An fMRI study of intentional and unintentional (embarrassing) violations of social norms.

The aim of this investigation was to identify neural systems supporting the processing of intentional and unintentional transgressions of social norms. Using event-related fMRI, we addressed this question by comparing neural responses to stories describing normal behaviour, embarrassing situations or violations of social norms. Processing transgressions of social norms involved systems previously reported to play a role in representing the mental states of others, namely medial prefrontal and temporal regions. In addition, the processing of transgressions of social norms involved systems previously found to respond to aversive emotional expressions (in particular angry expressions); namely lateral orbitofrontal cortex (Brodmann area 47) and medial prefrontal cortex. The observed responses were similar for both intentional and unintentional social norm violations, albeit more pronounced for the intentional norm violations. These data suggest that social behavioural problems in patients with frontal lobe lesions or fronto-temporal dementia may be a consequence of dysfunction within the systems identified in light of their possible role in processing whether particular social behaviours are, or are not, appropriate.