Book Review: Incognito

Posted: August 6th, 2011 under book review, education, philosophy, psychology.
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Neuroscientist David Eagleman proposes in his book Incognito: The Secret Lives of the Brain, that most of what you do, think and believe is generated by parts of your brain to which you have no access. His writing provokes thought and understanding.

The title of this book refers to its theme that we don’t really “know” ourselves. Eagleman describes how most of our thought processes are unconscious and not accessible to us, most of the activity going on without our being aware.

Almost the entirety of what happens in your mental life is not under your conscious control, and the truth is that it’s better this way.Incognito When consciousness meddles in details it doesn’t understand, the operation runs less effectively. One does not need to be consciously aware to perform sophisticated motor acts. We are not conscious of most things until we ask ourselves questions about them. The brain generally does not need to know most things; it merely knows how to go out and retrieve the data. It computes on a need-to-know basis. We are not conscious of much of anything until we ask ourselves about it. We are unaware of most of what should be obvious to our senses; it is only after deploying our attentional resources onto small bits of the scene that we become aware of what we were missing. Before we engage our concentration, we are typically not aware that we are not aware of those details. So not only is our perception of the world a construction that does not accurately represent the outside, but we additionally have the false impression of a full, rich picture when in fact we see only what we need to know, and no more. (p. 28)

Perception works not by building up bits of captured data, but instead by matching expectations to incoming sensory data. Neuroscientist Donald MacKay suggested that the primary visual cortex constructs an internal model that allows it to anticipate the data streaming up from the retina. The cortex sends its predictions to the thalamus, which reports on the difference between what comes in through the eyes and what was already anticipated. The thalamus sends back to the cortex only that difference information–that is, the bit that wasn’t predicted away. This unpredicted information adjusts the internal model so there will be less of a mismatch in the future. in this way, the brain refines its model of the world by paying attention to its mistakes. (p. 48-49)

Awareness of your surroundings occurs only when sensory inputs violate expectations. When you first learn to ride a bicycle, a great deal of conscious concentration is required; after some time, when your sensory-motor predictions have been perfected, riding becomes unconscious. You are unaware of how you’re holding the handlebars, applying pressure to the pedals, and balancing your torso. Your brain knows exactly what to expect. So you’re conscious neither of the movements nor of the sensations unless something changes–like a strong wind or a flat tire. Then these new situations cause your normal expectations to be violated, consciousness comes online and your internal model adjusts. This predictability that you develop between your own actions and the resulting sensations is the reason you cannot tickle yourself. Other people can tickle you because their tickling maneuvers are not predictable to you. Interestingly, schizophrenics can tickle themselves because of a problem with their timing that does not allow their motor actions and resulting sensations to be correctly sequenced. (p. 50)

Eagleman shares interesting insight into the way we perceive and accommodate to our differences:

If you are not color-blind, you may find it difficult to imagine yourself as color-blind. But some people see more colors than you do. A fraction of women have not just three but four types of color photoreceptors–and as a result they can distinguish colors that the majority of humankind will never differentiate. If you are not a member of that small female population, then you have just discovered something about your own impoverishments that you were unaware of. You may not have thought of yourself as color-blind, but to those ladies supersensitive to hues, you are. In the end, it does not ruin your day; instead, it only makes you wonder how someone else can see the world so strangely. And so it goes for the congenitally blind. They are not missing anything; they do not see blackness where vision is missing. Vision was never part of their reality in the first place, and they miss it only as much as you miss the extra scents of the bloodhound dog or the extra colors of the tetrachromatic women. (p. 78)

One in a hundred otherwise normal people experience the world with a condition called synesthesia, or “joined sensation.” In synesthetes, stimulation of a sense triggers an anomalous sensory experience: one may hear colors, taste shapes, or systematically experience other sensory blendings. Synesthesia is the result of increased cross talk among sensory areas in the brain. Synesthetes are not driven crazy by the extra dimensions. They’ve never known reality to be anything else. Most synesthetes live their entire lives never knowing that others see the world differently than they do. (p. 80-81)


Nature seems to have invented mechanisms for storing memory more than once. Under normal circumstances your memories of daily events are consolidated by an area of the brain called the hippocampus. But during frightening situations another area, the amygdala, also lays down memories along an independent, secondary memory track. Amygdala memories are difficult to erase and they can pop back up in “flashbulb” fashion. We’re not talking about a memory of different events, but multiple memories of the same event. (p. 126)

I think Eagleman does an excellent job explaining the wiring for our impulses and free will.

Hidden drives and desires can lurk undetected behind the neural machinery of socialization. When the frontal lobe is compromised, people become “disinhibited,” unmasking the presence of the seedier elements in the neural democracy. A common example of this disinhibited behavior is seen in patients with frontotemporal dementia, a tragic disease in which the frontal and temporal lobes degenerate. With the loss of the brain tissue, patients lose the ability to control hidden impulses. These patients unearth an endless variety of ways to violate social norms: shoplifting in front of store managers, removing their clothes in public, running stop signs, breaking out in song at inappropriate times, eating food scraps found in public trash cans, or being physically aggressive or sexually transgressive. (p. 155)

A slight change in the balance of brain chemistry can cause large changes in behavior. People’s brains can be vastly different–influenced not only by genetics but by the environments in which they grew up. Many chemical and behavioral “pathogens” can influence how you turn out. So when it comes to thinking about blameworthiness, the first difficulty to consider is that people do not choose their own developmental path. (162:) How exactly would we assign culpability to people for their varied behavior, when it is difficult to argue that the choice was ever really available? (p. 157)

Eagleman addresses at length the problem of our knee-jerk desire for punishment and revenge for “wrong-doers,” offenders, and prisoners rather than rehabilitation in the interest of improving society as a whole. His ideas of prison reform are astute and thought-provoking:

To help a citizen reintegrate into society, the ethical goal is to change him as little as possible to allow his behavior to come into line with society’s needs. Poor impulse control is a hallmark characteristic of the majority of criminals in the prison system. Many people have a strong retributive impulse: they want to see punishment, not rehabilitation. Often when we hear about a criminal committing an odious act, we are so angry that we want to take vigilante-style revenge. But just because we have the drive for something doesn’t make it the best approach. (p. 182-185)

The current version of the law uses crude divisions: If you’re eighteen we can kill you; if you’re one day shy of your eighteenth birthday you’re safe. If your IQ is 70, you get the electric chair; if it’s 69, get comfortable on your prison mattress. When punishing, what matters is not so much your intuition about blameworthiness but instead about modifiability. I speculate that someday we will be able to base punishment decisions on neuroplasty. Some people have brains that are better able to respond to classical conditioning (punishment and reward), while other people–because of psychosis, sociopathy, frontal maldevelopment, or other problems–are refractory to change. If a particular harsh sentence is meant to disincentivize prisoners from returning, there is no purpose of this punishment were there is not appropriate brain plasticity to receive it. If there is hope of using classical conditioning to effect a change in behavior that would allow social reintegration, then punishment is appropriate. When a convicted criminal is not going to be usefully changed by punishment, he should simply be warehoused. You do not punish or scold a non-housetrained puppy or a young child who shoplifts because you feel they had plenty of options, but instead because you understand the puppy or child to be modifiable. Societies in the future might experimentally derive an index to measure neuroplasticity–that is, the capacity to modify the circuitry. Punitive action may slake bloodlust for some, but there is no point in it for society more broadly. (p. 187-189)

Biological explanation will not exculpate criminals. Brain science will improve the legal system, not impede its function. For the smooth operation of society, we will still remove from the streets those criminals who prove themselves to be over-aggressive, under-empathetic, and poor at controlling their impulses. They will still be taken into the care of the government. But the important change will be in the way we punish the vast range of criminal acts–in terms of rational sentencing and new ideas for rehabilitation. The emphasis will shift from punishment to recognizing problems (both neural and social) and meaningfully addressing them. Further, as we come to better understand the brain, we can concentrate on building societal incentives to encourage good behavior and discourage bad behavior. This will reduce our emphasis on retribution in exchange for proactive, preventative policy making. Suppose we discovered that all serial murderers were abused as children; this encourages us to prevent child abuse, but it does nothing to change the way we deal with the particular serial murderer. We still need to warehouse him and keep him off the streets, irrespective of his past misfortunes. The judge must take action to keep society safe. The concept and word to replace blameworthiness with modifiability, a forward-thinking term that asks, What can we do from here? Is rehabilitation available? If not, will the punishment of a prison sentence modify future behavior? If punishment won’t help, then take the person under state control for the purposes of incapacitation, not retribution. (p. 190)

We see that self-knowledge requires as much work from the outside (in the form of science) as from the inside (introspection). Much of who we are remains outside our opinion or choice. Do we possess a soul that is separate from our physical biology–or are we simply an enormously complex biological network that mechanically produces our hopes, aspirations, dreams, desires, humor, and passions? The majority of people on the planet vote for the extrabiological soul, while the majority of neuroscientists vote for the latter: an essence that is a natural property that emerges from a vast physical system, and nothing more besides. The materialist viewpoint states that we are, fundamentally, made only of physical materials. In this view, the brain is a system whose operation is governed by las of chemistry and physics–with the end result that all of your thoughts, emotions, and decisions are produced by natural reactions following local laws to lowest potential energy. We are our brains and its chemicals, and any dialing of the knobs of your neural system changes who you are. Neurotransmitters (serotonin, dopamine, epinephrine), narcotics and hormones all influence your cognition in addition to genes and viruses. (p. 203-206)

Eagleman shares some interesting ideas about instincts, split-brain patients and brain hemispheres, how your brain interprets your body’s actions, brain rivalry, problem solving, automatism, and emergence.

I apologize for the long-winded review. There was so much in the book I considered significant and interesting. I found Incognito a very compelling read–one of my favorite books, in fact. The book, which is grounded in a massive amount of neuroscience research, is written in a conversational manner with lots of analogies and metaphors that make the information understandable and relevant. Brent actually had the pleasure of meeting and conversing with Eagleman at a Poptech conference last year. I am envious!

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