title: The influence of spontaneous brain oscillations on apparent motion perception.
abstract: A good example of inferential processes in perception is long-range apparent motion (AM), the illusory percept of visual motion that occurs when two spatially distinct stationary visual objects are presented in alternating sequence. The AM illusion is strongest at presentation frequencies around 3 Hz. At lower presentation frequencies, the percept varies from trial to trial between AM and sequential alternation, while at higher frequencies perception varies between AM and two simultaneously flickering objects. Previous studies have demonstrated that prestimulus alpha oscillations explain trial-to-trial variability in detection performance for visual stimuli presented at threshold. In the present study, we investigated whether fluctuations of prestimulus alpha oscillations can also account for variations in AM perception. Prestimulus alpha power was stronger when observers reported AM perception in subsequent trials with low presentation frequencies, while at high presentation frequencies there were no significant differences in alpha power preceding AM and veridical flicker perception. Moreover, when observers perceived AM the prestimulus functional connectivity between frontal and occipital channels was increased in the alpha band, as revealed by the imaginary part of coherency, which is insensitive to artefacts from volume conduction. Dynamic causal modelling of steady-state responses revealed that the most likely direction of this fronto-occipital connectivity was from frontal to occipital sources. These results point to a role of ongoing alpha oscillations in the inferential process that gives rise to the perception of AM and suggest that fronto-occipital interactions bias perception towards internally generated predictions.
authors.affiliation: Berlin School of Mind and Brain, Humboldt-Universität zu Berlin, Luisenstraße 56, Haus 1, 10117 Berlin, Germany.
authors.forename: Lia Lira Olivier
authors.initials: LL
authors.lastname: Sanders
authors.affiliation: Berlin School of Mind and Brain, Humboldt-Universität zu Berlin, Luisenstraße 56, Haus 1, 10117 Berlin, Germany; Wellcome Trust Centre for Neuroimaging, Institute of Neurology, University College London, 12 Queen Square, WC1N 3BG London, UK.
authors.forename: Ryszard
authors.initials: R
authors.lastname: Auksztulewicz
authors.affiliation: Neurophysics Group, Department of Neurology and Clinical Neurophysiology, Charité University Medicine Berlin, Hindenburgdamm 30, 12200 Berlin, Germany.
authors.forename: Friederike U
authors.initials: FU
authors.lastname: Hohlefeld
authors.affiliation: Berlin School of Mind and Brain, Humboldt-Universität zu Berlin, Luisenstraße 56, Haus 1, 10117 Berlin, Germany; Institute of Medical Psychology, Charité University Medicine, Luisenstr. 57, 10117 Berlin, Germany.
authors.forename: Niko A
authors.initials: NA
authors.lastname: Busch
authors.affiliation: Berlin School of Mind and Brain, Humboldt-Universität zu Berlin, Luisenstraße 56, Haus 1, 10117 Berlin, Germany; Charité University Medicine, Department of Psychiatry, Campus Charité Mitte, Charitéplatz 1, 10117 Berlin, Germany.
authors.forename: Philipp
authors.initials: P
authors.lastname: Sterzer
mesh_terms: D000328:Adult; D000513:Alpha Rhythm; D001499:Bayes Theorem; D004569:Electroencephalography; D005260:Female; D005625:Frontal Lobe / Q000502:physiology*; D006801:Humans; D007088:Illusions / Q000502:physiology*; D008297:Male; D009039:Motion Perception / Q000502:physiology*; D009778:Occipital Lobe / Q000502:physiology*; D010775:Photic Stimulation; D055815:Young Adult
keywords: Alpha power; Apparent motion; Spontaneous brain oscillations; Visual illusion