Intelligence vs Thinking Speed

Welcome back. Today’s question: Do people with higher IQs think faster than those with lower IQs?

Sorry, that’s sort of a trick question from the results of a recently published study. The study was part of an effort to simulate the human brain using computers to understand how decision-making processes work and why different people make different decisions.

The researchers were affiliated with the Brain Simulation Section at the Berlin Institute of Health at Charité and the Department of Neurology and Experimental Neurology of Charité--University Hospital in Berlin, with a colleague at the Center for Brain and Cognition, Computational Neuroscience Group, University of Pompeu Fabra in Barcelona.

Brain simulation helps us understand how our brain works (from brainsimulation.charite.de/en/).

Personalized Brain Models
The Berlin researchers begin with a human brain model derived from digital brain scan data, such as magnetic resonance imaging (MRI), and from models based on theoretical knowledge of biological processes. The next step is to refine the general model using data from individuals to produce “personalized” brain models.

Personalized brain models reproduce the activity of the participants’ brains very effectively. They behave differently from one another in the same way as their human counterparts, matching intellectual performance and reaction times.

For the current study, the researchers used data from 650 participants of the Human Connectome Project, a U.S. initiative that has been studying the brain’s neural connections for over a decade. The participants had undergone extensive cognitive testing, and their IQ scores were known.

Higher vs Lower IQ Thinking Speed
In one test (Penn Matrix Reasoning Test), the participants were asked to identify logical rules in a series of patterns. These rules became increasingly complex with each task and more difficult to decipher.

(Answer to trick question) Participants with higher intelligence scores solved simple tasks faster than people with lower IQ scores, but they took longer to solve difficult tasks.

Thinking Speed and Brain Synchronization
MRI scans showed that “slower” solvers’ brains were more synchronized; they had higher average functional connectivity between brain regions. This altered the properties of working memory and thus the ability to endure prolonged periods without a decision.

In essence, tackling more challenging tasks, higher IQ, slower solver brains store progress in working memory while they explore other solutions before integrating all to arrive at a decision. It may take longer yet the results are better.

In contrast, the personalized brain simulations allowed the researchers to determine that brains with reduced functional connectivity literally “jump to conclusions.” Lower IQ brains make decisions, wrong or right, without waiting for upstream brain regions to complete the processing steps needed to solve the problem.

Wrap Up
How are you at decision making?

Me? As I blogged in 2012, I’m big on intuition (ask Myers or her mother, Briggs); but I’m kind of wishy-washy if I don’t have a mountain of information and the results of surveying at least half the people on the East Coast (see: Decision-Making Time).

Thanks for stopping by. Do decide to visit again.

P.S.
Study of how brain network shapes decision-making in Nature Communications journal: www.nature.com/articles/s41467-023-38626-y
Article on study on EurekAlert! website: www.eurekalert.org/news-releases/991304
Human Connectome Project and Connectome Coordination Facility: www.humanconnectome.org/about-ccf