Abstract
To investigate the brain activity during human recognition of characters and symbols representing directional meaning, the authors recorded electroencephalograms (EEGs) from subjects in viewing four types of Kanji (Chinese characters being used currently in the Japanese language) and arrows presented on the CRT. Each of four characters or symbols means direction of upward, downward, leftward and rightward, respectively. Further, subjects were asked to make read the stimulus silently. Regardless of the directions, the reaction time was almost equal, when character or arrow was presented. EEGs were averaged in each stimulus type and direction, and event-related potentials (ERPs) were obtained. The equivalent current dipole source localization (ECDL) method was applied to these ERPs. After 300 ms from presentation of stimuli, ECDs were localized to areas related to the language, such as the left supramarginal gyrus, the Wernicke's area in the left middle temporal gyrus, the left angular gyrus and the left lingual gyrus. Then ECDs were localized to the Broca's area. With arrow symbols, ECDs were localized to areas related to the shape recognition, such as the right inferior or the right middle temporal gyrus. In both cases, ECDs were localized to areas related to working memory for the spatial perception.
