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.
Themes
The Nature of Human Uniqueness
The central tenet of The Tell-Tale Brain is that “humans are truly unique and special, not ‘just’ another species of primates” (xiv). While we see some of the same structures and functions in apes (and other species), they have become much more sophisticated in humans. Ramachandran explores several facets of human uniqueness.
Brain plasticity is one facet. Ramachandran’s research on phantom limbs demonstrates that our brains are incredibly plastic, meaning they can rewire and adapt to changing circumstances. Brain plasticity might be a key driver in our higher-order cognitive abilities compared with non-human primates. Human visual processing is also unique. Humans have one additional cone than most other mammals which allows us to see red, blue, and green light. Dogs, in contrast, cannot see red and green colors. Perception is also unique to humans. Humans also have the “so what” stream which enables them to have emotional responses to objects. This pathway helps humans to process information more quickly, which is critical in fight-or-flight scenarios.
Mirror neurons are another facet. While mirror neurons occur in apes, they are far more sophisticated in humans and enable several unique human traits. First, mirror neurons allow people to adopt another person’s perspective, called theory of mind. Second, mirror neurons might have enabled early humans to imitate other people’s lip and tongue movements, leading to verbal utterances. Ramachandran believes these two capabilities, “the ability to read someone’s intention and the ability to mimic their vocalizations” (122), led to the evolution of human language. Ramachandran also underscores that “no ape can match our imitative talents” (132). Imitation likely enabled cultural transmission through example. Mirror neurons also enable people to feel empathy. They might also play a key role in our ability to engage in abstract thinking. Ramachandran suggests several parts of the brain unique to humans are involved in abstraction.
While many animals communicate, language is another facet unique to humans. Ramachandran suggests there are five key differences between human language and animal communication. First, humans have an enormous vocabulary (lexicon). Second, language includes function words, such as “if” and “then,” which have no existence outside of their linguistic function. Words like “dog” and “cat” are not function words since they refer to actual objects. Third, humans can refer to things not immediately in front of them or that exist in the past, future, or a fictitious reality. Humans are also the only species to use metaphor and analogy. Finally, recursion only occurs in human language. Humans have developed novel areas in the brain, including the Wernicke and Broca areas, linked to language.
Humans are also the only species that can interact with the social world as well as maintain their own sense of self. Ramachandran suggests that our sense of self comes from having two brains. The first brain developed early in evolution and is found in other species. This brain focuses on external sensory stimuli that elicit a small number of reactions. The second brain developed later. It imbues objects from the first brain with meaning that allows humans to be consciously aware of the object (known as metarepresentation). Since our sense of self is unique, so too are the myriad of neurological disorders that fracture the self. Neuroscientists are just beginning to think about how to scientifically study the concept of self. Ramachandran believes doing so will reveal even more about what makes us human.
The Impact of Neurological Disorders
Ramachandran investigates unique (and sometimes bizarre) neurological disorders to better understand the healthy, normal brain and what it means to be human. In doing so, he also explores the impact of neurological disorders upon different aspects of the human experience.
One of Ramachandran’s patients, Victor, experienced phantom limb syndrome following an amputation. Amputees often have phantom limbs; however, Victor’s experience was unique because his phantom limb itched. After a series of experiments, Ramachandran uncovered that the brain has a map of sensations found throughout the body. The face houses the virtual hand. Victor was able to alleviate the itch by scratching the corresponding part of his face. This brain map explains why amputees still feel the presence of their limbs even after they are gone.
Synesthesia, a perceptual condition, reminds us of the subjective quality of perception. A young man named Spike, another of Ramachandran’s patients, was not only color blind but saw numbers tinged with color that he had never perceived in the real world. He called these colors “‘Martian colors that were ‘weird’ and seemed quite ‘unreal’” (114). Ramachandran attributes Spike’s experience due to cross-wiring between his fusiform (which processes number shapes) and the V4 color area. Ramachandran also argues that synesthesia might have been retained as an evolutionary advantage, as it is associated with higher levels of creativity.
Language is a quintessentially human trait, yet there are neural disorders that impact language. An example is Dr. Hamdi, who had been a world-renowned chemistry professor. A stroke damaged the neurons in his left frontal lobe region. Dr. Hamdi developed a language deficit known as Broca’s aphasia. Dr. Hamdi could convey what he was trying to say, but his speech was much slower and took more effort than before the stroke. He expresses frustration with his current experience, revealing some of the challenges that can accompany neurological disorders.
Finally, neurological conditions show that our understanding of self is wrong. Humans do not have one single self. Rather, there are several key components that comprise the concept of self. To better understand human experience, Ramachandran discusses how neurological conditions fracture this sense of self. One example is a young man who believed his mother was an imposter after waking up from a coma, known as misidentification syndrome. Ramachandran believes the part of the brain involved in attaching emotion to objects was damaged. For this reason, the sight of the man’s mother did not produce the normal emotional jolt. His brain rationalized this anomaly by insisting he was in the presence of an imposter. Interestingly, when his mother called him, the man responded to her normally, further supporting Ramachandran’s hypothesis. Through these case studies, Ramachandran seeks to demonstrate how neurological conditions can reshape normal human perceptions and experiences.
Evolution and Brain Development
Ramachandran agrees (mostly) with biologist Theodosius Dobzhansky that “‘nothing in biology makes sense except in light of evolution’” (xiv). For this reason, Ramachandran tries to explain human brain structures and function in the context of evolutionary history.
He begins by trying to tackle the belief that “gradual, small changes can only engender gradual, incremental results” (12). Humans often think linearly, which is why we assume the development of the brain happened in incremental steps. Ramachandran emphasizes, however, that nature is full of non-linear phenomena. He believes the emergence of modern humans (Homo sapiens) represents one example. Prior to modern humans, evolution tinkered with the brain, resulting in each new generation of hominins having a more sophisticated brain circuitry and being able to do some things better. Something happened 60,000-100,000 years ago that resulted in a mental phase transition for humans (which scientists call “the great leap forward”). Ramachandran notes that “all the same old parts were there, but they started working together in new ways that were far more than the sum of their parts” (13). This transition led to the development of culture, language, art, and the concept of self.
Ramachandran also explores the evolutionary context for aspects of vision and perception. As one example, synesthesia occurs at higher rates among artists, poets, and novelists than the general population. These individuals are more creative and make more metaphors than the average person. Creativity and metaphors involve making arbitrary links between seemingly unrelated things, which is what happens with higher forms of synesthesia. This higher form “involves abstract concepts rather than concrete sensory qualities” (109) and is rare (lower forms of synesthesia are more common). Individuals with greater capacity for creativity, while outliers in the overall human population, have likely helped drive human progress forward. Evolution has not weeded out synesthesia because it confers advantages on humankind.
Language is another area where Ramachandran hypothesizes about its evolutionary history. In fact, he believes that language did not evolve for communication. Ramachandran points to the independence of language’s three main components: syntax, lexicon, and semantics. Ramachandran believes that the bouba-kiki effect might have helped the emergence of protowords and simple vocabulary (lexicon). Ramachandran also argues that our extensive imitation skills might have been the precursor to semantics. Finally, syntax may have evolved from a neural circuit that helped our hominin ancestors use tools. There are many examples where the human brain evolved to use structures originally intended for another purpose in novel ways.
Finally, Ramachandran tries to uncover the evolutionary basis for art. As one example, he suggests that the law of grouping evolved to help hominins detect objects in messy scenes and defeat camouflage, which increased their reproductive opportunities. Being able to determine a lion hiding in foliage is a good example. Neuroscientists remain unsure about the neural circuits involved in this law. Ramachandran suggests that neural activity comes together to send a jolt to the emotional core of the brain. This jolt forces a person to pay attention to the object to determine if it is friendly or foe. Similarly, humankind’s attractiveness to the law of contrast might stem from our hominin ancestors needing to spot fruit in treetops. The law of grouping and contrast might seem contradictory, but they are not to Ramachandran. Both delineate and create boundaries for objects, both helped our hominin ancestors survive, and both titillate our senses and make us feel happy.
