Spatiotemporal Comparison by Use of EEG on Brain Activities During Tetrapod Image Recognition and Recalling Processes

Abstract

Otsuki had conducted categorical naming tasks on aphasia patients with categorical naming disorder, and reported a case in which the difference in performance was shown between "round objects" and "non-round objects", and showed that visual elements such as shape may have some influence on the recalling process [1]. Yamanoi et al. had presented images of a quadruped animal and measured EEGs from the subjects during recalling their names [4]. To these EEGs, the equivalent current dipole estimation was done. As a result, activities were estimated in areas related to visual cortex, memory, language cortex, etc., such as V1, hippocampus, and Broca's area. In images of typical animals with almost the same limb length, such as dogs and bears, brain activity was not estimated in the right angular gyrus, but brain activity was estimated in the right angular gyrus in atypical animals such as giraffes. In the study, the authors estimated the brain activity of the image recognition process of tetrapod image and compared with that of the recalling process. No activity of the right angular gyrus was observed in dogs in common with all subjects. For images of giraffe, brain activity was observed on the right angular gyrus in all subjects, and these tendencies were the same to those of the estimated brain activity in the recalling process. But activities were observed on the right angular gyrus for bear and lion in some subjects of the image recognition process.