University Of Arkansas Researchers Tease Out The Role Of Disgust In Phobias

Disgust may explain why one phobia in particular–fear of needles, blood and invasive procedures–has proved so difficult to treat, so Lohr and his colleagues are working to separate the emotions of fear and disgust in phobias.

"This one phobia always seems to have different results" when therapists try to address it, said graduate student Suzanne Meunier.

Lohr, Meunier and graduate student Bunmi Olatunji presented their findings at a recent meeting of the Association for the Advancement of Behavior Therapy in Reno, Nevada.

Researchers who treat phobia as a matter of simple fear may do so to their client’s peril, said Lohr.

"If you’re looking to try to change the behavior, there may be different mechanisms for changing loathing than for changing fear," Lohr said.

They have focused on fear and loathing of blood and guts, otherwise known as blood-injection-injury phobia. This phobia often manifests as a fear of needles, and people who suffer from it will avoid doctor’s offices or donating blood. This fear seems to involve a large disgust component, the "yuck!" factor, as opposed to the "yeow!" factor.

To separate the two emotions, the researchers first wanted to determine that people with and without blood-injection-injury fears could distinguish between them. They created images that might elicit fear or disgust–including images of surgeries, needle sticks, rotting food and feces–and images that depicted neutral scenes, such as piles of tools or kitchen utensils. The subjects were then shown an image on the left side of a screen for about eight seconds, and a facial expression on the right side of the screen for about two seconds. The facial expressions showed images of people expressing disgust (nose wrinkled, mouth scrunched up, eyes squeezed shut), fear (eyes and mouth open wide) or neutrality. Each picture was paired at different times with each facial expression. When asked to rate what percent of the time each face was paired with a picture, people paired the surgery and injection images with both fearful and disgusted expressions and the rotting foods and bodily function images with disgusted expressions. The students also paired the neutral expressions with neutral images. They did this even though each image was shown with each expression the same number of times.

"Their perceptions were inaccurate," Meunier said. They were associating the expressions in a biased manner with what they perceived to be the disgusting or fearful object.