Irrelevant visual details interfere with decisions under uncertainty, brain research shows

A recent study by researchers at the University of Chicago has shed light on how uncertainty can interfere with decision-making, particularly when irrelevant visual details are present. The research, published in Nature Neuroscience, involved both humans and monkeys who were asked to perform visual tasks that required focusing on one feature while ignoring another.

Researchers found that when the rules of these tasks changed suddenly, the brain's ability to process relevant information became impaired, leading to mistakes. This phenomenon, dubbed "feature interference," occurs because the brain holds onto irrelevant information, which then biases decision-making. The researchers used a machine learning model to reproduce the monkeys' choices and then compared this to the performance of a corrected model.

They discovered that mistakes during task switching were not random but followed a predictable pattern. When unsure of the current rule, both humans and monkeys tended to remember the irrelevant feature better, which biased their choices. The team also found that neural signals from the first stage of visual processing could be influenced by irrelevant information, leading to consistent errors.

These findings suggest that deficits in cognitive flexibility, which is common in conditions like Alzheimer's, Parkinson's, schizophrenia, and substance use disorders, may be due to the brain's struggle to separate relevant from irrelevant information. The study could pave the way for more targeted interventions for these conditions and improve existing neurocognitive models of mental flexibility.