Binocular switch suppression: A new method for persistently rendering the visible 'invisible'

Rendering the usually visible 'invisible' has long been a popular experimental manipulation. With one notable exception, 'continuous flash suppression' [Tsuchiya, N., & Koch, C. (2005). Continuous flash suppression reduces negative afterimages. Nature Neuroscience, 8, 1096-1101], existing methods of achieving this goal suffer from :being either unable to suppress stimuli from awareness for prolonged periods, from being unable to reliably suppress stimuli at specific epochs, or from a combination of both of these limitations. Here we report a new method, binocular switch suppression (BSS), which overcomes these restrictions. We establish that BSS is novel as it taps a different causal mechanism to the only similar pre-existing method. We also establish that BSS is superior to pre-existing methods both in terms of the depth and duration of perceptual suppression achieved. BSS should therefore prove to be a useful tool for the large number of researchers interested in exploring the neural correlates and functional consequences of conscious visual awareness. (C) 2008 Elsevier Ltd. All rights reserved.