|Budget Amount *help
¥2,700,000 (Direct Cost: ¥2,700,000)
Fiscal Year 2000: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 1999: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 1998: ¥1,400,000 (Direct Cost: ¥1,400,000)
Using a clinical MRI machine (GE Horizon 1.5 T), we conducted the functional magnetic resonance imaging (fMRI) experiments. Two kinds of methods were employed for the image acquisition, i.e. the whole brain image and the selected plane image. Statistical parametric mapping (SPM) method was mainly employed for the statistical image analysis.
Primary motor area and pre-motor area were activated under the finger opposition tasks. Phase shift was observed between two regions, suggesting the time-dependent phase delay (correlation) between two regions.
Broca's and frontal association area were activated during the word generation task. On the other hand, no activation was observed around the classical language area for the stuttering subjects. Instead, the activation of the anterior cingulate gyrus in the opposite side was observed. This is quite curious in light of the function of the anterior cingulate.
V2, V3, V5, IPS, STS and Broca's area were significantly activated by the stereopsis of the random dot stereogram based on the binocular disparity, indicating that the M-pathway is mainly involved. Frequency labeled multiple task (FLMT) method has been developed in order to analyze the inter-task interference. Broca's area did not interfere with other tasks, but not activated during monocular stereopsis, suggesting that this region is definitely involved in the distance evaluation from the binocular disparity. However, we could not observe any phase shift between the activated areas, suggesting that the stereopsis is processed in the human brain quite rapidly.
MTC-EPI method has been successfully applied to the finger opposition task. MTC-EPI was more sensitive to the brain activation compared to ordinary EPI using only the BOLD effect. On the other hand, MTC-EPI is not much sensitive for stereopsis so far. MTC-EPI may be advantageous for the localized activation. However, to conclude this, further investigation would be required.