酗酒者皮层脑电同步性分析

同步性可以度量不同脑区之间的相互作用,但目前对脑电的同步性研究多数是基于头皮数据进行的。脑电的容积导体效应,可能导致头皮电极之间出现伪相关,从而影响同步性的度量。实验所用的数据集包括正常(28例)和酗酒(28例)两类被试的61通道EEG时间序列,每一个被试参与3种条件的实验任务:单刺激(S1)、双刺激匹配(S2 match)、双刺激不匹配(S2 no match)。利用eLoreta溯源技术,在大脑皮层上自定义了61个感兴趣区域(ROI),计算两类被试之间的同步似然性,最后对酗酒被试和正常被试执行认知任务时的同步性差异进行统计分析。结果发现,执行相同认知任务时,酗酒被试全脑平均同步似然均小于正常被试,且在α、β1和θ波段上均有P<0.05,差异达到统计显著。在执行不同认知任务时,正常被试的同步性可以准确反映出不同认知任务的复杂程度(S2 match > S2 no match > S1),而酗酒被试的同步性则无规律变化。不同被试之间的区域MSL结果表明,在执行S2 match任务时,酗酒被试多个区域MSL均小于正常被试,且在α波段上额叶、左颞叶、中央和右颞叶区均有P<0.05,差异达到统计显著;在β1波段上,额叶区P<0.05,差异达到统计显著;在β2波段上,额叶、左颞叶区均有P<0.05,差异达到统计显著。研究结果表明,酗酒被试大脑不同区域之间的连接受到一定程度的损伤,这为研究酗酒引起的脑损伤提供一个新的角度和有力的证据。

Synchronization in Alcoholics Using Cortical EEG

Synchronization can measure the interaction between different brain regions. However, existing synchronization analyses on EEG synchronization are almost all based on the scalp EEG data. Due to the volume conductor effect, pseudo relevance between the scalp electrodes may occur, which further affects the measurement of synchronization. In this study, we selected the 61 channel EEG time series data of both the control subjects (28) and the alcoholics (28). For each trial, the subject was exposed to one of the following three different stimuli: a single stimulus (S1), two matched stimuli (S2 match), or two non-matched stimuli (S2 no match). The study used eLoreta and the self-defined 61 ROI (regions of interested) in the cerebral cortex. The synchronization between ROIs and the synchronization difference between alcoholic subjects and controls (non-alcoholics) during certain cognitive tasks were measured. Results indicated that the synchronization for the alcoholic group was lower than in the control group when performing the same cognitive task, the difference was statistically significant with α, β1 and θ band (P<0.05). The synchronization for the control group can reflect the complexity levels of the cognitive tasks (S2 match > S2 no match > S1), whereas the alcoholics only displayed erratic changes when the different cognitive tasks performed. The brain regional MSL between different subjects indicated that the alcoholic group was lower than control group when the S2 match performed,and in α band, frontal, left temporal area, central and right temporal area have significant differences (P<0.05); in β1 band, frontal showed significant differences (P<0.05); in β2 band, both frontal and left temporal area showed significant differences (P<0.05). These results indicate that in alcoholics, brain synchronization was reduced, and the connection between different brain regions was inhibited, meaning brain cognitive function is impaired. Our research provides indicated that long-term alcoholism causes functional damage to the brain from an entirely new perspective.