Investigation of fMRI Analysis Method to Visualize the Difference in the Brain Activation Timing

In general functional magnetic resonance imaging (fMRI) analysis, the task onset time of the statistical model is typically set according to the timing of stimulation. In this study, using a high temporal resolution fMRI data, we examined the way of dynamically visualizing the difference in the activation timing between the brain activation areas by analyzing the task onset time of the statistical model shifted from the actual stimulation timing.

fMRI data with high temporal resolution was acquired using 3 T magnetic resonance imaging for 10 right-handed healthy volunteers. While being scanned, the volunteers completed a task that comprised two sets of a rest and right hand grip movement task. Statistical Parametric Mapping 12 (SPM12) software was used to analyze fMRI data. After preprocessing, statistical analyses were performed by shifting the task onset time on the statistical model by about 1 second forward or backward from the actual stimulation timing. Activation maps of multiple time phases were then created.

Activity was observed to the left of the primary motor area and the supplementary motor area and to the right of the cerebellum (familywise error rate, P < .05). In the right hand grip movement, the primary motor area and the supplementary motor area were activated from 1.12 to 4.48 seconds earlier than the cerebellum.

Using this analysis method, we visualized the differences in activation timings of different areas of the brain.