Project

Consciousness; event related potentials; hemispheric specialisation; subliminal stimulation; Cerebral hemispheres; preconscious processing; Laterality; Split-brain

Lead
Lay summary
Probably the most fascinating finding of the "split-brain" research is that the two cerebral hemispheres appear to have each their own consciousness with different perceptions, volitions and actions, and that they seem "unaware" of each other. This "dual consciousness" can be demonstrated shortly after the surgical disconnection of the two half-brains, suggesting that this "duality" had been there prior to the disconnection.Although there has been a tremendous revival of interest into "subliminal" or "preconscious" processing and their cerebral correlates during the last 10 years, the question of "dual consciousness" has not been addressed. We propose to address together two major open questions in cognitive neuroscience, that of hemispheric specialisation and that of access to "conscious" recognition in combining bi-hemispheric "subliminal" behaviour experiments and recognition threshold assessments with advanced electrical neuroimaging techniques (high density EEG-ERP, distributed source analysis, brain resting state analysis)

Direct link to Lay Summary

Last update: 21.02.2013

Active participation

Number	Title	Start	Funding scheme

The currently ongoing project (32003B-118315), which will end in December 2010, concerned hemispheric specialisation and its modulation. The present project extends the topic of hemispheric specialisation into the domain of consciousness.We propose to address together two major open questions in cognitive neuroscience, that of hemispheric specialisation and that of access to “conscious” recognition in combining bi-hemispheric “subliminal” behaviour experiments and recognition threshold assessments with advanced electrical neuroimaging techniques (high density EEG-ERP, distributed source analysis, brain resting state analysis). Probably the most fascinating finding of the “split-brain” research is that the two cerebral hemispheres appear to have each their own consciousness with different perceptions, volitions and actions, and that they seem “unaware” of each other. This “dual consciousness” can be demonstrated shortly after the disconnection of the two half-brains, suggesting that this “duality” had been there prior to the disconnection. Although there has been a tremendous revival of interest into “subliminal” or “preconscious” processing and their cerebral correlates during the last 10 years, the question of “dual consciousness” has not been addressed. We propose to address this fundamental question with two series of experiments. 1) Using bilateral simultaneous presentation of “hemisphere specific” stimuli in a subliminal and supraliminal “liking without knowing” paradigm. We expect “liking” and “knowing” to be competing mutually exclusive processes in a visual field for a given stimulus type and exposure duration, and will assess when and where they are processed in the two hemispheres, and 2) to assess the characteristics of transition between “discrimination” and “recognition” in bilateral simultaneous forced choice experiments using the same stimuli with increasing exposure durations. We expect to find a non-linear transition between two stable states of the brain networks. This transition will not be S-shaped, but rather have a critical period during which the networks become unstable and performance is degraded until the next stable state is reached. We expect to localise in space and time this instability period in the two cerebral hemispheres.