Physiological basis of recognition

本研究的主要目的是研究再认记忆的神经元相关性。为了达到这个目的，我们必须采取适当的措施。在第一年，研究人员检查了通常用于婴儿记忆研究的“优先观看”方法是否适用于猴子。结果发现，成年猴子表现出“偏好的外观”。但事实证明，这种方法并不总是适合于单元记录实验。因此，当猴子执行延迟配对比较任务（一种识别任务）时，我们开始检查海马体的单个单位活动。在这个任务中，两个刺激（S1和S2）连续呈现一个短暂的延迟，当第一个（S1）和第二个（S2）刺激相同时，动物被要求执行“GO”反应。另一方面，当这两种刺激不同时，动物必须执行“NO-GO”反应。主要的兴趣集中在那些神经元的发现，表现出不同的活动在延迟期间，因为这些神经元可能与记忆过程（工作记忆）。在海马中发现了在延迟期间显示差异活性的这种差异延迟单位。结果表明，海马参与了再认任务，延迟过程中的差异活动代表了对第一个刺激的工作记忆。

The main aim of this project was to examine the neuronal correlate of recognition memory. In order to attain this aim we must employ an adequate task. In the first year it was examined whether 'preferential looking' method-usually employed in the study of infant memory-could be applied to the monkey. It was found that the adult monkeys exhibit 'preferential looking'. But it turned out that this method was not always adequate for unit recording experiment. Consequently, we began to examine the single unit activity of the hippocampus while the monkey was performing a a delayed-pair comparison task (a king of recognition task). In this task two stimuli (S1 and S2) were presented successively with a short delay, and the animal was required to perform 'GO' response when the first (S1) and the second (S2) stimuli were the same. On the other hand, the animal had to perform 'NO-GO' response when these two stimuli were different. The main interest centered on the discovery of those neurons which showed differential activity during the delay period since such neurons might be related to the mnemonic process (working memory). Such differential delay units showing differential activity during delay were found in the hippocampus. The result indicates that the hippocampus is involved in the recognition task, and the differential activity during delay represents the working memory' of the first stimulus.