The functioning of the human brain continues to be an enigma despite scientific advances in this field. In this organ there are approximately 100,000 million neurons and the number of synapses or connections that are established between them and that are essential for their survival is even greater. Basic functions such as heart rate or breathing are controlled from the brain and information is sent to the rest of the body, an activity so extensive and complex that it is very difficult to understand.
A new study to unravel the mysteries of our brain has made a curious and surprising finding because, contrary to what one might assume, people with a higher intelligence quotient (IQ) take longer to solve difficult problems than individuals with higher intelligence quotients (IQs). lower IQ scores, and are only faster when faced with simple tasks.
The research was carried out by scientists from the BIH and Charité-Universitätsmedizin Berlin, together with Gustavo Deco, director of the Computational Neuroscience group at Pompeu Fabra University in Barcelona, who verified in personalized brain simulations of the 650 participants that brains with reduced synchrony between brain areas literally “jumped to conclusions” when making decisions, rather than waiting until earlier brain regions could complete the processing steps necessary to solve the problem. In fact, the brain models of the higher-scoring participants also took longer to solve challenging tasks, even though they made fewer mistakes.
“We want to understand how the brain’s decision-making processes work and why different people make different decisions,” said Professor Petra Ritter, Head of the Brain Simulation Section at the Berlin Institute of Health at Charité (BIH) and the Department of Neurology and Experimental Neurology of the Charité–Universitätsmedizin Berlin, referring to this project, which they explain in an article published in Nature communications.
Artificial brains that act like their biological counterparts
Ritter and his team used digital data from brain scans such as magnetic resonance imaging (MRI) and mathematical models based on theoretical insights into biological processes to simulate the mechanisms of the human brain. As a result, they obtain a model of the general human brain, which they then improve using data from individual people to create “personalized brain models”.
In this case, they worked with data from 650 participants in the Human Connectome Project, an American project that has been studying neural connections in the human brain since September 2010. “Our virtual avatars match the intellectual performance and reaction times of their biological analogues,” says Ritter.
They found that the “slower” brains in both humans and models were more in sync with each other. This greater synchrony allowed neural circuitry in the frontal lobe to delay decisions longer than brains that were less coordinated. The models revealed how reduced temporal coordination results in information required for decision making not being available when needed, nor being stored in working memory.
Gathering evidence takes time and allows for correct decision making
Resting-state fMRIs showed that slower solvers had higher average functional connectivity, or temporal synchrony, between their brain regions. In personalized brain simulations of the 650 participants, the researchers were able to determine that brains with reduced functional connectivity literally “jumped to conclusions” when making decisions, rather than waiting until upstream brain regions had time to complete the processing steps required to make decisions. solve the problem.
They asked the participants to identify logical rules in a series of patterns, which became increasingly complex with each task and therefore more difficult to interpret. An easy task, for example, would be to brake quickly at a red light, while a difficult task would require methodically finding the best route on a road map.
In this model, a competition known as “winner takes all” takes place between different neuronal groups involved in a decision, prevailing the neuronal groups for which there is stronger evidence. However, when it comes to making complex decisions, such evidence is often not clear enough for quick decision making, literally forcing neural groups to jump to conclusions.
“Synchronization, that is, the formation of functional networks in the brain, alters the properties of working memory and, therefore, the ability to ‘endure’ long periods without making a decision,” explained Michael Schirner, author Principal of the study and a scientist in Ritter’s lab. “In more challenging tasks, you need to store past progress in working memory while you explore other solution paths and then integrate them with each other. This gathering of evidence for a particular solution can sometimes take longer, but it also leads to better results. We were able to use the model to show how the excitation-inhibition balance at the global level of the whole brain network affects decision making and working memory at a more granular level of individual neuronal groups.”
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