Awareness modulates responses of the amygdala and the visual cortex to highly arousing visual threat.

It is still a matter of debate under which conditions the neural processing of emotional stimuli can occur without conscious awareness. Using functional magnetic resonance imaging, we investigated brain responses to highly arousing threat-related versus neutral pictures which were presented very briefly during two backward-masking conditions resulting in either subliminal or supraliminal stimulus processing. Signal detection analysis confirmed the successful experimental manipulation of awareness that effectively prevented stimulus recognition during the subliminal condition. Participants showed stronger responses of the amygdala and extrastriate visual cortex during the supraliminal, but not during the subliminal condition. These results suggest that the processing of highly arousing visual threat requires conscious awareness during backward masking. This contradicts the assumption of pervasive neural responses to emotional stimuli.