Spatial frequency and orientation tuning dynamics in area V1
Spatial frequency and orientation tuning dynamics in area V1
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DOI：
10.1073/pnas.022638499
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发表时间：
2002-02-05
影响因子：
11.1
通讯作者：
Gallant, JL
中科院分区：
文献类型：
--
作者：
Mazer, JA;Vinje, WE;Gallant, JL
空间频率（SF）和方向调谐是初级视皮层（V1区）神经元的内在特性。为了研究神经机制介导的选择性清醒的动物，我们测量了SF和方向调谐的时间动态。我们采用了一种高速反向相关方法，以前用于表征麻醉动物的方向调谐动态有效地估计完整的时空感受野在V1区的行为猕猴。我们发现，SF和方向调谐在很大程度上是可分离的，随着时间的推移，在单个神经元。然而，时空感受野也包含一个小的不可分离的组成部分，反映了低和高SF刺激的反应潜伏期的显着差异。所观察到的刺激SF和潜伏期之间的关系代表了SF调谐的动态变化，并表明单个V1神经元可能会收到收敛输入的大细胞和小细胞处理流。虽然以前的研究与麻醉动物表明，方向调谐可以随着时间的推移发生显着变化，我们发现没有实质性的证据动态变化的方向调谐。
Spatial frequency (SF) and orientation tuning are intrinsic properties of neurons in primary visual cortex (area V1). To investigate the neural mechanisms mediating selectivity in the awake animal, we measured the temporal dynamics of SF and orientation tuning. We adapted a high-speed reverse-correlation method previously used to characterize orientation tuning dynamics in anesthetized animals to estimate efficiently the complete spatiotemporal receptive fields in area V1 of behaving macaques. We found that SF and orientation tuning are largely separable over time in single neurons. However, spatiotemporal receptive fields also contain a small nonseparable component that reflects a significant difference in response latency for low and high SF stimuli. The observed relationship between stimulus SF and latency represents a dynamic shift in SF tuning, and suggests that single V1 neurons might receive convergent input from the magno- and parvocellular processing streams. Although previous studies with anesthetized animals suggested that orientation tuning could change dramatically over time, we find no substantial evidence of dynamic changes in orientation tuning.