Functional interactions guiding adaptive processing of behavioral significance.

The ability to quickly decide on the nature of unexpected environmental changes is vital for adaptive behavior. Converging evidence suggests that the orbitofrontal cortex plays an important role in the rapid assignment of motivational significance and goal relevance to environmental stimuli. However, its putative role as a central part of a network involved in the prioritization of attentional selection, particulary when significant environmental changes occur unexpectedly or outside of attentional focus, remains to be established. Therefore, we used functional magnetic resonance imaging with a subsequent psychophysiological interaction analysis to reveal the functional connectivity of the right posterior orbitofrontal cortex (pOFC) in a context, in which subjects had to adjust goal-directed behavior to behaviorally relevant events presented outside of the current attentional focus. As expected, an increased functional interaction between pOFC and regions involved in the modulation of selective attention (pulvinar nucleus and inferior parietal lobule) and processing of "bottom-up" salience (substantia nigra) could be observed when unattended, but significant changes were relevant for behavior. Moreover, a positive correlation between level of accuracy and an increased functional connectivity between pOFC and extrastriate cortex suggested that a motivationally-triggered signal from pOFC may have increased visual processing of the relevant but currently unattended stimulus attribute. These data provide evidence that the interplay between the pOFC and these regions underlies a mechanism by which organisms rapidly achieve voluntary control of attentional resources to deal with behaviorally significant changes that occur outside of current attentional focus.