A new study by researchers from Tel Aviv University (Israel) and the University of Cambridge (UK) has revealed that interpreting others’ emotions as more positive than they actually are may be an early sign of dementia and cognitive decline.
This trait, which researchers refer to as “positive bias,” tends to develop with age. According to the socio-emotional selectivity theory, it is a mechanism that helps us focus on the good when our future feels less certain. It helps protect mental well-being by diminishing the impact of negative realities.
What Did the Researchers Discover?
Identifying others’ emotions as predominantly positive, according to the researchers, is a sign of cognitive decline and may even serve as an early warning for neurodegenerative diseases, such as Alzheimer’s disease.
The team involved 665 participants aged between 18 and 89, divided into age groups with approximately 10-year differences. Volunteers were asked to recognize emotions on computer-generated faces. Participants underwent brain scans using MRI and were tested for signs of cognitive decline and depression.
As expected, older adults were more likely than younger individuals to identify faces as expressing positive emotions, as reported by Science Alert. In particular, ambiguous or unclear emotions were most often interpreted as positive by older participants.
Brain scan data linked this tendency to lower gray matter volume in the hippocampus and amygdala—regions responsible for processing emotions.
The age-related tendency to perceive facial emotions as positive is associated not only with cognitive decline but also with symptoms of depression, the researchers noted.
This acquired trait supports the theory that positive bias arises from the deterioration of specific brain regions.
These findings complement previous research linking cognitive decline to an inability to recognize emotions, which is also observed in the early stages of Alzheimer’s disease. Scientists have suggested that the brain regions responsible for recognizing others’ emotions may be damaged in cases of developing dementia.
Negative emotions presented in these experiments, such as anger, fear, and sadness, were harder to identify than positive ones like happiness, which partly explains the results.
Neurobiologist Noham Volpe, the lead author of the study from Tel Aviv University, stated: “We are currently investigating how these results relate to older adults who show early signs of cognitive decline, especially those exhibiting signs of apathy, which is often another early indicator of dementia.”
The study’s findings were published in the journal Neuroscience.
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