Contrast gain control and horizontal interactions in V1: a DCM study.
Using high-density electrocorticographic recordings - from awake-behaving monkeys - and dynamic causal modelling, we characterised contrast dependent gain control in visual cortex, in terms of synaptic rate constants and intrinsic connectivity. Specifically, we used neural field models to quantify the balance of excitatory and inhibitory influences; both in terms of the strength and spatial dispersion of horizontal intrinsic connections. Our results allow us to infer that increasing contrast increases the sensitivity or gain of superficial pyramidal cells to inputs from spiny stellate populations. Furthermore, changes in the effective spatial extent of horizontal coupling nuance the spatiotemporal filtering properties of cortical laminae in V1 - effectively preserving higher spatial frequencies. These results are consistent with recent non-invasive human studies of contrast dependent changes in the gain of pyramidal cells elaborating forward connections - studies designed to test specific hypotheses about precision and gain control based on predictive coding. Furthermore, they are consistent with established results showing that the receptive fields of V1 units shrink with increasing visual contrast.
The Wellcome Trust Centre for Neuroimaging, University College London, Queen Square, London WC1N 3BG, UK. Electronic address: d.pinotsis@ucl.ac.uk.
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Pinotsis
Donders Institute for Brain, Cognition, and Behaviour, Radboud University Nijmegen, 6525 EN Nijmegen, Netherlands; Department of Neurological Surgery, University of Pittsburgh, PA 15213, USA.
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Brunet
Ernst Strüngmann Institute (ESI) for Neuroscience in Cooperation with Max Planck Society, Deutschordenstraße 46, 60528 Frankfurt, Germany; Center for Neuroscience and Center for Mind and Brain, University of California-Davis, Davis, CA 95618, USA.
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Bastos
Donders Institute for Brain, Cognition, and Behaviour, Radboud University Nijmegen, 6525 EN Nijmegen, Netherlands; Cognitive and Systems Neuroscience Group, Swammerdam Institute for Life Sciences, Center for Neuroscience, University of Amsterdam, 1098 XH Amsterdam, Netherlands.
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Bosman
The Wellcome Trust Centre for Neuroimaging, University College London, Queen Square, London WC1N 3BG, UK.
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Litvak
Ernst Strüngmann Institute (ESI) for Neuroscience in Cooperation with Max Planck Society, Deutschordenstraße 46, 60528 Frankfurt, Germany; Donders Institute for Brain, Cognition, and Behaviour, Radboud University Nijmegen, 6525 EN Nijmegen, Netherlands.
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Fries
The Wellcome Trust Centre for Neuroimaging, University College London, Queen Square, London WC1N 3BG, UK.
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Friston
D000818:Animals; D001288:Attention / Q000502:physiology; D003198:Computer Simulation; D063132:Connectome / Q000379:methods*; D015350:Contrast Sensitivity / Q000502:physiology*; D004569:Electroencephalography / Q000379:methods; D008253:Macaca mulatta; D008297:Male; D008959:Models, Neurological; D009415:Nerve Net / Q000502:physiology*; D009433:Neural Inhibition / Q000502:physiology*; D017966:Pyramidal Cells / Q000502:physiology*; D014793:Visual Cortex / Q000502:physiology*; D014794:Visual Fields / Q000502:physiology
Attention; Connectivity; Contrast; Dynamic causal modelling; Electrocorticography; Electrophysiology; Gamma oscillations; Neural field theory; V1; Visual cortex