Brain Metabolism May Determine Fluid Intelligence

A healthy brain is important to perform regular cognitive tasks, but researchers from the University of Illinois discovered that a healthy brain metabolism helps to solve unusual or complex problems. This comes in the area of fluid intelligence.

Researchers assessed the molecule N-acetyl asparatate (NAA), markers of "metabolic activity" in the brain while using magnetic resonance spectroscopy. They then observed the links between the NAA concentrations in various parts of the brain.

"Fluid intelligence is one of the most useful cognitive measures available," said lead study author Aki Nikolaidis, who led the research with Ryan Larsen, a research scientist at the Beckman Institute for Advanced Science and Technology, and Beckman Institute director Arthur Kramer. "This domain relates to an individual's job satisfaction and salary level, among other real-world outcomes."

Earlier research that related MR spectroscopy data to cognition was not consistent, as it did not account for relevant factors related to cognition, including brain size, in their analyses, Nikolaidis said. The current study tried to address the earlier contradictions.

"We wanted to do a more definitive study with a large sample size and with a higher quality methodological approach of acquiring the data," Nikolaidis said.

Researchers were also able to create a detailed map of NAA concentration in the brain compared to earlier studies.

The NAA concentration in brain regions linked to motor abilities in the frontal and parietal cortices was linked to fluid intelligence, but not to other related cognitive abilities.

Nikolaidis added that the brain's motor regions play a major role in the planning and visualizing movements that are carried out later. The findings reveal that mental visualization is important for fluid intelligence, which depends on brain metabolism and health for effective functioning.

The study was published in the journal Cerebral Cortex.