The Experience Machine
Andy Clark
- 8 minutes read - 1679 wordsAuthor: Andy Clark
Rating: ★★★
I’ve long been fascinated by the idea that what we naively perceive as “reality” simply can’t be what’s actually there.
The most interesting experiences exploit time and the maximal speed of electricity to show that e.g. given a stimulus, that stimulus’ signal could not travel up the nerves, to the brain, trigger a response, direct a response signal, trigger a muscular contraction on the time scales we observe. My dear, late professor Solomon once suggested that if a looming T. Rex-like shape were to suddenly darken the wide gallery windows atop Waggener hall, we would run for the exit without having much conscious appreciation of what we were running from.
So somehow, we are either beating the hard speed limit of information communication in our bodies or something more subtle and strange is happening. Books such as The Experience Machine suggest that our brains are designed to help us maintain our erroneous belief that we are in control of our responses – even when it’s manifestly impossible for that to have been so. If our brains burning calories to maintain that façade seems strange, remember that our bodies have only one goal: preservation and offspring. What if the veridical apprehension of reality is not helpful, or even harmful, against surmounting selective pressures (see: The Case Against Reality, or Consciousness)? Suddenly veridical apprehension of reality might not be so very important after all. Perhaps the better strategy would be lower-fi (non-veridical) but generally accurate-ish predictions?
Clark presents a lighter and more pop approach to this question about the disconnect between veridical apprehension and prediction in this enjoyable read.
{
"title": "The Experience Machine: How Our Minds Predict and Shape Reality",
"author": "Andy Clark",
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{
"highlight": "the human brain as a “prediction machine.”",
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"highlight": "According to the new theory (called “predictive processing”), reality as we experience it is built from our own predictions.",
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"highlight": "Contrary to the standard belief that our senses are a kind of passive window onto the world, what is emerging is a picture of an ever-active brain that is always striving to predict what the world might currently have to offer.",
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"highlight": "Nothing we do or experience—if the theory is on track—is untouched by our own expectations. Instead, there is a constant give-and-take in which what we experience reflects not just what the world is currently telling us, but what we—consciously or nonconsciously—were expecting it to be telling us.",
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"highlight": "we are never simply seeing what’s “really there,” stripped bare of our own anticipations or insulated from our own past experiences.",
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"highlight": "all human experience is part phantom—the product of deep-set predictions.",
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"highlight": "When the brain’s best guessing misses the mark, the mismatch with the actual sensory signal carries crucial new information. That information (prediction error) can be used to try again—to make a better guess at how things really are.",
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"highlight": "Whereas sensory information was often considered to be the starting point of experience, the emerging science of the predictive brain suggests a rather different role. Now, the current sensory signal is used to refine and correct the process of informed guessing (the attempts at prediction)",
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"highlight": "Instead, all human experience arises at the meeting point of informed predictions and sensory stimulations.",
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"highlight": "predictions formed deep in the brain reach down to alter responses all the way down to areas closer to the skin, eyes, nose, and ears—the sensory organs that take in signals from the outside world.",
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{
"highlight": "what we perceive today is deeply rooted in what we experienced yesterday, and all the days before that. Every aspect of our daily experience comes to us filtered by hidden webs of prediction—the brain’s best expectations rooted in our own past histories.",
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"highlight": "brains are never simply “turned on” from scratch—not",
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"highlight": "predictions and expectations are always in play,",
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"highlight": "we can, at times, change how we feel by changing what we (consciously or unconsciously) predict.",
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{
"highlight": "as in a simple camera, the direction of influence flowed mostly inward, moving forward from the eyes into the brain. Only at some point quite late in this process would lifetime memory and world knowledge become engaged, enabling you (the perceiver) to understand how things are in your world.",
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"highlight": "the smart camera (feedforward) view have been influential in philosophy, neuroscience, and AI. Such a view is intuitive because we typically think of perception as all about the flow of information from the world to the mind. That picture can be found, for example, in Descartes’s 1664 Treatise on Man.",
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"highlight": "Vision is here a matter of subjecting the raw signal to a series of operations, such as edge or stripe detection, that slowly reveal more and more complex patterns in the environment—the source of the incoming signal. Eventually, the complex detected patterns are brought into contact with knowledge and memory to deliver (though revealingly, this part of the puzzle was never satisfactorily solved) a kind of 3D picture of the worldly scene.",
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"highlight": "the brain down toward the eyes and other sensory organs. The number of neuronal connections carrying signals backward in this way is estimated to exceed the number of connections carrying signals forward by a very substantial margin,",
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"annotation": "With processing so clearly weighted in terms of cortical density, neither the Cartesian model nor the marr model satisfy"
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"highlight": "as much as four to one. What is all that downward connectivity feeding information from deep in the brain to regions closer to the sensory peripheries doing? This wiring runs in the opposite direction to the wiring needed to perform the processing tasks described in Marr’s early computational model, yet it reaches right down to those very regions.",
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"highlight": "the core operating principle of the perceiving brain is pretty much the opposite of the smart camera view.",
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"highlight": "A predictive brain is a kind of constantly running simulation of the world around us—or at least, the world as it matters to us. Incoming sensory information is used to keep the model honest—by comparing the prediction to the sensory evidence and generating an error signal when the two don’t match up. Despite the wiring costs, constant prediction brings many efficiencies, as we’ll shortly see. It also—and perhaps more importantly—makes us flexible, able to adapt our responses in ways that reflect the demands of our current tasks and context.",
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"highlight": "Before new sensory signals arrive, the predictive brain is already busy painting a rich picture of how things are most likely to be.",
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"highlight": "all that downward connectivity. It is carrying predictions from deep in the brain, pushing them toward the sensory peripheries.",
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"highlight": "explains the huge energy outlay used simply to sustain the brain’s intrinsic activity.",
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"highlight": "That activity is necessary to maintain the model that issues moment-by-moment predictions.",
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"highlight": "As a brain encounters new sensory information its job is to determine if there is anything in that incoming signal that looks like important “news”—unpredicted sensory information that matters to whatever it is that we are trying to see or do.",
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"highlight": "Despite its intuitive appeal, the right way to think about perception is not (for the most part) as a process that runs primarily from the eyes and other sense organs inward. Nor is the brain ever just sitting there waiting patiently for sensory information to arrive. Instead, it is actively anticipating the sensory information, using everything it knows about patterns and objects in the world—the",
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"highlight": "It is also making constant use of the active body, moving head, eyes, and limbs in ways that harvest new and better information.",
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"highlight": "Helmholtz",
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"highlight": "argued that we perceive the world only thanks to a kind of unconscious reasoning or inference in which the brain is asking itself, “Given everything I know, how must the world be for me to be receiving the pattern of signals currently present?” This is the question that perceptual systems are built to resolve.",
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{
"highlight": "guessing is altering the brain’s responses all the way “down” to early auditory processing areas, so as to bring those responses more into line with the expected sounds.",
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"highlight": "This is the brain doing what it does best, churning out “good hallucinations” by filling in and fleshing out the missing signal according to what it expects to hear.",
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"highlight": "Perception of this kind is highly active. It involves sending complex predictions down the chain from higher processing areas toward the sensory peripheries, generating error messages whenever a serious mismatch is detected.",
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"highlight": "We see the world by predicting the world. But where prediction errors ensue, the brain must predict again.",
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"annotation": "seems like the thesis of the book, really"
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"highlight": "benefit too. It enables the brain to process incoming sensory information in a way that is quite remarkably efficient.",
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{
"highlight": "information science stepped in with a clever way to increase efficiency.",
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