Temporal and spatial response to second-order stimuli in cat area 18
Temporal and spatial response to second-order stimuli in cat area 18
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DOI：
10.1152/jn.1998.80.6.2811
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发表时间：
1998-12-01
影响因子：
2.5
通讯作者：
Baker, CL
中科院分区：
文献类型：
--
作者：
Mareschal, I;Baker, CL
猫18区大约一半的神经元对对比包络刺激作出反应，对比包络刺激由正弦波载波组成，其对比度由较低空间频率的漂移正弦波包络调制。这些刺激应该不能引起传统线性神经元的响应，因为它们被设计为在细胞的亮度定义的频率通带内不包含空间频率分量。我们通过改变对比度调制的漂移率和空间频率来测量神经元对包络刺激的反应。然后将这些数据与用亮度定义的正弦波光栅获得的相同神经元的空间和时间特性进行比较。大多数神经元对包络刺激的反应在空间和时间上是带通的，其带宽与用亮度光栅测量的带宽相当。这些神经元的时间响应（时间频率调谐和潜伏期）系统慢，当测试与包络刺激比与亮度光栅。能够适应这些结果的最简单类型的模型是对亮度和包络刺激具有单独的、并行的带通处理流的模型。
Approximately one-half of the neurons in cat area 18 respond to contrast envelope stimuli, consisting of a sinewave carrier whose contrast is modulated by a drifting sinewave envelope of lower spatial frequency. These stimuli should fail to elicit a response from a conventional linear neuron because they are designed to contain no spatial frequency components within the cell's luminance-defined frequency passband. We measured neurons' responses to envelope stimuli by varying both the drift rate and spatial frequency of the contrast modulation. These data were then compared with the same neurons' spatial and temporal properties obtained with luminance-defined sinewave gratings. Most neurons' responses to the envelope stimuli were spatially and temporally bandpass, with bandwidths comparable with those measured with luminance gratings. The temporal responses of these neurons (temporal frequency tuning and latency) were systematically slower when tested with envelope stimuli than with luminance gratings. The simplest kind of model that can accommodate these results is one having separate, parallel streams of bandpass processing for luminance and envelope stimuli.