Surround suppression in primate V1
Surround suppression in primate V1
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DOI：
10.1152/jn.2001.86.4.2011
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发表时间：
2001-10-01
影响因子：
2.5
通讯作者：
Sillito, AM
中科院分区：
文献类型：
--
作者：
Jones, HE;Grieve, KL;Sillito, AM
我们研究了灵长类动物初级视觉皮层（VI）环绕抑制的空间组织。我们利用漂移刺激，配置从经典感受野（CRF）内延伸到周围视觉空间，或从周围视觉空间延伸到CRF或细分产生方向对比，以详细检查周围抑制的强度、空间组织、方向依赖性、机制和层流分布。大多数细胞（99/ 105,94%）对超过CRF的均匀刺激表现出抑制（平均减少67%），43%表现出超过70%的减少。对环的测试揭示了两种不同的环绕影响模式。一些细胞（37%的细胞），典型环绕抑制（CSS）细胞对环侵入CRF的反应小于空间求和曲线的平台。大多数（63%）中心门控包围抑制（CGSS）细胞对环空的响应等于或超过空间求和曲线的平台。分析表明，CSS机制在所有细胞中都实现了，而CGSS机制在整个样本中以不同的强度实现，极端反映在细胞中，细胞对环空的响应大于对中心刺激的响应。将CRF周围部分刺激的运动方向颠倒后，发现了四种不同的效应模式：抑制程度没有降低（22%的细胞），周围抑制程度降低（41%），对单独内部刺激的反应高于该水平的促进（37%），以及对单独内部刺激的反应高于该水平的促进也超过了与最佳内部刺激相关的值。只有在直径等于或大于CRF尺寸的中央和周围刺激之间的反向界面上才能看到促进效应。驱动抑制影响和方向对比促进的区域通常在空间上是异质的，对于许多细胞来说，它们与MT中报道的围绕机制的行为类别有着强烈的对比。这表明，在提取运动物体三维结构表征中的运动对比信息方面，它们具有潜在的作用。
We investigated the spatial organization of surround suppression in primate primary visual cortex (VI). We utilized drifting stimuli, configured to extend either from within the classical receptive field (CRF) to surrounding visual space, or from surrounding visual space into the CRF or subdivided to generate direction contrast, to make a detailed examination of the strength, spatial organization, direction dependence, mechanisms, and laminar distribution of surround suppression. Most cells (99/105, 94%) through all cortical layers, exhibited suppression (mean reduction 67%) to uniform stimuli exceeding the CRF, and 43% exhibited a more than 70% reduction. Testing with an annulus revealed two different patterns of surround influence. Some cells (37% of cells), classical surround suppression (CSS) cells exhibited responses to an annulus encroaching on the CRF that were less than the plateau in the spatial summation curve. The majority (63%), center-gated surround suppression (CGSS) cells, showed responses to annuli that equaled or exceeded the plateau in the spatial summation curve. Analysis suggested the CSS mechanism was implemented in all cells while the CGSS mechanism was implemented in varying strength across the sample with the extreme reflected in cells that gave larger responses to annuli than to a center stimulus. Reversing the direction of motion of the portion of the stimulus surrounding the CRF revealed four different patterns of effect: no reduction in the degree of suppression (22% of cells), a reduction in surround suppression (41%), a facilitation of the response above the level to the inner stimulus alone (37%), and a facilitation of the response above that to the inner stimulus alone that also exceeded the values associated with an optimal inner stimulus. The facilitatory effects were only seen for reverse direction interfaces between the central and surrounding stimulus at diameters equal to or more than the CRF size. The zones driving the suppressive influences and the direction contrast facilitation were often spatially heterogeneous and for a number of cells bore strong comparison with the class of behavior reported for surround mechanisms in MT. This suggests a potential role, for example, in extracting information about motion contrast in the representation of the three dimensional structure of moving objects.