Category Archives: Nevrofysiologi

3 weeks until the unique event in Barcelona – Understanding Consciousness

Filosofi, Nevrofysiologi, Nevrovitenskap, Psykologi

Human Brain Project (HBP) invites scientists, physicians, philosophers and students to join project’s first large international conference devoted to the understanding of consciousness.

The conference will focus on fundamentals and theory, experimental studies, computational models, and clinical-societal implications of consciousness research. This is the first in a series of large, HBP international conference.

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How does our subjective experience emerge from the brain? How does consciousness relate to the physical world? These age-old, deep questions are now at last being addressed directly and broadly by neuroscience and will become crucial in the decades to come.

Where does consciousness arise? Where is the boundary between insentient matter and a spark of subjectivity? The spectrum of consciousness-related conundrums is rapidly expanding: we are saving islands of human brain from devastating injuries, growing cerebral organoids in a vat, and building intelligent machines that perform faster and better than any healthy subject.

Society needs to be scientifically and culturally prepared to face these emerging questions. To do so, an approach with the broadest scope is needed: diverse theoretical frameworks, brain anatomy, physiology, and chemistry across scales and species, detailed and large-scale computer simulations, deep learning, neuromorphic computing, robotics, clinical neurology, anaesthesiology, psychology, behavioural, computational, and philosophical analysis must interact and blend on a single infrastructure.

In the European Human Brain Project, a number of teams work together on consciousness and related questions, connecting neuroscience, philosophy, and technology. At the conference this research will be presented and discussed, along with presentations by world-leading scholars from outside the project, like Karl Friston,  and David Chalmers, Ned Block, Rodolfo Llinas, Wolf Singer, Emery Brown, Olaf Blanke.

Programme and Further Information

 

UNDERSTANDING CONSCIOUSNESS – a scientific quest for the 21st century.

Filosofi, Nevrofysiologi, Nevrovitenskap

Option 1

The Human Brain Project is inviting scientists, physicians, and students to join HBP’s first large international conference, which is devoted to the understanding consciousness. The conference is open to all who are interested in this topic.

This is the first in a series of large, HBP international conferences and will take place in central Barcelona on two full days in June 21-22, 2018. This conference will focus on fundamentals and theory, computational models, and clinical-societal implications of consciousness research. For program and registration please see below.

Scientific program

Registration page

Abstract submission and full website would be available soon.

 

Symposium on Consciousness at the Society for Neuroscience in Washington DC, 15 Nov. 2017

Nevrofysiologi, Nevrologi, Nevrovitenskap,

Neural Correlates of Consciousness:

Progress and Problems

https://www.sfn.org/annual-meeting/neuroscience-2017

2017_SfN-talk_Slide1_JFS

Theme H: Cognition

Neural Correlates of Consciousness: Progress and Problems – Johan Storm

Chair: Johan Storm, PhD
University of Oslo
Co-Chair: Melanie Boly, MD, PhD
University of Wisconsin-Madison

Date & Time: Wednesday, November 15, 2017 1:30pm – 4pm

Location: Ballroom B
CME: 2.5

Consciousness research is developing rapidly. Using evidence from brain injury in patients and physiological and behavioral studies in humans and related animals (single neuron, fMRI, EEG, TMS, intracranial recordings), the symposium will highlight how different conscious states and contents arise in the brain. Speakers will discuss different experimental approaches and theoretical frameworks as well as the medical and ethical relevance of this area.

Abstract:

The nature of consciousness is widely regarded as one of the great challenges in science. Over the past decade there has been substantive empirical and theoretical progress in this field. This symposium presents results from this recent surge in consciousness research.

Melanie Boly will review evidence of frequent dissociation between consciousness and responsiveness in patients with brain damage. She will present recent evidence that after ruling out confounds, the anatomical neural correlates of consciousness are primarily localized to a posterior cortical hot zone, rather than to a fronto-parietal network involved in task performance and report, and discuss the potential clinical applications of these findings.

Marcello Massimimi will describe the rationale and validation of the perturbational complexity index (PCI), a theory-driven empirical metric designed to gauge the brain’s capacity for integrated information. He will show how this index can be employed at the bedside to assess and stratify unresponsive patients, independently of sensory processing and motor/executive functions, and will highlight physiopathological implications.

Melanie Wilke will discuss how to disentangle conscious perception from decision making and visuomotor processes. Drawing conclusions from electrophysiological and fMRI experiments in monkeys and humans, she will address which signals and brain regions continue to correlate with conscious perception without the requirement of a behavioral report. She will also show consequences of parietal and thalamic pulvinar perturbations on conscious perception versus visuomotor decisions. Finally, she will discuss how to avoid or control for report-related confounds in future studies of conscious perception.

Cyriel Pennartz will focus on the theoretical delineation of requirements for animal brains capable of sustaining consciousness. Next, he will review recent advances in uncovering neuronal population correlates of visual stimulus detection, which is considered an important component of sensory awareness. Finally, he will zoom out from visual cortex to larger interconnected neural systems, probed with multi-area ensemble recordings to investigate changes in local and long-range functional connectivity across the sleep-wake cycle.

http://www.abstractsonline.com/pp8/#!/4376/session/91

2017_SfN-Audience&Panel
Ballroom B (1100 seats)was quite full during the symposium 15 Nov.

2017_SfN-4speakers&J

2017_SfN-Review Article_JNSci

https://www.ncbi.nlm.nih.gov/pubmed/29118218

J Neurosci. 2017 Nov 8;37(45):10882-10893. doi: 10.1523/JNEUROSCI.1838-17.2017.

Consciousness Regained: Disentangling Mechanisms, Brain Systems, and Behavioral Responses.

Storm JF1, Boly M2,3, Casali AG4, Massimini M5,6, Olcese U7,8, Pennartz CMA7,8, Wilke M9,10,11.

Abstract

How consciousness (experience) arises from and relates to material brain processes (the “mind-body problem”) has been pondered by thinkers for centuries, and is regarded as among the deepest unsolved problems in science, with wide-ranging theoretical, clinical, and ethical implications. Until the last few decades, this was largely seen as a philosophical topic, but not widely accepted in mainstream neuroscience. Since the 1980s, however, novel methods and theoretical advances have yielded remarkable results, opening up the field for scientific and clinical progress. Since a seminal paper by Crick and Koch (1998) claimed that a science of consciousness should first search for its neural correlates (NCC), a variety of correlates have been suggested, including both content-specific NCCs, determining particular phenomenal components within an experience, and the full NCC, the neural substrates supporting entire conscious experiences. In this review, we present recent progress on theoretical, experimental, and clinical issues. Specifically, we (1) review methodological advances that are important for dissociating conscious experience from related enabling and executive functions, (2) suggest how critically reconsidering the role of the frontal cortex may further delineate NCCs, (3) advocate the need for general, objective, brain-based measures of the capacity for consciousness that are independent of sensory processing and executive functions, and (4) show how animal studies can reveal population and network phenomena of relevance for understanding mechanisms of consciousness.

2017_SfN-BallroomB_WashConventCenter-A4
Ballroom B (1100 seats) in Washington Convention Center was quite full during the symposium 15 Nov. 2017

 

 

 

Review article on Consciousness in The Journal of Neuroscience

Nevroanatomi, Nevrofysiologi, Nevrovitenskap

A Review article on Consciousness was recently published in The Journal of Neuroscience (8 Nov. 2017).

“Consciousness Regained: Disentangling Mechanisms, Brain Systems, and Behavioral Responses”
Johan F. Storm, Mélanie Boly, Adenauer G. Casali, Marcello Massimini, Umberto Olcese, Cyriel M.A. Pennartz and Melanie Wilke
The Journal of Neuroscience, 8 November 2017, 37(45):10882-10893;doi:10.1523/JNEUROSCI.1838-17.2017

Review

(http://www.jneurosci.org/content/37/45/10882?etoc=)

 

Abstract:

How consciousness (experience) arises from and relates to material brain processes (the “mind-body problem”) has been pondered by thinkers for centuries, and is regarded as among the deepest unsolved problems in science, with wide-ranging theoretical, clinical, and ethical implications. Until the last few decades, this was largely seen as a philosophical topic, but not widely accepted in mainstream neuroscience. Since the 1980s, however, novel methods and theoretical advances have yielded remarkable results, opening up the field for scientific and clinical progress. Since a seminal paper by Crick and Koch (1998) claimed that a science of consciousness should first search for its neural correlates (NCC), a variety of correlates have been suggested, including both content-specific NCCs, determining particular phenomenal components within an experience, and the full NCC, the neural substrates supporting entire conscious experiences. In this review, we present recent progress on theoretical, experimental, and clinical issues. Specifically, we (1) review methodological advances that are important for dissociating conscious experience from related enabling and executive functions, (2) suggest how critically reconsidering the role of the frontal cortex may further delineate NCCs, (3) advocate the need for general, objective, brain-based measures of the capacity for consciousness that are independent of sensory processing and executive functions, and (4) show how animal studies can reveal population and network phenomena of relevance for understanding mechanisms of consciousness.

 

Figures:

Figure 1. Examples of bistable stimuli. A, In binocular rivalry, two stimuli are shown to different eyes and perception wavers between left and right eye stimuli (Blake and Logothetis, 2002). B, Ambiguous structure-from-motion (SfM) stimulus. Dots moving back and forth on a flat screen, without perspective cues to differentiate between front and rear surfaces, induce the perception of a 3D rotating object that periodically switches direction. (Sterzer et al., 2009) C, Generalized flash suppression. A target stimulus (red dot) is shown parafoveally followed by the onset of a moving surround, causing the red target to disappear in ∼50% of trials (Wilke et al., 2003).
Figure 1.
Examples of bistable stimuli. A, In binocular rivalry, two stimuli are shown to different eyes and perception wavers between left and right eye stimuli (Blake and Logothetis, 2002). B, Ambiguous structure-from-motion (SfM) stimulus. Dots moving back and forth on a flat screen, without perspective cues to differentiate between front and rear surfaces, induce the perception of a 3D rotating object that periodically switches direction. (Sterzer et al., 2009) C, Generalized flash suppression. A target stimulus (red dot) is shown parafoveally followed by the onset of a moving surround, causing the red target to disappear in ∼50% of trials (Wilke et al., 2003).
Experimental outline for the no-report paradigm for NCC studies. A, Depiction of the problem. We aim for the correlation between a conscious content and a given brain state. What is measured experimentally is the correlation between a behavioral report and a measure of brain activity, which might be appropriate or not. Report-related neural activity poses a confound for the NCC. B, Involuntary physiological measures taken to infer the perceptual state of a subject to circumvent the behavioral report (Tononi et al., 1998; Leopold et al., 2003; Laeng and Endestad, 2012; Tsuchiya et al., 2015).
Experimental outline for the no-report paradigm for NCC studies. A, Depiction of the problem. We aim for the correlation between a conscious content and a given brain state. What is measured experimentally is the correlation between a behavioral report and a measure of brain activity, which might be appropriate or not. Report-related neural activity poses a confound for the NCC. B, Involuntary physiological measures taken to infer the perceptual state of a subject to circumvent the behavioral report (Tononi et al., 1998; Leopold et al., 2003; Laeng and Endestad, 2012; Tsuchiya et al., 2015).
Figure 3. A, Major cortical and subcortical brain regions where lesions lead to spatial neglect in humans (left), and corresponding recent experimental results in monkeys (right) (lateral view). In humans, lesions in frontal (Brodmann area 44), inferior parietal cortex (Brodmann area 40), superior temporal gyrus (STG), basal ganglia, and pulvinar have been reported to lead to spatially biased behavior that might appear as a visual consciousness deficit (Karnath, 2001). B, Recent pharmacological inactivation studies in monkeys have shown primarily effector-specific spatial deficits after lesions in parietal subregions such as the lateral intraparietal area (LIP, red shading) and the parietal reach region (PRR, which includes the medial intraparietal area MIP and area V6A, green shading). Dorsal pulvinar (dPULV, orange shading) inactivation leads to spatial orienting bias for both eye and hand movements which can be compensated by visual reward cues, suggesting that visual perception might be preserved. Ventral pulvinar (vPULV, purple shading) inactivation leads to change detection deficits resembling visual neglect. Summarized from local inactivation studies in monkeys (Wardak et al., 2002; Wilke et al., 2010; Hwang et al., 2012; Wilke et al., 2012; Wilke et al., 2013; Hwang et al., 2014; Christopoulos et al., 2015; Katz et al., 2016; Zhou et al., 2016).
Figure 3.
A, Major cortical and subcortical brain regions where lesions lead to spatial neglect in humans (left), and corresponding recent experimental results in monkeys (right) (lateral view). In humans, lesions in frontal (Brodmann area 44), inferior parietal cortex (Brodmann area 40), superior temporal gyrus (STG), basal ganglia, and pulvinar have been reported to lead to spatially biased behavior that might appear as a visual consciousness deficit (Karnath, 2001). B, Recent pharmacological inactivation studies in monkeys have shown primarily effector-specific spatial deficits after lesions in parietal subregions such as the lateral intraparietal area (LIP, red shading) and the parietal reach region (PRR, which includes the medial intraparietal area MIP and area V6A, green shading). Dorsal pulvinar (dPULV, orange shading) inactivation leads to spatial orienting bias for both eye and hand movements which can be compensated by visual reward cues, suggesting that visual perception might be preserved. Ventral pulvinar (vPULV, purple shading) inactivation leads to change detection deficits resembling visual neglect. Summarized from local inactivation studies in monkeys (Wardak et al., 2002; Wilke et al., 2010; Hwang et al., 2012; Wilke et al., 2012; Wilke et al., 2013; Hwang et al., 2014; Christopoulos et al., 2015; Katz et al., 2016; Zhou et al., 2016).
Figure 4. A, Summary of main findings on spike-based functional connectivity in rats (Olcese et al., 2016). Coupling was measured as pairwise cMI between single neurons. During wakefulness, cMI between neurons located in the same or different areas is largely balanced (left) for both excitatory and inhibitory neurons (black and red lines, respectively). In NREM sleep, interareal (but not intra-area) coupling between excitatory neurons is significantly reduced. This did not apply to intra-area cMI and interareal cMI (between interneurons). Line thickness indicates the proportion of neuronal pairs for which cMI was significantly >0. Asterisks indicate which connections showed a significant change between wakefulness and NREM sleep (the only significant differences found pertained to interareal coupling between excitatory neurons). Thus, during NREM sleep, neural computations may continue in local “islands of activity,” whereas global integration capabilities are reduced. B, Calculation of heterogeneity across a neuronal population (compare Montijn et al., 2015). A measure of a neuronal activity change (A, e.g., the relative fluorescence response of a neuron in 2-photon imaging, dF/F0) is computed across all neurons. Next, the responses are z-scored per neuron across all trials and all trial types (e.g., in a given session, visual stimuli are presented at 6 different contrasts; each contrast is presented 20 times; 120 trials in total). Per trial, the absolute difference in z-scored activity is then calculated across all pairs of neurons (e.g., ΔA1,2 is the difference between the responses of neurons 1 and 2). The population heterogeneity in a given trial is the mean of activity differences across all pairs. C, Examples of high (left) versus low heterogeneity (right) in a neuronal population, where response strength is indicated by color saturation. D, In a visual stimulus detection task performed by mice that were subjected to 2-photon imaging of V1 neuronal populations, heterogeneity was better capable of separating hit (detection) and miss (nondetection) trials than the mean fluorescence response (area under the curve resulting from receiver-operating characteristic analysis). Both measures predicted response behavior above chance: mean response, *p < 0.05; heterogeneity, ***p < 0.001; area under the curve = 0.5, chance level. Behavior was predicted better by heterogeneity than mean response (**p < 0.01). Values are mean ± SEM across animals. Data from Montijn et al. (2015).
Figure 4.
A, Summary of main findings on spike-based functional connectivity in rats (Olcese et al., 2016). Coupling was measured as pairwise cMI between single neurons. During wakefulness, cMI between neurons located in the same or different areas is largely balanced (left) for both excitatory and inhibitory neurons (black and red lines, respectively). In NREM sleep, interareal (but not intra-area) coupling between excitatory neurons is significantly reduced. This did not apply to intra-area cMI and interareal cMI (between interneurons). Line thickness indicates the proportion of neuronal pairs for which cMI was significantly >0. Asterisks indicate which connections showed a significant change between wakefulness and NREM sleep (the only significant differences found pertained to interareal coupling between excitatory neurons). Thus, during NREM sleep, neural computations may continue in local “islands of activity,” whereas global integration capabilities are reduced. B, Calculation of heterogeneity across a neuronal population (compare Montijn et al., 2015). A measure of a neuronal activity change (A, e.g., the relative fluorescence response of a neuron in 2-photon imaging, dF/F0) is computed across all neurons. Next, the responses are z-scored per neuron across all trials and all trial types (e.g., in a given session, visual stimuli are presented at 6 different contrasts; each contrast is presented 20 times; 120 trials in total). Per trial, the absolute difference in z-scored activity is then calculated across all pairs of neurons (e.g., ΔA1,2 is the difference between the responses of neurons 1 and 2). The population heterogeneity in a given trial is the mean of activity differences across all pairs. C, Examples of high (left) versus low heterogeneity (right) in a neuronal population, where response strength is indicated by color saturation. D, In a visual stimulus detection task performed by mice that were subjected to 2-photon imaging of V1 neuronal populations, heterogeneity was better capable of separating hit (detection) and miss (nondetection) trials than the mean fluorescence response (area under the curve resulting from receiver-operating characteristic analysis). Both measures predicted response behavior above chance: mean response, *p < 0.05; heterogeneity, ***p < 0.001; area under the curve = 0.5, chance level. Behavior was predicted better by heterogeneity than mean response (**p < 0.01). Values are mean ± SEM across animals. Data from Montijn et al. (2015).

Symposium on Consciousness in Oslo, August 26, 2016

Nevrofysiologi

Symposium on Consciousness in Oslo,  August 26, 2016

At the Scandinavian Physiological Society Annual Meeting, which will take place in Oslo, August 26th – 28th, 2016.

Venue:   The University of Oslo, Blindern Campus (Georg Sverdrups hus)

http://www.ccnorway.no/sps2016/

Symposium on Consciousness,

11:45 – 13:30  in Georg Sverdrups hus, University of Oslo, Blindern

 

Marzia De Lucia, Lausanne University Hospital, Switzerland: Prediction of comatose patients outcome based on EEG-based functional improvement over time

https://www.unil.ch/lren/en/home/menuinst/lab-members/principal-investigators—pis/marzia-de-lucia.html

 

Steven Laureys,  leader of the Coma Science Group, Liege, Belgium: Consciousness in coma and related states

https://en.wikipedia.org/wiki/Steven_Laureys

 

Nicholas D. Schiff, Weill Cornell Medical College, New York: Identification of Cognitive Motor Dissociation (CMD) after severe brain injury: mechanisms and challenges for restoring communication

http://vivo.med.cornell.edu/display/cwid-nds2001

 

Bjørn E. Juel, The Brain Signalling Group, University of Oslo: Electrophysiological markers of consciousness

http://www.med.uio.no/imb/english/research/groups/brain-signalling/ 

 

This symposium is co-hosted by the Forum for Consciousness Research and is open to the general Public.

All are welcome!

EU-midler til bevissthetsforskere i Oslo

Nevrofysiologi, Nevrokirurgi, Nevrologi, Nevrovitenskap, Ukategorisert

Et konsortium ledet fra Universitetet i Oslo (UiO) fikk i september 2015 bevilget midler til bevissthetsforskning (ca. 16 mill. NOK for de første 2 år; ), innenfor the Human Brain Project (HBP).

Prosjektet, som ledes av J.F. Storm, UiO, omfatter forskningsgrupper i Oslo, Belgia, Italia og Sveits:

Oslo: UiO (The Brain Signaling group, led by J.F. Storm) og Oslo Universitetssykehus (OUS, Rikshospitalet: overlege, dr.med. Pål Gunnar Larsson, Nevrokirurgisk avd. o.a.; og Sunnaas sykehus: Dr. Marianne Løvstad o.a.)

Belgia: The Coma Science Group, led by Dr. Steven Laureys, at the Cyclotron Research Centre of the University of Liège.

Italia:  Integrated Thalamo-Cortical Function (iTCf) research group (www.thalamocortical.org) led by Dr. Marcello Massimini, University of Milan.

Sveits: Sean Hill, co-Director of Neuroinformatics in Human Brain Project (HBP), Ecole Poly­tech­nique Fédérale de Lau­sanne (EPF), and Scientific Director of the International Neuroinformatics Coordinating Facility (INCF)

Prosjektets tittel: Experimental and computational exploration of consciousness mechanisms and methods in mice and humans  (Short name: Conscious Brain)

 

EU commision

2015_Sept_PRESS RELEASE from EU Commission

http://www.med.uio.no/imb/om/aktuelt/aktuelle-saker/2015/imb-human-brain-project.html

http://www.oslo-universitetssykehus.no/aktuelt_/nyheter_/Sider/EU-midler-til-bevissthetsforskere.aspx

Møte om FRI VILJE våren 2016 (mars-april)

Filosofi, Nevrofysiologi, Nevrovitenskap

Spørsmålet om vi har fri vilje, er et eldgammelt filosofisk problem som er nært beslektet med hjerne-bevissthets-problemet: “Fri vilje” og “bevisst vilje” betyr for mange nesten det samme. Dette spørsmålet er nylig  blitt aktualisert av ferske resultater fra hjerneforskning, og diskuteres i mange fora, også her til lands, bl.a.:

https://tv.nrk.no/serie/schrodingers-katt/DMPV73002215/17-12-2015

http://forskning.no/2015/12/har-vi-fri-vilje

http://www.nrk.no/viten/xl/mordere-har-ikke-noe-valg_-mener-forskere-1.12709180

https://radio.nrk.no/serie/ekko-hovedsending/MDSP25025215/18-12-2015#t=57m46s

Medias format gir imidlertid ofte for lite plass til motforestillinger og balansert, nyansert diskusjon.

Vi planlegger et møte om temaet “FRI VILE” i løpet av våren 2016, trolig i mars-april (tid og sted vil bli annonsert senere), med bl.a.:

WIRECENTER

John-Dylan Haynes

Prof. Dr. rer. nat., Professor (W3) for Theory and Analysis of Large-Scale Brain Signals

Director of Berlin Center for Advanced Neuroimaging (BCAN), Charité – Universitätsmedizin Berlin
Bernstein Center for Computational Neuroscience,Berlin

Edmund Henden,

professor i filosofi ved Høgskolen i Oslo og Akershus,

Øystein Elgarøy,

professor – Institutt for teoretisk astrofysikk, UiO, vil delta

——————————————————————————————————————————————————————————————–

Spørsmålet om fri vilje er også tema for programmet «Schrödingers katt» som sendes 17.12.2015 på NRK TV.

I den anledning har jeg skrevet en tekst som supplement til programmet. Den ble først skrevet som utkast til en «Ytring» på NRK.no etter forslag fra programskaperne bak «Schrödingers katt», men publiseres i stedet her:

Har vi fri vilje?

Av Johan F. Storm

 Ny hjerneforskning synes å vise at våre valg er forutbestemt av hjerneprosesser uten at vi vet det selv. Er dette sensasjonelle funn som forandrer alt? Er fri vilje bare er en illusjon? Er vi ikke ansvarlige for våre valg og handlinger? Eller er dette forhastede feilslutninger? Dette debatteres i flere fora og er tema for NRKs Shrödingers katt 17.desember*. Jeg vil hevde at man kan svare både ja og nei på spørsmålet om vi har fri vilje – avhengig av hva man mener med disse ordene. Disse spørsmålene må belyses fra flere sider for å kunne gi dekkende svar.    

Resten av teksten finnes her:   20151217_FRI VILJE – Bevissthetsforum_Suppl. Schrödingers katt_JFS13

 

Resten av teksten finnes her:   20151217_FRI VILJE – Bevissthetsforum_Suppl. Schrödingers katt_JFS13

 

 

Funding for TMS-EEG equipment for consciousness research in Oslo

Nevrofysiologi, Nevrokirurgi, Nevrologi

A consortium of neuroscience research groups and clinicians at the University of Oslo (UiO) and Oslo University Hospital (OUS) has recently obtained funding from the infastructure programme at UiO for acquiring TMS-EEG equipment for use in consciousness research.

Trans-cranial magnetic stimulation (TMS) combined With TMS-compatible high-density electroencephalography (hdEEG) have numerous applications in preclinical and clinical brain research, diagnosis and therapy, related to sensory, motor, and cognitive brain functions and diseases. TMS is widely used in research in humans and animals, and for diagnosis and monitoring of sensory, motor and cognitive dysfunctions, including altered states of consciousness due to brain injury or stoke. TMS can also be used for research and guiding in neurosurgery, monitoring anesthesia or rehabilitation after brain injury, treatment of neurological and psychiatric disorders including depression and multiple sclerosis.

Navigated TMS combined with high-density EEG (nTMS-hdEEG) has recently yielded highly promising results in consciousness research and diagnosis of disorders of consciousness, by providing a measurable index of consciousness.

 

Artikkel om “Mysteriet bevissthet” i Dagens Næringsliv 22. nov. 2014

Filosofi, Nevrofysiologi, Nevrovitenskap

 

Dagens Næringsliv 22. nov. 2014

“Mysteriet bevissthet”

Hjerneforskning kaster nytt lys over en stor, uløst gåte: Hva er bevissthet?

Johan F. Storm, Marianne Løvstad, Dagfinn Føllesdal, Pål G Larsson, Bjørn E Juel og Nils Chr. Stenseth

Nobelprisen til ekteparet Moser har gitt økt oppmerksomhet om en sterk tradisjon i norsk hjerneforskning; og vår tid er en gullalder for utforsking av hjernens mysterier. Endelig er det utviklet metoder som også kan kaste nytt lys over en av de største uløste gåtene om oss selv: Hva er egentlig bevissthet?

Vår bevissthet er alt vi opplever når vi er våkne eller drømmer – det som forsvinner i drømmeløs søvn eller koma. Knapt noe er mer sentralt i våre liv. Likevel anså mange hjerneforskere inntil nylig bevisstheten som noe håpløst diffust, og overlot den mest til filosofene. Hovedproblemet er at man ikke kan måle bevisstheten direkte eller gi noe klart svar på hvordan den kan oppstå fra hjerneprosesser, selv om man kan studere hjernen og atferd i detalj.

Dermed er bevisstheten tilsynelatende utilgjengelig for naturvitenskapelige metoder. Dette medfører etiske og medisinske dilemmaer i møte med pasienter med alvorlig hjerneskade som våkner fra koma, men ikke viser viljestyrt aktivitet. De ansees å mangle bevissthet, og kan være i en såkalt «vegetativ» tilstand i lang tid.

Kunnskapsrevolusjonen i vår forståelse av hjernen har gitt økt forståelse for at bevissthet også kan studeres naturvitenskapelig. Ledende hjerneforskere har utviklet bevissthetsforskningen til en stadig mer eksakt naturvitenskap, med lovende metoder, som nå også tas i bruk i Norge. Bevisstheten er knyttet til bestemte mønstre av hjerneaktivitet, mens mye av det som ellers skjer i hjernen er ubevisst. Derfor postulerte F. Crick (som tidligere fant strukturen til DNA) og C. Koch i 1995 at det måtte finnes en minste gruppe av hjerneprosesser som kan gi opphav til en spesifikk bevisst opplevelse (som en lyd, farge, tanke eller følelse). Man håper å finne lovmessigheter ved slike «korrelater» som kan lede til en god teori; og forskere som S. Dehaene og G. Tononi har hatt stor fremgang.

Tononi har utviklet en matematisk teori for bevissthet. I følge denne er våre bevisste opplevelser «integrert informasjon» i hjernens komplekse nettverk av celler. At det er stor hjerneaktivitet er ikke nok; den må være rik på informasjon og samvirke som en enhet for å gi bevissthet. Tononi og kolleger har videre utviklet en metode som bruker magnetisk stimulering og elektrofysiologiske målinger (EEG) til å påvise om personer har bevissthet. Andre forskere, som A. Owen, har brukt hjerneavbildning til å påvise at noen pasienter som atferdsmessig fremstår som «vegetative» trolig likevel har bevissthet. Et tverrfaglig forum for bevissthetsforskning (bevissthetsforum.no) er opprettet i samarbeid med Det Norske Videnskapsakademi. Vi håper at denne spennende utviklingen vil føre til bedre hjelp for hardt skadde pasienter, og kaste nytt lys over et av vitenskapens dypeste, ubesvarte spørsmål: Hvordan oppstår våre bevisste opplevelser fra materielle hjerneprosesser?