The Effects of Tapping Force and Speed on the Activation of Motor-related Cortices

This single participant functional magnetic resonance imaging (fMRI) study investigates the effects of tapping force and speed on the activation characteristics in motor-related cortices during bilateral self-paced tapping of hand fingers. The participant performed four types of self-paced hand finger tapping which are soft-slow (SS), soft-fast (SF), hard-slow (HS) and hard-fast (HF) in an fMRI scan. A general linear model (GLM) was implemented in generating brain activation. Statistical inferences were then made about the brain activations using Gaussian random field theory (RFT) at corrected signifiant level (α = 0.05), given that there is no activation. The results indicate that the brain coordinates bilateral selfpaced tapping of hand fi ngers with the involvement of motor-related cortices which are bilateral precentral gyrus (PCG), bilateral cerebellum and supplementary motor area (SMA). The increase in tapping force accentuate significant activation (p 0.05 corrected) in bilateral PCG (Brodmann Area (BA) 6) in accordance with its function in triggering motor action such as controlling the tapping force. The increase in tapping speed causes a signifi cant (p 0.05 corrected) increase in brain activation only in somatosensory associated region in the right superior parietal lobule (SPL) or right BA7. This suggests that SPL plays important roles in coordinating purposeful, skilled movements.