Funk Marion, Brugger Peter
Department of Neurology, University Hospital Zurich, Zurich, Switzerland.
J Int Neuropsychol Soc. 2008 Jan;14(1):81-9. doi: 10.1017/S1355617708080041.
We compared motor imagery performance of normally limbed individuals with that of individuals with one or both hands missing since birth (i.e., hand amelia). To this aim, 14 unilaterally and 2 bilaterally amelic participants performed a task requiring the classification of hands depicted in different degrees of rotation as either a left or a right hand. On the same task, 24 normally limbed participants recapitulated previously reported effects; that is, that the hand motor dominance and, more generally, a lifelong use of hands are important determinants of left-right decisions. Unilaterally amelic participants responded slower to hands corresponding to their absent, compared with their existing, hand. Moreover, left and right hand amelic participants showed prolonged reaction times to hands (whether left or right) depicted in unnatural orientations compared with natural orientations. Among the bilateral amelics, the individual with phantom sensations, but not the one without, showed similar differentiation. These findings demonstrate that the visual recognition of a hand never physically developed is prolonged, but still modulated by different rotation angles. They are further compatible with the view that phantom limbs in hand amelia may constrain motor imagery as much as do amputation phantoms.
我们将肢体正常的个体与自出生就缺失一只手或两只手（即无手畸形）的个体的运动想象表现进行了比较。为此，14名单侧无手畸形参与者和2名双侧无手畸形参与者完成了一项任务，该任务要求对以不同旋转角度呈现的手进行分类，判断是左手还是右手。在同一任务中，24名肢体正常的参与者重现了先前报道的效应；也就是说，手部运动优势，更普遍地说，一生对手的使用是左右判断的重要决定因素。单侧无手畸形参与者对与缺失手相对应的手的反应比对现存手的反应更慢。此外，与自然方向相比，左手和右手无手畸形参与者对以非自然方向呈现的手（无论是左手还是右手）的反应时间延长。在双侧无手畸形者中，有幻肢感觉的个体表现出了类似的差异，而没有幻肢感觉的个体则没有。这些发现表明，对从未实际发育过的手的视觉识别时间延长，但仍受不同旋转角度的调节。它们进一步支持了这样一种观点，即无手畸形中的幻肢对手部运动想象的限制可能与截肢后的幻肢一样大。
