title: Eyetracker-based gaze correction for robust mapping of population receptive fields.
abstract: Functional MRI enables the acquisition of a retinotopic map that relates regions of the visual field to neural populations in the visual cortex. During such a "population receptive field" (PRF) experiment, stable gaze fixation is of utmost importance in order to correctly link the presented stimulus patterns to stimulated retinal regions and the resulting Blood Oxygen Level Dependent (BOLD) response of the appropriate region within the visual cortex. A method is described that compensates for unstable gaze fixation by recording gaze position via an eyetracker and subsequently modifies the input stimulus underlying the PRF analysis according to the eyetracking measures. Here we show that PRF maps greatly improve when the method is applied to data acquired with either saccadic or smooth eye movements. We conclude that the technique presented herein is useful for studies involving subjects with unstable gaze fixation, particularly elderly patient populations.
authors.affiliation: MR Centre of Excellence, Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Währinger Gürtel 18-20, 1090 Vienna, Austria.
authors.forename: A
authors.initials: A
authors.lastname: Hummer
authors.affiliation: Department of Ophthalmology and Optometry, Medical University of Vienna, Währinger Gürtel 18-20, 1090 Vienna, Austria.
authors.forename: M
authors.initials: M
authors.lastname: Ritter
authors.affiliation: MR Centre of Excellence, Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Währinger Gürtel 18-20, 1090 Vienna, Austria.
authors.forename: M
authors.initials: M
authors.lastname: Tik
authors.affiliation: Department of Ophthalmology and Optometry, Medical University of Vienna, Währinger Gürtel 18-20, 1090 Vienna, Austria.
authors.forename: A A
authors.initials: AA
authors.lastname: Ledolter
authors.affiliation: MR Centre of Excellence, Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Währinger Gürtel 18-20, 1090 Vienna, Austria.
authors.forename: M
authors.initials: M
authors.lastname: Woletz
authors.affiliation: Institute of Ophthalmology, University College London, 11-43 Bath Street, London, EC1V 2PD, UK; Moorfields Eye Hospital, 162 City Road, London, EC1V 9EL, UK.
authors.forename: G E
authors.initials: GE
authors.lastname: Holder
authors.affiliation: Experimental Psychology, Helmholtz Institute, Utrecht University, Heidelberglaan 1, 3584 CS Utrecht, The Netherlands; Spinoza Centre for Neuroimaging, Meibergdreef 75, 1105BK, Amsterdam, The Netherlands.
authors.forename: S O
authors.initials: SO
authors.lastname: Dumoulin
authors.affiliation: Department of Ophthalmology and Optometry, Medical University of Vienna, Währinger Gürtel 18-20, 1090 Vienna, Austria.
authors.forename: U
authors.initials: U
authors.lastname: Schmidt-Erfurth
authors.affiliation: MR Centre of Excellence, Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Währinger Gürtel 18-20, 1090 Vienna, Austria. Electronic address: christian.windischberger@meduniwien.ac.at.
authors.forename: C
authors.initials: C
authors.lastname: Windischberger
mesh_terms: D000328:Adult; D001931:Brain Mapping / Q000379:methods*; D053483:Eye Movement Measurements; D005133:Eye Movements / Q000502:physiology*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D009039:Motion Perception / Q000502:physiology*; D010364:Pattern Recognition, Visual / Q000502:physiology*; D014793:Visual Cortex / Q000000981:diagnostic imaging*; D055815:Young Adult