The 81st KARC Colloquium
The 81st KARC Colloquium was ended. Thank you for the participation.
| Date&Time | Thursday, January 25th, 2007 14:00-16:00 |
| Place | Conference Room, 3F, Research Building 2,Advanced ICT Research Center |
| Lecturer | "Visualization of human visual processing by combined MEG/fMRI approach" |
| Speaker | Dr. Iwaki Sunao （National Institute of Advanced Industrial Science and Technology, Institute for Human Science and Biomedical Engineering, Senior Research Scientist） |
| Abstracts | Recent neuroimaging studies using functional magnetic resonance imaging (fMRI) techniques suggested the involvement of the parieto-occipital junction, the superior-occipital gyrus, and the ventral occipito-temporal junction in the perception of 3-D structure from motion. Here, we used both neuromagnetic measurements (magnetoencephalography: MEG) and hemodynamic measurements (fMRI) to detect and visualize the dynamic changes in both the evoked brain responses and the spontaneous brain activities related to 3-D structure perception from motion in humans. The event-related time-frequency (TF) wavelet decomposition of the recorded MEG raw signals was used to assess event-related changes in spontaneous oscillatory brain activity. Linearly-constrained minimum-variance beamformer and the fMRI-weighted distributed source modeling technique were used as well to reconstruct brain activities from event-related magnetic field. TF analysis showed significant suppression of alpha and beta band activities in the 3D-SFM condition compared to two other conditions in the parietal and the right occipito-temporal regions, while the analyses of the event-related responses revealed the increased neural activities in the occipito-temporal, parieto-occipital, posterior inferior temporal, and intra-parietal regions during 3D object perception. The results are in agreement with those obtained in the previous fMRI studies, and adding further insights into the temporal characteristics of the activities in these regions. The results were also consistent with the hypothesis that the local suppression of alpha- and beta- band spontaneous brain activities indicates the engagement of these regions to the relevant sensory functions. |
| Language | Japanese |
| Admission | Free |
| Organizer | Tsutomu Murata, Biological ICT Group, Advanced ICT Research Center,National Institute of Information and Communications Technology |