title: GABA predicts time perception.
abstract: Our perception of time constrains our experience of the world and exerts a pivotal influence over a myriad array of cognitive and motor functions. There is emerging evidence that the perceived duration of subsecond intervals is driven by sensory-specific neural activity in human and nonhuman animals, but the mechanisms underlying individual differences in time perception remain elusive. We tested the hypothesis that elevated visual cortex GABA impairs the coding of particular visual stimuli, resulting in a dampening of visual processing and concomitant positive time-order error (relative underestimation) in the perceived duration of subsecond visual intervals. Participants completed psychophysical tasks measuring visual interval discrimination and temporal reproduction and we measured in vivo resting state GABA in visual cortex using magnetic resonance spectroscopy. Time-order error selectively correlated with GABA concentrations in visual cortex, with elevated GABA associated with a rightward horizontal shift in psychometric functions, reflecting a positive time-order error (relative underestimation). These results demonstrate anatomical, neurochemical, and task specificity and suggest that visual cortex GABA contributes to individual differences in time perception.
authors.affiliation: Department of Experimental Psychology and Centre for Functional MRI of the Brain, Nuffield Department of Clinical Neurosciences, John Radcliffe Hospital, University of Oxford, Oxford OX3 9DU, United Kingdom, and Douglas Mental Health University Institute and Department of Psychiatry, McGill University, Verdun, Québec H4H 1R2, Canada.
authors.forename: Devin B
authors.initials: DB
authors.lastname: Terhune
authors.forename: Sonia
authors.initials: S
authors.lastname: Russo
authors.forename: Jamie
authors.initials: J
authors.lastname: Near
authors.forename: Charlotte J
authors.initials: CJ
authors.lastname: Stagg
authors.forename: Roi
authors.initials: R
authors.lastname: Cohen Kadosh
mesh_terms: D000293:Adolescent; D000328:Adult; D005260:Female; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D010775:Photic Stimulation; D013998:Time Perception / Q000502:physiology*; D014793:Visual Cortex / Q000378:metabolism*; D014796:Visual Perception / Q000502:physiology; D005680:gamma-Aminobutyric Acid / Q000378:metabolism*
chemical_list: D005680:gamma-Aminobutyric Acid