Tuesday, November 22, 2005

Born with the knowledge to know more...

` I have an article from the internet here, but I have no idea where it's from. It appears to be entitled 'Not as ignorant as they look...' I dug it up, though, and I think it's interesting nonetheless. It begins:

If you had been blind all your life and could suddenly see, could you distinguish by sight what you knew already by touch--say, a cube from a sphere? Would flowers look like flowers you'd felt and faces like faces, or would they all be confusing patterns? How would you start to make sense of the many objects in your immediate view? If we are born knowing nothing, how do we come to know anything?

Harvard University psychologist Elizabeth Spelke takes these questions to the people who may be best able to answer them: babies....

` Apparently, Spelke has come up with the possibly revolutionary theory of 'core knowledge', by observing that infants seem to be born with certain 'basic cognitive skills that let them make sense of the world.'
` It is a unifying theory as well, as this 'core knowledge' seems to underlie everything we humans learn throughout our lifetimes - from before we can talk and grasp objects until after we have a vast amount of life experience in our past.
` And, we all are born with these same abilities.
` This theory is so valuable to psychological studies, in fact, that in 2000, the American Psychological Association honored her with the William James Fellow Award.

` Though young babies have little control over their own movements, one thing they are sure to do is look a certain amount of time at an object after they have seen it several times. However, if you change the object in some way - for example, add two extra ears onto a toy bunny - and show it to them again, they will stare at it longer because they are seeing something they did not expect.
` This is called 'preferential looking', and was discovered over half a century ago by Robert L. Fantz, who controlled the infant's perception within a stage-like box. In this way, he and others found that newborn babies recognized that there was a difference between red and green, two-month olds could discriminate between red, blue, and yellow, and that three-month-olds preferred yellow and red to blue and green.
` They also discovered the levels of facial recognition in babies of different ages, and that six-month olds can interpret facial expressions.
` The article says of its featured scientist:

This work attracted Spelke when she was still an undergraduate at Radcliffe College. From 1967 to 1971, she studied with Harvard child developmental psychologist Jerome Kagan and quickly found herself hooked on the excitement of investigating the essential workings of human cognition by analyzing children. She continued that research while pursuing her Ph.D. in psychology at Cornell University, where the famed developmental psychologist Eleanor J. Gibson served as her graduate adviser and mentor. Gibson, one of only a handful of psychologists to win the National Medal of Science, had revealed much about infant cognition with some elegant experiments of her own. Her best known was the "visual cliff," a piece of heavy glass extending from a tabletop. Would early crawlers avoid the apparent drop-off? Most do, a discovery that revised theories of infants' spatial understanding.

` Spelke's Ph.D. thesis came from asking the question of whether babies looking and listening to something perceive the sight and sound as part of the same thing, or as two unrelated sensations? At dinner one night, she came up with a new, brilliant experiment: Set a baby in front of two movies, with a loudspeaker playing the sound from only one of them. Then, unpredictably, play the sound from the other movie. Would the baby look at the movie that corresponded to the sound?
` Indeed, when she performed the experiment, the babies showed that they recognized that there was a link between the sound coming from the loudspeaker and the movies on the screen. In other words, a baby can form a unified whole from more than one sense.
` No one knows how this happens, though Spelke was able to demonstrate that this ability would seem to be innate to each person.

` She has shown, for example, that a four-month old notices when a moving object does not continue at its logical speed, and an eight-month old expects an object to abide the principle of inertia.
` Interestingly, she has discovered that six-month old babies can distinguish an array of eight disks from an array of sixteen, and sixteen from thirty-two, they do not seem to notice any difference between eight and twelve disks, nor sixteen from twenty-four.
` She also found that when an adult looks at an object on a table and then reaches for it, a twelve-month old expects for them to reach for what they are looking at, though an eight-month old does not seem to notice.

As the data from such clever designs mounted, Spelke began to develop her theory of core knowledge, often inspired by or collaborating with colleagues such as noted Massachusetts Institute of Technology linguist Noam Chomsky, French mathematician turned cognitive neuropsychologist Stanislaus Dehaene and Harvard psychologist Susan Carey. Core knowledge systems, Spelke says, are neuronal "modules" that are in place at birth for building mental representations of objects, persons, spatial relationships and numerosity. Somewhat akin to the "deep grammar" that Chomsky believes underlies all human language, these core knowledge modules enable all infants to organize their perceptions.

The sophistication of these systems in infants resembles that of modules in nonhuman primates, suggesting an ancient, evolutionary development; a six-month-old baby understands numbers, space, objects and faces much as a mature rhesus monkey does. As Spelke sees it, these cognitive tools underlie all the more complex skills and knowledge we master as we grow up--spoken languages, number manipulation and other abstract mental operations. Core knowledge forms the basis for the robust cognitive machinery that gets us through life. And we almost completely ignore it.

"Even for adults," Spelke says, "most of what we know that lets us negotiate the world, guide our choice of paths through the environment, understand whether a car down the street might hit us or whether a falling object will miss us, even what we say as we're conversing--most of that is completely unconscious. How many things do we do that we hardly think about? Most of what we do is like that. We operate on richly structured cognitive systems that aren't usually accessible to introspection. To me, this is one more sign that most of our cognitive workings are much like those of babies and are built on the core knowledge that we had as babies."

` And if we all have these abilities, one question from Harvard president Lawrence Summers was her opinion on why there aren't that many women in the math and science departments. Is this an inborn trait?

"If you look at things Summers's way," she says in her office, leaning forward in her chair with a sly grin, "then to study innate cognitive abilities, like I do, is supposedly to study gender differences. In fact, I didn't know we were studying gender differences at all, because we don't find any. But since the subject came up"--she spread her hands, clasped them, then sat back in her chair, smiling--"I was happy to tell him about our work."

` Oh he got his answer, from both her and her colleague and friend, Steven Pinker. Decades of research show little, if any, gender differences in babies and toddlers, and this was discussed in a public, high profile debate.
` At those ages, culture has very little effect, though sex hormone levels are extremely high. As far as the numerous skills that relate to mathematical thinking go, no differences between boys and girls has been found.
` One such test is this one: If you put a four-year-old in an oddly-shaped room, hide a block in a corner, and have the child close their eyes and spin around, only some of the children will quickly distinguish the corner that the block is hidden in, and others remain somewhat disoriented. However, the percentages of who readily finds the block and who does not is the same for boys and girls both.

Meanwhile the expanding pile of data on infants, who are not tainted by culture, shows remarkable parity among sexes and races. "We're getting evidence for an intricate and rich system of core knowledge that everyone shares and that gives us common ground," Spelke declares. "In a world of so much conflict, I think that's something we badly need."

` I don't know about you, but I didn't know any of this beforehand. I think it's good to know that (at least most) babies, while personalities differ, have similar abilities from the start. And no evidence to the contrary is 'good' news in this case, I guess.

1 comment:

Galtron said...

So newboarn babies can't tell the difference between yellow and blue yet? Weird!