A healthy brain is critical for performing every day cognitive tasks. However, researchers from the University of Illinois discovered that it's important to have a healthy brain metabolism when it comes to solving unusual issues or complex problems, otherwise known as fluid intelligence.
During this recent study, researchers measured concentrations of the molecule N-acetyl asparatate (NAA), which is a marker of metabolic activity in the brain, when using magnetic resonance spectroscopy. Then, they examined the relationship between NAA concentrations in different 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."
Previous research relating MR spectroscopy data to cognition has been rather inconsistent. One explanation may be a failure to account for relevant factors that relate to cognition, including brain size, in their analyses, Nikolaidis said, and a goal of the current study was to address these previous 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. During the study, researchers were also able to create a more detailed map of NAA concentration in the brain than previous studies had.
Findings showed that NAA concentration in an area of the brain linked to motor abilities in both the frontal and parietal cortices were specifically linked to fluid intelligence. However, they were not linked to other closely related cognitive abilities.
Nikolaidis said that the brain's motor regions hold a role in both planning and visualizing movements that are carried out. These findings, in particular, reveal that mental visualization is key when it comes to fluid intelligence and that fluid intelligence depends on brain metabolism and health to function properly.
It's important to remember that overall brain size does not readily change. However, NAA levels and brain metabolism can be influenced by certain health interventions, including cognitive training, diet and exercise.
The study was published in the journal Cerebral Cortex.
