The impact of stimulus complexity and frequency swapping on stabilization of binocular rivalry Cognitive Neuroscience Research Unit, Hammel Neurorehabilitation and Research Center, MindLab, Aarhus University, Denmark Kristian Sandberg Institute of Cognitive Neuroscience, University College London, London, United Kingdom,& Wellcome Trust Centre for Neuroimaging, University College London, London, United Kingdom Bahador Bahrami Cognitive Neuroscience Research Unit, Hammel Neurorehabilitation and Research Center, MindLab, Aarhus University, Denmark Jonas Kristoffer Lindeløv Cognitive Neuroscience Research Unit, Hammel Neurorehabilitation and Research Center, MindLab, Aarhus University, Denmark,& Cognitive Neuroscience Research Unit, Department of Communication and Psychology, Aalborg University, Aalborg, Denmark Morten Overgaard Institute of Cognitive Neuroscience, University College London, London, United Kingdom,& Wellcome Trust Centre for Neuroimaging, University College London, London, United Kingdom Geraint Rees Binocular rivalry occurs when an image is presented to one eye while at the same time another, incongruent, image is presented to the other eye in the corresponding retinotopic location and conscious perception alternates spontaneously between the two monocular views. If a short blank period is inserted between intermittent presentations of rivaling stimuli, perception is stabilized and spontaneous alternations are drastically reduced. Whether the complexity of rivaling stimuli plays a role in stabilization is unknown. We replicated previous findings that swapping the stimuli between eyes across presentations abolishes stabilization for Gabors, but for more complex stimuli (a face and a house in our experiment), stabilization is eye-specific and not disrupted. Phase scrambling the rivaling face and house images did not change the stabilization pattern showing that the pattern can be observed without high-level perceptual content. We conclude that overlaps at low visual stages are the most likely cause of the eye-specific stabilization for both stimulus types. Additionally, we examined the impact of swapping the flicker frequency of the images and found a general impact on stabilization not specific to stimulus type. Taken together, the findings indicate that choice of stimulus features impact greatly on the results obtained in stabilization paradigms. Keywords: binocular vision, visual cortex, memory Citation: Sandberg, K., Bahrami, B., Lindeløv, J. K., Overgaard, M., & Rees, G. (2011). The impact of stimulus complexity and frequency swapping on stabilization of binocular rivalry. Journal of Vision, 11(2):6, 1–10, http://www.journalofvision.org/ content/11/2/6, doi:10.1167/11.2.6. Introduction Bistable stimuli such as the Necker cube (Necker, 1832) and Rubin’s vase (Rubin, 1915) are visual stimuli that are spontaneously perceived in two different ways and thus allow dissociation of changes in conscious perception from changes in physical stimulation (Andrews, Schluppeck, Homfray, Matthews, & Blakemore, 2002; Lumer, Friston, & Rees, 1998). Binocular rivalry (BR; Breese, 1899) is one form of bistable perception that occurs when an image is presented to one eye while at the same time another, Journal of Vision (2011) 11(2):6, 1–10 http://www.journalofvision.org/content/11/2/6 1 doi: 10.1167/11.2.6 Received July 12, 2010; published February 8, 2011 ISSN 1534-7362 * ARVO