Research on the cognitive memory functions of the hippocampal and parahippocampal neurous of the primate.

灵长类动物的颞叶在认知记忆功能中起着不可或缺的作用。它包含两个在系统发育上不同的结构，一个是位于海马区的新皮质，另一个是海马区。我们一直在提出灵长类视觉记忆系统的假说，认为TE区是记忆库。为了验证这一假设，在猴子执行视觉记忆任务(延迟匹配到样本任务，DMS)时，检测了大脑颞叶皮质神经元的单个单位活动。我们发现，在DMS任务的延迟期内，形状选择神经元表现出持续的活动。该活动对要记忆的图像信息具有高度的选择性，与物体的大小、方向、颜色或位置等物理属性无关，这表明延迟活动代表了对图像的分类知觉的短期记忆。此外，这些延迟放电的选择性是通过重复试验DMS任务而形成的。使用计算机生成的人工图案作为要记忆的刺激。神经元共同选择的少数几种模式经常通过训练过程中施加的刺激-刺激联系相互联系。因此，这些细胞获得的选择性被认为代表了对图片的联想长时记忆。这些观察结果不仅支持提出的假设，而且还为假定的记忆库的神经表示提供了更具体、更生动的形状。

Primate temporal lobe plays an indispensable role in the cognitive memory functions. It contains two phylogenetically different structures, the temporal neocortex in the parahippocampal cortex (area TE according to von Bonin ＆ Bailey) and the hippocampus. We has been proposing a hypothesis of the primate visual memory system in which the area TE is considered as the memory storehouse. To test this hypothesis, single-unit activities of the temporal cortical neurons were examined while the monkeys were performing a visual memory task (delayed matching-to-sample task, DMS). We found shape-selective neurons that exhibited sustained activity during the delay period of the DMS task. The activity was highly selective for the pictorial information to be memorized and was independent of the physical attributes such as size, orientation, color or position of the object, suggesting that the delay activity represents the short-term memory of the categorized percept of a picture. Moreover, the selectivity of these delay discharges developed through repeated trials of the DMS task. Computer-generated artificial patterns were used as the stimuli to be memorized. The few patterns for which a neuron was conjointly selective were frequently related to each other through stimulus-stimulus association imposed during the course of training. Thus, the selectivity acquired by these cells is suggested to represent the associative long-term memory of pictures. These observations not only support the proposed hypothesis but also give more concrete, vivid shape to the neural representation of the presumed memory storehouse.