Research: Facing the fear

3 April 2006

The brain registers frightened faces unconsciously, even if conflicting facial expressions are present, experiments reveal.

Although we are normally conscious of other people's facial expressions, we can sometimes register this information without being consciously aware of it.

But what happens when the brain is confronted with conscious and non-conscious stimuli? To answer this question, a team including Professor Ray Dolan from the Wellcome Department of Imaging Neuroscience at UCL, and colleagues in The Netherlands, performed a series of experiments on an individual with normal sight in one half of visual space, and blindness – but residual subconscious vision – in the other half.

To examine conscious and non-conscious recognition, they presented a range of pictures to the seeing and 'blind' visual fields respectively.

Greater activity was seen in parts of the brain associated with emotional processing when frightened faces were shown to either visual field, indicating that facial expressions can be registered even in the absence of conscious awareness. A frightened face in the blind field enhanced the response to a frightened face in the intact field. Strikingly, even if the seeing visual field was presented with a happy face, a frightened face presented in the blind field still triggered an emotional response – conscious awareness fails to swamp the unconscious negative response.

This influence appeared to be restricted to faces – other images with negative emotional connotations (such a pit bull terriers and snakes) did not show similar effects.

Image credit: Shelley James

External links

• de Gelder B et al. Unconscious fear influences emotional awareness of faces and voices. Proc Natl Acad Sci USA 2005;102(51):18682–7.