Open AccessNeural correlates of the continuous Wagon Wheel Illusion: A functional MRI study
Author(s) -
Reddy Leila,
Rémy Florence,
Vayssière Nathalie,
VanRullen Rufin
Publication year - 2011
Publication title -
human brain mapping
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.005
H-Index - 191
eISSN - 1097-0193
pISSN - 1065-9471
DOI - 10.1002/hbm.21007
Subject(s) - illusion , percept , psychology , perception , motion perception , stimulus (psychology) , neuroscience , neural correlates of consciousness , spurious relationship , psychophysics , cognitive psychology , cognition , computer science , machine learning
Abstract After prolonged viewing of a continuous periodic motion stimulus at frequencies around 10 Hz, observers experience a fleeting impression of reversed motion: the continuous Wagon Wheel Illusion (c‐WWI). To account for this phenomenon it has been proposed that attentional mechanisms discretely sample motion information. Alternative accounts argue that the illusion relies on the spurious activation of motion detectors, which under the effect of adaptation could trigger a reversed percept. We investigated the neural correlates of the c‐WWI using fMRI (3T). Subjects viewed a vertically bisected ring containing a radial grating unambiguously rotating at 10 Hz; they continuously reported the perceived motion direction within each half of the ring. The two halves always rotated in opposite directions, allowing us to separately explore illusory reversals occurring within each hemifield. Comparing BOLD activity during illusory (c‐WWI) or real perceptual periods revealed systematic differences in right parietal regions, in addition to the right motion complex MT+. This activation pattern did not depend on the side on which the illusion occurred, and could not be accounted for by purely perceptual switch‐related activity—known to encompass parietal regions during other bistable effects. This first characterization of the fMRI correlates of the c‐WWI may have implications for the different theoretical explanations of the phenomenon. Hum Brain Mapp, 2011. © 2010 Wiley‐Liss, Inc.