The effect of elastic-taping on long-latency somatosensory evoked potentials (SEPs) / 体力科学

Taping is widely used by sports trainers to prevent injury and to protect affected sites post-injury. However, it is not clear whether taping affect the perception of somatosensory stimulation. We sought to clarify the effect of taping on somatosensory stimulation using somatosensory evoked potentials (SEPs). We recorded SEPs following transcutaneous electrical stimulation of the right medial forearm in ten healthy volunteers. SEPs were recorded from 9 electrodes on the scalp under control, elastic-taping and white-taping conditions. Subjects relaxed on a comfortable reclining seat without taping in the control condition, while they were subjected to taping along the muscle of forearm with tension (elastic-taping) and without tension (white-taping) in the taping conditions. Results showed that the peak amplitude of N140 did not differ significantly among the three conditions but the peak amplitude of P250 was significantly lower in the elastic-taping condition than control and white-taping conditions. Elastic-taping with tension along the muscles changes various afferent inputs from muscle spindle or skin, and this may affect the perception of somatosensory stimulation.

The change of event-related potentials with choice task / 体力科学

Event-related potentials (ERPs) were recorded from 9 normal subjects engaged in a somatosensory target discrimination task. Subjects were instructed (1) to keep a mental count of each target or (2) to rotate a grip in the direction of abduction after each target stimulus using the right hand. Target stimuli were electrical pulses delivered randomly through ring electrodes to the left second digit with probabilities of 0.2, and nontarget stimuli were delivered to the left fifth digit with probabilities of 0.8.<BR>P 100 was prominent in somatosensory tasks, and had a widespread distribution on the scalp without having any relation to kinds of tasks, therefore, P 100 reflects the sensation of somatosensory stimulation. N 140 was largest at Fz in both counting and movement tasks, so our result supported the hypothesis that N 140 is generated in the frontal lobes regions. Moreover, N 140 latency was shorter during movement than during counting. These results indicate that N 140 is related to carrying out movement. P 300 was largest at Cz during counting, and largest at Pz and C4' during movement. These results also indicate that P 300 may have multiple intracerebral generators since P300 origin differs based on the kind of tasks or stimuli. In addition, the appearance of P300 after nontarget stimuli indicates that P 300 reflects a non-selective postdecision closure of cognitive activity. In conclusion, each component of ERPs may have a specific origin and specific characteristics.