Scientists talked about the impact of uncertainty on decision-making
When the rules of a task change and a person is not sure what to pay attention to, the brain continues to take into account unnecessary visual details. They interfere with the processing of important information and increase the likelihood of errors. This is the conclusion reached by researchers at the University of Chicago who studied the behavior of humans and monkeys. Why it becomes more difficult to concentrate after a task change and what scientists have discovered in the visual cortex is in the Izvestia material.
Why changing tasks leads to errors
The ability to adjust thinking and behavior when a situation changes is called cognitive flexibility. It allows you to switch between tasks, take into account new conditions, and abandon rules that no longer apply.
However, moving on to another task usually takes time. According to one of the lead authors of the study, Cheng Xue, decades of psychological experiments show that immediately after switching, people act more slowly and make mistakes more often. This happens even with healthy young participants.
"Even healthy young people have difficulties when they combine several tasks," the study said.
The team decided to find out what processes in the brain can explain such errors. The researchers were interested in a situation where a person or animal sees the necessary information, but does not fully understand which rule should be applied now.
How did the experiment go?
Humans and monkeys were shown images and asked to perform one of two visual tasks. For the correct answer, it was necessary to take into account one feature of the picture, ignoring the other.
During the experiment, the rule changed. A feature that previously needed to be paid attention to could become insignificant, and a previously unnecessary one could acquire significance. The participants had to determine which task to perform at the moment.
Under conditions of uncertainty, accuracy decreased. To understand the reasons, scientists have trained an artificial neural network to reproduce real decisions of monkeys, including errors. Then they created a second model that learned how to answer correctly.
This comparison made it possible to study which features of information processing are associated with the wrong choice. The model, which replicated the behavior of animals, pointed to a possible mechanism: information about an unnecessary feature interfered with the processing of the one that determined the correct answer.
The model's predictions were tested in additional behavioral experiments with humans, by analyzing the neural activity of monkeys, and by using small artificial influences on their visual cortex.
How unnecessary information shifts the choice
The mistakes turned out to be natural. The value of the feature that should have been ignored shifted the answers in a certain direction. The authors called this effect feature interference, the mutual influence of their representations in the brain.
"When we're not sure which rule is in effect, the brain holds onto information that it should ignore," Xue explained.
According to him, neural representations of different visual characteristics are not completely separated from each other. Therefore, the remaining information about an unnecessary feature can affect the processing of an important one and change the final decision.
Behavioral experiments provided additional confirmation: with unclear rules, people were better able to remember an image characteristic that was not required for the chosen task. In other words, this information continued to be processed, although it did not help to answer correctly.
The researchers found signs of this mutual influence in the primary visual cortex, designated V1. This is an area involved in the early processing of visual information. From neural signals usually associated with one feature, it was possible to obtain information about another.
Stimulation of one V1 region shifted the estimates of both characteristics in the direction predicted by the model. Thus, the results were consistent on several levels: in behavior, computer modeling, and neural activity.
The work points to one of the mechanisms for reducing accuracy with uncertainty. According to the authors' interpretation, some errors may occur due to the mutual influence of visual information, and not only due to limited attention resources.
What does this tell you about cognitive flexibility?
The authors plan to find out whether similar error patterns differ in different neuropsychiatric conditions. If such differences can be confirmed, they could potentially help in the development of diagnostic approaches and more targeted interventions in the future.
"We want to find out if error patterns can serve as distinguishing features of specific disorders," Xue said.
For now, we are talking about the direction of further research. The described experiments do not provide a ready-made method of early diagnosis and do not allow us to judge the presence of the disease by the difficulties of switching between everyday tasks.
Xue also suggested that the transition between tasks can be facilitated by a short pause: first finish one thing, then do something simple, such as tidy up the desktop, and only then proceed to the next. However, the effectiveness of this method was not tested in the described study.
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