Richard A. E. Edden1,2, Suresh D. Muthukumaraswamy3, Tom Freeman, Krish D. Singh3
1Russell H Morgan Department of Radiology and Radiological Sciences, The Johns Hopkins University, Baltimore, MD, United States; 2FM Kirby Center for Functional fMRI, Kennedy Krieger Institute, Baltimore, MD, United States; 3CUBRIC, School of Psychology, Cardiff University, United Kingdom
Edited MRS measurements of GABA concentration in visual cortex have recently been shown to correlate with functional metrics: the frequency of gamma ocillations, as measured by MEG; and BOLD signal change in fMRI. This study investigates whether these individual differences have behavioural consequences, using a psychophysical paradigm to measure orientation discrimination thresholds. Orientation discrimination has long been associated with GABAergic neurotransmission at a cellular level; we are able to draw a similar link at the level of individual performance differences.