Consciousness and the Brain Quotes

“Introspection makes our conscious motives and strategies transparent to us, while we have no sure means of deciphering them in others. Yet we never genuinely know our true selves. We remain largely ignorant of the actual unconscious determinants of our behavior, and therefore we cannot accurately predict what our behavior will be in circumstances beyond the safety zone of our past experience. The Greek motto “Know thyself,” when applied to the minute details of our behavior, remains an inaccessible ideal. Our “self” is just a database that gets filled in through our social experiences, in the same format with which we attempt to understand other minds, and therefore it is just as likely to include glaring gaps, misunderstandings, and delusions.”
― Stanislas Dehaene, Consciousness and the Brain: Deciphering How the Brain Codes Our Thoughts

“I do not mean, of course, that we can always accurately express our conscious thoughts with Proustian accuracy. Consciousness overflows language: we perceive vastly more than we can describe.”
― Stanislas Dehaene, Consciousness and the Brain: Deciphering How the Brain Codes Our Thoughts

“Vladimir Nabokov, in his Lectures on Literature (1980), saw it all: Literature was not born the day when a boy crying “wolf, wolf” came running out of the Neanderthal valley with a big gray wolf at his heels; literature was born on the day when a boy came crying “wolf, wolf” and there was no wolf behind him.”
― Stanislas Dehaene, Consciousness and the Brain: Deciphering How the Brain Codes Our Thoughts

“quite opposite to Descartes’s organ metaphor, our global neuronal workspace does not operate in an input-output manner, waiting to be stimulated before producing its outputs. On the contrary, even in full darkness, it ceaselessly broadcasts global patterns of neural activity, causing what William James called the “stream of consciousness”—an uninterrupted flow of loosely connected thoughts, primarily shaped by our current goals and only occasionally seeking information in the senses. René Descartes could not have imagined a machine of this sort, where intentions, thoughts, and plans continually pop up to shape our behavior. The outcome, I argue, is a “free-willing” machine that resolves Descartes’s challenge”
― Stanislas Dehaene, Consciousness and the Brain: Deciphering How the Brain Codes Our Thoughts

“Science often progresses by carving out new distinctions that refine the fuzzy categories of natural language.”
― Stanislas Dehaene, Consciousness and the Brain: Deciphering How the Brain Codes Our Thoughts

“Literature was not born the day when a boy crying “wolf, wolf” came running out of the Neanderthal valley with a big gray wolf at his heels; literature was born on the day when a boy came crying “wolf, wolf” and there was no wolf behind him. Consciousness”
― Stanislas Dehaene, Consciousness and the Brain: Deciphering How the Brain Codes Our Thoughts

“What counts as genuine consciousness, I will argue, is conscious access-the simple fact that usually, whenever we are awake, whatever we decide to focus on may become conscious. Neither vigilance nor attention alone is sufficient. When we are fully awake and attentive, sometimes we can see an object and describe our perception to others, but sometimes we cannot-perhaps the object was too faint, or it was flashed too briefly to be visible. In the first case, we are said to enjoy conscious access, and in the second we are not (and yet as we shall see, our brain may be processing the information unconsciously).”
― Stanislas Dehaene, Consciousness and the Brain: Deciphering How the Brain Codes Our Thoughts

“In point of fact, the greater one’s science, the deeper the sense of mystery. —Vladimir”
― Stanislas Dehaene, Consciousness and the Brain: Deciphering How the Brain Codes Our Thoughts

“The idea that the mind belongs to a separate realm, distinct from the body, was theorized early on, in major philosophical texts such Plato’s Phaedo (fourth century BC)”
― Stanislas Dehaene, Consciousness and the Brain: Deciphering How the Brain Codes Our Thoughts

“consciousness has a precise role to play in the computational economy of the brain—it selects, amplifies, and propagates relevant thoughts.”
― Stanislas Dehaene, Consciousness and the Brain: Deciphering How the Brain Codes Our Thoughts

“mechanistic stance, Descartes believed that the mind and the body were made of different kinds of stuff that interacted through the pineal gland.”
― Stanislas Dehaene, Consciousness and the Brain: Deciphering How the Brain Codes Our Thoughts

“contemporary idea that learning relies on changes in the brain’s connections (“neurons that fire together wire together”). Descartes even presented an explicit mechanical model of sleep, which he theorized as a reduced”
― Stanislas Dehaene, Consciousness and the Brain: Deciphering How the Brain Codes Our Thoughts

“could feed himself by bringing a cup to his mouth. His family”
― Stanislas Dehaene, Consciousness and the Brain: Deciphering How the Brain Codes Our Thoughts

“Vladimir Nabokov, had no patience with Freud’s method and nastily barked: “Let the credulous and the vulgar continue to believe that all mental woes can be cured by a daily application of old Greek myths to their private parts. I really do not care.”
― Stanislas Dehaene, Consciousness and the Brain: Deciphering How the Brain Codes Our Thoughts

“The oxymoronic term blindsight may seem bizarre, but it accurately describes these individuals’ Shakespearean condition: to see, but not to see. A lesion in the primary visual cortex should make a person blind, and it does deprive such patients of their conscious vision—they assure you that they cannot see anything in a specific part of the visual field (which corresponds precisely to the destroyed area of cortex), and they behave as if they were blind. Incredibly enough, however, when an experimenter shows them objects or flashes of light, they accurately point to them. 10 In a zombielike manner, they unconsciously guide their hand to locations that they do not see—blindsight indeed. Which intact anatomical pathways support unconscious vision in blindsight patients? Clearly, in these patients, some visual information still makes it through from the retina to the hand, bypassing the lesion that makes them blind. Because the entry point into the patients’ visual cortex had been destroyed, the researchers initially suspected that their unconscious behavior arose entirely from subcortical circuits. A key suspect was the superior colliculus, a nucleus in the midbrain that specializes in the cross-registration of vision, eye movements, and other spatial responses. Indeed, the first functional MRI study of blindsight demonstrated that unseen targets triggered a strong activation in the superior colliculus. 11 But that study also contained evidence that the unseen stimuli evoked activations in the cortex—and sure enough, later research confirmed that invisible stimuli could still activate both the thalamus and higher-level visual areas of the cortex, somehow bypassing the damaged primary visual area. 12 Clearly, the brain circuits that take part in our unconscious inner zombie and that guide our eye and hand movements include much more than just old subcortical routes.”
― Stanislas Dehaene, Consciousness and the Brain: Deciphering How the Brain Codes Our Thoughts

“Dan Simons demonstrated change blindness in a staged experiment using live actors. An actor asks a student for directions on the Harvard campus. The conversation is briefly interrupted by passing workers, and once it resumes, two seconds later, the original actor has been replaced by a second. Even though the two people have different hair and clothing styles, most students fail to notice the swap.”
― Stanislas Dehaene, Consciousness and the Brain: Deciphering How the Brain Codes Our Thoughts

“What is special and fascinating about self-consciousness is that it seems to include a strange loop.9 When I reflect upon myself, the “I” appears twice, both as the perceiver and as the perceived. How is this possible? This recursive sense of consciousness is what cognitive scientists call metacognition: the capacity to think about one’s own mind. The French positivist philosopher Auguste Comte (1798–1857) considered this a logical impossibility. “The thinking individual,” he wrote, “could not divide into two, one reasoning, the other watching the reasoning. The observed organ and the observing organ being identical in this case, how could the observation be made?”
― Stanislas Dehaene, Consciousness and the Brain: Deciphering How the Brain Codes Our Thoughts

“Freud’s own contribution appears speculative. It would not be a huge exaggeration to say that in his work, the ideas that are solid are not his own, while those that are his own are not solid.”
― Stanislas Dehaene, Consciousness and the Brain: Deciphering How the Brain Codes Our Thoughts

“In many experiments, the boundary between seeing and not seeing is relatively sharp: an image is downright invisible when presented for 40 milliseconds, but is easily seen, on most trials, when the duration is increased to 60 milliseconds. This fonding justifies the use of the words subliminal (below threshhold) and supraliminal (above threshhold). Metaphorically, the gateway to consciousness is a well-defined threshhold, and a flashed image is either in or out. The length of the threshhold varies across subjects, but it always falls close to 50 milliseconds. At this duration, one perceives the flashed image about half the time. Presenting visual stimuli at threshhold therefore offers a wonderfully controlled experimental paradigm: the objective stimulus is constant, yet its subjective perception varies from trial to trial.”
― Stanislas Dehaene, Consciousness and the Brain: Deciphering How the Brain Codes Our Thoughts

“A stream of symbols appears at the same location on a computer screen. Most of the symbols are digits, but some are letters, which the participant is told to remember. The first letter is easily remembered. If a second letter occurs half a second or more after the first, it too is accurately committed to memory. If the two letters appear in close succession, however, the second one is often completely missed. The viewer reports seeing only one letter and is quite surprised to learn that there were two of them. The very act of attending to the first letter creates a temporary "blink of the mind" that annihilates the perception of the second.”
― Stanislas Dehaene, Consciousness and the Brain: Deciphering How the Brain Codes Our Thoughts

“Conscious access is also the gateway to more complex forms of conscious experience. In everyday language, we often conflate our Consciousness with our sense of self-how the brain creates a point of view, an "I" that looks at its surroundings from a specific vantage point.
Consciousness can also be recursive: our "I" can look down at itself, comment on its own performance, and even know when it does not know something. The good news is that even these higher-order meanings of Consciousness are no longer inaccessible to experimentation. In our Laboratories we have learned to quantify what the "I" feels and reports, both about the external environment and about itself. We can even manipulate the sense of self so that people may have an out-of-body experience while they lie inside a magnetic resonance imager.”
― Stanislas Dehaene, Consciousness and the Brain: Deciphering How the Brain Codes Our Thoughts

“Playing Chess Unconsciously For another demonstration of the power of our unconscious vision, consider chess playing. When grand master Garry Kasparov concentrates on a chess game, does he have to consciously attend to the configuration of pieces in order to notice that, say, a black rook is threatening the white queen? Or can he focus on the master plan, while his visual system automatically processes those relatively trivial relations among pieces? Our intuition is that in chess experts, the parsing of board games becomes a reflex. Indeed, research proves that a single glance is enough for any grand master to evaluate a chessboard and to remember its configuration in full detail, because he automatically parses it into meaningful chunks.29 Furthermore, a recent experiment indicates that this segmenting process is truly unconscious: a simplified game can be flashed for 20 milliseconds, sandwiched between masks that make it invisible, and still influence a chess master’s decision.30 The experiment works only on expert chess players, and only if they are solving a meaningful problem, such as determining if the king is under check or not. It implies that the visual system takes into account the identity of the pieces (rook or knight) and their locations, then quickly binds together this information into a meaningful chunk (“black king under check”). These sophisticated operations occur entirely outside conscious awareness.”
― Stanislas Dehaene, Consciousness and the Brain: Deciphering How the Brain Codes Our Thoughts

“By definition, we have no access to our many unconscious processes—but this does not prevent us from making up stories about them. For instance, many people think that when they read a word, they recognize it instantaneously and “as a whole,” based on its overall shape; but actually a sophisticated series of letter-based analyses occurs in their brain, of which they are completely unaware.”
― Stanislas Dehaene, Consciousness and the Brain: Deciphering How the Brain Codes Our Thoughts

“These three ingredients—focusing on conscious access, manipulating conscious perception, and carefully recording introspection—have transformed the study of consciousness into a normal experimental science.”
― Stanislas Dehaene, Consciousness and the Brain: Deciphering How the Brain Codes Our Thoughts

“An important consequence of these observations is that our consciousness of unexpected events lags considerably behind the real world. Not only do we consciously perceive only a very small proportion of the sensory signals that bombard us, but when we do, it is with a time lag of at least one-third of a second. In this respect, our brain is like an astronomer who watches for supernovae. Because the speed of light is finite, the news from distant stars takes millions of years to reach us. Likewise, because our brain accumulates evidence at a sluggish speed, the information that we attribute to the conscious “present” is outdated by at least one-third of a second.”
― Stanislas Dehaene, Consciousness and the Brain: Deciphering How the Brain Codes Our Thoughts

“distinguish the mere correlates of consciousness from the genuine signatures of consciousness. Although the quest for the brain mechanisms of conscious experience is often described as a search for neural correlates of consciousness, this phrase is inadequate. Correlation is not causation, and a mere correlate is therefore insufficient. Too”
― Stanislas Dehaene, Consciousness and the Brain: Deciphering How the Brain Codes Our Thoughts

“glued to the top of the head. On conscious trials only, an ample voltage wave sweeps through this region. It starts around 270 milliseconds and peaks anywhere between 350 and 500 milliseconds. This slow and massive event has been called the P3 wave (because it is the third large positive peak after a stimulus appears) or the P300 wave (because it often starts around 300 milliseconds).14 It is only a few microvolts in size, a million times smaller than an AA battery. However,”
― Stanislas Dehaene, Consciousness and the Brain: Deciphering How the Brain Codes Our Thoughts