A multimodal cortical network for the detection of changes in the sensory environment.

Sensory stimuli undergoing sudden changes draw attention and preferentially enter our awareness. We used event-related functional magnetic-resonance imaging (fMRI) to identify brain regions responsive to changes in visual, auditory and tactile stimuli. Unimodally responsive areas included visual, auditory and somatosensory association cortex. Multimodally responsive areas comprised a right-lateralized network including the temporoparietal junction, inferior frontal gyrus, insula and left cingulate and supplementary motor areas. These results reveal a distributed, multimodal network for involuntary attention to events in the sensory environment. This network contains areas thought to underlie the P300 event-related potential and closely corresponds to the set of cortical regions damaged in patients with hemineglect syndromes.