Summary Written by Lindsay Recknell
"If our brains were simple enough to be understood, we wouldn’t be smart enough to understand them."

- Incognito, page 224

The Big Idea

We Only Need Half a Brain

"Our hopes, dreams, aspirations, fears, comic instincts, great ideas, fetishes, sense of humor, and desires all emerge from this strange organ – and when the brain changes so do we."- Incognito, page 4

Did you know that doctors can successfully remove one half of the brain of an eight year old child and he’ll be fine? (This is a proven treatment for intractable epilepsy caused by Rasmussen’s encephalitis). Not any half of the brain – they couldn’t remove just the front or back; they have to remove either the right side or the left side of the brain. But because the right and left halves reveal themselves as something like copies of each other, it is possible to remove one half and still have all the functionality you’d expect from a full-brained person (page 125).

Clearly, the brain is a mysterious and complicated thing, made up of cells, neurons, electrical impulses and the like which work together to make us who we are. Our subconscious runs the show while our conscious explains and verbalizes why we do what we do and, although we think we’re in control of our behaviour all the time, brain science is demonstrating that this isn’t always true. Based on the development of different parts of our brains, whether we’re “right-brain” thinkers or “left-brain” thinkers, and any damage our brains have experienced as a result of trauma or insufficient chemical composition, we all behave differently in various situations.

Insight #1

Emotional and Rational Battles

"You are a charioteer, and your chariot is pulled by two thunderous horses, the white horse of reason and the black horse of passion."- Incognito, page 115

Human beings are social animals, connecting most strongly to each other on emotional levels. Eagleman uses the following example to prove this point: “imagine a trolley is barreling down the train tracks, out of control. Five workers are making repairs way down the track, and you, a bystander, quickly realize that they will all be killed by the trolley. But you also notice that there is a switch nearby that you can throw, and that will divert the trolley down a different track, where only a single worker will be killed. What do you do? (Assume there are no trick solutions or hidden information.)” (page 111). If you’re like most people, you’d flip the switch so only one person is harmed instead of five – a terrible choice to make but better to sacrifice one for many perhaps. But now imagine you’re on a footbridge that goes over the tracks, those same workers are on the track and an obese man is standing next to you on the footbridge. You realize that if you were to push the obese man off the bridge, his weight would be enough to stop the momentum of the train and save the workers – but do you push him?

You’re likely more conflicted over the second choice than the first but why? Isn’t the math the same in both as far as one for many goes? Philosophers suggest the difference lies in how people are being used. In the first scenario, you are simply reducing a bad situation – in the second, you’re exploiting a human being as a means to an end. But Eagleman and other neuroscientists suggest there may be a brain-based approach – that the brain “pivots on the emotional component of actually touching someone” (page 112). This sort of personal interaction activates the emotional networks, changing an abstract, non-personal situation into something real and emotional. Research involving brain imaging reveals that when faced with the footbridge scenario, areas involved in motor planning and emotion become active. In contrast, in the track-switch scenario, only lateral areas involved in rational thinking become active. “People register emotionally when they have to push someone; when they only have to tip a lever, their brain behaves like Star Trek’s Mr. Spock” (page 113).

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Insight #2

Unequal Before the Law

"The built-in myth of human equality suggests that all people are equally capable of decision making, impulse control and comprehending consequences. While admirable, the notion is simply not true."- Incognito, page 187

Our modern legal system is somewhat based on the assumption that all humans are equal before the law – but this idea is “simply not true” (page 187). Humans bring all sorts of preconceived notions, experiences, morals and rules to the table, based on our environments, capacity for learning, family lives and how we were raised. Because of these differences, it is not reasonable to assume that we all understand actions and consequences in the same way nor do we respond to punishment or behaviour modification in the same way. Because of this, it is impossible for us to fairly sentence all criminals using the same punishments. And yet, this is exactly what we do, using precedence and history to dictate punishment instead of individual capacity, and thereby assuring ourselves that we’ve provided “fair” punishment.

As neuroscience improves, Eagleman and his scientific colleagues will be able to help tailor sentencing and rehabilitation to the individual offender, suggesting that science will help to replace intuition about blameworthiness with a fairer approach based on the individual’s capacity to modify their behaviour as indicated by what can be seen in their brain. For example, a teenager who hasn’t fully developed the frontal portion of the brain should be punished differently than someone with frontal lobe damage, who will never develop the capacity of socialization because of this damage. “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” (page 191).

Even though the brain has been studied for hundreds of years and neuroscience makes huge discoveries daily, the brain is still largely misunderstood. Scientists have been breaking our brains down into its individual parts, expecting that these parts will enable us to understand the whole but we’re still not sure if this approach will work in neuroscience. The brain is unlike anything scientists have studied so far – vast, complex, and almost magical – and fortunately, we’re part of the lucky generation with the technology, capability and will to turn our attention to it. “Whatever else exists beyond the limits of science is an open question for future generations” (page 224).

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David Eagleman

“I’m a neuroscientist during the day and a writer at night. As a believer in the endeavor of popular science, I travel frequently to give public lectures. It has been an incredible pleasure to meet warm, funny, like-minded readers everywhere I visit.”

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