Brain damage can cause emotional blindness, while making sideways faces more memorable
Researchers have found people with damage to a crucial part of the brain fail to recognise facial emotions, but they unexpectedly find faces looking sideways more memorable (University of Bath, 2017).
The findings are more evidence that damage to the amygdala affects how facial recognition and gaze perception work in unpredictable ways.
People with amygdala damage, which is common in epilepsy for example, struggle in their understanding of social signals as well as in everyday communication, which can lead to problems in their interactions with friends and family, finding life partners, and progressing with their professional careers. They often feel misunderstood which contributes to lower levels of life satisfaction.
Normally people tend to more readily remember faces showing emotions such as fear or anger than neutral expressions. When people are trying to predict another person’s actions, they decipher their facial expressions and follow their gaze to understand the focus of their attention and eventually of their emotion. This is an important process to understand the implications of the situation for someone’s own wellbeing, which is known as self-relevance, and to interpret social situations and cues.
The amygdala is particularly responsible for the processing of emotion and self-relevance. People with damage to the amygdala have been observed to have emotion recognition deficits while keeping the perception of other people’s eye gaze direction intact.
But now researchers from the University of Bath, working with neurosurgeons and psychologists in Warsaw, have shown that people with amygdala damage remembered faces looking to the side more than those looking towards them, in contrast with previous studies. However, in line with previous research they didn’t remember emotional faces any better than neutral faces.
Sylwia Hyniewska from the Department of Computer Science at the University of Bath said “Surprisingly we found that individuals with amygdala damage remembered faces looking to the side more than those looking towards them. This effect was independent of the emotional content of the face. This was unexpected given that all research so far focusing on other populations showed either an interaction effect between emotion and gaze, or an improved memory for faces looking towards the observer.
“We expected our patients to remember faces better when they were looking at them – presented with the direct gaze. However for some reason patients seem to remember faces looking away better. This means that the interaction between the processing of emotions and gaze is more complex than we thought, and not only emotions but also gaze should be studied further in this specific population to develop treatments improving these patients’ well-being.”
The research is published in Epilepsy and Behaviour.
The team showed forty people with mesial temporal lobe epilepsy (MTLE) and twenty healthy people who were used as controls a series of faces with neutral or emotional expressions. Half were looking straight ahead, and half sideways. As expected healthy people had better recognition of emotional faces. The people with epilepsy did not remember emotional faces any better than neutral ones, but did find patients gazing away more memorable than those looking straight ahead.