Klincewicz, Michal

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This article was downloaded by: [New York University], [lily Frank]On: 11 September 2013, At: 09:49Publisher: Taylor & FrancisInforma Ltd Registered in England and Wales Registered Number: 1072954 Registered office: Mortimer House,37-41 Mortimer Street, London W1T 3JH, UKAJOB NeurosciencePublication details, including instructions for authors and subscription information:http://www.tandfonline.com/loi/uabn20Consciousness Is More Complicated Than That:Theoretical Limitations of Interactive CapacityMichał Klincewicz a & Lily Frank ba Berlin School of Mind and Brain , Humboldt Universität Zu Berlinb Icahn School of Medicine at Mount Sinai and The Graduate Center , City University of NewYorkPublished online: 11 Sep 2013.To cite this article: Michał Klincewicz & Lily Frank (2013) Consciousness Is More Complicated Than That: TheoreticalLimitations of Interactive Capacity, AJOB Neuroscience, 4:4, 38-39To link to this article:  http://dx.doi.org/10.1080/21507740.2013.827758PLEASE SCROLL DOWN FOR ARTICLETaylor & Francis makes every effort to ensure the accuracy of all the information (the “Content”) containedin the publications on our platform. However, Taylor & Francis, our agents, and our licensors make norepresentations or warranties whatsoever as to the accuracy, completeness, or suitability for any purpose of theContent. Any opinions and views expressed in this publication are the opinions and views of the authors, andare not the views of or endorsed by Taylor & Francis. The accuracy of the Content should not be relied upon andshould be independently verified with primary sources of information. Taylor and Francis shall not be liable forany losses, actions, claims, proceedings, demands, costs, expenses, damages, and other liabilities whatsoeveror howsoever caused arising directly or indirectly in connection with, in relation to or arising out of the use ofthe Content.This article may be used for research, teaching, and private study purposes. Any substantial or systematicreproduction, redistribution, reselling, loan, sub-licensing, systematic supply, or distribution in anyform to anyone is expressly forbidden. Terms & Conditions of access and use can be found at http://www.tandfonline.com/page/terms-and-conditionsAJOB NeuroscienceConsciousness Is More ComplicatedThan That: Theoretical Limitationsof Interactive CapacityMichał Klincewicz, Berlin School of Mind and Brain, Humboldt Universita¨t Zu BerlinLily Frank, Icahn School of Medicine at Mount Sinai and The Graduate Center,City University of New YorkCurrently, theminimally conscious state (MCS) is diagnosedbased on a set of behavioral criteria, which often fail todistinguish the MCS from the vegetative state (VS). As aremedy for the high rate of misdiagnosis, David Fischerand Robert Truog (2013) recommend using interactive ca-pacity (IC), which is “the ability to receive communicatedinformation . . . and the intentional generation of a coherentresponse” (30), as diagnostic of MCS.CONSCIOUSNESS OF ENVIRONMENT AND CON-SCIOUSNESS OF SELFThe difference between VS and MCS is consciousness,which the authors define as “the awareness of one’s selfand environment” (26). But it is controversialwhether thesetwo senses of consciousness—awareness of one’s self andawareness of one’s environment—can be collapsed into one(Block 1995; Rosenthal 2004). The problem is compoundedby the ambiguity of the concept of self-consciousness it-self. Self-consciousness can refer, for example, to embar-rassment, awareness of one’s identity, or the ability tointrospect.The sense of self-consciousness relevant to the presentdiscussion is typically characterized as conscious experi-ence. Conscious experiences are those of which we are insome way aware, while unconscious experiences are thoseof which we are not aware in any way. One may resist thisdistinction and insist that there is no such thing as an expe-rience of the environmentwithout awareness of that experi-ence. However, the evidence of experience without aware-ness is compelling (for review see Dehaene and Changeux2011).In light of the distinction between these two types ofconsciousness, the authors’ proposal should be understoodto be about conscious experience, that is, consciousness ofoneself in the relevant sense. Consciousness of the environ-ment absent conscious experience may not carry the samekind of moral significance relevant to management of careand end-of-life decisions. Given this, for the remainder ofthis commentary, we assume that what the authors proposeis that IC is a sufficient condition for conscious experience.Thus clarified, the positive proposal of the article becomessuspect.Address correspondence to Michał Klincewicz, Humboldt Universita¨t Zu Berlin, Berlin School of Mind and Brain, Luisenstraße 56, Haus1, Room 317, 10117, Berlin, Germany. E-mail: michal.klincewicz@gmail.comNEUROSCIENTIFICADVANCESANDTHENEEDFOR IN-TERACTIVE CAPACITYThe evidence for IC as a sufficient condition for consciousexperience comes from a number of recent neuroimagingstudies of patients diagnosed as in VS (for review see Owen2013). For example, one patient diagnosed to be in VS bybehavioral criteria was shown to nonetheless intentionallygenerate objectively measurable neural responses that in-dicated the patient understood the experimenter’s instruc-tions to imagine oneself playing tennis (Owen et al. 2006).This kind of evidence is very compelling and suggests thatadvances in brain imagining technology can help better dis-tinguish patients in VS from patients in MCS. But it is notobvious how it can help establish IC as a diagnostic thresh-old of conscious experience.According to the authors, patients who are in MCS1,MCS2, and MCS3 are all conscious in the relevant sense. InMSC1, consciousness is undetectable using either behav-ioral measures or current technology, which means thatthese patients are “diagnostically indistinguishable” frompatients in VS. According to the authors, in order to pickthese patients out and delineate them fromVSpatients, clin-icians may be tempted to use more sensitive technologicalmethods to detect consciousness.As the authors note, this approach is doubly problem-atic. On the one hand, there is a risk of mistaking neu-ral activity indicative of consciousness of the environment,which can occur without conscious experience, for signs ofconscious experience, thus overdiagnosing patients in VS asminimally conscious. On the other hand, this approach fallsshort of definitively indicating conscious experience, sinceevenmore advanced and sensitive technologymaymiss therelevant neural activity. The authors’ proposal aims to avoidthese problems.LIMITATIONS OF INTERACTIVE CAPACITYUnfortunately, the two given reasons for adopting IC as asufficient condition for conscious experience are not con-vincing. The first reason given is that IC is consistent withthe traditionally used behavioral criteria andwould therebybe easily integrated with current practice thus facilitat-ing the transition for clinicians and the public. The high38 ajob Neuroscience October–December, Volume 4, Number 4, 2013Downloaded by [New York University], [lily Frank] at 09:49 11 September 2013 Conscientious of the Consciousrate of misdiagnosis under the behavioral criteria makesit puzzling why being consistent with it would be a goodthing. The authors acknowledge the high rate of misdiag-nosis and seem to think that their proposal can help re-duce this percentage. In light of all this, the first offeredreason for accepting IC as an indirect marker of conscious-ness of oneself is somewhat self-defeating and not veryconvincing.The second reason that the authors give is that there isa “general agreement that interactive capacity . . . is a reli-able indicator of consciousness” (30). This claim is doublymisleading. First, reliable indicators are not the same as suf-ficient conditions. Second, there is a good deal of disagree-ment about what reliably indicates conscious experience.Something is a reliable indicator of something else onlyif it is highly correlated with it. Smoke, for example, is areliable indicator of fire, but it is neither a sufficient or nec-essary condition for it. There are fires that produce no smokeand ways to make smoke without fire. Perhaps this is whysmoke is not used as a diagnostic of fire. What the authorsseem to have in mind is the stronger claim that IC is indeedsufficient for conscious experience, not merely a reliableindicator of it. Treating IC as a diagnostic threshold of con-scious experience would require as much.But let us assume that what the authors have in mindis the weaker claim, that IC is a reliable indicator and not asufficient condition. Can they now better support their pro-posal? Arguably, no, and this is because contrary to whatthe authors suggest, there seems to be little agreement in theempirical or philosophical literature on what reliably corre-lates with conscious experience. The only generally agreed-upon reliable indicators of conscious experience seem to besubjective verbal reports (Seth et al. 2008).Given the state of the field, even if IC can serve as areliable indicator of conscious experience, other measurescould do just as well. Indeed, different neurobiological ac-counts of consciousness would recommend different neuralcorrelates. Among these we could count activity in the pre-frontal cortex (Lau and Passingham 2006), recurrent activ-ity (Lamme and Roelfsema 2000), global accessibility (Baars2005), or specific kinds of neuronal oscillations (Crick andKoch 1990).What the authors need to support their recommenda-tion of IC as a diagnostic marker of conscious experience isa theory-independent reason to believe that “the ability toreceive communicated information . . . and the intentionalgeneration of a coherent response” is as good as or betterthan any of the other indicators of consciousness. Withoutsuch a reason, IC should not be adopted as a diagnosticthreshold of self-consciousness over any of these other op-tions.In addition, adopting IC as the marker of conscious-ness does not address the problem of how to treat pa-tients who are in the MCS1 category, that is, those who“retain an interactive capacity that is undetectable by cur-rent technologies or entirely lack the capacity to interact”(30). This puts in doubt the entire enterprise of the arti-cle. If IC is undetectable under certain conditions, whatreason do we have to adopt it as a diagnostic thresh-old that would weigh in on end-of-life decisions? To playthis role, it seems, IC would have to be a necessary, andnot merely a sufficient, condition for conscious experience.And it would certainly have to be more than a reliableindicator.INTERACTIVE CAPACITY AS ONE OF THE RELIABLEINDICATORS OF MCS?The arguments presented by Fischer and Truog for adopt-ing IC as a diagnostic ofMCS are tooweak to be convincing.However, the empirical results that they cite in support oftheir view are compelling and suggest what might be a bet-ter way of distinguishing patients in VS andMCS. The neu-ral correlates of IC and related capacities would certainlybe useful as a part of a pluralistic approach that takes intoaccount a variety of signatures of conscious experience dis-cussed in the neuroscience literature. The techniques usedin neuroscience can provide a suite of reliable indicators ofconscious experience that, in sum, can serve as a diagnosticthreshold of MCS.REFERENCESBaars, B. J. 2005. Globalworkspace theory of consciousness: Towarda cognitive neuroscience of human experience. Progress in BrainResearch 150: 45–53.Block, N. 1995. On a confusion about a function of consciousness.Behavioral and Brain Sciences 18(2): 227–287.Crick, F., and C. Koch. 1990. Towards a neurobiological theory ofconsciousness. Seminars in the Neurosciences 2: 263–275.Dehaene, S., and J.-P. Changeux. 2011. Experimental and theoreticalapproaches to conscious processing. Neuron 70(2): 200–227.Fischer, D. B., andR.D. Truog. 2013. Conscientious of the conscious:Interactive capacity as a threshold marker for consciousness. AJOBNeuroscience 4(4): 26–33.Lamme, V. A. F., and P. R. Roelfsema. 2000. The distinct modes ofvision offered by feedforward and recurrent processing. Trends inNeurosciences 23(11): 571–579.Lau, H. C., and R. E. Passingham. 2006. Relative blindsight innormal observers and the neural correlate of visual conscious-ness. Proceedings of the National Academy of Sciences USA 103(49):18763–18768.Owen, A. M. 2013. Detecting consciousness: A unique rolefor neuroimaging. Annual Review of Psychology 64: 109–133.Owen, A. M., M. R. Coleman, M. Boly, M. H. Davis, S. Laureys,and J. D. Pickard. 2006. Detecting awareness in the vegetative state.Science 313(5792): 1402–1402.Rosenthal, D. M. 2004. Varieties of higher-order theory. Advances inConsciousness Research 56: 17–44.Seth, A. K., Z. Dienes, A. Cleeremans, M. Overgaard, and L.Pessoa. 2008. Measuring consciousness: Relating behavioural andneurophysiological approaches. Trends in Cognitive Sciences 12(8):314–321.October–December, Volume 4, Number 4, 2013 ajob Neuroscience 39Downloaded by [New York University], [lily Frank] at 09:49 11 September 2013 

Consciousness Is More Complicated Than That: Theoretical Limitations of Interactive Capacity

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Consciousness Is More Complicated Than That: Theoretical Limitations of Interactive Capacity

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