Authors:

EWBANK, M.P., Fox, E., CALDER, A.J.

Reference:

Year of publication:

2009

CBU number:

7060

Abstract:

Angry and fearful facial expressions represent two qualitatively different forms of threat. Fearful faces have been proposed to signal the presence of an undetermined source of danger within the environment, referred to as ‘ambiguous threat’, while angry faces represent a more direct form of threat, often used in face-to-face encounters. Behavioural evidence shows that angry facial expressions are perceived as more threatening, and elicit greater anxiety, when their gaze is directed at, rather than away from the observer. By contrast, the influence of gaze on the processing of fearful faces is considerably less consistent, with a number of studies showing no effect of gaze on the perceived intensity of threat. Using fMRI, we addressed the influence of gaze on the neural response to these two expressions, taking account of recent evidence showing that the amygdala response to signals of threat is determined by participants’ level of anxiety. We found that the amygdala response to direct, but not averted gaze angry faces increased as a function of anxiety. For fearful expressions, however, we found amygdala correlations with anxiety irrespective of gaze direction. In addition, the effects of anxiety and gaze on emotional intensity ratings of the faces mirrored the effects found in the amygdala. Our results are difficult to reconcile with the proposal that the amygdala is preferentially involved in the processing of ambiguous threat, and accord more with the suggestion that the this region is involved in coding threat signals with personal relevance.