One of the most widely used paradigms for studying the neural correlates of consciousness is bistable visual perception. Bistable phenomena provide an effective tool for studying the neural basis of visual awareness because they allow for a stimulus to be suppressed from consciousness while remaining physically present. (That is, the input remains constant, but the percept alternates.) Therefore, we can measure the changes in neural activity that correspond to perceptual changes, thus potentially revealing the neural substrates and mechanisms of visual awareness. We have used various bistable visual illusions to determine the neural basis of visual awareness, including motion-induced blindness, binocular rivalry, and ambiguous figures. All of these exploit one simple idea: How does neural activity change during changes in the contents of perceptual awareness, even when perceptual inputs remain constant?
Hsieh, P.-J., Vul, E., and Kanwisher, N. (2010). Recognition alters the spatial pattern of fMRI activation in early retinotopic cortex. Journal of Neurophysiology. 103, 1501-1507. ( PDF) (Faculty 1000 Recommendation)
Hsieh, P.-J., and Tse, P.U. (2010). 'Brain-reading' of perceived colors reveals a feature mixing mechanism underlying perceptual filling-in in cortical area V1. Human Brain Mapping. 31, 1395-1407. (PDF)
Hsieh, P.-J., and Tse, P.U. (2010). BOLD signal in both ipsilateral and contralateral retinotopic cortex modulates with perceptual fading. PLoS ONE. 5, e9638. (PDF)
Hsieh, P.-J., and Tse, P.U. (2009). Microsaccade rate varies with subjective visibility during motion-induced blindness. PLoS ONE. 4: e5163. (PDF)
Hsieh, P.-J., Caplovitz, G.P., and Tse, P.U. (2006). Bistable Illusory Rebound Motion: Event-related functional magnetic resonance imaging of perceptual states and switches. NeuroImage. 32, 728-739. (PDF). (Demo of stimuli.)
Necker Cube (Bistable illusion): What happens in your brain when your percept alternates?
Binocular Rivalry: When two eyes receive conflicting images, conscious percept rivals. How and where does rivalry occur in the brain?