perceptual learning

 

Benedict Carey, How we learn, 2014                                          [ ]

p.180

The field, Gibson believed, was completely overlooking something fundamental: discrimination. How the brain learns to detect minute differences in sights, sounds, or textures. Before linking different names to distinct people, for example, children have to be able to distinguish between the sounds of those names, between Ron and Don, Fluffy and Scruffy. That's one of the first steps we take in making sense of the world. In hindsight, this seems on obvious point. Yet it took years for her to get anyone to listen. 

p.180

Gibson soon got the opportunity to study learning in young children, and that's when she saw that her gut feeling about discrimination learning was correct. 

 

p.183

Nor were their brains──as the English philosopher John Locke famously argued in the 17th century──empty vessels, passively accumulating sensations.  No, their brains came equipped with evolved modules to make important, subtle discriminations, and to put those differing symbols into categories.  

p.183

   “Let us consider the possibility of rejecting Locke's assumption altogether”, the Gibsons wrote. “Perhaps all knowledge comes through the senses in an even simpler way than John Locke was able to conceive──by way of variations, shadings, and subtleties of energy.”

p.183

   That is, the brain doesn't solely learn to perceive by picking up on tiny differences in what it sees, hears, and smells, or feels. In this experiment and a series of subsequent ones──with mice, cats, children, and adults──Gibson showed that it also perceives to learn. It takes the differences it has detected between similar-looking notes or letters or figures, and uses those to help decipher new, previously unseen material. Once you've got middle-C nailed on the treble clef, you use it as a benchmark for nearby notes; when you nail the A an octave higher, you use that to read its neighbors; and so on.  This “discrimination learning” builds on itself, the brain hoarding the benchmarks and signatures it eventually uses to read larger and larger chunks of information. 

pp.183-184

   In 1969, Eleanor Gibson published Principles of Perceptual Learning and Development, a book that brought together all her work and established a new branch of psychology: perceptual learning.  Perceptual learning, she wrote, “is not a passive absorption, but an active process, in the sense that exploring and searching for perception itself is active. We do not just see, we look; we do not just hear, we listen. Perceptual learning is self-regulated, in the sense that modification occurs without the necessity of external reinforcement. It is stimulus oriented, with the goal of extracting and reducing the information simulation. Discovery of distinctive features and structure in the world is fundamental in the achievement of this goal.”  

p.184

   Perceptual learning is active. Our eyes (or ears, or other senses) are searching for the right clues. Automatically, no external reinforcement or help required. We have to pay attention, of course, but we don't need to turn it on or tune it in.  It's self-correcting──it tunes itself.  The system works to find the most critical perceptual signatures and filter out the rest. Baseball players see only the flares of motion that are relevant to judging a pitch's trajectory──nothing else. The masters in Chase and Simon's chess study considered fewer moves than the novices, because they'd developed such a good eye that it instantly pared down their choices, making it easier to find the most effective parry. And these are just visual examples. Gibson's conception of perceptual learning applied to all the senses, hearing, smell, taste, and feel, as well as vision. 

pp.184-185

The flying conditions above Martha's Vineyard can change on a dime. Even when clouds are spare, a haze often settles over the island that, after nightfall, can disorient an inexperienced pilot. That's apparently what happened just after 9:40 P.M. on July 16, 1999, when John Kennedy Jr. crashed his Piper Saratoga into the ocean seven miles offshore, killing himself, his wife, and her sister. “There was no horizon and no light”, said another pilot who's flown over the island that night. “I turned left toward the Vineyard to see if it was visible but could see no lights of any kind nor any evidence of the island. I thought the island might have suffered a power failure.” 

p.185

The official investigation into the crash found that Kennedy had 55 hours of experience flying at night, and that he didn't have an instrument rating at all. In pilot's language, that means he was still learning and not yet certified to flying zero visibility, using only the plane's instrument panel as a guide. 

p.185

   The instruments on small aircraft traditionally include six main dials. One tracks altitude, another speed through the air. A third, the directional gyro, is like a compass; a fourth measures vertical speed (climb or descent). Two others depict a miniature airplane and show banking of the plane and its turning rate through space, respectively (newer models have five, no banking dial). 

p.185

   Learning to read any one of them is easy, even if you've never seen an instrument panel before. It's harder, however, to read them all in one sweep and to make the right call on what they mean collectively. Are you descending? Are you level? This is tricky for amateur pilots to do on a clear day, never mind in zero visibility. Add in communicating with the tower via radio, reading aviation charts, checking fuel levels, preparing landing gear, and other vital tasks──it's a multitasking adventure you don't want to have, not without a lot of training. 

pp.185-186

   This point was not lost on Philip Kellman, a cognitive scientist at Bryn Mawr College, when he was learning to fly in the 1980s. As he moved through his training, studying for aviation tests──practicing on instrument simulators, logging air time with instructors──it struck him that flying was mostly about perception and action. Reflexes. Once in the air, his instructors could see patterns that he could not. “Coming in for landing, an instructors may say to the student, ‘You're too high!’”  Kellman, who's now at UCLA, told me. “The instructor is actually seeing an angle between the aircraft and the intended landing point, which is formed by the flight path and the ground. The student can't see this at all. In many perceptual situations like this one, the novice is essentially blind to patterns that the experts has come to see at a glance.” 

p.186

   That glance took into account all of the instruments at once, as well as the view out the windshield. To hone the ability, it took hundreds of hours of flying time, and Kellman saw that the skill was not as straightforward as it seemed on the ground. Sometimes a dial would stick, or swing back and forth, creating a confusing picture. Were you level, as one dial indicated, or in a banking turn, like another suggested?  Here's how Kellman describes the experience of learning to read all this data at once with an instructor: “While flying in the clouds, the trainee in the left seat struggles as each gauge seems to have a mind of its own. One by one, he laboriously fixates on each one. After a few seconds on one gauge, he comprehends how it has strayed and corrects, perhaps with a jerk guaranteed to set up the next fluctuation. Yawning, the instructor in the right seat looks over at the panel and sees at a glance that the student has wandered off of the assigned altitude by 200 feet but at least has not yet turned the plane upside down.”

p.186

The training short-cut Kellerman developed is what he called a perceptual learning module, or PLM. 

   (Carey, Benedict., How we learn: the surprising truth about when, where, and why it happens/ Benedict Carey., 1. learning, psychology of., 2. learning., BF318.C366 2014, 153.1'5--dc23, 2014, )

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