Functional properties of neurons in macaque area V3
Functional properties of neurons in macaque area V3
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DOI：
10.1152/jn.1997.77.4.1906
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发表时间：
1997-04-01
影响因子：
2.5
通讯作者：
Levitt, JB
中科院分区：
文献类型：
--
作者：
Gegenfurtner, KR;Kiper, DC;Levitt, JB
我们研究了纹外V3区神经元的功能特性。V3接受来自大细胞和小细胞通路的输入，并向中颞区（MT区）和V4都有突出的投射。因此，它可能是整合和转换视觉信号的重要场所。我们记录了麻醉的麻痹猕猴的代表中央10度的单个单位的活动。我们测量了每个细胞的空间，时间，色彩和运动特性与使用各种刺激。结果进行了比较，在V2神经元在类似的偏心率的测量。与V2区相似，我们样本中的大多数神经元（80%）具有方向选择性，方向带宽的分布与V2区相似。V3神经元比V2神经元更偏好低的空间频率和高的时间频率。V3神经元的对比阈值极低。消色差对比敏感度远高于V2，与MT相似。大约40%的神经元表现出很强的方向选择性。我们没有发现强烈的方向性细胞在第4层的V3，该层中的大部分V1和V2的输入终止。该物业似乎在V3区内开发。对定向选择细胞对格子图案反应的分析表明，在V3区，与MT区一样，与V1和V2区不同，存在对格子图案运动敏感的细胞，而不是对组件运动敏感的细胞。被归类为对颜色有选择性的细胞的确切比例在很大程度上取决于实验和用于分类的标准。使用与先前V2细胞研究相同的条件，我们发现与V2（50%）一样多（54%）的颜色选择性细胞。此外，V3细胞对彩色正弦光栅的反应可以用视锥输入的线性组合来描述。对颜色和运动做出反应的两个细胞亚群在很大程度上重叠，我们发现很大一部分细胞对漂移的等亮度光栅做出可靠且方向性的反应。我们的研究结果表明，有一个显着的颜色和运动处理之间的相互作用，在V3区，V3细胞表现出更复杂的运动特性，通常观察到在视觉处理的后期阶段。
We investigated the functional properties of neurons in extrastriate area V3. V3 receives Inputs from both magno- and parvocellular pathways and has prominent projections to both the middle temporal area (area MT) and V4. It may therefore represent an important site for integration and transformation of visual signals. We recorded the activity of single units representing the central 10 degrees in anesthetized, paralyzed macaque monkeys. We measured each cell's spatial, temporal, chromatic, and motion properties with the use of a variety of stimuli. Results were compared with measurements made in V2 neurons at similar eccentricities. Similar to area V2, most of the neurons in our sample (80%) were orientation selective, and the distribution of orientation bandwidths was similar to that found in V2. Neurons in V3 preferred lower spatial and higher temporal frequencies than V2 neurons. Contrast thresholds of V3 neurons were extremely low. Achromatic contrast sensitivity was much higher than in V2, and similar to that found in MT. About 40% of all neurons showed strong directional selectivity. We did not find strongly directional cells in layer 4 of V3, the layer in which the bulk of V1 and V2 inputs terminate. This property seems to be developed within area V3. An analysis of the responses of directionally selective cells to plaid patterns showed that in area V3, as in MT and unlike in V1 and V2, there exist cells sensitive to the motion of the plaid pattern rather than to that of the components. The exact proportion of cells classified as being selective to color depended to a large degree on the experiment and on the criteria used for classification. With the use of the same conditions as in a previous study of V2 cells, we found as many (54%) color-selective cells as in V2 (50%). Furthermore, the responses of V3 cells to colored sinusoidal gratings were well described by a linear combination of cone inputs. The two subpopulations of cells responsive to color and to motion overlapped to a large extent, and we found a significant proportion of cells that gave reliable and directional responses to drifting isoluminant gratings. Our results show that there is a significant interaction between color and motion processing in area V3, and that V3 cells exhibit the more complex motion properties typically observed at later stages of visual processing.