NEURAL CODING OF VISUAL STIMULI IN THE AWAKE MONKEY

我们正在记录猴子视觉系统中的单个神经元， 试图揭示视觉感知的神经机制， 视觉识别 其中一组实验是在神经元中进行的， 下颞叶皮层已经表明，改变注意力或 视觉任务的认知需求改变了神经元对视觉任务的反应， 刺激。 例如，当任务变得更加困难时， 猴子犯了更多的错误，神经元对刺激的反应是 增加 此外，神经元对刺激的反应取决于 动物是否根据自己的 质地或形状。 在第二组实验中，涉及记录来自 下颞叶和纹状体皮质的单个神经元，不同 视觉刺激被发现产生不同的时间序列的行动 潜力 我们已经开发了定量技术来识别 这种时间调制的特征在传递信息方面是重要的 关于刺激。 因此，我们现在已经能够分析神经元， 一个通信信道，以下列顺序携带编码信息： 动作电位 分析表明，如果代码使用 时间调制时，神经元传输的信息是 该代码仅使用动作电位的数量。 行动次数 电位与传输的信息无关。

We are recording from single neurons in the visual system of monkeys in the attempt to uncover the neuronal mechanisms underlying visual perception and visual recognition. One set of experiments carried out of neurons of inferior temporal cortex has shown that changing the attentional or cognitive demand of visual tasks changes the neuronal responses to a visual stimulus. For example, when the task was made more difficult so that the monkey committed more errors, the neuronal responses to the stimulus were increased. Also, neuronal responses to the stimulus differed depending on whether the animal was discriminating it from another on the basis of its texture or shape. In a second set of experiments, involving recording from single neurons of both inferior temporal and striate cortex, different visual stimuli were found to yield different temporal sequences of action potentials. We have developed quantitative techniques to identify which features of this temporal modulation are significant in carrying messages about stimuli. As a result, we have now been able to analyze the neuron as a communication channel carrying encoded information in the sequence of action potentials. The analysis showed that with a code that makes use of temporal modulation the neurons transmits twice as much information as when the code uses only the number of action potentials. The number of action potentials is not correlated with the information transmitted.