Program
WEEK 1:
Monday, June 15
09:30 - 10:30 | Cyriel Pennartz – Cognitive and Systems Neuroscience Group, University of Amsterdam, Amsterdam, The Netherlands
Welcome and introduction
10:30 - 13:00 | Steven Laureys – Head of Department of Neurology, Centre Hospitalier Universitaire Sart Tilman, Liegravege, Belgium
Overview & Introduction to Visual Consciousness & the Brain
Patients in a vegetative state (VS) and minimally conscious state (MCS) continue to pose problems in terms of their diagnosis, prognosis and treatment. Consciousness is a subjective first-person experience on which studies have remained in the field of philosophy for the past millennia. That time has finally changed and empirical evidence from functional neuroimaging is offering a genuine glimpse on the solution to the infamous mind-body conundrum. New technological and scientific advances offer the neurological community unique ways to improve our understanding and management of severely brain-damaged patients.
Good medical management starts by making a correct diagnosis. There is an irreducible limitation in knowing for certain whether any other being is conscious. Vegetative patients can move extensively and clinical studies have shown how difficult it is to differentiate reflex or ‘automatic’ from voluntary or ‘willed’ movements. This results in an underestimation of behavioural signs of consciousness and hence a misdiagnosis, estimated to occur in about one third to nearly half of chronically vegetative patients.
PET and fMRI studies have not yet shown to be reliable markers of recovery of consciousness. However, they have permitted to reject the ancient view that vegetative patients are neocortically dead or a-pallic. A succession of neuroimaging data has shown cerebral activation in isolated and disconnected islands of “lower level” cortices or “pallium” in response to auditory, visual, somatosensory and noxious stimuli. Functional neuroimaging studies have also provided scientific evidence that residual brain function in VS is very different from the brain’s integrative capacity in MCS. These studies have confirmed that VS and MCS truly are different physiological entities. However, in the absence of a full understanding of the neural correlates of consciousness, even a normal activation in response to passive sensory stimulation cannot be taken as incontestable proof of consciousness. In contrast, repeated and prolonged activation in response to the instruction to perform a mental imagery task would provide undeniable evidence of voluntary task-dependent brain activity, and hence of consciousness. This ground-breaking approach was recently validated in healthy controls and has been successfully applied to identify conscious perception in a – so far unique – patient behaviourally diagnosed as being in a post-traumatic VS.
Brain computer interfaces (BCI) permit communication via voluntary EEG control, without any motor involvement. Technological improvements in such devices now enable locked-in patients to control their surroundings in ways never possible before. BCI can not only be employed as a communication instrument in LIS but also as a diagnostic tool in disorders of consciousness. It is thrilling to witness the use of this powerful approach in the assessment of possible residual consciousness in patients clinically diagnosed as “VS” or “MCS”. The question of what it feels like to be minimally conscious has not yet been solved but the technology to at least try to answer the issue does now exist.
14:00 - 17:00 | Overview of workshops; meet workshop tutors; start on literature
Tuesday, June 16
09:30 - 12:30 | Lionel Naccache – Service de Neurologie, Hopital de la Salpetriere, Paris, France; Inserm-CEA Cognitive Neuroimaging Unit, EA/SAC/DSV/DRM/NeuroSpin, Gif sur Yvette, France
Visual consciousness and the brain -
Behavioural, EEG, SEEG & fMRI studies in patients & controls
The last 40 years have been marked by a remarkable progress in the scientific exploration of perceptual consciousness, particularly in the visual modality. This significant achievement partly results from a stimulating and productive “ménage à trois” between clinical neurophysiology, experimental psychology and functional brain-imaging. During this talk, I will expose the sufficient and necessary conditions for a conscious subject presented with a visual stimulus to subjectively report its presence and identity (conscious access). I will briefly discuss here the completeness of this reportability, in the light of current debates about visual phenomenal consciousness (Block; Lamme) or “local consciousness” (Zeki & Ffytche). Through the exploration of various visual neuropsychological syndromes such as “blindsight”, “visual agnosias”, “Balint syndrome”, “visual hallucinations” or “visual neglect” we will unravel some general principles of visual conscious access, the generality of which can then be tested in normal controls through behavioural and functional brain imaging studies of various phenomena such as subliminal perception or attentional blink. I will then synthesize those results in a theoretical model of conscious access: the “global workspace” (GW) model initially proposed by Bernard Baars, then further developed by Stanislas Dehaene, Jean-Pierre Changeux and me. I will then use this model to predict visual conscious access impairments in two diseases affecting long-distance cortico-cortical connectivity (Multiple Sclerosis & Schizophrenia). I will then present a recent intracranial EEG empirical work, by our group, driven by GW theoretical predictions. This allowed us to specify some aspects of the GW model, and to confirm some crucial predictions of our theory related to the fine temporal dynamics of conscious access, through the combination of 4 complementary measures derived from the raw iEEG (ERPs, ERSP, phase synchrony & Granger causality). Finally, I will expose a recent translation of these theoretical ideas to patient bedside in Intensive Care Units to diagnose conscious perception in non-communicating patients.
14:00 - 17:00 | Research groups (note: not all afternoons contain contact hours)
Wednesday, June 17
09:30 - 12:30 | Victor Lamme – Department of Cognitive Psychology, University of Amsterdam, Amsterdam, The Netherlands
Visual consciousness and the brain, continued
14:00 - 17:00 | Research groups
Thursday, June 18
09:30 - 12:30 | Toemme Noesselt – Department of Neurology II, Otto-von-Guericke University, Magdeburg, Germany
Visual Awareness and Multisensory Interplay
Many everyday-life objects stimulate more than one sensory modality. However, traditional sensory research has often studied each sensory modality in isolation. Only recently, there has been a dramatic increase in interest in the causal interplay between different senses.
Many multisensory phenomena have now been reported in which perceptual judgments concerning one sense can be affected by other senses. Importantly, recent studies on the neural basis of multisensory integration (MSI) indicate that ‘sensory-specific’ brain regions are modulated by information from other modalities - challenging classic modular approaches.
I will review old challenges, recent progress and still unresolved issues of this field and highlight possible underlying neural mechanisms governing MSI. These may include feedforward integration, possibly within thalamic nuclei, and/or feedback from multisensory regions to ‘sensory-specific’ brain areas. Finally, we will discuss how these mechanisms could relate to the generation of a coherent representation of our environment.
14:00 - 17:00 | Research groups
Friday, June 19
09:30 - 12:30 | Cyriel Pennartz – Cognitive and Systems Neuroscience Group, University of Amsterdam, Amsterdam, The Netherlands
Identification and integration of sensory modalities: neural basis and relation to consciousness
A key question in studying consciousness is how neural operations in the brain can identify streams of sensory input as belonging to distinct modalities, which contributes to the representation of qualitatively different experiences. The basis for identification of modalities is proposed to be constituted by self-organised comparative operations across a network of unimodal and multimodal sensory areas. However, such network interactions alone cannot answer the question how sensory feature detectors collectively account for an integrated, yet phenomenally differentiated experiential content. This problem turns out to be different from, although related to, the binding problem. It is proposed that the neural correlate of an enriched, multimodal experience is constituted by the attractor state of a dynamic associative network. Within this network, unimodal and multimodal sensory maps continuously interact to influence each other’s attractor state, resulting in a fast re-coding of feature information by single neurones.
14:00 - 17:00 Research groups
WEEK 2:
Monday, June 22
09:30 - 12:30 | Jean-René Duhamel – Institut des Sciences Cognitives, CNRS, Bron, France. Director of Research and Director of Neurophysiology of Movement and Perception group
Neurophysiology of Multisensory Integration
14:00 - 16:00 Research groups
Tuesday, June 23
09:30 - 12:30 | Olaf Blanke – Department of Neurology, University Hospital, Geneva, Switzerland; Director of the Laboratory of Cognitive Neuroscience, Ecole Polytechnique Fédérale de Lausanne (EPFL), Swiss Federal Institute of Technology, Brain-Mind Institute, Lausanne, Switzerland
Consciousness of Self - Experiments and Psychophysics
Many different aspects of self-consciousness have been categorised and these aspects have been continuously refined and expanded, including many different sensory, emotional or cognitive layers. This has led to an excess of definitions, in the absence of a widely accepted model of self-consciousness that is based on empirical neurobiological data. More recent theories converge on the relevance of bodily self-consciousness, i.e., the non-conceptual representation and processing of body-related information, as one promising approach for the development of a comprehensive neurobiological model of self-consciousness.
I will review research investigating behavioural and brain correlates of bodily self-consciousness. (1) The experimental manipulation of bodily self-consciousness in healthy subjects using multisensory and/or sensorimotor conflict and virtual reality technology. (2) Neuroimaging data during experimentally altered states of bodily self-consciousness using an exciting new research platform that merges virtual reality and robotics with high-resolution EEG and fMRI. Both sets of data will be linked to data in neurological patients suffering from altered states of bodily self-consciousness. These approaches may lead to a better understanding of bodily self-consciousness as well as cognitive aspects of the self.
Wednesday, June 24
09:30 - 12:30 | Steven Scholte
14:00 - 17:00 | Research groups – reporting / Student presentations commented by Christof Koch
Thursday, June 25
09:30 – 14:30 | Workshop “Debates on Consciousness”
The Workshop can be attended separately from the Summer School; registration is necessary.
Click here for more information on the Workshop
20:00 – 21:00 | Frijda lecture by Christof Koch - Division of Biology and Division of Engineering and Applied Sciences, California Institute of Technology
The Frijda lecture can be attended separately from the Summer School.
Click here for more information on the Frijda Lecture
Friday, June 26
Symposium “Neural Basis of Consciousness”
The Symposium can be attended separately from the Summer School; registration is necessary.
Click here for more information on the Symposium