detected by MMG. Contraction time and half relaxation time were calculated from the single twitches. For repetitive stimulations, followed by eliminating DC component from torque signals, the root mean square values calculated from the torque and MMG signals, which were torque fluctuation and RMS-MMG, respectively. For the 10 Hz stimulation condition, reductions in the torque fluctuation and RMS-MMG were concomitantly observed with increasing elbow angle, and there was a significant correlation between the torque fluctuation and RMS-MMG. On the other hand, for 30 Hz stimulation, there were no significant differences in the torque fluctuation and RMS-MMG over all elbow angles, and no significant correlation between the two parameters. Moreover, the torque fluctuation and RMS-MMG for 10 Hz stimulation were correlated with the contraction time and half relaxation time obtained at each elbow angle, while there were no correlations for the 30 Hz condition. These data suggest that MMG could be a reliable tool to study the development of fusion and the changes in muscle contractile properties during repetitive unfused contractions.

Adult↗

PubMed2005

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 40 W for 3 min, increasing by 40 W every 3 min until 240 W in a step-wise manner. During incremental exercise, RT measurements were performed 1 min and 30 s 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 240 W, negatively correlated with maximal oxygen uptake VO(2max) 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.

Adult↗

PubMed2005

Intensive baseball practice improves the Go/Nogo reaction time, but not the simple reaction time.

Baseball hitters are required to make decisions whether to swing or not as quickly as possible. Therefore, we can assume that skilled baseball players have a quicker response. To verify this hypothesis, we assessed the effect of baseball experience or skill levels on simple reaction times and Go/Nogo reaction times in 82 university students (22 baseball players, 22 tennis players, and 38 nonathletes) and 17 professional baseball players. Also, to clarify whether this ability was innate or acquired, we examined the effects of long-term practice for baseball hitting in 94 senior high school students (26 baseball players and 68 non-baseball players). There were no differences in simple reaction time either for sports experience or for skill levels. On the contrary, the Go/Nogo reaction time for baseball players was significantly shorter than that of the tennis players and nonathletes. The Go/Nogo reaction time of higher-skill baseball players was significantly shorter than that of lower-skill players, while that of the professional baseball players was the shortest. The professional players showed the highest (almost linear) correlation between the Go/Nogo reaction time and simple reaction time. A longitudinal study showed that 2 years of hitting practice improved the Go/Nogo reaction time, while the simple reaction time remained constant. A cross-sectional study of high school non-baseball players showed no differences either in the simple or Go/Nogo reaction times in relation to school year. In conclusion, intensive practice, including Go or Nogo decision making, improved the Go/Nogo reaction time, but not the simple reaction time.

Adult↗

PubMed2004

Retention of practice effects on simple reaction time for peripheral and central visual fields.

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.

Adult↗

PubMed2003

Mechanomyographic and electromyographic responses of the triceps surae during maximal voluntary contractions.

The objective of this study was to examine the effect of joint angle on the electromyogram (EMG) and mechanomyogram (MMG) during maximal voluntary contraction (MVC). Eight subjects performed maximal isometric plantar flexor torque productions at varying knee and/or ankle angles. Maximal voluntary torque, EMG, and MMG from the soleus (Sol), medial (MG) and lateral gastrocnemius (LG) muscles were measured at different joint angles. At varying knee angles, the root mean squared (rms) MMG amplitude of the MG and LG increased with knee joint extension from 60 degrees to 180 degrees (full extension) in steps of 30 degrees, whereas that of the Sol was constant. At varying ankle angles, the rms-MMG of all muscles (Sol, MG, and LG) decreased with torque as ankle joint extending from 80 degrees (10 degrees dorsiflexion position) to 120 degrees (30 degrees plantar flexion position) in steps of 10 degrees. In each case, changes in the rms-MMG of the three muscles were almost parallel to those in torque. In contrast, there were no significant differences in the rms-EMG of all muscles among all joint angles. Our data suggest that the MMG amplitudes recorded from individual muscles during MVCs can represent relative torque-angle relationships that cannot be represented by the EMG signals.

Adult↗

PubMed2002

Practice effects on reaction time for peripheral and central visual fields.

The present study examined whether EMG-RT (RT) 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 system's processing time in common between two RT tasks.

Adult↗

PubMed2002

Attention can be oriented to intermediate locations within the large area of the visual field.

The present study examined whether attention can be evenly distributed within the large area of the visual field. The stimulus was presented at one of four locations on the horizontal meridian (0 degrees, 10 degrees, 20 degrees, and 30 degrees to the right). In the Fixed Location condition, the stimulus appeared repeatedly at the same location. In the Random Location condition, the stimulus appeared at one of four locations as determined randomly with equal probability. Reaction times (RTs) in the Random Location condition were significantly longer than those in the Fixed Location condition at the 0 degrees and 30 degrees locations, while there were no significant differences at the 10 degrees and 20 degrees locations. The differences in the RT between conditions were significantly larger at the 0 degrees and 30 degrees locations than those at the 10 degrees and 20 degrees locations. These results suggest that attention was oriented to intermediate locations within the large area of the visual field.

Adult↗