February 11, 2012

Incognito by David Eagleman

Incognito by David Eagleman
The secret lives of the brain.

In 1949, Arthur Alberts travelled to villages in West Africa and he recorded some of the most important music ever to come out of Africa. But Alberts ran into social troubles while using the tape recorder. One West African native heard his voice played back and accused Alberts of ‘stealing his tongue’. Albert only narrowly averted being pummeled by taking out a mirror and convincing the man that his tongue was still intact. It’s not difficult to see why the natives found the tape recorder so counterintuitive. A vocalization seems ephemeral and ineffable.

In a recent experiment, men were asked to rank how attractive they found photographs of different women’s faces. Unbeknownst to the men, in half the photos the eyes of those women were dilated and in the other half they were not. The men were consistently more attracted to the women with dilated eyes. Women’s dilated eyes correlates with sexual excitement and readiness. Men’s brain knew this without learning it explicitly. Brains are in the business of gathering information and steering behavior appropriately. [The pupils of our eyes dilate and grow by almost 3 times when we see someone we are attracted to, or something we are interested in. No wonder candlelight dinners and wine are such a popular choice for a romantic rendezvous. Apart from hiding minor physical flaws and adding a warm glow to your face, the low light setting of candlelight influences our pupil size. The pupils dilate to let in more light into the eye. At the same time, we unconsciously give out the signal that we are interested and attracted to the person across the table. It is the perfect set up to get your point across without saying anything at all. Add wine to the list and it emphasizes your interest. Alcohol not only acts as a social lubricant, but also accentuates pupil dilation.]

you see evidence of this when your foot gets halfway to the brake before you consciously realize a red Toyota is backing out of a driveway on the road ahead of you. You see it when you notice your name spoken in a conversation across the room that you thought you weren’t listening to, when you find someone attractive without knowing why, or when you’re nervous system gives you a ‘hunch’ about which choice you should make. You can notice this when you begin to duck from a snapping tree branch before you are aware that it’s coming toward you or when you are already jumping up when you first become aware of the phone’s ring. The conscious mind is not at the center of the action in the brain; instead, it is far out on a distant edge, hearing but whispers of the activity.

In the traditionally taught view of perception, data from the sensorium pours into the brain, works its way up the sensory hierarchy and makes itself seen, heard, smelled, tasted, felt - “perceived’. But a closer examination of the data suggests this is incorrect. Internal data is not generated by external sensory data but merely ’modulated by it. The deep secret of the brain is that not only the spinal cord but the entire central nervous system works this way. In this view, the difference between being awake and being asleep is merely that the data coming in from the eyes ‘anchors’ the perception. Asleep vision (dreaming) is perception that is not tied down to anything in the real world.

Vision usually dominates over hearing, but a counter example is the illusory flash effect: when a flash effect: when a flashed spot is accompanied by two beeps, it appears to flash twice. This is related to another phenomenon called ‘ auditory driving’ in which the apparent rate of a flickering light is driven faster or slower by an accompanying beeping sound presented at a different rate.

What people select as beautiful qualities primarily reflect signs of fertility brought on by hormonal changes. Until puberty the faces and body shapes of boys and girls are similar. The rise in estrogen in pubescent girls gives them fuller lips, while testosterone in boys produces a more prominent chin, a larger nose and a fuller jaw. For female, full lips, full buttocks, and a narrow waist broadcast a clear message and for a male, it is the full jaw, stubble and broad chest. This is what we are programmed to find beautiful. Form reflects function.

As women become older, their functions change in ways that depart from these proportions. Middles thicken, lips thin, breasts sag, and so on. All of which broadcast the signal that they are past peak fertility. Even a male teenager with no biology education will be less attracted to an elderly woman than to a young woman. His circuits have a clear mission (reproduction)l his conscious mind receives only the nee-to-know headline (she is attractive, pursue her!) and nothing more.

American neuroscientist Paul MacLean (1950s) suggested that the brain is made of three layers representing successive stages of evolutionary development: the reptilian brain (involved in survival behaviors), the limbic system (involved in emotions) and the newocortex (used in high -order thinking).

Arthur C Clarke was fond of pointing out that any sufficiently advanced technology is indistinguishable from magic. The complexity of the system we are is so vast as to be indistinguishable from Clark’s magical technology. In this same way that the cosmos is larger than we ever imagined, we ourselves are something greater than we had intuited by introspection. The brain is an organ that feels alient and outlandish to us, and yet its detailed wiring patterns sculpt the landscape of our inner lives

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