兒童手側化之發展

Handedness Development in Childen

本研究採橫貫調查方式，針對四至十二歲共九個年級的744位普通學童進行手側化特質的瞭解，研究者使用由家長填寫的本土兒童手側化量表做為主要研究工具，該量表含二因素並已建立良好的信效度，於回收家長填寫的手側化量表後進行資料分析。本研究得到兩個主要的研究結果，分別為（1）手側化商數於四歲與五歲兒童組均明顯低於大班以上兒童，（2）因素一活動（「精細/多步驟」）的平均商數值於各年級均明顯高於因素二活動（「簡易/單步驟」）。
兒童右手偏側化比例在小學一年級才偏高與穩定，可能反映著（1）大班開始所從事的活動傾向複雜與精細化，因此使用慣用手的比例逐漸增加，（2）大班時寫字機會增多，導致慣用手的決定受社會壓力影響機會增多，以及（3）大班階段大腦側化的穩定性開始成熟。因素一商數比因素二高的現象反映出活動情境特性對於決定使用哪隻手具有影響力，從事「精細/多步驟」活動時傾向使用慣用手， 而執行「簡單/單步驟」活動時的偏側化趨勢則降低，從事精細多步驟活動時更需要持續的視覺參與， 導致慣用手的使用機會提升。

The characteristics of handedness were surveyed in 744 4-to 12-year-old typical children, using a 14-item questionnaire answered by the parents. The questionnaire included two factors, sequenced/complex and non-sequenced/simple tasks. Results demonstrated 4 and 5-year-old were lower scored and less right handed than other groups and the factor I tasks were more right lateralized than factor II tasks. Less right lateralized in 4-and 5-year-old reflects the year in the senior class of kindergarten (6-year-old) is the most critical period in the process of establishing stable hand preference. More opportunities to engage in complex activities, more social stress and more stable hemispheric lateralization in this 6-year-old group are important factors contributing to this phenomenon. The higher laterality quotient on factor I tasks than factor II tasks for all ages indicates activity context may critically influence manual preference for action. Besides, the more continual visual guidance needed while engaging in factor I tasks may facilitate the use of the preferred hand to meet the demand of task complexity.