Nelson – how experiences and biology interact

So there are many ways to illustrate how experience and biology interact. Here’s a few examples. Children who are again born with cataracts and are deprived of seeing the world normally… those cataracts or if for example they don’t have cataracts, they’re cross-eyed; if those two things aren’t corrected their vision will not develop normally. And the reason is that their visual system needs to be driven by experience.  

Language would be another example. We know that in the first six or 12 months infants throughout the world can discriminate virtually every speech sound in any language. So a Canadian baby can discriminate English, Thai, Czech, Japanese and the like and Janet Werker of UBC has shown that as kids get to be a little beyond a year they start to lose that ability and they’re better at discriminating the sounds from the language they’re exposed to. Much like the example I gave earlier with faces and monkey faces. Initially a baby can discriminate monkey faces and human faces but as they get older when they’ve never seen monkey faces they can only do human faces. So that’s another example of how experience influences the brain.  

So it would be, it’s unfortunate that we have sometimes have tried to apportion variance which is a fancy way of saying how much of behavior is genetic and how much of it is experience when we know that the experiences we have on a day-to-day basis weave themselves into the brain, which changes the brain, and changes how the brain functions. So it’s an iterative process. And that is something that begins at birth and continues throughout life. Learning and memory is the best example of that of course, something we do throughout our lives, where the fact that we can acquire new information and learn about the world is the way our brain has been changed.