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Towering above such pussies, Metzinger takes the bull by the balls. His “World-zero” hypothesis not only explains the subjective sense of self, but also why such an illusory first-person narrator would be an emergent property of certain cognitive systems in the first place. I have no idea whether he’s right—the man’s way beyond me—but at least he addressed the real question that keeps us staring at the ceiling at three a.m., long after the last roach is spent. Many of the syndromes and maladies dropped into Blindsight I first encountered in Metzinger’s book. Any uncited claims or statements in this subsection probably hail from that source.

If they don’t, then maybe they hail from Wegner’s The Illusion of Conscious Will[102] instead. Less ambitious, far more accessible, Wegner’s book doesn’t so much deal with the nature of consciousness as it does with the nature of free will, which Wegner thumbnails as “our mind’s way of estimating what it thinks it did.” Wegner presents his own list of syndromes and maladies, all of which reinforce the mind-boggling sense of what fragile and subvertible machines we are. And of course, Oliver Sacks[103] was sending us memos from the edge of consciousness long before consciousness even had a bandwagon to jump on.

It might be easier to list the people who haven’t taken a stab at “explaining” consciousness. Theories run the gamut from diffuse electrical fields to quantum puppet-shows; consciousness has been “located” in the frontoinsular cortex and the hypothalamus and a hundred dynamic cores in between.[104], [105] [106], [107], [108], [109], [110], [111], [112], [113], [114](At least one theory[115] suggests that while great apes and adult Humans are sentient, young Human children are not. I admit to a certain fondness for this conclusion; if childen aren’t nonsentient, they’re certainly psychopathic).

But beneath the unthreatening, superficial question of what consciousness is floats the more functional question of what it’s good for. Blindsight plays with that issue at length, and I won’t reiterate points already made. Suffice to say that, at least under routine conditions, consciousness does little beyond taking memos from the vastly richer subconcious environment, rubber-stamping them, and taking the credit for itself. In fact, the nonconscious mind usually works so well on its own that it actually employs a gatekeeper in the anterious cingulate cortex to do nothing but prevent the conscious self from interfering in daily operations116, 117, 118.[116], [117], [118] (If the rest of your brain were conscious, it would probably regard you as the pointy-haired boss from Dilbert.)

Sentience isn’t even necessary to develop a “theory of mind”. That might seem completely counterintuitive: how could you learn to recognise that other individuals are autonomous agents, with their own interests and agendas, if you weren’t even aware of your own? But there’s no contradiction, and no call for consciousness. It is entirely possible to track the intentions of others without being the slightest bit self-reflective.[119] Norretranders declared outright that “Consciousness is a fraud”.[120]

Art might be a bit of an exception. Aesthetics seem to require some level of self-awareness—in fact, the evolution of aethestics might even be what got the whole sentience ball rolling in the first place. When music is so beautiful if makes you shiver, that’s the reward circuitry in your limbic system kicking in: the same circuitry that rewards you for fucking an attractive partner or gorging on sucrose.[121] It’s a hack, in other words; your brain has learned how to get the reward without actually earning it through increased fitness.[122] It feels good, and it fulfills us, and it makes life worth living. But it also turns us inward and distracts us. Those rats back in the sixties, the ones that learned to stimulate their own pleasure centers by pressing a lever: remember them? They pressed those levers with such addictive zeal that they forgot to eat. They starved to death. I’ve no doubt they died happy, but they died. Without issue. Their fitness went to Zero.

Aesthetics. Sentience. Extinction.

And that brings us to the final question, lurking way down in the anoxic zone: the question of what consciousness costs. Compared to nonconscious processing, self-awareness is slow and expensive.[123] (The premise of a separate, faster entity lurking at the base of our brains to take over in emergencies is based on studies by, among others, Joe LeDoux of New York University[124], [125]). By way of comparison, consider the complex, lightning-fast calculations of savantes; those abilities are noncognitive,[126] and there is evidence that they owe their superfunctionality not to any overarching integration of mental processes but due to relative neurological fragmentation.[127] Even if sentient and nonsentient processes were equally efficient, the conscious awareness of visceral stimuli—by its very nature—distracts the individual from other threats and opportunities in its environment. (I was quite proud of myself for that insight. You’ll understand how peeved I was to discover that Wegner had already made a similar point back in 1994.[128]) The cost of high intelligence has even been demonstrated by experiments in which smart fruit flies lose out to dumb ones when competing for food,[129] possibly because the metabolic demands of learning and memory leave less energy for foraging. No, I haven’t forgotten that I’ve just spent a whole book arguing that intelligence and sentience are different things. But this is still a relevant experiment, because one thing both attributes do have in common is that they are metabolically expensive. (The difference is, in at least some cases intelligence is worth the price. What’s the survival value of obsessing on a sunset?)

While a number of people have pointed out the various costs and drawbacks of sentience, few if any have taken the next step and wondered out loud if the whole damn thing isn’t more trouble than it’s worth. Of course it is, people assume; otherwise natural selection would have weeded it out long ago. And they’re probably right. I hope they are. Blindsight is a thought experiment, a game of Just suppose and What if. Nothing more.

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102

Wegner, D.M. 2002. The Illusion of Conscious Will. MIT Press, Cambridge. 405pp.

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103

Sacks, O. 1970. The Man who mistook his wife for a hat and other clinical tales. Simon & Shuster, NY.

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McFadden, J. 2002. Synchronous firing and its influence on the brain’s electromagnetic field: evidence for an electromagnetic field theory of consciousness. J. Consciousness Studies, 9, No. 4, 2002, pp. 23–50.

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Penrose, R. 1989. The Emperor’s New Mind. Oxford University Press.

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Tononi, G., and G.M. Edelman. 1998. Consciousness and Complexity. Science 282: 1846-1851.

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Baars, B.J. 1988. A Cognitive Theory of Consciousness. Cambridge Univ. Press, New York.

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Hilgetag, C.C. 2004. Learning from switched-off brains. Sci. Amer. 14: 8-9.

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Roth, G. 2004. The quest to find consciousness. Sci. Amer. 14: 32-39.

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Pauen, M. 2004. Does free will arise freely? Sci. Amer. 14: 41-47.

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Zimmer, C. 2003. How the mind reads other minds. Science 300:1079-1080.

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Crick, F.H.C., and C. Koch. 2000. The unconscious homunculus. In Neural Correlates of Consciousness—Empirical and Conceptual Questions (T. Metzinger, Ed.) MIT Press, Cambridge.

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Churchland, P.S. 2002. Self-Representation in Nervous Systems. Science 296: 308-310.

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Miller, G. 2005. What is the biological basis of consciousness? Science 309: 79.

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Blakeslee, S. 2003. The christmas tree in your brain. Toronto Star, 21/12/03.

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Matsumoto, K., and K. Tanaka. 2004. Conflict and Cognitive Control. Science 303: 969-970.

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Kerns, J.G., et al. 2004. Anterior Cingulate Conflict Monitoring and Adjustments in Control. Science 303: 1023-1026.

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Petersen, S.E. et al. 1998. The effects of practice on the functional anatomy of task performance. Proceedings of the National Academy of Sciences 95: 853-860.

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Zimmer, C. 2003. How the mind reads other minds. Science 300:1079-1080.

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Norretranders, T. 1999. The User Illusion: Cutting Consciousness Down to Size. Penguin Press Science. 467pp.

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Altenmüller, E.O. 2004. Music in your head. Scientific American. 14: 24-31.

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Pinker, S. 1997. How the mind works. WW Norton & Co., NY. 660pp.

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Matsumoto, K., and K. Tanaka. 2004. Conflict and Cognitive Control. Science 303: 969-970.

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Helmuth, L. 2003. Fear and Trembling in the Amygdala. Science 300: 568-569.

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Dolan, R.J. 2002. Emotion, cognition, and behavior. Science 298: 1191-1194.

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Treffert, D.A., and G.L. Wallace. 2004. Islands of genius. Scientific American 14: 14-23.

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Anonymous., 2004. Autism: making the connection. The Economist, 372(8387): 66.

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Wegner, D.M. 1994. Ironic processes of mental control. Psychol. Rev. 101: 34-52.

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