| Project/Area Number |
14201011
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| Research Category |
Grant-in-Aid for Scientific Research (A)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
実験系心理学
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| Research Institution | HIROSHIMA UNIVERSITY |
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Principal Investigator |
HORI Tadao Hiroshima University, Faculty of Integrated Arts and Sciences, Professor, 総合科学部, 教授 (10020132)
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| Co-Investigator(Kenkyū-buntansha) |
NITTONO Hiroshi Hiroshima University, Faculty of Integrated Arts and Sciences, Research Associate, 総合科学部, 助手 (20304371)
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| Project Period (FY) |
2002 – 2004
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| Project Status |
Completed (Fiscal Year 2004)
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| Budget Amount *help |
¥40,820,000 (Direct Cost: ¥31,400,000、Indirect Cost: ¥9,420,000)
Fiscal Year 2004: ¥6,890,000 (Direct Cost: ¥5,300,000、Indirect Cost: ¥1,590,000)
Fiscal Year 2003: ¥14,820,000 (Direct Cost: ¥11,400,000、Indirect Cost: ¥3,420,000)
Fiscal Year 2002: ¥19,110,000 (Direct Cost: ¥14,700,000、Indirect Cost: ¥4,410,000)
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| Keywords | Dreaming / REM sleep / Rapid eye movement / Electroencephalogram / Saccade / Imagery / Event-related potential / Topography / 脳電位 |
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| Research Abstract |
The relationship between rapid eye movements (REMs) in REM sleep and dreaming has been suggested for over 30 years. However, few studies have examined this relationship in detail. The purpose of the present study is to propose a hypothesis about the process of dreaming through systematic investigation of REMs and REM-related brain potentials. The following eight points are revealed by this three-year research. (1)Presaccadic negativity and presaccadic positivity, which occur about 600 ms and 150 ms before saccade onset in wakefulness, respectively, do not appear before REM onset in REM sleep. (2)REMs in REM sleep are preceded by a negative slow potential, which does not appear in wakefulness and whose generator is estimated in a deeper part of the brain. (3)Positive potentials that resemble the lambda response, which occurs about 100 ms after saccade offset in wakefulness, appear also before REM offset in REM sleep. (4)This lambda-like response consists of two positive waves with peak latencies of about 80 ms and 180 ms after REM offset. (5)The lambda-like response in REM sleep is distributed more anteriorly than the lambda response in wakefulness. (6)The power of gamma-band electroencephalogram (35-45 Hz), which is assumed to reflect higher-order mental activity, is increased after REMs in REM sleep. (7)Dream reports after awakening from REM sleep suggests that strength of dream impression is positivity correlated with the REM density before awakening. (8)Brain electrical responses to external stimuli are reduced during the period in which REMs occur in REM sleep. Summarizing these findings, we propose the following hypothesis about the process of dreaming in REM sleep. In REM sleep, external sensory inputs are reduced by sensory gating, and REMs are triggered by a neural circuit different from that produce saccades in wakefulness. REMs then activate brain areas including visual cortex, which makes dream more vivid and impressive.
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