Timescales of sensory- and decision-related activity in the middle temporal and medial superior temporal areas.
Timescales of sensory- and decision-related activity in the middle temporal and medial superior temporal areas.
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DOI：
10.1523/jneurosci.2336-10.2010
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发表时间：
2010-10-20
期刊：
影响因子：
--
通讯作者：
Born RT
中科院分区：
文献类型：
--
作者：
Price NS;Born RT
感觉神经元对外部刺激事件的感知决策的贡献已经受到了很多关注，但不太清楚感觉反应如何随着时间的推移而整合，以产生快速可靠的决策。为了解决这个问题，我们记录从MT和MST神经元在恒河猴执行一项任务，需要检测和识别不可预测的速度变化。我们研究了神经元活动如何编码速度变化的信号，并预测了动物的行为判断和反应时间，重点是神经元活动提供信息的时间尺度。在错误检测试验中，动物报告了速度变化，即使没有发生，根据动物的辨别判断进行分组。通过比较两组错误检测试验之间的神经元反应，我们能够从单个神经元的感觉活动中预测动物的选择，其水平明显优于机会。这些选择概率测量在选择扫视开始前150 ms结束的80 ms窗口中使用尖峰计数是最强的，但是在短至10 ms的窗口中观察到显著的选择概率。虽然速度变化后尖峰速率的最大偏差在瞬态响应中是明显的，在较长的时间窗口中平均神经元活动可以提供更多关于刺激和动物行为判断的信息。因此，本研究中发现的时间尺度代表了在产生快速反应和克服短时间窗口中固有的噪声之间的权衡。
The contribution of sensory neurons to perceptual decisions about external stimulus events has received much attention, but it is less clear how sensory responses are integrated over time to produce decisions that are both rapid and reliable. To address this issue, we recorded from MT and MST neurons in rhesus macaques performing a task requiring the detection and discrimination of unpredictable speed changes. We examined how neuronal activity encoded the sign of the speed change and predicted the animals’ behavioral judgments and reaction times, with a focus on the timescales over which neuronal activity is informative. False detection trials, on which animals reported a speed change even though none had occurred, were grouped according to the animals’ discrimination judgment. By comparing the neuronal responses between the two groups of false detection trials, we were able to predict the animals’ choices from the sensory activity of single neurons at levels significantly better than chance. These choice probability measurements were strongest using spike counts in an 80 ms window ending 150 ms before a choice saccade began, but significant choice probabilities were observed in windows as short as 10 ms. While the maximum deviation in spiking rate following a speed change is evident in the transient response, averaging neuronal activity in longer time windows can be more informative about both the stimulus and the animals’ behavioral judgments. Thus the timescales found in this study represent a trade-off between producing rapid reactions and overcoming the noise inherent in short time windows.