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We are astoundingly poor observers. And our introspection is useless on these issues: we believe we’re seeing the world just fine until it’s called to our attention that we’re not.
This intrigued Sherrington, and he finally inferred that his experience of moving his arm was “a mental product.… derived from elements which are not experienced as such and yet … the mind uses them in producing the percept.”
consciousness is a way of projecting all the activity in your nervous system into a simpler form. The billions of specialized mechanisms operate below the radar
It may come as a surprise that about one-third of the human brain is devoted to vision.
For decades, vision researchers barked up the wrong tree by trying to figure out how the visual brain reconstructed a full three-dimensional representation of the outside world. Only slowly did it become clear that the brain doesn’t actually use a 3-D model—instead, it builds up something like a 2½-D sketch at best.
the conscious experience of vision occurs only when there is accurate prediction of sensory consequences,
To the brain, it doesn’t matter where those pulses come from—from the eyes, the ears, or somewhere else entirely. As long as they consistently correlate with your own movements as you push, thump, and kick things, your brain can construct the direct perception we call vision.
At least 15 percent of human females possess a genetic mutation that gives them an extra (fourth) type of color photoreceptor—and this allows them to discriminate between colors that look identical to the majority of us with a mere three types of color photoreceptors.
The deep secret of the brain is that not only the spinal cord but the entire central nervous system works this way: internally generated activity is modulated by sensory input.
Asleep vision (dreaming) is perception that is not tied down to anything in the real world; waking perception is something like dreaming with a little more commitment to what’s in front of you. Other examples of unanchored perception
what we call normal perception does not really differ from hallucinations, except that the latter are not anchored by external input. Hallucinations are simply unfastened vision.
Throughout the brain there is as much feedback as feedforward—a feature of brain wiring that is technically called recurrence and colloquially called loopiness.
Vision usually dominates over hearing, but a counter example is the illusory flash effect: when a flashed spot is accompanied by two beeps, it appears to flash twice.
The assembly line model of vision in introductory textbooks isn’t just misleading, it’s dead wrong.
it permits an organism to transcend stimulus–response behavior, and instead confers the ability to make predictions ahead of actual sensory input.
The parameters of the predictive internal models are trained by lifelong exposure in normal, Earth-bound experience.
As early as the 1940s, thinkers began to toy with the idea that perception works not by building up bits of captured data, but instead by matching expectations to incoming sensory data.45
He suggested that the primary visual cortex constructs an internal model that allows it to anticipate the data streaming up from the retina (see the appendix for an anatomical guide). The cortex sends its predictions to the thalamus, which reports on the difference between what comes in through the eyes and what was already anticipated. The thalamus sends back to the cortex only that difference information—that is, the bit that wasn’t predicted away.
perception reflects the active comparison of sensory inputs with internal predictions.
awareness of your surroundings occurs only when sensory inputs violate expectations.
This predictability that you develop between your own actions and the resulting sensations is the reason you cannot tickle yourself.
Your perceptual world always lags behind the real world.
auditory and visual information are processed at different speeds in the brain;
The bottom line is that time is a mental construction, not an accurate barometer of what’s happening “out there.”
So the first lesson about trusting your senses is: don’t. Just because you believe something to be true, just because you know it’s true, that doesn’t mean it is true.
The most important maxim for fighter pilots is “Trust your instruments.” This is because your senses will tell you the most inglorious lies,
You are not consciously aware of the vast majority of your brain’s ongoing activities, and nor would you want to be—it would interfere with the brain’s well-oiled processes.
although experience with the world is stored in memory, not all memory is accessible.
Hermann Ebbinghaus, who wrote that “most of these experiences remain concealed from consciousness and yet produce an effect which is significant and which authenticates their previous experience.”
To the extent that consciousness is useful, it is useful in small quantities, and for very particular kinds of tasks.
the first surprise is that implicit memory is completely separable from explicit memory: you can damage one without hurting the other.
Even people with certainty about their attitudes toward different races, genders, and religions can find themselves surprised—and appalled—by what’s lurking in their brains. And like other forms of implicit association, these biases are impenetrable to conscious introspection.
People tend to love reflections of themselves in others. Psychologists interpret this as an unconscious self-love, or perhaps a comfort level with things that are familiar —and they term this implicit egotism.
The magnetic power of unconscious self-love goes beyond what and whom you prefer. Incredibly, it can subtly influence where you live and what you do, as well.
We are influenced by drives to which we have little access, and which we never would have believed had not the statistics laid them bare.
Priming underscores the point that implicit memory systems are fundamentally separate from explicit memory systems: even when the second one has lost the data, the former one has a lock on it.
It will come as no surprise to you that the mere exposure effect is part of the magic behind product branding, celebrity building, and political campaigning:
“The only bad publicity is no publicity,” or “I don’t care what the newspapers say about me as long as they spell my name right.”20
the illusion-of-truth effect: you are more likely to believe that a statement is true if you have heard it before—whether or not it is actually true.
AI research twitter is an echo chamber.
investigators discovered that if there is a hidden pattern to the lights, your reaction times will eventually speed up, indicating that you have picked up on the sequence and can make some sort of predictions about which light will flash next.
In other words, the gut feeling was essential for advantageous decision making.
physical states of the body provide the hunches that can steer behavior. These hunches turn out to be correct more often than chance would predict, mostly because your unconscious brain is picking up on things first, and your consciousness lags behind.
prosopagnosia
Cue: Ted Chiang
Turns out this is scientific!!
So the next time a friend laments that she cannot decide between two options, tell her the easiest way to solve her problem: flip a coin. She should specify which option belongs to heads and which to tails, and then let the coin fly. The important part is to assess her gut feeling after the coin lands. If she feels a subtle sense of relief at being “told” what to do by the coin, that’s the right choice for her. If, instead, she concludes that it’s ludicrous for her to make a decision based on a coin toss, that will cue her to choose the other option.
Conscious parts of the brain train other parts of the neural machinery, establishing the goals and allocating the resources.
While many animals are properly called intelligent, humans distinguish themselves in that they are so flexibly intelligent, fashioning their neural circuits to match the tasks at hand.
Kasparov has spent a lifetime burning chess strategies into economical rote algorithms.
In the logic of the brain, if you don’t have the right tool for the job, create it.
FPGA vs general purpose computers. Speed and efficiency necessitate specialized hardware.
When athletes make mistakes, coaches typically yell, “Think out there!” The irony is that a professional athlete’s goal is to not think. The goal is to invest thousands of hours of training so that in the heat of the battle the right maneuvers will come automatically, with no interference from consciousness.
