Article

Converging evidence suggests a specific role for the orbitofrontal cortex (OFC)
in processing of reinforcer value and stimulus hedonicity. However, in a recent
study posterior parts of the OFC were also activated in the absence of physical
reward or positive reinforcement, namely when affectively neutral stimuli were
perceived as salient and required an immediate adjustment of behaviour. This
suggests that the OFC may be similarly responsive to different types of
behaviourally significant events irrespective of their affective valence or the
associated response demands. The present functional neuroimaging study aimed at
testing this hypothesis. By systematically varying the exact nature of the
behavioural significance of experimental stimuli we were able to directly compare
neural responses to significant events that signalled the chance to gain a
monetary reward for correct performance with brain activation related to salient,
but affectively neutral events that occurred unexpectedly and required a rapid
adjustment of behaviour towards these events. The observed commonalities in
orbitofrontal activation for different types of significant events, which
occurred independent of the hedonic value or the actual response requirements,
confirmed the hypothesis that the OFC may be more generally involved in
evaluating the behavioural relevance of salient environmental stimuli and is not
restricted to the processing of reward and positive incentive value. Our findings
thus further underscore the putative role of the OFC in the prioritisation of
attentional selection and behavioural control.
CI - Copyright (c) 2011 Elsevier Ltd. All rights reserved.

Langue : ANGLAIS