This, I surmised, from a side-note in a study that otherwise was very interesting in and of itself.
Facial expressions have greater impact on kids with bipolar disorder
Children with bipolar disorder respond differently to facial expressions than children without psychiatric disorders, according to a new study led by a Bradley Hospital researcher. [...]
The study included 23 children with bipolar disorder and 22 typically developing children without psychiatric disorders between the ages of 7 and 17. Dickstein and his team used functional magnetic resonance imaging (MRI), a non-invasive technique that localizes regions of the brain activated during cognition and experience, to scan the children while they â€œencodedâ€ different facial expressions.
During the MRI scan, the children viewed photos of 32 different actors â€“ eight actors each displaying one of four emotions (angry, fearful, happy and neutral) â€“ from standard gray-scale photograph sets of facial expressions. After seeing the photos four times, they rated each face by answering questions such as â€œHow afraid are you”â€ â€œHow hostile is the face”â€ and â€œHow wide is the nose”â€
Thirty minutes after the MRI scan, children were given a surprise out-of-scanner memory task, during which they viewed 48 actors (half of which were seen previously during the MRI and half that were not previously viewed). They were then asked whether they recalled seeing the face during the earlier test.
During the encoding of â€œhappyâ€ faces, researchers observed increased activity in the region of the brain (striatum) associated with rewards in the children with bipolar disorder. Increased activity was also found in the part of the brain (orbitofrontal cortex) liked to irritability when the same children encoded â€œangryâ€ faces. Brain activity in both instances was significantly greater than in children without bipolar disorder.
Based on the number of correct identifications during the memory task, Dickstein and colleagues also found that children with bipolar disorder demonstrated reduced memory for emotional faces as compared to children without bipolar disorder â€“ particularly with “fearful” faces. (Source: Eurekalert)