Involvement of Selective Attention in Somatosensory Extinction and its Relation to Conscious Stimulus Perception: Evidence from Event-Related Potentials (ERPs)

Conscious perception of a weak somatosensory „target“ stimulus can be suppressed in a significant number of trials by a rapidly succeeding higher-intensity „mask“ stimulus applied to the contralateral finger at an ISI of 50–100 ms. A recent fMRI analysis of such somatosensory backward-masking (Blankenburg et al. NeuroImage 2003; 19: 1432) revealed comparable activations for perceived and extinguished targets in the contralateral primary somatosensory cortex. When the target was consciously perceived, there was additional bilateral BOLD activity in the inferior parietal cortices and frontal insulae. In the presen…