Intelligent people are faster when tackling simple tasks but take longer to solve complex problems compared to people with lower IQ scores, according to a study published in Nature Communications. The researchers claim that people with poor synchrony between different brain areas can easily jump to conclusions when making decisions rather than wait for the brain to fully process all the information to solve the problem. As a result, people with a high IQ take longer to solve problems but make fewer mistakes.
Researchers at the BIH and Charité – Universitätsmedizin Berlin used multiple computers to simulate how different areas of the brain work together to make decisions. “We want to understand how the brain’s decision-making processes work and why different people make different decisions,” said Prof. Petra Ritter, head of the Brain Simulation Section at the Berlin Institute of Health at Charité (BIH) and at the Department of Neurology and Experimental Neurology of Charité – Universitätsmedizin Berlin.
The team scanned over 600 participants (MRI scan) to create these models and used mathematical models of different biological processes. The first step was to produce a general human brain model, which was then refined using data from individual participants to create personalised 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.”
Participants were asked to follow logical rules in a series of patterns. Patterns became increasingly complex and harder to identify with each step. The team found that slower brains — those that take longer to make decisions — tend to be more synchronised and with better connections between different brain areas. This means the frontal lobe will wait to make a decision until it has all the information processed in different parts of the brain. In contrast, brains that make fast decisions make more mistakes because the brain doesn’t wait for all the different areas to process information.
“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,” explained Michael Schirner, lead author of the study. “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 take 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.”
The team hopes these personalised brain models can be used to help patients dealing affected by neurodegenerative diseases like dementia and Parkinson’s disease, for example. “The simulation technology used in this study has made significant strides and can be used to improve personalized in silico planning of surgical and drug interventions as well as therapeutic brain stimulation. For example, a physician can already use a computer simulation to assess which intervention or drug might work best for a particular patient and would have the fewest side effects,” concludes Schirner.
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