It鈥檚 hard to ignore a face filled with disgust, but people with an unsightly skin disorder seem to have a muted response to such facial expressions. This reduced sensitivity may serve to protect them from hurtful reactions.
, a dermatologist at Manchester University, UK, and colleagues showed people with psoriasis 鈥� a non-infectious skin condition that produces reddening and lesions 鈥� a series of images of faces while scanning their brains.
Images of disgusted faces elicited less activation in the insular cortex, which processes feelings and observations of disgust, compared with a control group. Images of fearful faces produced normal levels of activation in the amygdala, which responds to fear, in both groups.
Advertisement
Volunteers with psoriasis were also less likely to identify disgust in faces that showed only subtle signs of the emotion, compared with controls.
People often react with disgust to psoriasis, even thought it is not infectious, says Griffiths. He reckons the brain adaptations in people with the disease 鈥渆merged to protect people that do not conform to facial norms鈥�.
The psychological burden of the disorder is always far worse than the physical pain, says , a psychodermatologist based in London who specialises in the social effects of skin disorders.
鈥淭his study is fascinating. It鈥檚 the first I know of that shows neurological changes in psoriasis sufferers, but the results don鈥檛 surprise me,鈥� she says. 鈥淧eople with obvious skin disorders often show behavioural changes.鈥�
Journal reference:
