Foundas A L, Hong K, Leonard C M, Heilman K M
Department of Psychiatry and Neurology, Tulane University School of Medicine, Veterans Affairs Medical Center, New Orleans, Louisiana 70112-2632, USA.
Neuropsychiatry Neuropsychol Behav Neurol. 1998 Apr;11(2):65-71.
Hand preference is perhaps the most evident behavioral asymmetry observed in humans. Anatomic brain asymmetries that may be associated with hand preference have not been extensively studied, and no clear relationship between asymmetries of the motor system and hand preference have been established. Therefore, using volumetric magnetic resonance imaging methodologies, the surface area of the hand representation was measured along the length of the central sulcus in 15 consistent right- and 15 left-handers matched for age and gender. There was a significant leftward asymmetry of the motor hand area of the precentral gyrus in the right-handers, but no directional asymmetry was found in the left-handers. When asymmetry quotients were computed to determine the distribution of interhemispheric asymmetries, the left motor bank was greater than the right motor bank in 9 of 15 right-handers, the right motor bank was greater than the left motor bank in 3 of 15 right-handers, and the motor banks were equal in 3 of 15 right-handers. In contrast, among left-handers, the left motor bank was greater than the right motor bank in 5 of 15, the right motor bank was greater than the left motor bank in 5 of 15, and the motor banks were equal in 5 of 15. Although no direct measure of motor dexterity and skill was performed, these data suggest that anatomic asymmetries of the motor hand area may be related to hand preference because of the differences in right-handers and left-handers. Furthermore, the predominant leftward asymmetry in right-handers and the random distribution of asymmetries in the left-handers support Annett's right-shift theory. It is unclear, however, whether these asymmetries are the result of preferential hand use or are a reflection of a biologic preference to use one limb over the other.
用手偏好可能是人类中观察到的最明显的行为不对称现象。可能与用手偏好相关的大脑解剖学不对称尚未得到广泛研究，并且运动系统的不对称与用手偏好之间尚未建立明确的关系。因此，使用容积磁共振成像方法，在15名年龄和性别匹配的惯用右手者和15名惯用左手者中，沿着中央沟的长度测量了手部代表区的表面积。在惯用右手者中，中央前回的运动手区存在显著的向左不对称，但在惯用左手者中未发现方向不对称。当计算不对称商以确定半球间不对称的分布时，15名惯用右手者中有9名左运动区大于右运动区，15名惯用右手者中有3名右运动区大于左运动区，15名惯用右手者中有3名运动区相等。相比之下，在惯用左手者中，15名中有5名左运动区大于右运动区，15名中有5名右运动区大于左运动区，15名中有5名运动区相等。虽然没有对运动灵活性和技能进行直接测量，但这些数据表明，由于惯用右手者和惯用左手者的差异，运动手区的解剖学不对称可能与用手偏好有关。此外，惯用右手者中主要的向左不对称以及惯用左手者中不对称的随机分布支持了安妮特的右移理论。然而，尚不清楚这些不对称是优先使用手的结果还是使用一侧肢体而非另一侧的生物学偏好的反映。
