Yokosawa Koichi, Takase Ryoken, Chitose Ryota, Kimura Keisuke
Annu Int Conf IEEE Eng Med Biol Soc. 2018 Jul;2018:5-8. doi: 10.1109/EMBC.2018.8512221.
It is known that alpha-band rhythm during memory maintenance is enhanced by increasing memory load. This enhancement is generally thought to be caused by active inhibition of task-irrelevant visual inputs. During sequential memory processing, we previously found that alpha-band activity increases from beginning to midterm during memory encoding, and conversely decreases from midterm to ending. In the present study, we conducted two experiments to determine the spatial and functional role of alpha-band rhythm during sequential memory processing. The first experiment showed that alpha-band rhythm increased in the occipital brain region, suggesting that active inhibition of task-irrelevant visual inputs continues from midterm to ending of memory encoding. The second experiment, in which subjects could not anticipate the ending of the sequential presentation of memory items, demonstrated that alpha-band rhythm is suppressed in correspondence with preparation for memory recall. These results indicate that alpha-band rhythm is simultaneously modulated by multiple brain processes in sequential memory encoding.
众所周知，在记忆维持期间，α波段节律会随着记忆负荷的增加而增强。这种增强通常被认为是由对与任务无关的视觉输入的主动抑制所引起的。在顺序记忆处理过程中，我们之前发现，在记忆编码期间，α波段活动从开始到中期会增加，相反，从中期到结束会减少。在本研究中，我们进行了两项实验，以确定在顺序记忆处理过程中α波段节律的空间和功能作用。第一个实验表明，枕叶脑区的α波段节律增加，这表明对与任务无关的视觉输入的主动抑制在记忆编码的中期到结束阶段持续存在。第二个实验中，受试者无法预测记忆项目顺序呈现的结束，该实验表明，α波段节律会随着记忆回忆的准备而受到抑制。这些结果表明，在顺序记忆编码过程中，α波段节律会同时受到多个脑过程的调节。
