GABA, not BOLD, reveals dissociable learning-dependent plasticity mechanisms in the human brain.
Published version
Peer-reviewed
Repository URI
Repository DOI
Change log
Authors
Abstract
Experience and training have been shown to facilitate our ability to extract and discriminate meaningful patterns from cluttered environments. Yet, the human brain mechanisms that mediate our ability to learn by suppressing noisy and irrelevant signals remain largely unknown. To test the role of suppression in perceptual learning, we combine fMRI with MR Spectroscopy measurements of GABA, as fMRI alone does not allow us to discern inhibitory vs. excitatory mechanisms. Our results demonstrate that task-dependent GABAergic inhibition relates to functional brain plasticity and behavioral improvement. Specifically, GABAergic inhibition in the occipito-temporal cortex relates to dissociable learning mechanisms: decreased GABA for noise filtering, while increased GABA for feature template retuning. Perturbing cortical excitability during training with tDCs alters performance in a task-specific manner, providing evidence for a direct link between suppression and behavioral improvement. Our findings propose dissociable GABAergic mechanisms that optimize our ability to make perceptual decisions through training.
Description
Keywords
Journal Title
Conference Name
Journal ISSN
2050-084X
Volume Title
Publisher
Publisher DOI
Sponsorship
Alan Turing Institute (EP/N510129/1)
Biotechnology and Biological Sciences Research Council (BB/P021255/1)
Wellcome Trust (205067/Z/16/Z)
Leverhulme Trust (RF-2011-378)
Medical Research Council (MC_UU_00005/14)