短期记忆与脑电事件相关电位特征的初步研究

The Preliminary Study of the Event-related Potential and Short time memory

关键词:  40HZ事件相关电位(40Hz ERP)  半球不对称性  短期记忆  记忆容量

Key words:  40Hz ERP  asymmetry-hemispheres  memory capacity

摘要:

对32名被试者进行两字汉语词汇和平面图形的辩识测试,以及4~9个两字汉语词汇的回忆测试,结果是词汇、图形辩识测试中,左右半球40Hz事件相关电位(ERP)的发放率(ACT)和平均发放时间间隔(AT)参数存在不对称性。词汇测试中,左半球40Hz ERP的ACT(16.96)明显大于右半球(14.5),P<0.01;右半球的AT(25.4)明显大于左半球(21.9),P<0.025。图形测试中,右半球的ACT(16.8)明显大于左半球(15.0),P<0.025;左半球AT值(23.9),明显大于右半球(21.1),P<0.025。左右半球不对称的消失与汉语词汇短期记忆有固定组块(7个)的记忆容量有关。

Abstract:

40Hz Event-related potential (ERP) is a short aperiodic burst of EEG activity with a norrow frequence band (36~44) centered at 40Hz. It has been established as an indicator of the state of "focused arousal", and proved to be an useful approach for cognition research of brain.With this system, we recorded 40Hz ERPs of 32 persons who took three tests:memorizing and recognizing Chinese vocabularies of two words, memorizing and recognizing geomitric figures, and recalling 4~9 Chinese vocabularies of two words. Parameters such as duration of the 40Hz ERP bursting activity (ACT) and mean bursting interval (AT, defining 1/AT as bursting speed) of the left and the right hemispheres are computed. We acquire the following conclusion:There exists clear asymmetry between left and right hemispheres in bursting activity and the bursting speed of 40HzERP recorded during the test procedures of the recognition of vocabulary and geomitric. The disappearance of asymmetry between the left and the right hemispheres is related to the fact Chinese vocabularies short time memory capacity having fixed number of chunds.