| Project/Area Number |
17530536
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (C)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
Experimental psychology
|
|---|
| Research Institution | Okayama Prefectural University (2006)
Kanazawa Institute of Technology (2005) |
|---|
Principal Investigator |
HAMADA Yasukazu Okayama Prefectural University, Dept. of systems engineering for sports, Faculty of computer science and system engineering, Professor (90244722)
|
|---|
| Project Period (FY) |
2005 – 2006
|
| Project Status |
Completed (Fiscal Year 2006)
|
| Budget Amount *help |
¥2,500,000 (Direct Cost: ¥2,500,000)
Fiscal Year 2006: ¥1,100,000 (Direct Cost: ¥1,100,000)
Fiscal Year 2005: ¥1,400,000 (Direct Cost: ¥1,400,000)
|
|---|
| Keywords | somatosensory / attention / magnetoencephalofraphy / non-invasive measurement / vision / evoked magnetic field / リファレンスフレーム |
|---|
| Research Abstract |
Attention is one of important mechanism in the brain to select sensory information and to facilitate the information processing. However its neuronal mechanism has not been clearly elucidated. Recent studies using fMRI and MEG have reported neuronal substrates correlated to attentional modulation of cortical activities. My previous studies using MEG also reported that cortical activities in the secondary somatosensory area were increased when the stimuli were applied approximately 400ms after subjects started directing their attention to the finger. In the preset study, I investigated temporal properties of attentional modulation of the somatosensory cortical activities when the hands were in the different positions. The subjects were instructed to direct their attention to a hand indicated by a cue, arrow direction, as soon as possible. After the cue lead time, 200, 300, 400 or 500ms, the electrical current was delivered on the attended index finger. Somatosensory magnetic fields evoked by the current stimuli were measured by using a 160 channel whole head type MEG. Equivalent current dipole (ECDs) moments calculated from the measured fields were compared between the parallel and crossed hand position. The mean ECD moment for the secondary somatosensory activations across the subject tended to increase when the stimuli were applied 400 and 500 ms after the cue onset. The result from one of the subjects showed remarkable difference in the temporal property of the attentional modulation between the two hand position conditions. The attentional modulation appeared with delay of approximately 100 ms in the crossed hand potion condition. This delay might be explained by time for calculation of the hand position. After calculation, the attention was directed a spatial point, at which the hand was located. Although somatosensory attention might be directed with reference of spatial frame rather than body coordinates, further analysis is necessary for this consequence.
|
