The Tell-Tale Brain by V. S. Ramachandran explores the neuroscience behind perception, synesthesia, blindsight, empathy, belief, consciousness, and creativity.

It is impossible to understand how the brain works without also understanding how it evolved. (xiv)

In biological systems there is a deep unity between structure, function, and origin. (xiv)

Nature is full of nonlinear phenomena (e.g., phase transitions) (12)

The number of possible brain states [exceeds] the number of elementary particles in the known universe. (14)

When I ask you to salute, you conjure up a visual image of the salute and, in a sense, use the image to guide your arm movements. (20)

Mirror neurons fire not only when you perform an action, but also when you watch someone else perform the same action. [empathy, imitation, anticipation] (22)

When an arm is amputated, there is no longer an arm, but there is still a map of the arm in the brain. [phantom limb] (26)

Acute pain causes you to instantly remove your hand from the stove to prevent further tissue damage. Chronic pain motivates you to keep your fractured hand immobilized to prevent reinjury while it heals. (35)

[People experience pain and paralysis in phantom limbs] (36)

The distinction between perception and action exists in our ordinary language, but it is one that the brain evidently doesn’t always respect. (43)

This illusion shows that the visual system automatically assumes that light shines from above. [cognition shapes perception] (53)

It’s as if each of us is hallucinating all the time and what we call perception involves merely selecting the one hallucination that best matches the current input. (57)

There are at least as many fibers (actually many more) coming back from each stage of processing to an earlier stage as there are fibers going forward from each area into the next area higher up in the hierarchy. [perception = sensory input + iterative categorization] (57)

The brain abhors discrepancies of any kind and an absurdly far-fetched delusion is sometimes the only way out. (70)

Whenever Francesca closes her eyes and touches a particular texture, she experiences a vivid emotion: Denim, extreme sadness. Silk, peace and calm. Orange peel, shock. Wax, embarrassment. She sometimes feels subtle nuances of emotions. Grade 60 sandpaper produces guilt, and grade 120 evokes “the feeling of telling a white lie.” (75)

Synesthesia [involves] a surreal blending of sensation, perception, and emotion (we taste colors, see sounds, hear shapes, touch emotions). (75)

Our ordinary language is replete with synesthetic metaphors (loud shirt, sharp cheese) (79)

We all experience emotions with certain colors (calm blue, red passion). (83)

Your ability to group and segregate similar features probably evolved mainly to defeat camouflage and discover hidden objects in the world. (89)

Your brain knits together the fragments of tawny fur to discern the global shape, and activates your visual category for lion. (89)

In a hierarchical system, each “higher” level carries out more sophisticated tasks but, just like in a corporation, there is an enormous amount of feedback and crosstalk. (95)

The evolutionary rationale for neurally linking color with emotion was probably initially to attract us to ripe fruits, tender new shoots, and leaves. (102)

Just as synesthesia involves making arbitrary links between seemingly unrelated perceptual entities like colors and numbers, metaphor involves making nonarbitrary links between seemingly unrelated conceptual realms. (104)

Even a single word like “Juliet” or “sun” [as in “Juliet is the sun”] can be thought of as the center of a semantic whirlpool, or of a rich swirl of associations. (105)

The use of metaphor and our ability to uncover hidden analogies is the basis of all creative thought. (105)

Maybe metaphors allow you to carry out a sort of virtual reality in the brain. (105)

The angular gyrus may have originally evolved for mediating cross-sensory associations and abstractions, but then, in humans, was coopted for making all kinds of associations, including metaphorical ones. (106)

Puns are actually the opposite of metaphor. A metaphor exploits a surface-level similarity to reveal a deep hidden connection. A pun is a surface-level similarity that masquerades as a deep one – hence its comic appeal. (106)

Your brain represents numbers in some sort of actual mental number line which you consult “visually” to determine which is greater. (111)

On the other hand (no pun intended), the brain’s representation of space is almost as ancient as mental faculties come. Given the opportunistic nature of evolution, it is possible that the most convenient way to represent abstract numerical ideas, including sequentiality, is to map them onto a preexisting map of visual space. (113)

Culture [spreads] through two core mediums, language and imitation. (117)

The ability to see the world from another person’s vantage point is also essential for constructing a mental model of another person’s complex thoughts and intentions in order to predict and manipulate his behavior. (118)

“Gandhi neurons” blur the boundary between self and others. (124)

If you see a person being poked with a needle, your pain neurons fire. [inhibitory circuits stop you from literally feeling their pain] (124)

[Mirror neurons] allow you to figure out someone else’s intentions. (128)

You can also see yourself as others see you. [self-conscious] (128)

Many autistic children have difficulty with miming and imitating other people’s actions. This simple observation suggested to me a deficiency in the mirror-neuron system. (137)

You use your theory of mind to automatically project intentions, perceptions, and beliefs into the minds of others. (138)

There is a branch of cognitive science known as embodied cognition, which holds that human thought is deeply shaped by its interconnection with the body and by the inherent nature of human sensory and motor processes. (143)

Action and perception are much more closely intertwined in the brain than is usually assumed. [can’t detect smile while biting pencil] (143)

Although the mirror-neuron system evolved initially to create an internal model of other people’s actions and intentions, in humans it may have evolved further — turning inward to represent (or re-represent) one’s own mind to itself. (144)

Words like “enormous” and “large” entail an actual physical enlargement of the mouth. (173)

“Go” involves pouting the lips outward, whereas “come” involves drawing the lips together inward. (174)

[Mirror neurons] link concepts across brain maps. (174)

Abstraction [is] the ability to extract the common denominator between entities that are otherwise utterly dissimilar. (176)

Meaning [is] a word that conceals vast depths of ignorance (expecting to find the meaning of a word in a dictionary). (176)

Successful grouping feels good. You get an internal “Aha!” sensation. (202)

As soon as the features are grouped into a whole object, all the spike trains become perfectly synchronized. (205)

Science often progresses by resolving apparent contradictions. (206)

The peak-shift effect [says] your brain responds to exaggerated stimuli (caricatures, the more rectangular the better, art, beauty, sex). (207)

Artists [tap] into the figural primitives of our perceptual grammar. (212)

A sketch is effective because cells in your primary visual cortex, where the earliest stage of visual processing occurs, only care about lines. [boundaries, edges] (221)

We are hardwired to love solving puzzles, and perception is more like puzzle solving than most people realize. (228)

The line between perceiving and hallucinating is not as crisp as we like to think. In a sense, when we look at the world, we are hallucinating all the time. (229)

Your brain always tries to find a plausible alternate, generic interpretation to avoid the [suspicious] coincidence. (232)

Freud [said] your “conscious life” is an elaborate after-the-fact rationalization of things you really do for other reasons. (249)

The phenomenon of blindsight is a particularly clear indicator that there may be a grain of truth in Freud’s theory of the unconscious. (249)

She is blind. She experiences none of the qualia associated with vision. If you project a spot of light on the wall in front of her, she will tell you categorically that she does not see anything. Yet if asked to reach out to touch the spot, she can do so with uncanny accuracy even though to her it feels like a wild guess. (249)

The brain has an innate body image, and when that body image doesn’t match up with the sensory input from the body — whether visual or somatic — the ensuing disharmony can disrupt the self’s sense of unity as well. (254)

The brain abhors internal anomalies. (257)

The discrepancy between internally specified sexual body image and external anatomy [in a transgender person] leads to an intense discomfort and, again, a yearning to reduce the mismatch. (259)

Information arriving through the senses is ordinarily merged with preexisting memories to create [an internally consistent] belief system about yourself and the world. (266)

If there is a small piece of anomalous information that doesn’t fit your “big picture” belief system, the left hemisphere tries to smooth over the discrepancies and anomalies in order to preserve the coherence of self and the stability of behavior. (267)

The left hemisphere sometimes even fabricates information [confabulation] to preserve its harmony and overall view of itself. [to reduce cognitive dissonance] (267)

[The right hemisphere may counter confabulation with a detached, objective view] (267)

Dichotomania [is] the brain’s tendency to simplify the world by dividing things into polarized opposites (night-day, yin-yang, male-female). (267)

Control mechanisms that stabilize a system and help avoid oscillations are the rule rather than the exception in biology. (267)

Confabulation [is] the tendency to make things up to protect your self image. This is done unconsciously; there is no deliberate intention to deceive. (270)

Reaction formation [is] the tendency to assert the opposite of what you unconsciously know to be true about yourself (e.g., the lady doth protest too much). (270)

Belief is not a single thing. (271)

Implicit in the idea of the self is the notion of sequentially organized memories accumulated over a lifetime. (284)

Categories

I’m trail running in the woods, lost in thought, when I find myself mid-jump, unsure why I’m in the air. As my feet hit the dirt, I see the snake, then realize it’s only a bit of rope. My blind jump reveals a hidden aptitude for rapid, nonlinguistic, unconscious classification. I don’t know if the unlabeled category roughly corresponds to snake or dangerous things, but it does appear to prime my initial conscious misclassification.

Importantly, I never see a snake and a rope at the same time. The change is instant. When we reclassify, we literally see differently — categorizing is seeing is believing.

Connections

Our mum links words and numbers with colors. As I child, she thought everyone saw this way. As a teen, she hid her madness. As an adult, she discovered synesthesia and saw she’s not alone. My strange connections are analogies which can be colorful too. We are all on the synesthesia spectrum. We all experience cross-sensory associations.

This is exactly what’s going on in the bouba-kiki effect: your brain is performing an impressive feat of abstraction in linking your visual and auditory maps. The two inputs are entirely dissimilar in every way except one — the abstract properties of jaggedness or curviness. (129)

Confabulation

V. S. Ramachandran is a genius. Ironically, he’s also guilty of confabulation and dichotomania. He says humans are the only species capable of language, metaphor, culture, playfulness, theory of mind, self awareness, abstract thought, planning, remembering, or making tools for future use. He’s wrong on most counts, and I think he (unconsciously) knows it — methinks the neuroscientist doth protest too much.

As I work on Natural Information Architecture, I’m sharing notes and quotes from my sources of inspiration and provocation. As always, your questions and suggestions are welcome.