SSAI
SSAI 2013

Plenary Speakers

SSAI 2013 CONGRESS, TURKU, FINLAND - Focusing on the Brain
What is general anaesthesia? How do general anaesthetics work?  How is unconsciousness induced by general anaesthetics different from natural sleep and disorders of consciousness such as coma, vegetative and minimally conscious states, and the locked-in syndrome? Could anaesthesiology and neuroimaging help in understanding how consciousness arises from brain activity? These important questions and many others relevant to our speciality will be discussed and answered by world-leading scientists and experts in the

Plenary Symposium: Exploring the Mystery of General Anaesthesia and Consciousness

of the 32rd SSAI Congress in Turku, Finland on Tuesday 27 August 2013 starting at 10 a.m. Each presentation will be 30 min including 5 min for discussion. The symposium will include the following four presentations (a short biosketch of each lecturer in italics after the title):

1) Antti Revonsuo: "Neurophilosophy of Consciousness”
Antti Revonsuo is Professor of Cognitive Neuroscience in the School of Humanities and Informatics at the University of Skövde, Skövde, Sweden, and Professor of Psychology at the University of Turku, Turku, Finland. He has conducted research on consciousness since the early 1990s and has directed an undergraduate degree programme on consciousness studies since 1997. He is internationally best known for his evolutionary–psychological theory of dreaming, the threat-simulation theory.

The field investigating traditional philosophical problems by interacting with neuroscience is called “Neurophilosophy”. Consciousness is one of the main topics of Neurophilosophy, because the ancient philosophical mind-body problem is, for current neuroscience, the problem of understanding how consciousness arises from brain activity. The problem is hard to solve, because neural activities in the brain seem to be entirely different in kind from the subjective mental phenomena we experience and feel in consciousness.  So far, neuroscience has not discovered any plausible mechanism in the brain that could transform objective physical phenomena to subjective mental consciousness.  Thus, it remains a mystery for neuroscience how and why certain neural activities produce consciousness. “Consciousness” is a concept of central importance also in anaesthesiology. For the neuroscientific study of consciousness, general anaesthesia offers an important tool to experimentally manipulate and study the neural mechanisms that are selectively activated when consciousness returns and deactivated when consciousness fades. In this presentation, Professor Revonsuo will review the philosophical problems and the recent empirical findings from the neurophilosophy of consciousness, and elucidate what kind of role neuroscience and anaesthesiology might play in understanding how consciousness arises from brain activity.

2) Nicholas Franks: "Molecular Mechanisms of General Anaesthesia"
Nicholas Franks, PhD, FSB, FRCA, FMedSci, FRS is Professor of Biophysics and Anaesthetics at Imperial College London where he is the Head of the Division of Cell and Molecular Biology and Head of Biophysics. Throughout his career, Nick Franks has been interested in how general anaesthetics act and he has demonstrated that the traditional view that general anaesthetics acted on lipid bilayers was incorrect. He and his collaborators have demonstrated that, despite their chemical diversity, anaesthetics act by directly and selectively binding to a small number of protein targets in the CNS. He has also shown that anaesthetics and sleep may share common neuronal mechanisms.

Because the potencies of most anaesthetics can be accurately predicted by lipid partitioning (the Meyer-Overton correlation), they have long been considered to be archetypal “non-specific” drugs. However, this view has now changed radically and it is recognised that even the simplest anaesthetics (including the inert gas xenon) can be surprisingly selective in their actions and exert their effects by binding directly to protein targets. Identifying which protein targets are pharmacologically relevant, and which are not, has been a major challenge, yet great progress has been made in recent years. In his talk, Professor Franks will review the evidence on the nature and identity of anaesthetic binding sites in the CNS and show that for some commonly used agents, the relevant targets can be unambiguously identified. He will show how anaesthetics are able to affect the activities of their protein targets even though they cause no local structural perturbations.

3) Michael Alkire: "Neuroimaging of Anaesthesia and Consciousness"
Michael Alkire is Associate Professor in Residence of Anesthesiology and a Fellow member of the Center for the Neurobiology of Learning and Memory (CNLM) at the University of California, Irvine (UCI), USA. He has used anaesthesia as a tool for investigating memory, consciousness and pain processing in both animal and human models. Dr. Alkire was the first to publish a PET neuroimaging study investigating the mechanisms of anaesthetic action in the human.  Subsequently, he completed a series of neuroimaging studies in humans on the effects of various anaesthetic agents. Dr. Alkire’s work has led to a number of insights regarding the nature of anaesthetic effects on consciousness.

Anaesthesia and neuroimaging offer an important tool for the scientific study of consciousness.  In his presentation, Professor Alkire will discuss recent works with an aim towards answering basic questions regarding the nature of human consciousness and how it is removed by anaesthesia.  He will explore the role played by neuroimaging in helping to identify what brain areas and systems must be turned off to remove consciousness and what brain regions or key processes must be turned back on to restore consciousness.  The lecture will touch upon these key topics in order to provide the background needed for understanding future developments in anaesthesia research.

4) Steven Laureys:  “The Neural Correlates of Conscious Awareness Revealed by the Study of Coma and Related States”
Professor Steven Laureys, MD, PhD, is director of the Coma Science Group at the Neurology Department and Cyclotron Research Centre of the University Hospital and University of Liège, Belgium. His team assesses the recovery of neurological disability and neuronal plasticity in acquired brain injury and altered states of consciousness (e.g., comatose, “vegetative”/unresponsive, minimally conscious and locked-in syndromes) confronting clinical expertise and bedside behavioural evaluation with multimodal neuroimaging (PET and MRI) and electrophysiology studies (EEG and EEG-TMS). He has also been interested in the ethical implications of this translational clinical research.

The past 15 years have provided an unprecedented collection of discoveries that bear upon our scientific understanding of recovery of consciousness in the human brain following severe brain damage. Highlighted among these discoveries are unique demonstrations that patients with little or no behavioural evidence of conscious awareness may retain critical cognitive capacities and the first scientific demonstrations that some patients, with severely injured brains and very longstanding conditions of limited behavioural responsiveness, may nonetheless harbour latent capacities for recovery.  In this presentation, Professor Laureys will summarize recent studies showing that awareness is an emergent property of the collective behaviour of frontoparietal top-down connectivity. Within this network, external (sensory) awareness depends on lateral prefrontal/parietal cortices while internal (self) awareness correlates with precuneal/mesiofrontal midline activity. Current technology now permits to show command-specific changes in EEG or fMRI signals providing motor-independent evidence of conscious thoughts and in some cases even of communication. He will conclude by discussing related ethical issues and the challenge of measuring and improving quality of life in these challenging patients with disorders of consciousness.

Abstract submission deadline 17 April 2013 - Early registration date 12 June 2013