47 pages • 1 hour read
V. S. RamachandranThe Tell-Tale Brain
Nonfiction | Book | Adult | Published in 2011A modern alternative to SparkNotes and CliffsNotes, SuperSummary offers high-quality Study Guides with detailed chapter summaries and analysis of major themes, characters, and more.
Chapters 4-6Chapter Summaries & Analyses
Chapter 4 Summary: “The Neurons That Shaped Civilization”
Ramachandran introduces mirror neurons in Chapter 4. Mirror neurons are found in all primates. They enable primates to mimic the movement they see other primates perform. Imitation is a critical trait for social creatures like primates.
Neuroscientists study mirror neurons in apes by opening their skulls and probing single neurons with microelectrodes. Investigating mirror neurons in humans is more difficult since scientists cannot normally study single neurons. As a result, most evidence of mirror neurons in humans comes from indirect evidence.
Ramachandran cites three pieces of indirect evidence. The first is the unique disorder called anosognosia, which is when people deny or appear unaware of their paralysis. Ramachandran also found that a small number of these individuals also denied paralysis in another person (despite that person truly being paralyzed). Ramachandran suggests this denial stems from damage to mirror neurons: “It’s as if anytime you want to make a judgment about someone else’s movements, you have to run a virtual-reality simulation of the corresponding movements in your own brain. And without mirror neurons you cannot do this” (123).
The second piece of evidence stems from examining brain waves, particularly mu waves, in humans. Ramachandran found that mu waves are suppressed when people perform or watch someone else perform motor actions. Ramachandran argues this is evidence that the mirror neuron system causes mu wave suppression.
The final piece of evidence is that newborn infants mimic their mothers when they protrude their tongue. Since this capability occurs starting at infancy, Ramachandran suggests that humankind’s ability to imitate is innate. Not all researchers agree with Ramachandran’s assertion.
Mirror neurons are more sophisticated in humans and enable several unique human traits, including theory of mind (our ability to adopt another person’s perspective), imitation, empathy, and abstraction. Imitation and empathy might have been the precursors for the evolution of language. All these traits enabled humans to create culture. Ramachandran strongly believes that culture would not have been possible without a sophisticated mirror neuron system.
Chapter 5 Summary: “Where Is Steven? The Riddle of Autism”
In Chapter 5, Ramachandran explores how problems with the mirror-neuron system may underlie autism, a developmental disorder. Ramachandran classifies this disorder into two groups: social cognitive and sensorimotor. Social detachment, mental aloneness, and inability to engage in conversation manifest with the first group. Distress caused by specific sensory stimuli which leads to physical outbursts characterizes the second group. Autistic children and adults in both groups also have difficulty imitating others, feeling empathy, intention-reading, and learning languages. These traits led Ramachandran to believe a deficiency in the mirror-neuron system might explain autism.
Ramachandran turns to chronicling his quest to pursue this hypothesis. He found that autism alters particular synaptic connections which disrupts information processing. As one example, using electroencephalography (EEG) to study mu waves, Ramachandran and colleagues found that mu wave suppression did not occur when an autistic child watched someone else perform an action. Researchers have used other methods and arrived at similar conclusions. Ramachandran suggests that mu wave suppression might be why autistic children struggle with language learning, social interaction, and strong self-identification (autistic children have trouble correctly using “I” and “you” in conversation).
Mirror neurons do not fully explain autism; a point made by Ramachandran. He suggests that a distorted salience landscape might help explain why autistic children beat themselves, avoid eye contact, rock back and forth, and prefer strict routines. Salience landscape is how a person identifies their relevance and existence. Abnormal connections in certain parts of the brain uncovered by galvanic skin response (GSR) in autistic individuals, including the amygdala, lead to a distorted salience landscape.
Ramachandran concludes by suggesting that the discovery of the connection between mirror neurons and autism could lead to novel therapeutic treatments, including biofeedback and use of certain drugs.
Chapter 6 Summary: “The Power of Babble: The Evolution of Language”
In Chapter 6, Ramachandran details the role mirror neurons played in the emergence of language. Language is not confined to a single area within the brain, but the left inferior parietal lobe seems especially important, particularly to the representation of word meaning. Interestingly, this area is rich in mirror neurons in monkeys. Chimpanzees can be taught to sign simple sentences, such as “‘Give me fruit’” (160), but they cannot create more complex sentences. Ramachandran argues that language is unique to humans.
There are three main aspects of human language. Lexicon, a person’s vocabulary, represents the first. The second is syntax, which is the set of rules we use to arrange words to create well-formed sentences. Semantics, or the definition of words, represents the final aspect. Different parts of the brain are specialized for these three aspects. Broca’s area, located in the frontal part of the brain’s left hemisphere, is specialized for syntax and other languages that have formal rules (e.g., algebra or computer programming). Wernicke’s area, located in the left temporal lobe, seems specialized for semantics.
Ramachandran next turns to detailing his quest to discover what enabled language to evolve from primitive noises. He believes there is a logical sequence that led from primitive noises to full-blown, complex language. Unfortunately, it is difficult to study the emergence of language using the fossil record; thus, we do not know what intermediate steps might have looked like between primitive noises and language.
Intellectuals have hypothesized about the origin of language for centuries. Victorian-era intellectuals, such as Alfred Russell Wallace, believed God put language into human brains. Modern linguists, such as Noam Chomsky and Steven Pinker, suggest there is an innate ability within the human brain for language. Evolutionary theorists, such as the late Stephen Jay Gould, argue language evolved as a by-product for selection of other abilities (also known as an expectation). Gould believes thinking evolved first, followed by language. Ramachandran agrees with Gould that language did not evolve for communication; however, he disagrees with his second idea.
Ramachandran does not agree with any of these theories. Instead, he proposes a new framework called “‘synesthetic bootstrapping theory’” (168), which argues that language emerged, similar to synesthesia, as a byproduct of cross-wiring in the human brain. Ramachandran believes that the bouba-kiki effect has deep implications for language evolution. It refers to the non-arbitrary associations in the mind between particular speech sounds and visual shapes. Ramachandran extends this argument to language by suggesting that humans do not arbitrarily name objects.
Chapters 4-6 Analysis
Chapters 4-6 focus on mirror neurons, which Ramachandran believes are “crucial in making us human” (xv), thus illustrating The Nature of Human Uniqueness. Around 60,000-100,000 years ago, a number of traits that we consider uniquely human emerged, including use of complex language, body adornment, art, fire, multicomponent tools, and shelters. Anthropologists attribute this change to multiple gene mutations that occurred simultaneously in the brain. Ramachandran agrees with gene involvement, but he also thinks something more happened. He believes this genetic change (the sophistication of mirror neurons) enhanced our ability to learn from one another and pass these learnings onto others, marking the emergence of culture. Ramachandran believes culture freed “our brain from its Darwinian shackles” (133), explaining the significant behavioral and cognitive gap between humans and apes.
While Ramachandran staunchly defends science and his mirror neuron hypothesis, he also acknowledges that many aspects of human brain evolution still baffle scientists (including himself). As one example, the brain achieved its present size nearly 300,000 years ago, yet our unique human traits (e.g., language) arrived much later. We do not know what was happening to the brain during this incubation period.
In this section, Ramachandran builds on his theory of using neurological disorders to explain human experiences, exploring The Impact of Neurological Disorders. In particular, he believes that understanding these disorders can lead to novel treatments for them. He focuses on examples of such treatments in his discussion on autism. Ramachandran suggests that doctors could use mu wave suppression as an early diagnostic screening tool in young children. Biofeedback, which is a type of therapy that helps people take control of involuntary body functions like breathing and heart rate, might be another useful tool. The goal of this therapy is for subjects to gain conscious control over the bodily function (which they lacked prior to therapy). Certain drugs that increase the abundance of neurotransmitters is another possible tool. A high abundance of neurotransmitters is possibly linked to increased feelings of empathy. Imitation dance might also help improve empathy and compassion in autistic children.
With the story of Humphrey, who had a phantom arm following an amputation, Ramachandran also begins to ponder the concept of self, which he more fully explores in Chapter 9. Humphrey was an unusual case. He felt tactile sensations in his phantom limb when Ramachandran touched another volunteer’s arm. Humphrey’s phantom fingers also felt cold when he saw another student hold an ice cube. Ramachandran calls this phenomenon “acquired hyperempathy.” He hypothesizes that there was a broken connection between the brain’s veto signal and Humphrey’s mirror neurons. This research illustrates the dynamic nature of brain circuitry and its impact on human experiences.
At the time of publication, this section of Ramachandran’s work faced the most criticism. Several studies had cast doubt on the role mirror neurons played in imitation, understanding the actions of others, and autism. Ramachandran might have had a good reason to ignore these studies, but his authoritative tone, which is a popular science writing method, leads readers to assume his hypotheses are based on solid peer-reviewed science rather than speculations. One of the weaknesses with popular science writing is that authors cannot always explain nuances or add qualifiers (See: Background).
