Laboratorium voor Neuro- en Psychofysiologie, Katholieke Universiteit Leuven, Leuven, Belgium.
J Neurophysiol. 2012 Feb;107(3):995-1008. doi: 10.1152/jn.00248.2011. Epub 2011 Nov 16.
The macaque anterior intraparietal area (AIP) is crucial for visually guided grasping. AIP neurons respond during the visual presentation of real-world objects and encode the depth profile of disparity-defined curved surfaces. We investigated the neural representation of curved surfaces in AIP using a stimulus-reduction approach. The stimuli consisted of three-dimensional (3-D) shapes curved along the horizontal axis, the vertical axis, or both the horizontal and the vertical axes of the shape. The depth profile was defined solely by binocular disparity that varied along either the boundary or the surface of the shape or along both the boundary and the surface of the shape. The majority of AIP neurons were selective for curved boundaries along the horizontal or the vertical axis, and neural selectivity emerged at short latencies. Stimuli in which disparity varied only along the surface of the shape (with zero disparity on the boundaries) evoked selectivity in a smaller proportion of AIP neurons and at considerably longer latencies. AIP neurons were not selective for 3-D surfaces composed of anticorrelated disparities. Thus the neural selectivity for object depth profile in AIP is present when only the boundary is curved in depth, but not for disparity in anticorrelated stereograms.
猕猴前顶内沟区（AIP）在视觉引导抓取中至关重要。AIP 神经元在现实世界物体的视觉呈现期间做出反应，并对视差定义的曲面的深度轮廓进行编码。我们使用刺激简化方法研究了 AIP 中曲面的神经表示。刺激物由沿着水平轴、垂直轴或形状的水平和垂直轴弯曲的三维（3-D）形状组成。深度轮廓仅由沿着形状的边界或表面或沿着形状的边界和表面变化的双目视差定义。大多数 AIP 神经元对水平或垂直轴上的弯曲边界具有选择性，并且神经选择性在短潜伏期出现。仅在形状的表面上变化视差的刺激物（边界上的视差为零）在 AIP 神经元中引起选择性的比例较小，潜伏期也长得多。AIP 神经元对由相关视差组成的 3-D 表面没有选择性。因此，当只有边界在深度上弯曲时，AIP 中对物体深度轮廓的神经选择性存在，但在相关视差立体图中不存在。
