by Bor, Daniel
verbal
World Economic Forum
World Health Organization (WHO)
Yantis, Steven
Zeidan, Fadel
Zinacantecos babies/toddlers
Zolpidem
1 Throughout this book, I will assume that “awareness” and “consciousness” have the same meaning.
2 Actually, some blind humans do learn a form of echolocation sufficiently advanced, they claim, to distinguish between the front and back of a parked car. For an interesting article describing this, see “Echo Vision: The Man Who Sees with Sound,” by Daniel Kish, in the April 11, 2009, edition of the New Scientist.
3 A marginally more believable version of this philosophical argument is to keep the comparison within the same person. For instance, imagine that I had some bizarre surgery to rewire my color brain centers so that what I used to experience as red I now experience as blue and vice versa. But my objections still apply here. Even without any surgery, my perception of red today will not be my perception of red tomorrow: My experiential history and all the other senses and feelings that occur as I see red will be different each time, as my brain will be. So there is absolutely no hope for this much more radical surgical change.
4 Currently, every year computer “chatterboxes” compete for the Loebner Prize, which provides a forum for programs to attempt to pass the Turing Test, and convince a sufficient proportion of ordinary people that they are text-chatting to a human and not software. Every example of software to date has been an obvious simulation, not anything anyone would consider conscious. Nevertheless, these chatterboxes can maintain surprisingly realistic conversations, thanks to some very clever programming. To read more and try chatting to a few of the winners yourself, go to www.loebner.net/Prizef/loebner-prize.html.
5 That’s a 1 with 80 zeroes after it, or, in words, a hundred million trillion trillion trillion trillion trillion trillion. If we hadn’t put a limit on the sentence size, then the number of possible sentences would have been infinite.
6 Whether or not this is practicable, efforts to reach this goal are already underway. For instance, in one project, the mouse brain is being mapped at a resolution of 5 nanometers, which is sufficient to capture the detail of every cell in the brain. See www.mcb.harvard.edu/lichtman/ATLUM/ATLUM_web.htm.
7 This system is an amazingly powerful and efficient way of storing information, bearing marked similarities to conventional computers, despite the apparently meager alphabet of four letters. This may sound terribly limiting for an information processing device, but you can in principle code for an infinite variety of things with it. A standard computer can manage with just two options: a 1 and a 0. These two alternative digits can nevertheless represent huge quantities of different types of information, as long as the sequence of these 1’s and 0’s is long enough. If there’s just one digit, it can hold just two different possible pieces of information (21—either a 1 or a 0). If I have two digits, that’s four possible pieces (22—00, 01, 10, and 11). If I have ten digits, that’s increasing handsomely, to 1,024 possible states (210—0000000000, 0000000001, 0000000010, and so on up to 1111111111). RNA (and DNA) works in a similar way, just with two extra number types in addition to 1 and 0. These four RNA possibilities could easily be labeled 0, 1, 2, and 3, but instead are commonly labeled A, G, C, and U to reflect the names of the actual chemical bases that these letters stand for. These are adenine, guanine, cytosine, and uracil. These are identical bases to DNA, except that the U (uracil) is a substitute for T (thymine) in DNA.
Why does this code utilize three letter words? A triplet sequence of any three letters allows for sixty-four (43) different combinations, more than enough for each possible three-letter word to represent the twenty amino acids, while two-letter sequences would fall short at sixteen (42) possibilities. That’s why DNA/RNA words to code for amino acids in the recipe for proteins are three letters long.
8 The human genome includes around 23,000 genes—making it far smaller than that of many other organisms and surprisingly minuscule compared to what you might expect for an organism that contains the most complex organ on the planet—the human brain. However, by using many clever techniques—one gene coding for many proteins, hierarchies of controlling genes, and so on—we make the most of our meager genetic lot. A better index of organism complexity than number of genes is probably the range of proteins that an organism makes—and on those terms we are indeed heavy hitters.
9 In actual fact, most animals have a second active form of internal evolution, via their immune systems. Because the range of parasites we face is vast, and their frequency is incredibly high, the risk of death from these invaders is very real. Therefore, we need an immune system that can cope with virtually any eventuality. The way our immune systems can “learn” to combat invaders is very similar to standard natural selection—or brain processes. The immune system creatively generates many alternative possibilities, has those alternatives interact with the pathogens, and then, when some particular possibility finds a match (i.e., it has learned something), the hypothesis that such enemies are around is classed as well founded, and this successful antibody effectively breeds, so that it becomes a prominent feature of the immune system itself.
10 This result has now been loudly amplified within popular culture, with newspaper articles written all over the world, including titles such as “Want to Make a Complicated Decision? Just Stop Thinking.” It also is the major theme of Malcolm Gladwell’s book Blink: The Power of Thinking Without Thinking, in which he argued that immediate instinctive decisions can often be superior to long deliberation.
11 Another reason, possibly, that Dijksterhuis’s study has lent itself so easily to media coverage is that it appears to explain our “eureka” moments, when flashes of insight seem to appear suddenly, as if by magic, from the darkest depths of our unconscious. But is that really how it is? If our insights were truly unconscious, all we’d need to do would be to frame a complex problem, then stick our pens on some clean white paper and let our unconscious minds take control. Of course, if we did this, we’d be left with a dense nest of random lines, and we’d certainly be no nearer to the solution. Instead, most sparks of insight require a heavy investment of conscious thought. We need to develop strategies for exploring the terrain of possibilities, we need painstakingly to try each worthy permutation of the multitude of parameters, and finally, we need to have sufficient conscious understanding of the field to know when we’ve actually arrived at the solution. It’s true that sometimes merely diverting ourselves, going for a walk, or having a nap seems somehow to dislodge our thoughts and make insights more likely. But is that because of the unbridled power of the unconscious, or instead because the break has allowed us to consciously take a fresh angle when we return to the problem?
12 These actions by the CIA and the U.S. government are themselves iconic examples of poor, knee-jerk decision making, and they emphasize how choice quality can be improved by pausing, deliberating carefully and consciously, and relying as much as possible on proper scientific data, such as peer-reviewed publications, with good evidence of effects being repeated in different labs.
13 And if we do subscribe to the idea that no one has any free will in the stronger sense, because we are all just machines, then one logical consequence of this is to forgive, or even simply and fully to accept all the actions that everyone makes, just as we might accept natural events from inanimate sources. This might not be a realistically attainable perspective, but it would certainly be one free from anger, intolerance, and hatred.
14 Even though the human brain is a mere 2 percent of total body weight, in newborns this single organ requires a staggering 87 percent of the body’s total energy. A five-year-old has a brain that greedily guzzles nearly half of all the energy the child consumes, and even in adults this figure is at least a quarter, though that proportion can rise dramatically if we’ve had a mentally taxing day—for instance, when studying for exams. In fact, some bio
logists have suggested that the energy demands and complexity of a human brain are nearing the endpoint of what is biologically possible and that if you started trying to cram even more neuronal wires into the brain, the additional miniaturization that this would entail would turn all brain signal into random noise—and the cleverest organ in the known universe would suddenly become one of the dumbest.
15 To try examples out yourself from the original study, visit www.psych.ubc.ca/~rensink/flicker/download/.
16 For a video example of this from the original authors, visit http://youtu.be/FWSxSQsspiQ.
17 For an example of the video used in this experiment, visit http://youtu.be/vJG698U2Mvo.
18 It’s possible that in most, if not all, other examples of emergentism one would care to mention—for example, the collective intelligence of ants or macroeconomics—the recipe is little more than positive and negative feedback loops at the lower levels interacting to generate a more accurate, fitting informational solution at the level above.
19 The cause of this surprising limitation is a matter of intense current debate. One explanation suggests that three or four items are plenty, in almost all circumstances, to be the focus of our attention. There are exceptions, however. A student who is struggling with a mathematics assignment at school, or someone trying to learn the ins and outs of the latest overly complex gadget, may well wish it were possible for the human mind to handle more. But in our evolutionary past, we were rarely simultaneously faced with more than a few predators about to eat us, and we rarely chased after more than one or two sources of food or potential sexual partners. We didn’t need more in order to face the dangers of the world and take advantage of its benefits. In other words, perhaps there was never an evolutionary need to attend to more than just a few items at a time.
Another explanation, supported by computational models of how neurons interact, suggests that somewhere between three and four items is actually the maximum that can be practically sustained within a brain. Once attention has increased the signal for a given item, any neurons throughout the cortex that relate to any features of the object not only fire more actively, but also link together in a signature rhythm. If more than one object is being attended to simultaneously, multiple brain rhythms are required in order to keep the signals separate. But the brain can only sustain about three or four of these harmonies—any more and they begin to blend into each other too much, and the result becomes a disjunctive neural noise, where objects become confused with each other or simply forgotten.
20 At the time of this study, a normal person using a strategy to vastly improve his working memory was a highly unusual result. But about a decade later, in the early 1990s, the world memory championships started, where many other normal people would use their own heavily practiced strategies to compete on similar tasks. Now, after about twenty years of vibrant competitions, this initial feat of remembering 80 digits seems unimpressive. Many new techniques have been explored and there has been an increasing number of serious mental athletes. The current world record holder on virtually the exact same task as just described can correctly recall 240 numbers just spoken to him in sequence. The results from other tasks are equally awe-inspiring. The current world record for numbers of cards memorized in sequence in an hour is 1,456, and the shortest time to memorize a single pack of 52 cards is 21.9 seconds!
21 In Douglas Hofstadter’s whimsical and influential book Gödel, Escher, Bach: An Eternal Golden Braid, these logical structures in music and art are carefully explored, especially in terms of how they relate to the human mind.
22 The main neuroscientific evidence for the language instinct comes from the discovery of a gene called FOXP2. A mutation in this gene, it has been claimed, causes a selective language impairment, especially in the ability to speak fluently. But the mutation also causes general cognitive deficits, such as a lowering of IQ, which might underlie an impairment in the kind of chunking processes I’m describing rather than anything specific to language.
23 Actually, the primary visual cortex is not quite as dumb as all that. It can also act as a flexible slave system to more advanced regions of the brain. For instance, attention can enhance our perception of one part of space, partly via later regions controlling the activity of the primary visual cortex, so that those subregions within it, say, that code for the upper right quadrant, are more active, and so more ready to pick up changes in this location.
24 This theory is similar to two other modern theories of the brain, proposed by Gerald Edelman and Anil Seth, which also try to mathematically equate consciousness with the complexity of information the brain processes. I chose to highlight information integration theory because it is the most prominent and detailed of the three.
25 Actually, in this model there definitely is such a thing as too many connections, and some ugly compromise of connectivity is the ideal. The critical factor here is just how many different states a network can be in. This can be physically imagined by appeal to symmetries. Say there is a 3 by 3 by 3 cube of nodes, thus 27 nodes total. If all the nodes are connected to all the others (or similarly, if none of the nodes are connected), one corner node lighting up is the same as all the others. But say there is a middle ground, with each node connected to somewhere between 5 and 20 of the other 26 nodes. This time when a corner node lights up, its connections mean it is unique; there are no other corner nodes with the same configuration of connections as this one, and so its information state is unique. Because there are no symmetries of wiring, this particular cube could represent the most information out of the three options.
26 For some videos of the crows using tools, see www.thenakedscientists.com/HTML/content/interviews/interview/1202/ and www.newscientist.com/article/dn17556.
27 The original scientist who ran this study, Patricia Greenfield, provided evidence for the thesis that this staged development of abilities to chunk movements mirrored a child’s ability to learn the complexities of language—for instance, combining subcomponents of words together to form more complex words, and using multiple words in a grammatical structure. This task therefore is another clue that our ability for language might just boil down to our ability to chunk, especially in a hierarchical way.
28 It turns out that there are many factors that need to be taken into account for an accurate, useful ratio of brain to body to be determined. For instance, recent evidence suggests that some species are far better at packing in more neurons per brain weight than others, so measuring brain weight alone isn’t very informative.
29 I suspect that synesthesia is more prevalent in autistics than in the general population, although I don’t know of any studies that have as yet looked into this.
30 There is a clear relationship between chronic poor sleep and obesity, although the mechanism for this is unclear. I suspect that one part of the effect is the daily playing out of the equivalent of this chocolate-cake study, where poor sleep shrinks working memory, and thus mental control—and a less healthy diet ensues.
31 There’s some provisional evidence, however, that cognitive training is useful in staving off dementia in those over the age of sixty-five.
Copyright © 2012 by Daniel Bor
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Library of Congress Cataloging-in-Publication Data
Bor, Daniel.
The ravenous brain : how the new science of consciousness explains our insatiable search for meaning / Daniel Bor.
p. cm.
Includes bibliographical references and index.
eISBN : 978-0-465-03296-9
1. Consciousness—Physiological aspects. 2. Brain. 3. Mind and body. I. Title.
QP411.B59 2012
612.8’2—dc23
2012016971
