title: EEG Correlates of Relative Motion Encoding.
abstract: A large portion of the visual cortex is organized retinotopically, but perception is usually non-retinotopic. For example, a reflector on the spoke of a bicycle wheel appears to move on a circular or prolate cycloidal orbit as the bicycle moves forward, while in fact it traces out a curtate cycloidal trajectory. The moving bicycle serves as a non-retinotopic reference system to which the motion of the reflector is anchored. To study the neural correlates of non-retinotopic motion processing, we used the Ternus-Pikler display, where retinotopic processing in a stationary reference system is contrasted against non-retinotopic processing in a moving one. Using high-density EEG, we found similar brain responses for both retinotopic and non-retinotopic rotational apparent motion from the earliest evoked peak (around 120 ms) and throughout the rest of the visual processing, but only minor correlates of the motion of the reference system itself (mainly around 100-120 ms). We suggest that the visual system efficiently discounts the motion of the reference system from early on, allowing a largely reference system independent encoding of the motion of object parts.
authors.affiliation: Laboratory of Psychophysics, Brain Mind Institute, École Polytechnique Fédérale de Lausanne (EPFL), Station 19, 1015, Lausanne, Switzerland. evelina.thunell@cerco.ups-tlse.fr.
authors.forename: Evelina
authors.initials: E
authors.lastname: Thunell
authors.affiliation: Laboratory of Psychophysics, Brain Mind Institute, École Polytechnique Fédérale de Lausanne (EPFL), Station 19, 1015, Lausanne, Switzerland.|Functional Brain Mapping Lab, Department of Fundamental Neuroscience, University of Geneva, 24 Rue du Général-Dufour, 1211, Geneva 4, Switzerland.
authors.forename: Gijs
authors.initials: G
authors.lastname: Plomp
authors.affiliation: Department of Electrical and Computer Engineering, Center for Neuro-Engineering and Cognitive Science, University of Houston, N 308 Engineering Building 1, Houston, TX, 77204-4005, USA.
authors.forename: Haluk
authors.initials: H
authors.lastname: Ögmen
authors.affiliation: Laboratory of Psychophysics, Brain Mind Institute, École Polytechnique Fédérale de Lausanne (EPFL), Station 19, 1015, Lausanne, Switzerland.
authors.forename: Michael H
authors.initials: MH
authors.lastname: Herzog
mesh_terms: D000328:Adult; D001931:Brain Mapping; D004569:Electroencephalography; D005074:Evoked Potentials, Visual / Q000502:physiology*; D005260:Female; D005403:Fixation, Ocular / Q000502:physiology; D006801:Humans; D008297:Male; D009038:Motion; D009039:Motion Perception / Q000502:physiology*; D010775:Photic Stimulation; D011930:Reaction Time / Q000502:physiology; D013223:Statistics as Topic; D014793:Visual Cortex / Q000502:physiology*; D014795:Visual Pathways / Q000502:physiology; D055815:Young Adult
keywords: Apparent motion; Electroencephalography (EEG); Non-retinotopic processing; Ternus–Pikler display