Текст книги "Туннель Эго"

Автор книги: Томас Метцингер

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Как нам добиться взаимного оплодотворения между двумя сильными сторонами человеческого ума? Может ли нейрофеноменологическая обработка помочь нам оптимизировать критическую научную рациональность? Могли бы учёные быть лучшими учёными, если бы они больше путешествовали, скажем, если бы они научились осознанным сновидениям? Могла бы строгая, редукционная когнитивная нейробиология развить форму турбо-медитации, помогая монахам быть лучшими монахами и мистикам быть лучшими мистиками? Ведь возможно, что практика глубокой медитации способствует самостоятельности мышления, принятию на себя ответственности за свою жизнь и становлению политически зрелым гражданином? Могли бы мы найти способ выборочной стимуляции dorsolateral prefrontal cortex во время фаз сна целью сделать осознанные сновидения доступными каждому? Если мы сможем наладить безопасную и управляемую индукцию искусственных опытов выхода из тела, сможет ли это помочь танцорам или атлетам улучшить свою тренированность? А что это даст полностью парализованным пациентам? Может ли безжалостное материалистическое исследование того, как зеркальная система развивается в молодом мозгу человека, помочь нам культивировать эмпатию и интуитивное созвучие в наших детях способами, которые ранее себе никто представить не мог? Если мы не попробуем, то никогда и не узнаем.

Много страха связано с тем, что, вследствие натуралистического поворота в образе ума, мы потеряем наше достоинство. «Достоинство» – это термин, печально известный трудностью своего определения. Обычно, его используют тогда, когда испытывают нехватку аргументов. Однако, есть один смысл, который связан с уважением к себе и к другим, а именно – безусловная воля к самопознанию, достоверности и фактам. Достоинство есть отказ от унижения, связанного с поиском иного пути или побегом в некий метафизический Диснейленд. Если в нас действительно есть что-то вроде достоинства, мы можем показать это тем, как мы встречаем приходящие вызовы, некоторые из которых упоминались в этой книге. Мы можем наблюдать исторические изменения в образе самих себя творчески и с волей к ясности. Также ясно, как можно лишиться собственного достоинства: взывая к прошлому, развивая культуру запретов, соскальзывая в различные формы иррационализма и фундаментализма. Рабочие концепции «этики сознания» и «культуры сознания» как раз служат сохранению нашего достоинства путём помещения их на новых уровнях автономии нашего сознательного ума. Мы не должны потерять самоуважение, но мы также должны оставаться реалистами и не предаваться утопическим иллюзиям; шансы успешно оседлать тигра, по крайней мере, длительно удерживаться не его спине, не очень высоки. Но если мы возьмёмся за это, тогда новая культура сознания сможет заполнить вакуум, который возникнет как следствие Революции Сознания, которая сейчас свершается на огромной скорости. Здесь есть практические вызовы и теоретические вызовы. Величайший практический вызов заключается в применении результатов последующих этических дебатов. Величайший теоретический вызов может заключаться в вопросе: Как, учитывая нашу данную ситуацию, интеллектуальная честность и духовность смогу примириться, и смогут ли вообще? Но это уже совсем другая история.

Примечания

INTRODUCTION

1. M. Botvinick & J. Cohen, «Rubber Hand 'Feels' Touch That Eyes See,» Nature ШН: ШН (ИШН).

2. B. Lenggenhager et al., «Video Ergo Sum: Manipulating Bodily SelfConsciousness,» Science.

3. For a concise conceptual interpretation, see O. Blanke & T. Metzinger, «Full-body Illusions and Minimal Phenomenal Selfhood,» Trends Cog. Sci.

4. «Transparency» is a technical term in the modern philosophy of mind; a conscious representation is transparent if the system using it cannot, by means of introspection alone, recognize it as a representation. As philosophers might say, we see only the content, never the carrier-only «intentional properties» are accessible to introspection. Subjectively, this creates the feeling of being in direct contact with reality.

5. Thomas Metzinger, Being No One: The Self-Model Theory of Subjectivity (Cambridge, MA: MIT Press). The shortest freely available summary can be found in Scholarpedia Н(НН):ИШН, at www.scholarpedia.org/ article/Self_Models; for overviews, see Metzinger, Precis of «Being No One,» Psyche), at http://psyche.cs.monash.edu.au/symposia/metzinger/precis.pdf; and Metzinger, «Empirical Perspectives from the SelfModel Theory of Subjectivity,» Progress in Brain Res. (electronic offprint available from author).

CHAPTER 1

I. See T. Metzinger, «Beweislast fur Fleischesser,» Gehirn & Geist 5:70–75 (2006), reprinted in C. Konneker, Wer erklart den Menschen? Hirnforscher, Psychologen und Philosophen im Dialog (Frankfurt am Main: Fischer, 2006); A. K. Seth et al., «Criteria for Consciousness in Humans and Other Mammals,» Consciousness and Cognition 14:119–139 (2005); and D. B. Edelman et al., «Identifying Hallmarks of Consciousness in Non-Mammalian Species,» Consciousness and Cognition 14:169–187 (2005). Octopi are particularly interesting, because their brain architecture is very different from that of mammals, but they turn out to be much smarter than was assumed in the past. Although cognitive complexity perse is not an argument for the existence of subjective experience, we now have evidence that makes at least primary consciousness quite plausible in octopi; see J. A. Mather, «Celaphod Consciousness: Behavioural Evidence,» Consciousness and Cognition 17:37–48 (2008).

2. See Patrick Wilken, «ASSC-10 Welcoming address,» in 10th Annual Meeting of the Association for the Scientific Study of Consciousness, 23–36 June 2006, Oxford, U.K., 6. At http://eprints.assc.caltech.edu/138/01/ASSC 10_welcome_final.pdf.

3. See Thomas Metzinger, ed., Conscious Experience (Thorverton, UK, and Paderborn, Germany: mentis & Imprint Academic, 1995).

4. See the special issue on the neurobiology of animal consciousness in Consciousness and Cognition 14(1):1-232 (2005), in particular A. K. Seth et al., «Criteria for Consciousness in Humans and Other Mammals,» 119–139.

5. See Thomas Metzinger, ed., Neural Correlates of Consciousness: Empirical and Conceptual Questions (Cambridge, MA: MIT Press, 2000).

6. See Colin McGinn, «Can We Solve the Mind-Body Problem?» Mind 98:349–366 (1989). Reprinted in Ned Block et al., eds., The Nature of Consciousness: Philosophical Debates (Cambridge, MA: MIT Press, 1997); and Metzinger, «Introduction: Consciousness Research at the End of the Twentieth Century,» in Metzinger, ed., Neural Correlates of Consciousness (2000).

7. Antti Revonsuo, Inner Presence: Consciousness as a Biological Phenomenon (Cambridge, MA: MIT Press, 2006), 144ff.

CHAPTER 2

1. In philosophical parlance, a «zombie» is a hypothetical entity that behaves exactly like a person and is objectively indistinguishable from one, but has no inner awareness of anything. If zombies were at least logically possible, this could perhaps show that there is no entailment from physical facts to facts about consciousness.

2. See, for example, Rocco J. Gennaro, ed., Higher-Order Theories of Consciousness: An Anthology (Philadelphia: John Benjamins, 2004); and David Rosenthal, Consciousness and Mind (New York: Oxford University Press, 2006).

3. See S. P. Vecera & K. S. Gilds, «What Is It Like to Be a Patient with Apperceptive Agnosia?» Consciousness and Cognition 6:237–266 (1997).

4. A. Marcel, «Conscious and Unconscious Perception: An Approach to the Relations Between Phenomenal Experience and Perceptual Processes,» Cog. Psychology 15:292 (1983).

5. See, for example, G. Tononi & G. M. Edelman, «Consciousness and Complexity,» Science 282:1846-51 (1998); and Tononi et al., «Complexity and the Integration of Information in the Brain,» Trends Cog. Sci. 2:44–52 (1998). For an exciting recent application to the difference between waking and sleeping, see M. Massimini et al., «Breakdown of Cortical Effective Connectivity During Sleep,» Science 309:2228-32 (2005). For a popular description, see Edelman and Tononi, A Universe of Consciousness: How Matter Becomes Imagination (New York: Basic Books, 2000).

6. Thomas Metzinger, Being No One: The Self-Model Theory of Subjectivity (Cambridge, MA: MIT Press, 2003).

7. In Greek mythology, the analogy between sleep and death was even closer: Hypnos, the god of sleep, and Thanatos, the god of death, were twins, the sons of Nyx, the night. Morpheus, the god of dreams, was Hypnos' son. As in Shakespeare, to sleep, and possibly to die, is perchance to dream.

8. See V. A. F. Lamme, «Towards a True Neural Stance on Consciousness,» Trends Cog. Sci. 10(11):494–501 (2006); S. Dehaene et al., «Conscious, Preconscious, and Subliminal Processing: A Testable Taxonomy,» Trends Cog. Sci. 10(5):204–211 (2006).

9. A. Lutz, «Changes in the Tonic High-Amplitude Gamma Oscillations During Meditation Correlates with Long-Term Practitioners' Verbal Reports,» poster at the 9th ASSC conference, Pasadena, CA (2005); Lutz et al., «Long-Term Meditators Self-Induce High-Amplitude Synchrony During Mental Practice,» Proc. Nat. Acad. Sci. 101(46):16369-73 (2004). A good recent review is A. Lutz et al., «Attention Regulation and Monitoring in Meditation,» Trends Cog. Sci. 12(4):163–169 (2008).

10. Although I ultimately disagree with his theory of the «objective self,» perhaps the most beautiful and readable exposition of this problem and its application to self-consciousness can be found in chapter 4 of Thomas Nagel's The View from Nowhere (New York: Oxford University Press, 1986).

11. R. L. Gregory, «Visual Illusions Classified,» Trends Cog. Sci. 1:190–194 (1997).

12. Ernst Poppel, Mindworks: Time and Conscious Experience (New York: Harcourt Brace Jovanovich, 1988); E. Ruhnau, «Time-Gestalt and the Observer,» in Thomas Metzinger, ed., Conscious Experience (Thorverton, UK, and Paderborn, Germany: mentis & Imprint Academic, 1995).

13. R. M. Halsey & A. Chapanis, «Number of Absolutely Identifiable Hues,» Jour. OpticalSoc. Amer. 41(12):1057-58 (1951). For an excellent philosophical discussion, see D. Raffman, «On the Persistence of Phenomenology,» in Thomas Metzinger, ed., Conscious Experience (Thorverton, UK, and Paderborn, Germany: mentis & Imprint Academic, 1995).

14. Raffman, «On the Persistence of Phenomenology,» 295 (1995).

15. Clarence I. Lewis, Mind and the World Order (New York: Scribner's, 1929). See also Daniel C. Dennett, «Quining Qualia,» in A. J. Marcel & E. Bisiach, Consciousness in Contemporary Science (New York: Oxford University Press, 1988).

16. Diana Raffman, Language, Music, and Mind (Cambridge, MA: MIT Press, 1993).

17. P. Churchland, «Eliminative Materialism and the Propositional Attitudes,» Jour. Phil. 78(2):67–90 (1981).

18. Quoted after the extensively revised 1991 edition by M. David Enoch and Hadrian N. Ball, Uncommon Psychiatric Syndromes (London: Butterworth-Heinemann, 1991), 167.

19. I am grateful to Dr. Richard Chapman of the University of Utah's Pain Research Center for pointing out to me the concept of an «immunculus»: the network of natural autoantibodies targeting extracellular, membrane, cytoplasmic, and nuclear self-antigens. The repertoires of natural auto antibodies are surprisingly constant in healthy persons and, independently of gender and age, are characterized by only minimal individual variations.

CHAPTER 3

1. M. Botvinick & J. Cohen, «Rubber Hand 'Feels' Touch That Eyes See,» Nature 391:756 (1998).

2. K. C. Armel & V. S. Ramachandran, «Projecting Sensations to External Objects: Evidence from Skin Conductance Response,» Proc. Roy. Soc. Lond. 270:1499–1506 (2003).

3. M. R. Longo et al., «What Is Embodiment? A Psychometric Approach,» Cognition 107:978–998 (2008).

4. See Antonio Damasio, The Feeling of What Happens: Body, Emotion, and the Making of Consciousness (London: Vintage, 1999), 19. See also A. D. Craig, «How Do You Feel? Interoception: The Sense of the Physiological Condition of the Body,» Nat. Rev. Neurosci. 3:655–666 (2002) and «Interoception: The Sense of the Physiological Condition of the Body,» Curr. Opin. Neurobiol. 13:500–505 (2003).

5. For an excellent recent review-including a new, empirically informed synthesis-of the classical intuition of David Hume (that the self is just a bundle of impressions and everything can be explained «bottom-up») as opposed to the classical Kantian intuition (self-consciousness is a necessary prior condition for experiencing the body as a whole and everything must be explained «top-down»), see F. De Vignemont et al., «Body Mereology,» in Gunther Knoblich et al., eds., Human Body Perception from the Inside Out (New York: Oxford University Press, 2006).

6. The terminology was never entirely clear, but it frequently differentiated between an unconscious «body schema» and a conscious «body image.» The body schema (a notion introduced in 1911 by Sir Henry Head and Gordon Holmes, two British neurologists) would be a functional entity, providing an organized model of the bodily self in the brain, whereas the body image would also include our conscious perceptions of our own body as well as thoughts about and attitudes toward it. For a philosophical perspective on the conceptual confusion surrounding both notions, see Shaun Gallagher, How the Body Shapes the Mind (New York: Oxford University Press, 2005). For an excellent review of the empirical literature, see A. Maravita, «From 'Body in the Brain' to 'Body in Space': Sensory and Intentional Components of Body Representation,» in Knoblich et al., Human Body Perception (2006).

7. A. Maravita & A. Iriki, «Tools for the Body (Schema),» Trends Cog. Sci. 8:79–86 (2004). An excellent recent overview is A. Iriki & O. Sakura, «The Neuroscience of Primate Intellectual Evolution: Natural Selection and Passive and Intentional Niche Construction,» Phil. Trans. R. Soc. B 363:222941 (2008).

8. See A. Iriki et al., «Coding of Modified Body Schema During Tool-Use by Macaque Post-Central Neurons,» Neuroreport 7:2325-30 (1996); and Maravita & Iriki, «Tools for the Body (Schema)» (2004).

9. J. M. Carmena et al., «Learning to Control a Brain-Machine Interface for Reaching and Grasping by Primates,» PLoS Biology 1:193–208 (2003).

10. Here is how Iriki and Sakura put this important point: «If external objects can be reconceived as belonging to the body, it may be inevitable that the converse reconceptualization, i.e., the subject can now objectify its body parts as equivalent to external tools, becomes likewise apparent. Thus, tool use may lead to the ability to disembody the sense of the literal flesh-andblood boundaries of one's skin. As such, it might be precursorial to the capacity to objectify the self. In other words, tool use might prepare the mind for the emergence of the concept of the meta-self, which is another defining feature of human intelligence.» See Iriki & Sakura, «The Neuroscience of Primate Intellectual Evolution,» 2232 (2008).

11. See O. Blanke & T. Metzinger, «Full-Body Illusions and Minimal Phenomenal Selfhood,» Trends Cog. Sci. 13(1):7-13 (2009).

12. See T. Metzinger, «Out-of-Body Experiences as the Origin of the Concept of a 'Soul,'» Mind and Matter 3(1):57–84 (2005).

13. E. R. S. Mead, The Doctrine of the Subtle Body in Western Tradition (London: John M. Watkins, 1919).

14. It is important to be clear about the potential ontological conclusions: Even if a fully reductive explanation of all subtypes of OBEs should be achieved-and even if my hypothesis about the history of the concept of a soul is correct-it still remains logically possible that souls do exist. True, we would no longer need the concept of a soul for the purposes of science or philosophy; it would no longer figure in any rational, data-driven theory about the human mind. Logical possibility is something very weak, but it is hard to prove the nonexistence of something, and it always remains possible that one day we will discover a new sense in which the soul is not an empty concept at all.

15. It is interesting to note how the earliest historical meaning of the word «information» in English was the act of informing, or giving form or shape to the mind. What I call the «self-model» is exactly this: the «inner form» an organism gives to itself, the shaping of a mind.

16. Susan J. Blackmore, Beyond the Body: An Investigation of Out-of-theBody Experiences (London: Granada, 1982).

17. In addition to Beyond the Body, see S. Blackmore, «A Psychological Theory of the Out-of-Body Experience,» Jour. Parapsychol. 48:201–218 (1984); and S. J. Blackmore, «Where Am I? Perspectives in Imagery and the Out-of-Body Experience,» Jour. Mental Imagery 11:53–66 (1987).

18. E. Waelti, Der dritte Kreis des Wissens (Interlaken: Ansata, 1983), 18, 25. English translation by T. Metzinger.

19. C. S. Alvarado, «Out-of-Body Experiences,» in E. Cardena et al., eds., Varieties of Anomalous Experience: Examining the Scientific Evidence (Washington, DC: American Psychological Association, 2000).

20. See, for example, J. Palmer, «A Community Mail Survey of Psychic Experience,» Jour. Am. Soc. Psychical Res. 73:21–51 (1979); S. Blackmore, «A Postal Survey of OBEs and Other Experiences,» Jour. Soc. Psychical Res. 52:225–244 (1984).

21. See Alvarado, «Out-of-Body Experiences» (2000) for an overview of many studies; Blackmore, «Spontaneous and Deliberate OBEs: A Questionnaire Survey,» Jour. Soc. Psychical Res. 53:218–224 (1986); Harvey J. Irwin, Flight of Mind (Metuchen, NJ: Scarecrow Press, 1985), 174 ff; O. Blanke & C. Mohr, «Out-of-Body Experience, Heautoscopy, and Autoscopic Hallucination of Neurological Origin: Implications for Neurocognitive Mechanisms of Corporeal Awareness and Self Consciousness,» Brain Res. Rev. 50:184–199 (2005).

22. O. Devinsky et al., «Autoscopic Phenomena with Seizures,» Arch. Neurol. 46:1080-8 (1989).

23. See, for example, P. Brugger, «Reflective Mirrors: Perspective-Taking in Autoscopic Phenomena,» Cog. Neuropsychiatry 7:179–194 (2002); Brugger et al., «Unilaterally Felt Presences: The Neuropsychiatry of One Invisible Doppelganger,» Neuropsychiatry, Neuropsychology, and Behavioral Neurology 9:114–122 (1996); Brugger et al., «Illusory Reduplication of One's Own Body: Phenomenology and Classification of Autoscopic Phenomena,» Cog. Neuropsychiatry 2:19–38 (1997); Devinsky et al., «Autoscopic Phenomena» (1989).

24. U. Wolfradt, «AuGerkorpererfahrungen (AKE) aus differentiellpsychologischer Perspektive,» Zeitschriftf. Paraps. u. Grenzgeb. D. Psych. 42/43:65-108 (2000/2001); U. Wolfradt & S. Watzke, «Deliberate Out-ofBody Experiences, Depersonalization, Schizotypal Traits, and Thinking Styles,» Jour. Amer. Soc. Psychical Res. 93:249–257 (1999).

25. H. J. Irwin, «The Disembodied Self: An Empirical Study of Dissociation and the Out-of-Body Experience,» Jour. Parapsych. 64(3):261–277 (2000).

26. See Wolfradt, «AuGerkorpererfahrungen (AKE)» (2000/2001).

27. Ibid. Other studies find only 22–36 percent; see Alvarado, «Out-ofBody Experiences» (2000).

28. Wolfradt, «AuGerkorpererfahrungen» (2000/2001).

29. C. Green, Out-of-the-Body Experiences (London: Hamish Hamilton, 1968).

30. O. Blanke et al., «Stimulating Illusory Own-Body Perceptions,» Nature 419:269–270 (2002).

31. For a more detailed hypothesis concerning the role of the temporoparietal junction, see Blanke et al., «Out-of-Body Experience and Autoscopy of Neurological Origin,» Brain 127:243–258 (2004); S. Bunning & O. Blanke, «The Out-of-Body Experience: Precipitating Factors and Neural Correlates,» Prog. Brain Res. 150:333–353 (2005); O. Blanke & S. Arzy, «The Out-of-Body Experience: Disturbed Self-Processing at the Temporo-Parietal Junction,» The Neuroscientist 11:16–24 (2005); and F. Tong, «Out-of-Body Experiences: From Penfield to Present,» Trends Cog. Sci. 7:104–106 (2003).

32. Blanke et al., «Linking Out-of-Body Experience and Self-Processing to Mental Own-Body Imagery and the Temporoparietal Junction,» Jour. Neurosci. 25:550–557 (2005).

33. For more on this point, see Blanke & Metzinger, «Full-Body Illusions and Minimal Phenomenal Selfhood,» 13(1):7-13 (2009).

34. See Wolfradt, «AuGerkorpererfahrungen (AKE)» (2000/2001), 91.

35. Can you imagine what it would be like to look at yourself from the outside and shake your own hand? Henrik Ehrsson of the Karolinska Institute in Stockholm, Sweden, is one of the leading figures in self-model research. He created one of the classic full-body illusion experiments and also demonstrated that upper limb amputees can be induced to experience a rubber hand as their own and extended the field by focusing on behavioral and neuroimaging evidence. Recently, members of his team managed to not only trigger the illusion that another person's body was one's own, but also create the phenomenal experience of being in that other person's body while actually facing their own body and shaking their own hand. See Valerie I. Petrovka & H. Henrik Ehrsson, «If I Were You: Perceptual Illusion of Body Swapping,» PLoS ONE 3(12):e3832 (2008), H. Henrik Ehrsson, «The Experimental Induction of Out-of-Body Experiences,» Science 3127:1048 (2007), H. Henrik Ehrsson et al., «Upper Limb Amputees Can Be Induced to Experience a Rubber Hand as their Own,» Brain 131:3443–3452; Tamar R. Makin et al., «On the Other Hand: Dummy Hands and Peripersonal Space,» Beh. Brain. Res. 191:1-10 (2008).

36. See W. Barfield et al., «Presence and Performance Within Virtual Environments,» in Woodrow Barfield & Thomas A. Furness III, eds., Virtual Environments and Advanced Interface Design (New York: Oxford University Press, 1995). See also M. V. Sanchez-Vives & M. Slater, «From Presence to Consciousness Through Virtual Reality,» Nat. Rev. Neur. 6.332339 (2005). Mel Slater, for many years a leading researcher in the field of virtual reality, has recently demonstrated that the feeling of ownership can also be induced for simulated body parts in virtual environments (rather than, as in our experiment, having people still look at their «real» body). Obviously, this permits experiments that would never have been possible in the physical world, including real-time modifications of virtual bodies not only in terms of length, size, and appearance, but also complex motion patterns. As the authors put it: «For the future our work also suggests that people can have their 'self' enter the virtual domain in a genuine sense of the word, and not just metaphorically as in current day computer games and online communities. In combination with BCI [brain-computer interfaces] we envisage a functioning virtual body that is felt as their own by participants, with a significant application in VR training, limb prosthetics, and entertainment.» See M. Slater et al., «Towards a Digital Body: Th Virtual Arm Illusion,» Frontiers Hum. Neurosci. 2:6. doi:10.3389/neuro.09.006.2008.

37. See www.dukemednews.org/news/article.php?id=10218.

38. See, for example, R. A. Sherman et al., «Chronic Phantom and Stump Pain Among American Veterans: Results of a Survey,» Pain 18:83–95 (1984).

39. S. W. Mitchell, «Phantom Limbs,» Lippincott's Mag. Pop. Lit. & Sci. 8:563–569 (1871).

40. See V. S. Ramachandran et al., «Scientific Correspondence: Touching the Phantom Limb,» Nature 377:489–490 (1995); V. S. Ramachandran & D. Rogers-Ramachandran, «Synaesthesia in Phantom Limbs Induced with Mirrors,» Proc. Roy. Soc. Lond. B:377–386 (1996); and V. S. Ramachandran & Sandra Blakeslee, Phantoms in the Brain (New York: William Morrow, 1998).

41. V. S. Ramachandran, «Consciousness and Body Image: Lessons from Phantom Limbs, Capgras Syndrome and Pain Asymbolia,» Phil. Trans. Roy. Soc. Lond. B353:1851-9 (1998). For clinical and experimental details, see Ramachandran and Rogers-Ramachandran, «Synaesthesia in Phantom Limbs» (1996).

42. P. Brugger et al., «Beyond Re-membering: Phantom Sensations of Congenitally Absent Limbs,» Proc. Nat. Acad. Sci. USA 97:6167-72 (2000).

43. See § 12 and § 13 of The Ethics.

CHAPTER 4

1. Adapted from the case report of a sixty-eight-year-old woman suffering from stroke-related, transient alien hand syndrome. From D. H. Geschwind et al., «Alien Hand Syndrome: Interhemispheric Disconnection Due to Lesion in the Midbody of the Corpus Callosum,» Neurology 45:802–808 (1995).

2. See K. Goldstein, «Zur Lehre der Motorischen Apraxie,» Jour. fur Psychologie und Neurologie 11:169–187 (1908); W. H. Sweet, «Seeping Intracranial Aneurysm Simulating Neoplasm,» Arch. Neurology & Psychiatry 45:86-104 (1941); S. Brion & C.-P. Jedynak, «Troubles du Transfert Interhemispherique (Callosal Disconnection). A Propos de Trois Observations de Tumeurs du Corps Calleux. Le Signe de la Main Etrangere,» Revue Neurologique 126:257–266 (1972); G. Goldberg et al., «Medial Frontal Cortex Infarction and the Alien Hand Sign,» Arch. Neurology 38:683–686 (1981). For an important new conceptual distinction, see C. Marchetti & S. Della Sala, «Disentangling the Alien and the Anarchic Hand,» Cog. Neuropsychiatry 3:191–207 (1998).

3. Goldberg et al., «Medial Frontal Cortex Infarction,» 684 (1981).

4. G. Banks et al., «The Alien Hand Syndrome: Clinical and Postmortem Findings,» Arch. Neurology46:456–459 (1989).

5. Ibid.

6. For more on the representational architecture of volition and akinetic mutism, see T. Metzinger, «Conscious Volition and Mental Representation: Towards a More Fine-Grained Analysis,» in Natalie Sebanz & Wolfgang Prinz, eds., Disorders of Volition (Cambridge, MA: MIT Press, 2006).

7. S. Kremer et al., Letter to the Editor, «The Cingulate Hidden Hand,»

Jour. Neurology, Neurosurgery, and Psychiatry 70:264–265 (2001); see also a classical study by I. Fried et al., «Functional Organization of Human Supplementary Motor Cortex Studied by Electrical Stimulation,» Jour. Neurosci. 11:3656-66 (1991). In this study, subjects stimulated with electrical currents of different strength reported the illusory conscious perception of ongoing movement, or the anticipation of movement, or the «urge» to perform a movement, all «in the absence of overt motor activity.»

8. D. M. Wegner & T. Wheatley, «Apparent Mental Causation: Sources of the Experience of Will,» Amer. Psychol. 54(7):480–492 (1999).

9. Wegner & Wheatley, «Apparent Mental Causation» (1999), 488.

10. Ibid., 483.

11. See, for instance, P. Haggard, «Conscious Awareness of Intention and of Action,» in Johannes Rossler & Naomi Eilan, eds., Agency and Self-Awareness-Issues in Philosophy and Psychology (Oxford, UK: Clarendon Press, 2003). A good recent review is Patrick Haggard, «Human Volition: Towards a Neuroscience of Will,» Nat. Rev. Neurosci. 9:934–946 (2008).

12. It is true that indeterminacy exists on the subatomic level, but the mind cannot somehow sneak into the physical world through indeterminate quantum processes. (Nor is chance what we want: Philosophically, randomness in the brain would be just as bad as full determination.) Quantum theories of free will are empirically false as well: There may be different kinds of brains somewhere else in the universe, but in human brains the firing of neurons and so on take place on the macroscopic scale. For such huge objects as nerve cells at 37°C body temperature, quantum events simply play no role.

13. The voluntary inhibition of voluntary actions seems to be mostly determined by unconscious events in the anterior median cortex. See M. Brass & P. Haggard, «To Do or Not To Do: The Neural Signature of SelfControl,» J. Neurosci. 27:9141–9145. (2007).

14. See T. Metzinger, «The Forbidden Fruit Intuition,» The Edge Annual Question-2006: What Is Your Dangerous Idea? www.edge.org/q2006/ q06_7.htmlfflmetzinger. Reprinted in J. Brockman, ed., What Is Your Dangerous Idea? Todays's Leading Thinkers on the Unthinkable (New York: HarperPerennial, 2007), 153–155.

15. It would not be a new thought in the history of philosophy. Vasubandhu, a fourth-century Buddhist teacher and one of the most important figures in the development of Mahayana Buddhism in India, reports: Buddha has spoken thus: 'O, Brethren! actions do exist, and also their consequences (merit and demerit), but the person that acts does not. There is no one to cast away this set of elements and no one to assume a new set of them. (There exists no individual), it is only a conventional name given to (a set) of elements.' Appendix to the VIIIth chapter of Vasubandhu's Abhidarmakoga, § 9: 100.b.7; quoted after T. Stcherbatsky, «Th Soul Thory of the Buddhists,» Bull. Acad. Sci. Russ. 845 (1919).

CHAPTER 5

1. The second question, of course, is the one Descartes asked in the first Meditation, when he realized that everything he had ever believed to be certain-including his impression of sitting by the fire in his winter coat and closely inspecting the piece of paper in his hands-could equally well have occurred in a dream. What makes the problem of dream skepticism so intractable is that even in a «best-case scenario» of sensory perception, there is apparently no reliable, fool-proof method of distinguishing wakefulness and dreaming. According to dream skepticism, literally all of our experiences of waking life could be nothing more than a dream, and we are unable, even in principle, ever to decide this question with certainty. For a detailed discussion of the problem of dream skepticism, see, for instance, Barry Stroud, The Significance of Philosophical Scepticism (New York: Oxford University Press, 1984). For the status of the phenomenal and the epistemic subject in the dream state, see J. Windt & T. Metzinger, «The Philosophy of Dreaming and Self-Consciousness: What Happens to the Experiential Subject During the Dream State?» in Patrick McNamara & Deirdre Barrett, eds., The New Science of Dreaming (Westport, CT: Praeger, 2007). See http://eprints.assc.caltech.edu/200/01/Dreams.pdf.

2. See J. A. Hobson et al., «Dreaming and the Brain: Toward a Cognitive Neuroscience of Conscious States,» Behavioral and Brain Sci. 23:793–842 (2000); and Antti Revonsuo, Inner Presence: Consciousness as a Biological Phenomenon (Cambridge, MA: MIT Press, 2006).

3. Helen Keller, The World I Live In (New York: New York Review Books, 2003).