2023 Author: Bryan Walter | [email protected]. Last modified: 2023-05-21 22:24
The desire to make more risky decisions is explained by fluctuations in the activity of parts of the brain that are part of the dopaminergic system. This was found by British scientists who evaluated how the work of the parts of the brain responsible for the synthesis of dopamine at rest explains risky behavior. It turned out that the lower the activity of the sites examined, the more willingly people take risks, and regardless of how much they can potentially win or lose, scientists write in the Proceedings of the National Academy of Sciences.
Economic models devoted to making consumer decisions in the market do not always correspond to reality - in reality, human behavior is very difficult to predict (you can read more about this, for example, in our small series of blogs on cognitive biases). This is especially noticeable in situations where a decision must be made in conditions of great certainty and when there is some risk. The study of decision making in such situations is successfully studied by experts in the field of behavioral economics, who mainly consider the influence of external factors. However, there are internal factors as well: the way the human brain works has a lot to do with decision making.
This is largely related to the work of the brain's reward system, as well as related areas of the prefrontal cortex responsible for cognitive functions (in particular, for example, for cognitive control, which prevents overly risky decisions). The connection between these two systems is largely ensured by dopaminergic pathways, and the neurotransmitter dopamine itself is one of the key ones not only in ensuring the work of motor functions, but also in the reward system.
Until now, however, it is not completely clear how the individual characteristics of the work of the dopaminergic system outside the influence of external stimuli affect the decision-making process. Scientists from University College London, led by Benjamin Chew, decided to figure this out.
Scientists conducted an experiment using fMRI. In fact, this method does not provide an objective assessment of the work of dopamine in the brain, but it can be traced by the activity of two areas entering the midbrain - in the substantia nigra and in the ventral tegmental area. In these areas, dopamine is synthesized in the greatest amount, and both of them are involved in decision-making at risk.
In total, 43 people took part in the experiment. The researchers assessed the activity of the substantia nigra and the ventral tegmental area using fMRI at rest - that is, without any exposure to an external stimulus - and then divided it into high and low by group. After that, the participants had to go through an experiment in which they were given two options for choosing money. One was relatively safe: by choosing it, the participant received, for example, £ 2.8 to his total winnings. In the second option, with an unknown probability, the participant could either get a prize of six pounds, or get nothing.
Scientists found that if the activity of the substantia nigra and the ventral region of the tire was lower, the participants chose the riskier option in 59.6 percent of the cases, and if it was higher, in 56.2 percent, it was small but significant (p <0, 001) a difference, the size of which is explained by an indirect measurement of the work of the dopaminergic system. At the same time, changes in the activity of the considered zones were not related to what kind of gain the participant could get: participants with reduced activity of the substantia nigra and the ventral region of the tire went for risky behavior, regardless of how much money was at stake. In addition, the activity of the dopaminergic system at rest was also associated with what it would be during the task with the adoption of risky decisions.
The authors concluded that the variability in decision-making in high-risk settings is largely due to fluctuations in the work of dopaminergic neurons before a decision has to be made, and is influenced by it. In fact, the greater preference for risky options with low activity of the substantia nigra and ventral tegmental area is explained by the involvement of these departments in the process of cognitive control, which, apparently, is significantly reduced.
We write quite often about making risky decisions and the factors that influence it (both internal and external). For example, you can read about how sourness and wearing a bicycle helmet makes people take risks (even off the road), and how anxious people's brains keep them from taking risks.