Smarter Brains Run on Sparsely Connected Neurons

Summary: A new study reveals the brains of higher IQ people tend to have leaner, yet more efficient neural connections. Researchers report, the more intelligent a person, the fewer dendrites they have in their cerebral cortex.

The more intelligent a person, the fewer connections there are between the neurons in his cerebral cortex. This is the result of a study conducted by neuroscientists working with Dr Erhan Genç and Christoph Fraenz at Ruhr-Universität Bochum; the study was performed using a specific neuroimaging technique that provides insights into the wiring of the brain on a microstructural level.

Together with colleagues from the University of New Mexico in Albuquerque, Humboldt University of Berlin and the Lovelace Biomedical and Environmental Research Institute in Albuquerque, the team from the biopsychology research unit in Bochum published their report in the journal Nature Communications on May 15, 2018.

Intelligence is determined by the number of dendrites

The researchers analysed the brains of 259 men and women using neurite orientation dispersion and density imaging. This method enabled them to measure the amount of dendrites in the cerebral cortex, i.e. extensions of nerve cells that are used by the cells to communicate with each other. In addition, all participants completed an IQ test. Subsequently, the researchers associated the gathered data with each other and found out: the more intelligent a person, the fewer dendrites there are in their cerebral cortex.

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