Neuroscientist Vasily Klyucharev explains how our brain makes decisions, how they are influenced by the opinions of other people, and what neurons have in common with bees.
Every second we make a lot of decisions. From the point of view of neuroeconomics, our behavior consists of constant moments of choice between different options for action. For example, when we read a book, we determine for ourselves what language the text is written in, what the meaning of the words is, we try to guess what will happen next. There are decisions that are given to us simply, such as whether to eat an apple or a pear for lunch. But if you have an apple and a piece of cake in front of you and you are on a diet, the task becomes more complicated. One way or another, the need for choice haunts us all the time.
How does the decision making process work in the brain? To do this, neuroscientists Mike Shadlen (Michael Shadlen) and Bill Newsome (Bill Newsome) proposed using the so-called diffuse model. Suppose you have a choice of two options. You begin to accumulate information – you choose evidence from the external environment in favor of both decisions. This process continues until a certain decision threshold is reached. And then you make a choice. There are detector neurons in the brain that collect information coming to them from other areas. It, in turn, is accumulated by other neurons – integrators, which are “responsible” for choosing one of the options.
Neuroeconomics – interdisciplinary direction in science at the intersection of economics, neurobiology and psychology. It studies the decision-making process in the choice of alternatives, the distribution of risk and reward.
Fighting neurons
Since there can be several solutions, a struggle arises between neurons. For example, you see a picture in front of you, but you cannot distinguish whether it is a house or a face. Recognition includes areas of the brain that are sensitive to houses and areas that are sensitive to faces. Both groups strive to provide integrator neurons with as much evidence as possible in favor of their version. Let’s say one of the integrator neurons accumulates more data from a group of “houses”. At some point, he reaches the “decision threshold” – and we see the house! At the same time, the neuron suppresses the activity of “competitors” who also strive to reach the threshold.
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Influenced by others
The diffuse model can be used not only in neuroscience, but also in the study of social perception. We are often influenced by those around us. Often, even the number of “likes” under a post on Facebook determines how we will react to what is written. The question arises – how do others influence us? And what exactly do they affect? Other people’s behavior can even make us see certain things. We all know about situations of mass religious visions. And how to explain why believers, looking at a piece of toasted bread, suddenly begin to “see” in it the face of a saint? From the perspective of our model, the opinions of others somehow change how we process information.
We have done a simple experiment. The subjects were presented with “noisy” stimuli (illegible pictures) in which the image of a face or a car was encrypted, and they were required to answer as quickly as possible what they see. Before that, they asked the opinion of the group. We manipulated it, the group’s decisions were faster and more accurate than the decisions of the subjects. The results showed that the group influenced the subjects, forcing them to analyze the information more deeply, to pull out something from it that they themselves would not have guessed to find.
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- Make a choice: why is it so difficult
What are the bees dancing about?
Colleagues who study decision making in groups of bees use the same model in a strange way. It is known that bees can communicate with each other – for example, transmit information about the source of food and the direction to it. How does a group of bees decide to take off and fly towards the food? They create a swarm. At first, the scout bees conduct reconnaissance, looking for a good place. Returning back to the colony, they begin to dance, indicating in their dance the quality of the place and the direction to it. At some point, there are already many different scouts who “advertise” different directions. Some scouts involve others in their dance. Gradually, one of the directions is gaining more and more supporters, and at some point all the scouts are already dancing in this direction. And then the whole swarm takes off and flies to where the most scouts show. You can see a similarity between the behavior of bees and neurons. This similarity is probably no coincidence. This is what neuroeconomics seeks to find a common language with which you can study the same processes at different levels of complexity.
Vasily Klyucharev – Neuroscientist, specialist in the neurobiological foundations of social behavior and neuroeconomics, lecturer at the Higher School of Economics. The material was prepared on the basis of a lecture given at the psychological conference “Fork” on April 19, 2015.