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.