Functional organization of primary somatosensory cortex depends on the focus of attention
Functional organization of primary somatosensory cortex depends on the focus of attention
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DOI：
10.1006/nimg.2002.1277
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发表时间：
2002-11-01
期刊：
影响因子：
5.7
通讯作者：
Roberts, LE
中科院分区：
文献类型：
--
作者：
Braun, C;Haug, M;Roberts, LE
我们在人类受试者中使用磁源成像来揭示由注意力调节的初级体感皮层内的侏儒手表征在受试者内部的变化。在一种条件下，受试者被训练检测左手手指上连续向左或向右的刺激运动（“手”条件），在另一种条件下，受试者被训练检测这只手上特定手指上的刺激运动（“手指”条件）。传入输入是通过对两个任务中的数字施加完全相同的刺激模式来控制的。随着练习的开始，相对于手的状况，在手指上观察到躯体性手表征的分离（数字2和数字5表征之间距离的增加）。随后在手部和手指条件下的训练并没有改变隔离，这表明隔离是一种任务效应，而不是训练效应。这些发现表明，初级体感皮层中的手表征不是静态固定的，而是由自上而下的机制动态调节的，以支持任务要求。大脑皮层功能组织调节能力越强，学习和任务表现越好。(C) 2002 Elsevier Science （USA）。
We used magnetic source imaging in human subjects to reveal within-subject variations of the homuncular hand representation within the primary somatosensory cortex modulated by attention. In one condition subjects were trained to detect sequential leftward or rightward stimulus motion across the fingers of the left hand ("hand" condition) and in a different condition to detect stimulus motion at a specific finger on this hand ("finger" condition). Afferent input was controlled by applying exactly the same stimulus pattern to the digits in the two tasks. Segregation of the somatotopic hand representation (an increase in the distance between the representations of digits 2 and 5) was observed, commencing with the onset of practice, in the finger relative to the hand condition. Subsequent training in the hand and finger conditions with feedback for correctness did not modify segregation, indicating that segregation was a task effect and not a training effect. These findings indicate that the hand representation within the primary somatosensory cortex is not statically fixed but is dynamically modulated by top-down mechanisms to support task requirements. A greater capacity for modulation of the functional cortical organization was positively correlated with superior learning and task performance. (C) 2002 Elsevier Science (USA).