title: Region-dependent asymmetrical or symmetrical variations in the oxygenation and hemodynamics of the brain due to different mental stimuli.
abstract: The present paper demonstrates region-dependent variations in the oxygenation and hemodynamics of the brain hemispheres due to three different types of mental stimulation. The variations were observed with a four-channel optical imaging system using tissue-transparent near-infrared light and described changes from baseline of both the hemoglobin oxygenation state and blood volume during three kinds of psychological or mental tasks. During the mirror drawing task, a lateralized hemisphere response (the dominant hemisphere response pattern) was observed in 57% of 14 right handed volunteers in the frontal region (Brodmann's area 10), while in the temporal region (area 38), 80% showed the bilateral response pattern. A large majority of the subjects showed the bilateral response pattern in the frontal and temporal regions while calculating. A smaller majority showed this while looking at anatomical charts, though 30% did not show any response at all in the temporal region. This showed that there were region-dependent asymmetrical or symmetrical variations of the oxygen delivery-oxygen utilization relationship due to different types of mental stimuli.
authors.affiliation: Health Administration Center, Hokkaido University, Sapporo, Japan.
authors.forename: F
authors.initials: F
authors.lastname: Okada
authors.forename: Y
authors.initials: Y
authors.lastname: Tokumitsu
authors.forename: N
authors.initials: N
authors.lastname: Takahashi
authors.forename: Y
authors.initials: Y
authors.lastname: Hoshi
authors.forename: M
authors.initials: M
authors.lastname: Tamura
mesh_terms: D000328:Adult; D001923:Brain Chemistry / Q000502:physiology*; D002560:Cerebrovascular Circulation / Q000502:physiology*; D007839:Functional Laterality / Q000502:physiology; D006452:Hemoglobinometry; D006801:Humans; D008297:Male; D008606:Mental Processes / Q000502:physiology*; D010101:Oxygen Consumption / Q000502:physiology*; D013055:Spectrophotometry, Infrared