The Tell-Tale Brain by V.S. Ramachandran

The Book in Three Sentences

Humans are unique among the animal kingdom because of their brain. The human brain evolved through two methods: biological evolution, which takes a long time and cultural evolution, which is incredibly fast by comparison. These evolutionary processes have resulted in the development of mirror neurons, which contribute to our remarkable levels of creativity, ambition, communication.

The Tell-Tale Brain summary

This is my book summary of The Tell-Tale Brain by V.S. Ramachandran. My notes are informal and often contain quotes from the book as well as my own thoughts. This summary also includes key lessons and important passages from the book.

• The author has unearthed many of his discoveries by working with people who have interesting or strange brain injuries and disabilities.
• The Heinsenberg Principle reveals that at the subatomic level even our most basic sense of cause and effect breaks down.
• The deciphering of the genetic code in the 1950s marked the birth of modern biology.
• Humans are different, plain and simple. We are not “just another ape.”
• It is impossible to understand the human brain without understanding how it evolved.
• “Nothing in biology makes sense, except in light of evolution.” -Theodosius Dobzhansky
• Fascinating: many traits evolved from previous traits with very different functions. For example, wings evolved from scales. The original purpose was insulation not flight.
• Evolution found ways to radically repurpose functions in the ape brain into remarkably more powerful functions in the human brain.
• “All good science emerges from an imaginative conception of what might be true.” -Peter Medawar
• Ramachandran loves “small science” which doesn’t require big teams or lots of technology and can be repeated by almost anyone.
• Homogeneity breeds weakness. Science (and life) needs many different styles and viewpoints.
• Application for mental models: Many scientists let the most expensive equipment drive their research and not the most interesting questions. If your lab spends $1 million on a state of the art brain imaging machine, then you tend to get pressured to use it at all times. Every scientific problem gets forced through the lens of one machine. Consider how often we do this with our thinking and our decision making. How often do we let one identity (politics, religion, capitalism, etc.) dictate all of our thinking? (See Paul Graham’s “Keep your identity small.”) How often does the highest paid person’s mental model win out? (See: HiPPOs.) Be careful to not let investments overpower mental models.
• Humans are part of the animal kingdom, descendants of apes, but also transcendent and unique among the animal kingdom. We are both.
• Incremental changes do not always lead to incremental results. Sometimes there is a “phase transition” like heating a block of ice from 31 degrees to 32 degrees.
• Phase transitions can occur in society as well. The rise of the Internet, new political orders, etc.
• Sometime around 150,000 years ago, this phase transition happened within the human brain.
• We can view evolution as going through two avenues: biological, which takes a very long time and cultural, which is shockingly fast by comparison. Ideas evolve much faster than bodies do.
• The cortex of most other mammal brains is mostly smooth and flat whereas the human cortex has grown so much that it has developed many folds and valleys to increase surface area (the walnut-like appearance).
• The cortex is especially well developed in dolphins and primates.
• An intention tremor is an example of an oscillating feedback loop in the human body. (Thinking in Systems makes the point that delays in feedback loops lead to oscillations in systems.)
• Biology so clearly drives behavior. Damage to the basal ganglia, for example, can lead to Parkinson’s and a shuffling gate. This new behavior (a shuffling walk) is not a choice on the patient’s part. It is simply a consequence of changes in the neurological structure of the brain. We are quick to admit the influence of biological factors on behavior in cases like these, but we too often overlook them otherwise.
• Wernicke’s area in the brain plays a critical role in language and deciphering meaning. It is 7x larger in human than in other primates and is one of the key biological differences between our brain and other animals.
• Some of the complex traits that embody human nature: ambition, empathy, and foresight.
• At least three areas have developed extraordinarily rapidly in human brains relative to other primates: Wernicke’s area, the prefrontal cortex, and the IPL region in each parietal lobe. These three areas structurally evolved in small steps, but functionally they led to massive leaps forward compared to other primates.
• Within some of these regions there is a special class of nerve cells called mirror neurons. These fire not only when you perform an action, but also when you watch someone else perform an action.
• Mirror neurons are incredibly important and are an area of huge research focus right now. They may be central to social learning, imitation, and the cultural transmission of skills and attitudes.
• Mirror neurons are hyper developed in humans compared to animals. This allowed humans to learn new skills within just one or two generations as opposed to the hundreds or thousands of generations required for genetic evolution. Cultural evolution operates at light speed compared to genetic evolution.
• Look up servo loop.
• Experience modifies the brain by strengthening or weakening the synapses that link neurons together.
• The regions of the brain are not cleanly divided in their roles and functions, but rather work together in a remarkable fashion. They are strongly linked and some regions can even take over functions for damaged areas. There is much redundancy among the brain areas.
• Humans are the only species to use neural plasticity to such an extreme degree. You’ve probably noticed how reliant humans are on their parents compared to say, how a baby giraffe can walk within hours of being born. This is not a weakness, but rather a strength because it allows humans to maintain remarkable brain plasticity during the first ten years of life.
• Vision is so incredibly powerful for living creatures that it evolved separately in different species.
• When you see something the light rays seen by your eye are converted into nerve impulses. There is no image in your head. Just impulses that describe it to your brain – like writing could describe how a chair looks even though the words on the paper look nothing like the chair itself.
• Wieskrantz’s studies on blindsight offer an interesting look at nonconscious sight. The patient was able to point at a spot on the wall correctly time after time despite saying that he could not see the spot at all.
• The Coolidge Effect: the phenomenon where males are sexually excited by new partners over and over again. Proven by a seldom known rat study where a sex deprived rat has sex with a female until exhausted. Then a new female is introduced and it happens again. And then again even though the rat was seemingly exhausted before.
• Synesthesia occurs when someone experiences the combining of senses. For example, the number 7 might seem red or chicken might taste “pointy.”
• In the fetus there is a massive over connection of neurons and then they are gradually pruned down to strengthen and prioritize certain connections.
• One fascinating explanation of synesthesia is that two adjacent areas of the brain are crosswired which leads to increased crosstalk between, say, colors and numbers.
• Interesting theory: a high percentage of artists and creators have been reported to have synesthesia. It’s quite possible that the cross linkage between neurons that leads to synesthesia also enables artists to create metaphors and connections between ideas in an easier fashion than most people.
• It is very possible that the crosswiring of adjacent areas of the brain was selected for by evolution because it enabled those people to be more creative (and thus increase the odds of survival) with the unharmful side effect that some people would experience synesthesia.
• This is how science works: begin with simple, tractable questions that can be answered and will pave the way to the big questions.
• Humans mature at a glacial pace compared to most animals. What do we gain from this vulnerable period that would seem to decrease our odds of survival? The answer is culture.
• Culture is transferred from person to person through language and imitation. Accurate imitation depends on our unique human ability to see the world from someone else’s vantage point.
• Humans can develop a mental model of what others think of them. This is known as a “theory of mind” and our ability to construct these scenarios in our head is unique to humans.
• There are still many important questions about the evolution of the human mind that remain unanswered. Here are Ramachandran’s five big unanswered questions about the evolution of the human brain:
• Wallace’s Problem: The human brain reached its present size about 300,000 years ago, yet many of our modern attributes like tool making, fire, and perhaps even language appeared only about 75,000 years ago. Why did it take so long for all of this latent potential to blossom? And why did it blossom so suddenly?
• 2) Homo habilis likely created the first tools 2.4 million years ago. What was the role of tool use in shaping human cognition?
• 3) Why was there a sudden explosion in human cognition around 60,000 years ago? Widespread clothing and shelters show up around this time. (Jared Diamond refers to this as “the great leap.”)
• 4) Why are humans so good at reading one another’s intentions? Why can we develop theories of others minds? Why do humans have better neural circuits for this than any other animal?
• 5) How did language evolve?
• Natural selection can only select for expressed abilities, not latent ones.
• Giacomo Rizzolatti’s study showed that monkeys had some ability to read another monkey’s mind, which means they had some mirror neurons.
• Mirror neurons are like “nature’s own virtual reality simulations of the intentions of other beings.” They allow you to envision what someone else is doing and to predict what will happen next. This is how we interpret other people’s complex intentions.
• Mirror neurons also allow you to imitate the skills of others, which makes it possible for us to inherit the skills and culture of others.
• Anytime you watch someone doing something, the neurons your brain would use to do the same thing become active as if you yourself were doing it.
• The brain and free will: Your brain has to inhibit yourself from imitating everything you see, so there are some inhibitory circuits that cut off those actions. This might be how free will occurs. You are presented with many options and your brain ignores all but one of them.
• The brain has multiple layers of communication between neurons. If you see someone experiencing pain but your skin receptors do not experience pain, then your body knows it is not happening to you and so you empathize with that person rather than actually feel their pain.
• Mirror neurons appear to be wired from birth to some degree. A newborn baby, just a few hours old, will often echo its mother by sucking its tongue out when watching its mother do it.
• Mirror neurons have multiple functions. They allow you to predict another person’s intentions. They allow you to adopt someone else’s point of view and to see yourself as others see you (self-awareness). They allow you to transform a map in one dimension into a map in another dimension (ex. visual to auditory).
• Imitation was one of the key steps in the evolution of humans. Imitation allows us to learn by example, which means we made the massive shift from Darwinian evolution (which takes millions of years) to cultural evolution (which can spread ideas and skills rapidly).
• IQ as a measure of intelligence sort of misses the point because intelligence is a collection of complex, multifaceted abilities not one general ability.
• Interesting: two doctors discovered autism independently and, incredibly, they both named the condition “autism.”
• Ramachandran ran an experiment where subjects bit a pencil horizontally, so it shaped their mouth somewhat like a smile. While in this position, their brains would register someone’s frown, but would not imitate someone else’s smile. The hypothesis was that the mirror neurons which would fire while looking at and imitating someone else’s smile were already busy with the own person’s smile (or similar shape), thus they did not fire. In some ways, this link between imitation and action reminds me of Brene Brown’s idea that it is much harder to be closed off emotionally if you are active physically. It’s like if the body is moving, the activity in your neurons makes it harder to “close off” emotional pathways.
• Humans have an incredible capacity for language. It is one of the traits that separates us most clearly from the rest of the animal kingdom.
• Interesting definition of natural selection: the progressive series of chance variations that enhance the organism’s ability to pass on its genes to the next generation.
• Alfred Russell Wallace independently discovered natural selection. He deserves more credit than he gets.
• You can’t get very far in science by trying to explain one mystery with another mystery.
• Trying to ascribe a numerical value to how much genes or environment impact the outcome misses the point. Both impact it and the percentage to which it impacts it can vary widely. The key is to realize they are connected and not to worry about some single numerical value. Psychologists often make this mistake – especially when discussing IQ as a single trait.
• The PKU example showcases how the same problem can appear completely genetic or completely environmental under different conditions.
• How it is possible for neural circuitry to embody meaning is one of the great unsolved mysteries of neuroscience.
• The three bones in the inner ear of mammals – the malleus, incus, and stapes – actually evolved from the jaws of reptiles, which have three bones in their jaw rather than the one bone (mandible) in mammals. It’s fascinating how many functions in the body would never have been designed that way from scratch, but just resulted from “works for now” evolutionary adaptations.
• There seem to be some universal factors in the recognition of beauty. For example, tropical male birds developed remarkably beautiful feathers to attract females of their own species, but humans find them beautiful as well and use them in headdresses. Perhaps there is a fundamental “truth” of aesthetics that speaks to all creatures.
• Bowerbirds create very detailed nests in an effort to court a mate. They are even original artists with different birds (within the same species) having different aesthetic tastes and styles. Another interesting example of how beauty might have some fundamental principles that extend outside the human concept of art.
• Three questions to ask when analyzing any human trait. 1) What is the internal logical structure of the trait you are looking at? 2) Why does the particular trait have the structure it does? What did it evolve for? 3) How is this trait mediated by the neural machinery in the brain?
• Knowing the small details doesn’t mean you comprehend the whole picture.
• Vision evolved to discover and respond to objects: recognize them, eat them, catch them, or mate with them quickly and reliably.
• Ramachandran refers to a phenomenon known as The Peak Shift Effect, which is also called supernormal stimuli by other experts. It seems like a very powerful concept to me. It essentially says that the brain learns certain rules for discriminating between things and that if you present the brain with an exaggerated version of that rule, it strongly prefers it. Tinbergen’s famous studies on herrings provide a good example. Baby herrings will peck at a red spot on their mother’s beak when they want food. If a research presents a fake beak with three red spots, then the baby herring goes berserk. This supernormal stimuli is preferred by the brain as if the baby bird is saying, “Wow! What a beak.”
• Caricatures are an example of supernormal stimuli in human art. Caricatures amplifying the features of a given face. Also, many female sculptures have exaggerated breasts and hips, which seems to be preferred by our brains.
• Most theories are stated in a way that doesn’t even allow them to be tested or proven wrong. This isn’t really science. It’s just conjecture. Science requires you to state a hypothesis (or theory) and then develop an experimental way of testing to see if it is confirmed or refuted.
• There are three ways to test ideas about peak shift (and other supernormal stimuli). 1) Galvanic skin response (GSR) tests, 2) recording nerve impulses from single nerve cells in the visual area in the brain, 3) utilizing your “laws” or hypotheses to create more reliable, consistent, or successful results.
• Your brain has 100 billion nerve cells, but only a small subset can be active in any given instant. (How many, exactly?)
• Ramachandran conducts an interesting exercise in class where people must rank three drawings of a horse. One drawn by an autistic seven year old is often preferred to one down by Leonardo DaVinci. (The three pictures.)
• The Isolation Principle. There appears to be some aspect of isolation in the brain that can lead to enhanced creativity. For example, when autistic children have damaged or poorly functioning areas of the brain it often opens up the ability for one area (like the right parietal lobe) to receive more attention and results in remarkable creativity (like drawing).
• Idea: I also wonder how much other areas of the brain dampen signals to a given area and when they are damaged (like in autistic children) reduced dampening leads to greater creativity.
• It’s possible regular folks have latent creative talent waiting to be unleashed but it is being held back by inhibition from other brain areas (which is normal) and only arises when those inhibitors are damaged.
• There were some remarkable brain studies conducted in Australia, which used TMS (transcranial magnetic stimulation) to deactivate parts of normal people’s brains for a few moments. Almost instantly they could draw better or perform mathematical feats. This supports The Isolation Principle.
• The process of vision is carried out through a series of processes and feedback loops in the brain. This occurs in such a way that multiple visual options are presented, but only one wins out – the final image you see. In this sense, vision and hallucination are closely related. We are always “hallucinating” and our brain selects the one hallucination that seems to most closely match reality based on the external stimuli we receive.
• Our minds prefer symmetrical faces. Even minor deviations in symmetry are seen as undesirable. There is an evolutionary explanation for this. Parasitic infestations During infancy can cause small variations in symmetry. So, biological health is somewhat tied to symmetry.
• Interestingly, the male brain may prefer blondes over brunettes because it is easier to identify certain ailments like jaundice in a fair blonde complexion than in brunettes. In other words, it’s easier to judge if a blonde is a healthy mate.
• The self consists of many components and the notion of one, unitary self may be an illusion.
• Qualia is the word for your unique sense and perception of the world. It refers to how things seem to you. Examples: the pain of breaking your leg or the color of a sunset. Qualia refers to your subjective experience of the world.
• Qualia (your subjective experience) and the self are different things, but you can’t get qualia without a self.
• Freud, despite his faults, was correct that the modern brain is largely unconscious and that the conscious self is but a small slice of our whole world.
• The self seems to emerge from a relatively small cluster of brain areas.
• Blindsight is an example of how your conscious mind is tied to your visual cortex, yet a lot of other information you are taking in can be processed nonconsciously.
• The human brain and body seem to have a default tendency for harmony. We feel tension that needs to be resolved if there is a mismatch between our conscious mind and nonconcious body. (Extreme examples: transsexual man trapped in female body or phantom limb.)
• Neuroscience is currently at the stage chemistry was at in the 19th century. Grouping together the basic elements of the field and not yet attempting any grand, all-encompassing theories.
• Science tells us that humans are animals, another type of beast. But, importantly, we don’t feel that way. We feel like angels who aspire to become something more than a mere animal. So, perhaps we are both an animal and an angel.

Reading Suggestions

This is a list of authors, books, and concepts mentioned in The Tell-Tale Brain, which might be useful for future reading.

• Stephen Jay Gould’s essays on natural history.
• Eye and Brain by Richard Gregory
• Pat Churchland’s writings on philosophy and neuroscience
• Macbeth, Act 5, Scene 5 is an awesome description of life and death
• Niko Tinbergen’s studies on animal behavior, which won the Nobel Prize
• Alan Snider’s writing and theories on creativity
• Arthur (Bud) Craig’s work on neuroanatomy and consciousness
• Richard Francis Burton and his expeditions

Additional Thoughts

This is a list of interesting notes, side stories, or additional thoughts that were sparked as as I read the book.

• How do primates learn to use tools? Does each one learn it anew? Is it passed down through their “culture”? If so, do they have mirror neurons, but just less of them than humans?
• Can we apply the Coolidge Effect and the brain’s thirst for novelty to other areas of life outside of sexual interest? For example, are we wired to naturally seek new stimulation with our goals rather than mastery?

The Tell-Tale Brain by V.S. Ramachandran

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