Dr. David Eagleman is a neuroscientist and director of the Laboratory for Perception and Action at Baylor College of Medicine.
Incognito asks the question "If the conscious mind - the part you consider to be you - is just the tip of the iceberg, what is the rest doing?"
As a neuroscientist, he begins by offering mind-boggling statistics about the human brain: "Your brain is built of cells called neurons and glia - hundreds of billions of them. Each one of these cells is as complicated as a city. There are as many connections in a single cubic centimeter of brain tissue as there are stars in the Milky Way galaxy.
The first thing we learn from studying our own circuitry is a simple lesson: most of what we do and think and feel is not under our conscious control. The conscious you is the smallest part of what's transpiring in your brain. Your consciousness is like a tiny stowaway on a transatlantic steamship, taking credit for the journey without acknowledging the massive engineering underfoot.
Brains are in the business of gathering information and steering behavior appropriately. It doesn't matter whether consciousness is involved in the decision-making. And most of the time, it's not. Consciousness evolved because it was advantageous - but advantageous only in limited amounts."
Eagleman points out that the philosopher and polymath Gottfried Leibniz (1646-1716) was among the first to acknowledge the power of the unconscious mind. Leibniz suggested that there are some perceptions of which we are not aware, and he called these "petite perceptions." He went on to suggest that there were strivings and tendencies ("appetitions") of which we are also unconscious but that can nonetheless drive our actions.
In chapter 2, "The Testimony of the Senses", Dr. Eagleman dismantles the common-sense belief that vision is a passive reflection of the outside world. "It may come as a surprise that about one-third of the human brain is devoted to vision. Strictly speaking, all visual scenes are ambiguous. Your brain goes through a good deal of trouble to disambiguate the information hitting your eyes by taking context into account, making assumptions, and using tricks." This is why patients who surgically recover perfect vision nonetheless can not immediately see, despite perfect optical health: their brain must learn how to interpret the data coming in.
"There is some difficulty in rigorously defining `illusion,' as there is a sense in which all of vision is an illusion. One of the most pervasive mistakes is to believe that our visual system gives a faithful re-presentation of what is `out there' in the same way that a movie camera would."
"There is a sizeable patch in the retina in each eye where the photoreceptors are missing. This blind spot is huge - imagine the diameter of the moon in the night sky. You can fit 17 moons into your blind spot. One reason we are usually unaware of these blind spots is because there are two eyes and the blind spots are in different, non-overlapping locations, so with both eyes open you have full coverage of the scene. But more significantly, the brain "fills in" the missing information from the blind spot. Your brain invents a patch of the background pattern. Your brain, with no information from that particular spot in visual space, fills in with the patterns around it. You're not perceiving what's out there. You're perceiving whatever your brain tells you."
"The trickle of data moving from the eyes to the brain is too small to really account for the rich experience of vision. The brain makes assumptions about the incoming data, and these assumptions are based on previous experience. In other words, given a little information your brain uses its best guesses to turn it into something larger."
"Perception reflects the active comparison of sensory inputs with internal predictions. Awareness of your surroundings occurs only when sensory inputs violate expectations."
"Anton's syndrome is a disorder in which a stroke renders a person blind - and the patient denies her blindness. A group of doctors will stand around the bedside and say, `Mrs. Johnson, how many of us are around your bed?' and she'll confidently answer `Four', even though in fact there are seven of them. Those with Anton's syndrome are not pretending they are not blind; they truly believe they are not blind. They are experiencing what they take to be vision, but it is all internally generated. Often a patient with Anton's syndrome will not seek medical attention for a little while after the stroke, because she has no idea she is blind. It is only after bumping into enough walls that she begins to feel that something is amiss."
"Our sense of time - how much time passed and what happened when - is constructed by our brains. And this sense is easily manipulated, just like our vision can be. So the first lesson about trusting your senses is: don't. The most important maxim for a fighter pilot is `Trust your instruments', because your cockpit dials are much more reliable than your senses."
"The ability to remember motor acts like changing lanes is called procedural memory, and it is a type of implicit memory - meaning that your brain holds knowledge of something that your mind cannot explicitly access. To the extent that consciousness is useful, it is useful in small quantitities, and for very particular tasks." (cf. Dr. Neale Martin's Habit: The 95% of Behavior Marketers Ignore).
Eagleman demolishes the myth - reflected in the now-discredited AIDA model, but still too widespread in marketing circles - that you have to have conscious recall of something for it to have an influence on your behaviour:
"The effects of previous exposure can be long lasting. If you have seen a picture of someone's face before, you will judge them to be more attractive upon a later viewing. This is true even when you have no recollection of having seen them previously. This is known as the mere exposure effect. The mere exposure effect is part of the magic behind product branding, celebrity building, and political campaigning: with repeated exposure to a product or face, you come to prefer it more."
"One real-world manifestation of implicit memory is known as the illusion-of-truth effect: you are more likely to believe that a statement is true if you have heard it before - whether or not it is actually true, and whether or not you remember having heard it." In other words, a re-presentation is mistaken for a presentation (reality), the more one is exposed to the re-presentation. "The illusion of truth effect highlights the potential danger for people who are repeatedly exposed to the same religious edicts or political slogans." (cf. Dr. Daniel Dennett's Breaking the Spell).
See something often enough and you will tend to like it; hear something often enough and you will tend to believe it. These are two of the main reasons why Share of Voice is so critical in marketing.
"A simple pairing of concepts can be enough to induce an unconscious association and the sense that there is something familiar and true about the pairing. In George W. Bush's 2000 campaign $2.5 million ad against Al Gore, a frame with the word RATS flashes on the screen in conjunction with `The Gore prescription plan.' In the next moment it becomes clear that the word is actually the end of the word BUREAUCRATS." (cf. the chapter on subliminal advertising in Martin Lindstrom's Buyology).
"In a recent study, researchers tested whether being unconsciously primed for the concept of alcohol would also unconsciously tickle the concepts associated with alcohol, such as sex and sexual desire. Men were shown words like `beer' or `bean', but the words were flashed too rapidly to be consciously perceived. The men then rated the attractiveness of photographs of women. After being unconsciously primed with the alcohol-related words, the subjects rated the photographs as more attractive. And the males who more strongly believed that alcohol increases sexual desire showed the strongest effect." (cf. the discussion of priming in Dr. Gerald Zaltman's How Customers Think).
"The feelings produced by physical states of the body come to guide behavior and decision making. Body states become linked to outcomes of events in the world. When something bad happens, the brain leverages the entire body (heart rate, contraction of the gut, weakness of the muscles, and so on) to register that feeling, and that feeling becomes associated with the event. When the event is next pondered, the brain essentially runs a simulation, reliving the physical feelings of the event. Those feelings then serve to navigate, or at least bias, subsequent decision making. If the feelings from a given event are bad, they dissuade the action; if they are good, they encourage it. Hunches turn out to be correct more often than chance would predict, because your unconscious brain is picking up on things first, and your consciousness lags behind." (cf. Dr. Antonio Damasio's Self Comes to Mind; The Feeling of What Happens; Descartes Error; and Looking for Spinoza).
Eagleman offers a practical example on how to access somatic knowledge that is normally inaccessible: "The next time a friend laments that she cannot decide between two options, tell her the easiest way to solve her problem: flip a coin. She should specify which option belongs to heads and which to tails, and then let the coin fly. The important part is to assess her gut feeling after the coin lands. If she feels a subtle sense of relief at being `told' what to do by the coin, that's the right choice for her. If instead she concludes that it's ludicrous for her to make a decision based on a coin toss, that will cue her to choose the other option. Read more ›