Bathurst K, Kee D W
Department of Psychology, California State University, Fullerton 92634.
Brain Cogn. 1994 Jan;24(1):123-36. doi: 10.1006/brcg.1994.1007.
Verbal cerebral asymmetry was examined in 96 right- and left-handed college students using dual-task methods. The manual task was finger-tapping; verbal tasks were anagram-solution in silent and aloud conditions; nonverbal tasks were solution of Raven's Progressive Matrices and forms memory. Both handedness groups were sensitive to the task manipulation, i.e., verbal tasks produced a significant change in tapping rate from a no-change rate of zero; nonverbal tasks produced no significant change in tapping rate. Right-handers experienced the expected asymmetric manual performance indicative of left-hemisphere language laterality. Left-handers as a group experienced no asymmetric pattern but rather a percentage decrease in both hands which suggested bilateralization of language functions. Only when examining manual performance patterns within specific left-handed subpopulations (composed of a complete crossing of handwriting posture, familial sinistrality, and sex) did laterality patterns emerge. Specifically, asymmetric manual performance was found only in familial sinistral inverted posture females. Results demonstrate the advantage of controlling for subject characteristics when assessing cerebral laterality in left-handers.
采用双任务方法对96名右利手和左利手大学生的言语脑不对称性进行了研究。手动任务是手指敲击；言语任务是在安静和出声条件下解变位词；非言语任务是解决瑞文渐进性矩阵问题和图形记忆。两个利手组都对任务操作敏感，即言语任务使敲击速率从不变的零速率产生了显著变化；非言语任务使敲击速率没有显著变化。右利手表现出预期的不对称手动表现，表明左半球语言优势。左利手群体没有表现出不对称模式，而是双手敲击速率都有一定比例的下降，这表明语言功能双侧化。只有在检查特定左利手亚群体（由书写姿势、家族性左利手和性别完全交叉组成）的手动表现模式时，才出现了优势模式。具体而言，仅在家族性左利手、书写姿势相反的女性中发现了不对称手动表现。结果表明，在评估左利手的脑优势时，控制受试者特征具有重要意义。
