[[alternative]]A Comparison between Table Tennis Players and Nonathletes on Premotor Time, Motor Time, and Reaction Time

[[abstract]]本研究主要在探討桌球運動員與非運動員，在三種不同提示警告訊號（中性、有效、無效）情境中前動作時間（premotor time,PMT）、動作時間（motor time,MT）與反應時間（reaction time,RT）之比較。實驗參與者是十七位我國男子甲組桌球選手與十六位一般大專男性學生。以雙極誘導方式將EMG電極置於雙手前臂紀錄反手推球動作啟動的肌電訊號。就本研究目的而言，採用EMG與RT資料做後續之分析處理。整段肌電資料以反應訊號為零點，前1000ms與後800ms做為完整的肌電資料之間隔，加以濾波處理後，記錄每個肌電啟動點作為RMT，將RT減去PMT，即可獲得 MT 之資料。以2x2x3（團體x雙手x情境）混合設計之三因子變異數分析進行統計處理。結果發現，就團體而言，運動員在PMT與RT皆快於非運動員。就雙手而言，非慣用手之PMT是快於慣用手，但在MT卻是慢於慣用手。在三種情境裡，PMT、MT以及RT均是有效最快，中性次之，無效最慢。本研究結果顯示：（1）運動員在面臨不確定性高的情境中，其中樞傳導訊息的能力速度及反應時間均較非運動員快。（2）當非慣用手面臨不確定訊息需作反應時，肌肉因不熟悉的反應動作而表現在MT上，但個體覺醒水平與大腦中樞的補償機制則互補性的顯現來避免反應遲緩，故整體的RT因PMT而顯得與慣用手相當。（3）三情境中，因有效情境所提供的警告訊息充分引導參與者注意力的方向準備，故其PMT、MT與RT均為最短。 This study was to examine premotor time, motor time, and reaction time of two hands for athletes and nonathletes in three conditions (i.e., neutral, valid, and invalid) with information cues. Seventeen pre-elite table tennis players and 16 sedentary counterparts were recruited for this study. EMG of response hand was recorded with bipolar electrodes placed below elbow of both hands. The filter band-pass was 0.05-100Hz. The signal of EMG was sampled at 500Hz and was rectified to identify the time of onset. A visual1y cued reaction time task that has been used in a previous study was used in the current study. In addition to premotor time that is the internal signal between the presentation of imperative stimulus and the onset of EMG, reaction time and motor time were also measured. 3-way mixed designed ANOVAs were performed on each dependent variable, separately. The results showed significant differences on three dependant variables except motor time of groups and reaction time of hands. The interaction effects were found on hands and conditions of premotor time and motor time. The results of the current study suggest that athletes were quicker in processing information in the cued attention task, but this enhanced processing ability was limited to central process only as reflected by premotor time. When response hands were compared, the unfamiliarity of nondominant hand to task resulted in a central compensatory mechanism to prevent from delayed response.[[notice]]補正完