Neural mechanisms underlying attribution of hostile intention in nonaggressive individuals: An ERP study

- Critical words that violate hostile intention expectations elicited an N400 effect.
- N400 effect was significantly correlated with self-report hostile attribution bias.
- Nonaggressive individuals evaluate rapidly, on-line, their attributions of the hostile intent of others.

Although the perception of hostile intentions in other people can have a clear adaptive function, researchers have paid little attention to the capacity of nonaggressive individuals to infer hostile intentions in others. The goal of the present study was to study brain mechanisms associated with expectations of hostile/non-hostile intent and their on-line evaluation. Scenarios with a hostile versus non-hostile social context followed by a character's ambiguous aversive behavior were presented to readers, and we recorded and analyzed event-related brain potentials (ERPs) to critical words that disambiguated the hostile versus non-hostile intent behind the behavior. Fifty nonaggressive individuals participated in the study. Non-hostile critical words that violated hostile intention expectations elicited a larger negative-going ERP deflection with central and posterior maximums between 400 and 600 ms after word onset compatible with an N400 effect. Finally, there were marginally significant correlations between N400 effect sizes and hostile as well as neutral attribution bias measured by a self-report questionnaire. The results suggest that nonaggressive individuals evaluate rapidly, on-line, their attributions of the hostile intent of others. The methodology we developed provides the field with a new paradigm with which to study social attributions of hostile intent likely to contribute to hostile or aggressive reactions.