Temporal-frequency selectivity in monkey visual cortex
Temporal-frequency selectivity in monkey visual cortex
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DOI：
10.1017/s0952523800008154
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发表时间：
1996-05-01
影响因子：
1.9
通讯作者：
Grosof, DH
中科院分区：
文献类型：
--
作者：
Hawken, MJ;Shapley, RM;Grosof, DH
我们研究了纹状皮层（V1）和外侧膝状核（LGN）神经元的动态变化，以研究LGN和外侧膝状核之间的时间-频率调谐转换。此外，我们比较了简单细胞与复杂细胞、方向选择细胞与非方向选择细胞的时间频率调谐，以确定V1内不同功能类别细胞的时间频率调谐是否存在显著差异。此外，我们比较了V1初级输入层（4a、4c α和4c β）中的细胞与主要是二级和高级输入层（2、3、4b、5和6）中的细胞。我们测量了漂移正弦光栅的时频响应。对于LGN神经元和简单细胞，我们使用基本反应的振幅和相位。对于复杂细胞，脉冲速率（FO）对漂移光栅的提升是响应度量。在LGN和V1的输入层之间存在明显的低通滤波，并伴随着3毫秒的视觉延迟增加。在V1输入层和V1的二阶和高阶神经元之间有进一步的低通滤波。这导致LGN和V1输出层之间的高截止时间频率平均下降约20 Hz，平均视觉延迟增加约12-14 ms。最显著的结果之一是，与外侧膝状突起细胞相比，V1细胞的动态特性多样性增加，这可能反映了V1细胞之间功能的特化。简单细胞和复杂细胞具有相似的时频调谐特性分布。方向选择细胞和非方向选择细胞具有相似的首选频率和高截止时间频率，但方向选择细胞几乎完全是带通的，而非方向选择细胞在带通和低通类别之间平均分布。视觉延迟的整合时间，V1比LGN长约10毫秒。在V1中，积分时间分布相对广泛，简单细胞为40-80 ms，复杂细胞为60-100 ms，而在LGN中，积分时间分布较窄。
We investigated the dynamics of neurons in the striate cortex (V1) and the lateral geniculate nucleus (LGN) to study the transformation in temporal-frequency tuning between the LGN and V1. Furthermore, we compared the temporal-frequency tuning of simple with that of complex cells and direction-selective cells with nondirection-selective cells, in order to determine whether there are significant differences in temporal-frequency tuning among distinct functional classes of cells within V1. In addition, we compared the cells in the primary input layers of V1 (4a, 4c alpha, and 4c beta) with cells in the layers that are predominantly second and higher order (2, 3, 4b, 5, and 6). We measured temporal-frequency responses to drifting sinusoidal gratings. For LGN neurons and simple cells, we used the amplitude and phase of the fundamental response. For complex cells, the elevation of impulse rate (FO) to a drifting grating was the response measure. There is significant low-pass filtering between the LGN and the input layers of V1 accompanied by a small, 3-ms increase in visual delay. There is further low-pass filtering between V1 input layers and the second- and higher-order neurons in V1. This results in an average decrease in high cutoff temporal-frequency between the LGN and V1 output layers of about 20 Hz and an increase in average visual latency of about 12-14 ms. One of the most salient results is the increased diversity of the dynamic properties seen in V1 when compared to the cells of the lateral geniculate, possibly reflecting specialization of function among cells in V1. Simple and complex cells had distributions of temporal-frequency tuning properties that were similar to each other. Direction-selective and nondirection-selective cells had similar preferred and high cutoff temporal frequencies, but direction-selective cells were almost exclusively band-pass while nondirection-selective cells distributed equally between band-pass and low-pass categories. Integration time, a measure of visual delay, was about 10 ms longer for V1 than LGN. In V1 there was a relatively broad distribution of integration times from 40-80 ms for simple cells and 60-100 ms for complex cells while in the LGN the distribution was narrower.