2012 Fiscal Year Final Research Report
Investigating brain function that is affected by alteration of arousal level
Project/Area Number |
22700287
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Research Category |
Grant-in-Aid for Young Scientists (B)
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Allocation Type | Single-year Grants |
Research Field |
Cognitive science
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Research Institution | National Institute for Physiological Sciences (2011-2012) National Institute of Information and Communications Technology (2010) |
Principal Investigator |
KOIKE Takahiko 生理学研究所, 大脳皮質機能研究系, 特別協力研究員 (30540611)
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Project Period (FY) |
2010 – 2012
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Keywords | EEG-fMRI同時計測 / 覚醒レベル / 機能的脳イメージング |
Research Abstract |
Empirically, we know that decreased arousal level causes decreased performance, and that the decrease of performance might be due to alteration of brain activity. In this study, we have attempted to identify the relationship across decreasing arousal level, decreasing human performance, and alteration of brain activity by combining the electro- encephalogram (EEG) recording, functional magnetic resonance imaging (fMRI) and psychological tasks. Firstly, we tested our idea with alteration of arousal level between sleep stages. Our analysis revealed that there is significant difference of functional connectivity on the prefrontal component of default mode network (DMN), which have an essential role in keeping arousal level and consciousness level. Secondly, by combining graph-theory and EEG-fMRI simultaneous recording, we investigated changes in brain network structure associated with arousal level decrease during wakefulness. The analysis identified that the DMN and visual area is prominently influenced by decrease of arousal level. Thirdly, our study found that the optokinetic nystagmus (OKN), which is a reflective eye movement, is also affected by slight decrease of arousal level during wakefulness with eyes-opened. Our consequent research shows that the brain network structure is altered by decrease of arousal even participants feel they are perfectly awake.
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