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Consciousness and the two brains

English title Consciousness and the two brains
Applicant Landis Theodor
Number 132967
Funding scheme Project funding (Div. I-III)
Research institution Unité d'EEG et d'exploration de l'épilepsie Service de Neurologie Hôpitaux Universitaires de Genève
Institution of higher education University of Geneva - GE
Main discipline Neurophysiology and Brain Research
Start/End 01.02.2011 - 31.07.2013
Approved amount 244'732.00
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Keywords (8)

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

Lay Summary (English)

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

Responsible applicant and co-applicants

Employees

Publications

Publication
An LCD tachistoscope with submillisecond precision.
Sperdin Holger, Repnow Marc, Herzog Michael, Landis Theodor (2013), An LCD tachistoscope with submillisecond precision., in Behavior research methods, 45, 1347-1357.
Hemispheric specialization varies with EEG brain resting states and phase of menstrual cycle.
Cacioppo Stephanie, Bianchi-Demicheli Francesco, Bischof Paul, Deziegler Dominique, Michel Christoph, Landis Theodor (2013), Hemispheric specialization varies with EEG brain resting states and phase of menstrual cycle., in PloS one, 8(4), 63196-63196.
Submillisecond Unmasked Subliminal Visual Stimuli Evoke Electrical Brain Responses
Sperdin Holger, Spierer Lucas, Becker Robert, Michel Christoph, Landis Theodor, Submillisecond Unmasked Subliminal Visual Stimuli Evoke Electrical Brain Responses, in Human Brain Mapping.

Collaboration

Group / person Country
Types of collaboration
EPFL Switzerland (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Publication

Scientific events

Active participation

Title Type of contribution Title of article or contribution Date Place Persons involved
Organization for human brain mapping (OHBM), 2013 Poster Category-dependent effects of non-masked subliminal primes during a visual categorization task 16.06.2013 USA, Seattle , United States of America Sperdin Holger Franz;
SSN Meeting 2013 Poster TO SEE OR NOT TO SEE: HIGH-DENSITY EEG CORRELATES OF SUBMILISECOND VISUAL STIMULATION 02.02.2013 Switzerland, Geneva, Switzerland Sperdin Holger Franz;
Alpine brain imaging meeting 2013 Poster TO SEE OR NOT TO SEE: HIGH-DENSITY EEG CORRELATES OF SUBMILISECOND VISUAL STIMULATION 06.01.2013 Switzerland, Champéry, Switzerland Sperdin Holger Franz;
8th FENS Forum of Neuroscience 2012 Poster TO SEE OR NOT TO SEE: HIGH-DENSITY EEG CORRELATES OF SUBMILISECOND VISUAL STIMULATION 14.07.2012 Spain, Bareclona, Spain Sperdin Holger Franz;


Associated projects

Number Title Start Funding scheme
7383 Verbal awareness and motor speech asymmetry: New measures of functional asymmetry of the cerebral hemispheres. 01.04.1982 Project funding (Div. I-III)
7977 Alternative functions and affective asymmetry of the cerebral hemispheres 01.04.1984 Project funding (Div. I-III)
118315 Uncovering right hemispheric language functions: a project combining TMS and EEG 01.01.2008 Project funding (Div. I-III)
65096 Hemispheric specialization and state-dependency: en evoked poten-tial mapping study 01.10.2001 Project funding (Div. I-III)

Abstract

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.
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