Journal of Neuroscience
July 1, 1999
Ramesh Srinivasan, D. Patrick Russell, Gerald M. Edelman et al.
438 citations
During binocular rivalry, where each eye sees a different image and perception alternates between them, the brain activity corresponding to the consciously perceived image shows increased synchronization. Red vertical and blue horizontal gratings were presented to each eye, each flickering at a distinct frequency. Magnetoencephalography recorded stronger steady-state magnetic fields at the frequency of the perceived grating over occipital, temporal, and frontal cortices. Coherence analysis revealed increased interhemispheric and intrahemispheric synchronization at the stimulus frequency when that stimulus was perceived. The results demonstrate a direct correlation between conscious perception and synchronous activity of large populations of neocortical neurons.
Proceedings of the National Academy of Sciences
July 5, 2006
Anil K. Seth, Eugene M. Izhikevich, George N. Reeke et al.
327 citations
No single quantitative measure—neural complexity, information integration, or causal density—fully captures the multidimensional complexity of the neural systems underlying consciousness, and each has practical limitations. The analysis suggests that combining alternative measures may improve quantitative characterization, but some aspects of consciousness likely resist quantification entirely, so a satisfactory theory should blend qualitative and quantitative elements.
Proceedings of the National Academy of Sciences
March 17, 1998
Giulio Tononi, Ramesh Srinivasan, D. Patrick Russell et al.
259 citations
During binocular rivalry, where each eye sees a different image but only one is consciously perceived at a time, neuromagnetic responses in the brain show activity at frequencies corresponding to both stimuli, even for the unseen one. However, when a stimulus is not consciously perceived, the power of its neural response is reduced by 50-85% across many brain regions, including areas outside the visual cortex. This modulation is widespread but not global, indicating that conscious perception correlates with the strength of synchronized neural activity in large neuronal populations.