Fig. 4.

In the concurrent TMS-fMRI study by Blankenburg et al. (2008), TMS was applied over right anterior parietal cortex (as indicated schematically by lightning-flash symbols), in the presence or absence of electrical somatosensory stimulation for the right hand, during concurrent whole-brain fMRI. The fMRI data revealed an inter-hemispheric effect of the right parietal TMS. Specifically, the BOLD signal for left S1 (as indicated on the transverse and coronal views here, for slices taken through the MNI coordinate shown) in response to right-hand somatosensory input was enhanced when combined with high intensity (versus low) TMS. See plot on right for the differential TMS effect (high minus low) as a function of the presence or absence of concurrent right-hand somatosensory input. See main text for discussion of how this relates to the previous purely behavioural TMS findings of Seyal et al. (1995) concerning inter-hemispheric effects of right parietal cortex on left-hemisphere somatosensory processing that might potentially relate to clinical somatosensory extinction or neglect after pathological right-parietal disruption