SPATIAL AND TEMPORAL FREQUENCY-SELECTIVITY OF NEURONS IN VISUAL CORTICAL AREAS V1 AND V2 OF THE MACAQUE MONKEY
SPATIAL AND TEMPORAL FREQUENCY-SELECTIVITY OF NEURONS IN VISUAL CORTICAL AREAS V1 AND V2 OF THE MACAQUE MONKEY
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DOI：
10.1113/jphysiol.1985.sp015776
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发表时间：
1985-01-01
影响因子：
5.5
通讯作者：
POLLEN, DA
中科院分区：
文献类型：
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作者：
FOSTER, KH;GASKA, JP;POLLEN, DA
采用阈上对比光栅，研究了猕猴纹状皮层V1区148个神经元和第二视觉皮层V2区122个神经元在空间和时间上的频率选择性。V1和V2的神经元对不同但部分重叠的空间频谱范围具有选择性。大多数V1神经元和部分V2神经元在5.6-8.0 Hz的频率下反应良好，但在更高的频率下反应下降。在V2中，带通调谐曲线在时间频谱上的最小重叠表明，至少存在2种不同的带通时间频率机制，以及在每个空间频率上具有低通时间频率调谐的神经元。空间和时间频率组合矩阵被用来作为神经元的刺激，在V1和V2中具有带通时间频率选择性。由此产生的时空表面提供了证据，表明神经元对空间频率的偏好基本上与测试的时间频率无关；然而，在V2中，当测试高于或低于首选值的非最佳空间频率值时，时间频率峰值有向较低频率略微移动的趋势。具有明显定向选择性的神经元在很宽的空间频率范围内被发现，尽管在两个皮质区域中，在具有低空间频率和高时间频率选择性的神经元中，定向选择性的发生率有增加的趋势。V1和V2的神经元在部分重叠但本质上不同的空间频谱范围内具有相似的空间频带宽度，而V1和V2的神经元在时间频谱范围内具有相似的范围但具有不同的时间频带通特性。V1和V2中的神经元在空间频率和时间频谱的扩展范围内分析视觉场景的部分局部子域。
The spatial and temporal frequency selectivity of 148 neurons in the striate cortex, V1, and of 122 neurons in the 2nd visual cortical area, V2, of the macaque monkey were studied using sine-wave gratings of suprathreshold contrast drifting over the receptive field at the preferred orientation and direction. Neurons in V1 and V2 were selective for different but partially overlapping ranges of the spatial frequency spectrum. Most neurons in V1 and some in V2 responded well at temporal frequencies up to 5.6-8.0 Hz before their responses dropped off at still higher frequencies. In V2 the minimal overlap of bandpass tuning curves across the temporal frequency spectrum suggests that there are at least 2 distinct bandpass temporal frequency mechanisms as well as neurons with low-pass temporal frequency tuning at each spatial frequency. A matrix of spatial and temporal frequency combinations was employed as stimuli for neurons with bandpass temporal frequency selectivity in both V1 and V2. The resultant spatio-temporal surfaces provided evidence that a neuron''s preference for spatial frequency is essentially independent of the test temporal frequency; however, in V2 there was some tendency for temporal frequency peaks to shift slightly towards lower frequencies when non-optimum values of spatial frequency either above or below the preferred value were tested. Neurons with pronounced directional selectivity were encountered over a wide range of spatial frequencies, although in both cortical areas there was a tendency for an increased incidence of directional selectivity among neurons which were selective for lower spatial frequencies and higher temporal frequencies. Neurons in V1 and V2 span partially overlapping but essentially different ranges of the spatial frequency spectrum yet have similar spatial frequency band widths, whereas neurons in V1 and V2 span similar ranges of the temporal frequency spectrum but have different temporal frequency bandpass characteristics. Neurons in V1 and V2 analyse partially localized subdomains of the visual scene across an extended range of both the spatial frequency and temporal frequency spectrum.