Concurrent Multimodal Imaging Demonstrates That EEG-Based Excitation/Inhibition Balance Reflects Glutamate and GABA Balance
Year: 2026
Type: article
Study design: Observational Study
Abstract: Magnetic resonance spectroscopy (MRS)-derived excitation/inhibition (E/I) ratio is recognized as a valuable index of attentional modulation, the plasticity and stability of learning states, and disordered functioning. Inferring the E/I ratio from electroencephalography (EEG), however, offers greater accessibility and superior temporal resolution and therefore holds strong potential for advancing research on dynamic neural processes. Yet, the underlying neurochemical mechanisms contributing to changes in EEG-based E/I ratio remain unclear. In this study we used concurrent EEG and MRS to examine how the EEG-based E/I ratio correlates with the MRS-based E/I ratio in sleeping humans of both sexes ( n = 15). The MRS-based E/I ratio was calculated as the ratio of Glx (glutamate + glutamine) to GABA + (GABA + coedited macromolecules) concentrations in early visual areas. We estimated 10 candidate EEG-based E/I indices using four algorithms across multiple spontaneous frequency bands from the occipital region. Uniquely, we quantified the associations between EEG- and MRS-based E/I ratios by separately analyzing between-subject and within-subject variations. We found that each EEG-based E/I algorithm showed reliable and positive associations with MRS-based E/I, particularly in the alpha band, which is known to play a key role in attentional modulation and in the plasticity and stability of learning states. These results highlight the potential of EEG-based E/I measures to serve as practical indices of neurochemical dynamics in early visual cortex.
Source: Journal of Neuroscience
Institutions: Brown University, RIKEN
Language: English
Subfield: Radiology, Nuclear Medicine and Imaging
Field: Medicine
Domain: Health Sciences
Open Access status: hybrid
Awards: Development and verification of sleep neurofeedback, Role of sleep in learning transfer, Roles of Non-REM and REM sleep in facilitating visual perceptual learning, Comprehensive frameworks of perceptual learning, COBRE Center for Central Nervous System Function, Mechanisms of Perceptual Learning Transfer, Systematic Psychophysical Investigation of Visual Learning
OpenAlex ID: W7131278776