Past fMRI Studies
Two fMRI studies that together included more than 30 subjects were carried out with fMRI compatible haptic robot. The first study observed human brain activation during reaching in a virtual environment. The second study observed brain activation during the planning and execution phases of a pattern connection task.
For the first study, a virtual environment application was programmed where a human subject could perform reaching movements. The haptic dimensions of the virtual room are 140 mm x 100 mm x 80 mm. The position of a white cursor ball in the virtual room reflects the position of the end-effector point of the fMRI compatible haptic robot. The virtual environment session consists of four tasks: rest before reaching (RR), target reaching (R), rest before extending (RE) and extending (E) - non-targeted reaching. During the RR and RE tasks the edges of the room are colored red, indicating that the subject should rest. The subject is instructed to observe the room and not perform any movements. When the edges of the room turn green, the subject performs reaching (R task) and arm extension (E task) movements. It is essential that the subject feels the impact with the target located on the back wall during R and E. A complete session consists of eight blocks, each containing four of the above tasks. The duration of each block is 2 min., with 30 s for each task in the block.
Comparison of reaching to the rest reaching task (R–RR) revealed activations in the left primary sensorimotor cortex (SM1), bilateral premotor cortex (PMC), inferior frontal gyrus (IFG), supplementary motor area (SMA), inferior and superior posterior parietal cortex (PPC), visual cortex, left basal ganglia (BG) and predominantly the right cerebellar hemisphere. During extending (E–RE), similar but less prominent brain activations were found, including right SM1, bilateral PMC, IFG, SMA, inferior PPC, visual cortex and right CRB. Direct comparison of reaching to extending (R–E) revealed that areas showing greater activation during R were the bilateral prefrontal cortex, SMA, right visual cortex and right CRB.