AUTHOR=Marsman Anouk , Mandl René C. W. , Klomp Dennis W. J. , Cahn Wiepke , Kahn René S. , Luijten Peter R. , Hulshoff Pol Hilleke E. 

TITLE=Intelligence and Brain Efficiency: Investigating the Association between Working Memory Performance, Glutamate, and GABA

JOURNAL=Frontiers in Psychiatry

VOLUME=8

YEAR=2017

URL=https://www.frontiersin.org/journals/psychiatry/articles/10.3389/fpsyt.2017.00154

DOI=10.3389/fpsyt.2017.00154

ISSN=1664-0640

ABSTRACT=<p>Intelligence is a measure of general cognitive functioning capturing a wide variety of different cognitive functions. It has been hypothesized that the brain works to minimize the resources allocated toward higher cognitive functioning. Thus, for the intelligent brain, it may be that not simply more is better, but rather, more efficient is better. Energy metabolism supports both inhibitory and excitatory neurotransmission processes. Indeed, in glutamatergic and GABAergic neurons, the primary energetic costs are associated with neurotransmission. We tested the hypothesis that minimizing resources through the excitation–inhibition balance encompassing gamma-aminobutyric acid (GABA) and glutamate may be beneficial to general cognitive functioning using 7 T <sup>1</sup>H-MRS in 23 healthy individuals (male/female = 16/7, 27.7 ± 5.3 years). We find that a higher working memory index is significantly correlated with a lower GABA to glutamate ratio in the frontal cortex and with a lower glutamate level in the occipital cortex. Thus, it seems that working memory performance is associated with the excitation–inhibition balance in the brain.</p>