Intersubject variability and induced gamma in the visual cortex: DCM with empirical Bayes and neural fields.
This article describes the first application of a generic (empirical) Bayesian analysis of between-subject effects in the dynamic causal modeling (DCM) of electrophysiological (MEG) data. It shows that (i) non-invasive (MEG) data can be used to characterize subject-specific differences in cortical microcircuitry and (ii) presents a validation of DCM with neural fields that exploits intersubject variability in gamma oscillations. We find that intersubject variability in visually induced gamma responses reflects changes in the excitation-inhibition balance in a canonical cortical circuit. Crucially, this variability can be explained by subject-specific differences in intrinsic connections to and from inhibitory interneurons that form a pyramidal-interneuron gamma network. Our approach uses Bayesian model reduction to evaluate the evidence for (large sets of) nested models-and optimize the corresponding connectivity estimates at the within and between-subject level. We also consider Bayesian cross-validation to obtain predictive estimates for gamma-response phenotypes, using a leave-one-out procedure. Hum Brain Mapp 37:4597-4614, 2016. © The Authors Human Brain Mapping Published by Wiley Periodicals, Inc.
The Picower Institute for Learning & Memory and Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts.|The Wellcome Trust Centre for Neuroimaging, University College London, Queen Square, London, WC1N 3BG.
Dimitris A
DA
Pinotsis
Cardiff University Brain Research Imaging Centre (CUBRIC), School of Psychology, Cardiff University, Park Place, Cardiff, Wales, CF10 3AT, United Kingdom.
Gavin
G
Perry
The Wellcome Trust Centre for Neuroimaging, University College London, Queen Square, London, WC1N 3BG.
Vladimir
V
Litvak
Cardiff University Brain Research Imaging Centre (CUBRIC), School of Psychology, Cardiff University, Park Place, Cardiff, Wales, CF10 3AT, United Kingdom.
Krish D
KD
Singh
The Wellcome Trust Centre for Neuroimaging, University College London, Queen Square, London, WC1N 3BG.
Karl J
KJ
Friston
D000328:Adult; D001499:Bayes Theorem; D005260:Female; D065818:Gamma Rhythm / Q000502:physiology*; D006801:Humans; D015225:Magnetoencephalography / Q000379:methods; D008297:Male; D008959:Models, Neurological; D012815:Signal Processing, Computer-Assisted; D014793:Visual Cortex / Q000502:physiology*; D014796:Visual Perception / Q000502:physiology*; D055815:Young Adult
Bayesian model reduction; classification; dynamic causal modeling; empirical Bayes; gamma oscillations; neural fields; random effects