Ghahramani Z, Wolpert D M, Jordan M I
Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
J Neurosci. 1996 Nov 1;16(21):7085-96. doi: 10.1523/JNEUROSCI.16-21-07085.1996.
During visually guided movement, visual representations of target location must be transformed into coordinates appropriate for movement. To investigate the representation and plasticity of the visuomotor coordinate transformation, we examined the changes in pointing behavior after local visuomotor remappings. The visual feedback of finger position was limited to one or two locations in the workspace, at which a discrepancy was introduced between the actual and visually perceived finger position. These remappings induced changes in pointing, which were largest near the locus of remapping and decreased away from it. This pattern of spatial generalization highly constrains models of the computation of the visuomotor transformation in the CNS. A simple model, in which the transformation is computed via the population activity of a set of units with large sensory receptive fields, is shown to capture the observed pattern.
在视觉引导的运动过程中,目标位置的视觉表征必须转换为适合运动的坐标。为了研究视觉运动坐标转换的表征和可塑性,我们在局部视觉运动重新映射后检查了指向行为的变化。手指位置的视觉反馈被限制在工作空间中的一两个位置,在这些位置引入了实际手指位置与视觉感知手指位置之间的差异。这些重新映射引起了指向的变化,在重新映射的位置附近变化最大,远离该位置则减小。这种空间泛化模式对中枢神经系统中视觉运动转换计算的模型有高度限制。一个简单的模型显示,通过一组具有大感觉感受野的单元的群体活动来计算转换,可以捕捉到观察到的模式。