Research groups at the University of Tsukuba, Hokkaido University, Kyushu University, Tohoku University, and Institute of Physical and Chemical Research have information on the phase difference (Note) of brain wave rhythms of different frequencies, theta waves and alpha waves, when humans manipulate images in the brain. It was discovered by using EEG data analysis and numerical simulation that the distribution was performed.
Humans can flexibly select and think about necessary information from various information under various circumstances.This is called working memory, and understanding this brain mechanism is important for the realization of brain-type computers.Therefore, as a basic research, we investigated the brain mechanism related to visual and auditory working memory.Until now, it has been reported that there are networks that synchronize with EEG rhythms of various frequencies between brain parts that are active during working memory, but the mechanism between these EEG rhythms has not been clarified.
This time, we measured the brain waves when performing the visual work memory task (image manipulation using figures on the PC display) and the auditory work memory task (mental arithmetic using earphones), and compared the brain wave analysis results for both tasks. bottom.
As a result, it was found that the phases of the theta wave and the alpha wave in the forehead are synchronized in both tasks.Interestingly, it was found that there is a phase difference between theta and alpha waves in the visual and auditory working memory tasks.Furthermore, by creating a mathematical model and simulating it numerically, it was found that the phase difference between the two working memory tasks plays an important role during the working memory task.
This shows that information processing in the brain is not only achieved by the combination of brain region and EEG rhythm as previously known, but also the phase difference of EEG rhythm can have information. It is said to be the first to show the possibility of pushing the limits.
(Note) Phase is a quantity that indicates the timing of a wave that repeatedly vibrates periodically during one cycle. Two or more waves may be in phase or out of phase.This deviation is called a phase difference.
