2012 Volume 42 Pages 13-26
The author has estimated the brain activity using EEG coherence, last few years. In the study in the first semester in 2011, electroencephalogram (EEG) and electrocardiogram (ECG) were recorded simultaneously from two healthy subjects (all of them is female and 21 years old), ongoing the mental arithmetic tasks and the pictorial tasks specialized for the visual cortex of working memory tasks. EEG coherence obtained from EEG was employed to examine the networks among the brain regions. In addition, heat rate variabilities during their tasks loading were recorded and used as references to the coherence analyses, for checking the mental condition against the relax. As a result, it is presumed that the increases of coherence on lower theta band reflect the degree of concentration to a task. Moreover, the involvement of the specific frequency band (theta-4 to lower alpha band (around 8-10 Hz)) to the visual information processing must be considered. From the past results, it is considered that the autonomic nerve activity is probably, strongly linked to the alpha band but not to the theta band.
