title: Encoding-related brain activity during deep processing of verbal materials: a PET study.
abstract: The recent advent of neuroimaging techniques provides an opportunity to examine brain regions related to a specific memory process such as episodic memory encoding. There is, however, a possibility that areas active during an assumed episodic memory encoding task, compared with a control task, involve not only areas directly relevant to episodic memory encoding processes but also areas associated with other cognitive processes for on-line information. We used positron emission tomography (PET) to differentiate these two kinds of regions. Normal volunteers were engaged in deep (semantic) or shallow (phonological) processing of new or repeated words during PET. Results showed that deep processing, compared with shallow processing, resulted in significantly better recognition performance and that this effect was associated with activation of various brain areas. Further analyses revealed that there were regions directly relevant to episodic memory encoding in the anterior part of the parahippocampal gyrus, inferior frontal gyrus, supramarginal gyrus, anterior cingulate gyrus, and medial frontal lobe in the left hemisphere. Our results demonstrated that several regions, including the medial temporal lobe, play a role in episodic memory encoding.
authors.affiliation: Division of Neuropsychology, Department of Disability Medicine, Tohoku University Graduate School of Medicine, 2-1 Seiro-machi, Aoba-ku, Sendai 980-8575, Japan. fujii@mail.cc.tohoku.ac.jp
authors.forename: Toshikatsu
authors.initials: T
authors.lastname: Fujii
authors.forename: Jiro
authors.initials: J
authors.lastname: Okuda
authors.forename: Takashi
authors.initials: T
authors.lastname: Tsukiura
authors.forename: Hiroya
authors.initials: H
authors.lastname: Ohtake
authors.forename: Maki
authors.initials: M
authors.lastname: Suzuki
authors.forename: Ryuta
authors.initials: R
authors.lastname: Kawashima
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Itoh
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Fukuda
authors.forename: Atsushi
authors.initials: A
authors.lastname: Yamadori
mesh_terms: D000328:Adult; D001931:Brain Mapping; D002540:Cerebral Cortex / Q000000981:diagnostic imaging* / Q000502:physiology*; D007839:Functional Laterality / Q000502:physiology; D006801:Humans; D007807:Language Tests; D008297:Male; D008568:Memory / Q000502:physiology*; D009415:Nerve Net / Q000033:anatomy & histology / Q000000981:diagnostic imaging / Q000502:physiology; D009434:Neural Pathways / Q000000981:diagnostic imaging / Q000502:physiology; D011597:Psychomotor Performance / Q000502:physiology; D013067:Speech Perception / Q000502:physiology*; D014055:Tomography, Emission-Computed; D014705:Verbal Behavior / Q000502:physiology*