title: Eye Velocity Gain Fields in MSTd During Optokinetic Stimulation.
abstract: Lesion studies argue for an involvement of cortical area dorsal medial superior temporal area (MSTd) in the control of optokinetic response (OKR) eye movements to planar visual stimulation. Neural recordings during OKR suggested that MSTd neurons directly encode stimulus velocity. On the other hand, studies using radial visual flow together with voluntary smooth pursuit eye movements showed that visual motion responses were modulated by eye movement-related signals. Here, we investigated neural responses in MSTd during continuous optokinetic stimulation using an information-theoretic approach for characterizing neural tuning with high resolution. We show that the majority of MSTd neurons exhibit gain-field-like tuning functions rather than directly encoding one variable. Neural responses showed a large diversity of tuning to combinations of retinal and extraretinal input. Eye velocity-related activity was observed prior to the actual eye movements, reflecting an efference copy. The observed tuning functions resembled those emerging in a network model trained to perform summation of 2 population-coded signals. Together, our findings support the hypothesis that MSTd implements the visuomotor transformation from retinal to head-centered stimulus velocity signals for the control of OKR.
authors.affiliation: Clinical Neurosciences Bernstein Center for Computational Neuroscience, Munich 81377, Germany.
authors.forename: Lukas
authors.initials: L
authors.lastname: Brostek
authors.affiliation: Clinical Neurosciences German Vertigo Center IFB, Ludwig-Maximilians-Universität , Munich 81377, Germany.
authors.forename: Ulrich
authors.initials: U
authors.lastname: Büttner
authors.affiliation: Department of Ophthalmology and Washington National Primate Research Center, University of Washington, Seattle, WA 98195, USA.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Mustari
authors.affiliation: Clinical Neurosciences German Vertigo Center IFB, Ludwig-Maximilians-Universität , Munich 81377, Germany Bernstein Center for Computational Neuroscience, Munich 81377, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Glasauer
mesh_terms: D000818:Animals; D053483:Eye Movement Measurements; D007257:Information Theory; D008253:Macaca mulatta; D008839:Microelectrodes; D016571:Neural Networks, Computer; D009474:Neurons / Q000502:physiology*; D010296:Parietal Lobe / Q000502:physiology*; D010775:Photic Stimulation / Q000379:methods; D011698:Pursuit, Smooth / Q000502:physiology*; D012815:Signal Processing, Computer-Assisted; D014796:Visual Perception / Q000502:physiology*
keywords: coordinate transformation; information theory; optokinetic nystagmus; parietal cortex; tuning function