Fig. 5.

Schematic model of dynamic bottom–up and top–down interactions underlying attentional control. Stage 1 About 150 ms post-stimulus primary sensory areas detect a deviant stimulus as indexed by the mismatch negativity (MMN) component of the evoked potential. Stage 2 This “bottom–up” MMN signal is transmitted to other brain regions, including the anterior insula (AI). The anterior insula provides selective amplification of salient events and triggers a strong response in the anterior cingulate cortex (ACC). Stage 3 About 200–300 ms post-stimulus, the ACC generates a “top–down” control signal as indexed by the N2b/P3a component of the evoked potential. This signal is simultaneously transmitted to primary sensory and association cortex, as well the central executive network. Stage 4 About 300–400 ms post-stimulus, neocortical regions, notably the premotor cortex and temporo-parietal areas, respond to the attentional shift with a signal that is indexed by the time-average P3b evoked potential. Stage 5 The ACC also facilitates response selection and motor response via its links to the midcingulate cortex, supplementary motor cortex, and other motor areas (adapted from Crottaz-Herbette and Menon 2006)