Neural codes for perceptual discrimination in primary somatosensory cortex
Neural codes for perceptual discrimination in primary somatosensory cortex
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DOI：
10.1038/nn1513
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发表时间：
2005-09-01
影响因子：
25
通讯作者：
Romo, R
中科院分区：
文献类型：
--
作者：
Luna, R;Hernández, A;Romo, R
我们试图确定振动触觉刺激频率辨别的神经代码。我们通过分析受过训练的猴子的初级体感皮层中记录的单个神经元的反应来测试五种可能的候选代码，同时它们区分两个连续的振动触觉刺激。可以使用以下信息来区分两个刺激的频率差异：(i) 尖峰之间的时间间隔，(ii) 每次刺激期间的平均尖峰速率，(iii) 每个刺激引起的尖峰绝对数量，(iv) 尖峰突发的平均速率或 (v) 每个刺激引起的尖峰突发的绝对数量。然而，只有尖峰计数代码（其中尖峰在每个刺激周期的前 250 毫秒内具有大部分质量的时间窗口内进行积分，并在逐次试验的基础上与行为协变）与操纵刺激持续时间引起的心理物理学偏差一致，并产生与行为心理物理学阈值类似的神经测量辨别阈值。
We sought to determine the neural code(s) for frequency discrimination of vibrotactile stimuli. We tested five possible candidate codes by analyzing the responses of single neurons recorded in primary somatosensory cortex of trained monkeys while they discriminated between two consecutive vibrotactile stimuli. Differences in the frequency of two stimuli could be discriminated using information from (i) time intervals between spikes, (ii) average spiking rate during each stimulus, (iii) absolute number of spikes elicited by each stimulus, (iv) average rate of bursts of spikes or ( v) absolute number of spike bursts elicited by each stimulus. However, only a spike count code, in which spikes are integrated over a time window that has most of its mass in the first 250 ms of each stimulus period, covaried with behavior on a trial-by-trial basis, was consistent with psychophysical biases induced by manipulation of stimulus duration, and produced neurometric discrimination thresholds similar to behavioral psychophysical thresholds.