Physiological basis of recognition

本课题的主要目的是研究识别记忆的神经元关联。为了达到这个目的，我们必须采用适当的任务。第一年，研究人员检查了通常用于研究婴儿记忆的“优先观察”方法是否适用于猴子。研究发现，成年猴子表现出“偏爱的外貌”。但事实证明，这种方法并不总是适用于单元记录实验。因此，我们开始检查当猴子执行延迟配对比较任务（识别任务之王）时海马体的单个单元活动。在本实验中，实验以较短的延迟连续呈现两种刺激（S1和S2），并要求动物在第一刺激（S1）和第二刺激（S2）相同时做出“GO”反应。另一方面，当这两种刺激不同时，动物必须做出“NO-GO”反应。主要的兴趣集中在发现那些在延迟期表现出不同活动的神经元，因为这些神经元可能与记忆过程（工作记忆）有关。这种在延迟期间表现出不同活动的差异延迟单元在海马体中被发现。结果表明，海马参与了识别任务，延迟期间的差异活动代表了第一刺激的“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.