During experiments on monkeys, neuroscientists were able to decipher the mechanism of procrastination and explain why people put off certain tasks for later.
During experiments on monkeys, neuroscientists were able to decipher the mechanism of procrastination and explain why people put off certain tasks for later.
According to a recent scientific study cited by Wired, the brain avoids unpleasant tasks, even if they promise a reward.
The reason why you decide to postpone important household or work tasks and waste time browsing social media or other fruitless pastimes can be explained by the work of one of the neural circuits in the brain.
Indeed, recent studies have identified a distinct neural pathway responsible for delaying the initiation of actions associated with unpleasant experiences, even when these actions offer a clear reward upon completion.
The study, led by Kyoto University neuroscientist Ken-ichi Amemori, aimed to analyze the brain mechanisms that reduce motivation to act when a task is associated with stress, punishment, or discomfort.
The scientists conducted an experiment with macaques that were trained to perform various decision-making tasks. In the first stage of the experiment, the animals were given limited access to water and could press one of two levers that gave them access to different amounts of liquid. One option offered a smaller reward, the other a larger one.
This experiment allowed us to assess how reward affects the willingness to perform an action.
The next stage of the experiment included an unpleasant moment for the animals: the monkeys were offered the choice of drinking a moderate amount of water without negative consequences for themselves or drinking a larger amount of water on the condition of receiving a direct stream of air in their muzzle. Although the reward for choosing the second option was greater, it was accompanied by discomfort.
«As the researchers expected, the macaques’ motivation to complete the task and access the water decreased significantly after the introduction of an unpleasant stimulus. This behavior allowed them to identify a brain circuit that acts as a brake on motivation in the face of the consequences of expected adverse situations,» the publication writes.
In particular, it was found that the connection between the ventral striatum and the ventral pallidum, two brain structures located in the basal ganglia, is involved in this case. They are known for their role in regulating pleasure, motivation, and reward systems.
Neural analysis has shown that when the brain anticipates an unpleasant event or potential punishment, the ventral striatum is activated. It sends an inhibitory signal to the ventral pallidum, which is normally responsible for the intention to perform an action. In other words, this message reduces the impulse to act when the task is associated with a negative experience.
To find out the specific role of this connection, the researchers used a chemogenetic method: by administering a specialized drug, the connection between two areas of the brain was temporarily disrupted. Thanks to this, the monkeys regained their motivation to perform tasks — even in tests that involved blowing air into their faces.
This result suggests that the circuit does not regulate motivation in general, but rather is specifically activated to suppress it when discomfort is anticipated. In this sense, apathy towards unpleasant tasks seems to develop gradually as communication between these two brain regions increases.
In addition to explaining why people tend to unconsciously resist starting household chores or uncomfortable commitments, these findings also have important implications for understanding disorders such as depression or schizophrenia.
However, Amemori emphasizes that this circuit serves an important protective function. «Overloading is very dangerous. This circuit protects us from burnout,» he said in comments published in the journal Nature.
Therefore, the scientist warns that any attempt to externally modify this neural mechanism should be approached with caution. He believes that further research is needed to avoid interfering with the brain’s natural protective processes.
