Scientists have revealed the brain's ability to build a map of human emotions

The human brain can organize knowledge about emotions according to the principle of a coordinate grid, similar to how it navigates in physical space. Scientists have discovered that a certain area of the brain encodes emotional states, taking into account their relative location in the conventional space of feelings. This helps to explain how a person compares different experiences and uses emotional experience when assessing what is happening. How the brain builds a map of emotions is described in the Izvestia article.

The brain builds a map of emotions

This is the conclusion reached by researchers from Emory University in the USA. They found a characteristic signal in the ventromedial prefrontal cortex, an area of the brain that is involved in evaluating information and making decisions. According to scientists, it encodes emotional concepts according to the principle of a grid coordinate system. The results of the work are published in the journal PLOS Biology.

We are not talking about a literal map on which each feeling occupies a separate cell. Researchers have identified a pattern in brain activity characteristic of the so-called grid coding. A similar principle was previously discovered when studying how the brain represents physical space and other abstract concepts. Now scientists have shown that it can also be used to organize knowledge about emotions.

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Two coordinates of emotional experience

The model is based on two dimensions — valence and excitation. Valence indicates how pleasant or unpleasant an experience is, and arousal reflects its intensity: from a calm state to a strong emotional uplift. Together they form a so-called emotional space in which different feelings can be positioned relative to each other.

For example, joy is usually associated with positive valence, while fear, anger, and sadness are associated with negative valence. At the same time, fear and surprise can be accompanied by a high level of arousal, while calmness implies a low level. Thus, emotions differ not only in whether they are pleasant or unpleasant, but also in the intensity of the experience. The authors tested whether the brain reflects this coordinate system when processing different emotional signals.

How did the experiment go?

The final analysis included data from 18 people. During functional magnetic resonance imaging (fMRI), they were shown gradually changing facial expressions and sequences of phrases that conveyed different emotional states. Participants had to determine whether the emotional coloring of the stimulus increased or decreased, or the level of arousal, or whether there were no changes.

After the scan, the volunteers additionally evaluated the faces and phrases they saw according to the same two parameters. This allowed the researchers to place stimuli in an emotional space and match them with brain activity. The scientists found that in the ventromedial prefrontal cortex, signals changed in a six-directional manner: activity was related to the direction in which the emotional state changed. Moreover, the pattern was revealed when working with both images of faces and language stimuli.

The researchers did not find a similar retinal signal in the hippocampus, an area of the brain associated with memory. According to the authors, this may indicate a division of functions: the hippocampus is involved in the representation of individual emotional concepts, and the ventromedial prefrontal cortex helps organize the relationship between them.

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What is a feeling card for?

Such a system can help the brain to generalize emotional experience and apply it in new circumstances. If different experiences are not presented in isolation, but are interconnected, it is easier for a person to compare the current situation with already familiar states and assess the possible consequences. The authors suggest that such an organization of knowledge can participate in forecasting and flexible decision-making.

At the same time, the study does not prove that the ventromedial prefrontal cortex independently forms emotions or that without it a person is unable to navigate emotional experience. The work is based on fMRI data, which allows us to observe patterns of activity, but does not establish how much a specific area of the brain is needed for a particular process.

In addition, the sample was small, so scientists will have to test the results on a larger number of participants and find out how the emotional map changes under the influence of individual experience.