This is how the brain works when macaques and bats interact with their peers
Two studies conducted in rhesus monkeys and egyptian fruit bats have located the neural groups in the prefrontal and frontal cortex, respectively, which are activated when an individual interacts with others.
The articles, published in the magazine Science, aimed to find out how animals that are grouped into large social structures know how to interact with each other, even based on previous meetings.
We deciphered the macaque’s neural activity by finding out its decision before it acted
Raymundo Báez-Mendoza (Harvard University)
In the first article, a team led by the researcher Raymundo Báez-Mendoza, del Hospital General de Massachusetts, Harvard University (USA) arranged three monkeys (Macaca mulatta) on a turntable with apples, and each individual could offer food to their partner in sequence.
Macaques act on the memory of past interactions
Throughout these social interactions, the researchers found that the primates remembered whether their mate had offered them food – or not – in the past, and acted accordingly, retaliating or offering food back.
“We have found a presentation in a population of neurons in the corteza prefrontal dorsomedial that it is more active when the individual in particular acts and receives a reward ”, explains Báez-Mendoza to SINC.
A group of macaques and their relationship highlighted by lines. / J. Sliwa
“We use algorithms based on machine learning to decipher in the neural activity of this area a representation of the previous decision of other individuals. What’s more, we were also able to decode in neuronal activity whether the macaque would correspond to what the other had done previously or would retaliate ”, emphasizes the scientist.
The results suggest that this area in the cerebral cortex, involved in cognitive processes such as memory, attention and temporal planning, among others, plays an important role in decision making strategies, such as evaluating, based on previous interactions, with whom it is most advantageous to interact. This would have repercussions when it comes to understanding the neurobiological processes that are triggered when interacting with others.
The cerebral cortex has an important role in making strategic decisions, such as evaluating, based on previous interactions, with whom it is most advantageous to interact
According to the researcher, the dorsomedial prefrontal cortex is crucial to generate a map of what others are doing. “Treatments that are aimed at improving the functionality of this cortical area, either directly or indirectly, could improve the quality of life of people suffering from neuropsychiatric conditions in which this ability is affected”, indicates Báez-Mendoza.
The vocalizations of fruit bats
In the second study, also published in Science, the team led by Maimon Rose, from University of California at Berkeley (USA) investigated the cortical activity that occurs during group communication processes in the egyptian fruit bat (Rousettus aegyptiacus), mammals that live in large groups and create stable social relationships.
The results reveal that the brain patterns of these animals vary according to social context in which they are, and also attending to the social preferences of the individual.
The brain patterns of bats vary according to the social context in which they are found, and also according to the social preferences of the individual
As part of the study, the scientists made wireless electrophysiological recordings of both spontaneous and task-induced (with training) vocal interactions with these animals, which are guided by echolocation. The scientists found that the activity of individual neurons distinguished between self-produced vocalizations and others, and also distinguished between specific individuals.
A group of four bats. / U. California, Berkeley
On the other hand, they discovered that the group of bats analyzed, by vocalizing, “synchronized their brain activity in a bidirectional way”, a fact that remained stable during the weeks that the recording lasted.
The researchers determined that brain patterns were modulated by the individual’s social preferences. Thus, bats that preferred the company of others showed higher levels of brain synchronization, as well as a greater representation of neural identity with them.
Rights: Creative Commons.