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hubie [soylentnews.org] writes:

Do intelligent people think faster? [bihealth.org]

There are 100 billion or so neurons in the human brain. Each one of them is connected to an estimated 1,000 neighboring or distant neurons. This unfathomable network is the key to the brain's amazing capabilities, but it is also what makes it so difficult to understand how the brain works.

[...] To simulate the mechanisms of the human brain, Ritter and her team use digital data from brain scans like magnetic resonance imaging (MRI) as well as mathematical models based on theoretical knowledge about biological processes. This initially results in a "general" human brain model. The scientists then refine this model using data from individual people, thus creating "personalized brain models."

[...] "We can reproduce the activity of individual brains very efficiently," says Ritter. "We found out in the process that these in silico brains behave differently from one another – and in the same way as their biological counterparts. Our virtual avatars match the intellectual performance and reaction times of their biological analogues."

Interestingly, the "slower" brains in both the humans and the models were more synchronized, i.e., in time with one other. This greater synchrony allowed neural circuits in the frontal lobe to hold off on decisions longer than brains that were less well coordinated. The models revealed how reduced temporal coordination results in the information required for decision-making neither being available when needed nor stored in working memory.

Resting-state functional MRI scans 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 could determine that brains with reduced functional connectivity literally "jump to conclusions" when making decisions, rather than waiting until upstream brain regions could complete the processing steps needed to solve the problem.

[...] "Synchronization, i.e., the formation of functional networks in the brain, alters the properties of working memory and thus the ability to 'endure' prolonged periods without a decision," explains Michael Schirner, lead author of the study and a scientist in Ritter's lab. "In more challenging tasks, you have to store previous progress in working memory while you explore other solution paths and then integrate these into each other. This gathering of evidence for a particular solution may sometimes takes longer, but it also leads to better results. We were able to use the model to show how excitation-inhibition balance at the global level of the whole brain network affects decision-making and working memory at the more granular level of individual neural groups."

Journal Reference:
Schirner, M., Deco, G. & Ritter, P. Learning how network structure shapes decision-making for bio-inspired computing. Nat Commun 14, 2963 (2023). https://doi.org/10.1038/s41467-023-38626-y [doi.org]

Original Submission