WEBVTT 00:00:14.216 --> 00:00:15.704 When we think about learning, 00:00:15.704 --> 00:00:18.365 we often picture students in a classroom or lecture hall, 00:00:18.365 --> 00:00:19.673 books open on their desks, 00:00:19.673 --> 00:00:21.941 listening intently to a teacher or professor 00:00:21.941 --> 00:00:23.599 in the front of the room. 00:00:23.599 --> 00:00:26.511 But in psychology, learning means something else. 00:00:26.511 --> 00:00:30.152 To psychologists, learning is a long-term change in behavior 00:00:30.152 --> 00:00:32.283 that's based on experience. 00:00:32.283 --> 00:00:34.379 Two of the main types of learning are called 00:00:34.379 --> 00:00:36.021 classical conditioning 00:00:36.021 --> 00:00:39.066 and operant, or instrumental, conditioning. 00:00:39.066 --> 00:00:41.969 Let's talk about classical conditioning first. 00:00:41.969 --> 00:00:45.505 In the 1890's, a Russian physiologist named Ivan Pavlov 00:00:45.505 --> 00:00:48.404 did some really famous experiments on dogs. 00:00:48.404 --> 00:00:49.736 He showed dogs some food 00:00:49.736 --> 00:00:51.780 and rang a bell at the same time. 00:00:51.780 --> 00:00:55.290 After a while, the dogs would associate the bell with the food. 00:00:55.290 --> 00:00:56.942 They would learn that when they heard the bell, 00:00:56.942 --> 00:00:58.420 they would get fed. 00:00:58.420 --> 00:01:00.454 Eventually, just ringing the bell 00:01:00.454 --> 00:01:01.915 made the dogs salivate. 00:01:01.915 --> 00:01:05.461 They learned to expect food at the sound of a bell. 00:01:05.461 --> 00:01:07.564 You see, under normal conditions, 00:01:07.564 --> 00:01:11.015 the sight and smell of food causes a dog to salivate. 00:01:11.015 --> 00:01:13.565 We call the food an unconditioned stimulus, 00:01:13.565 --> 00:01:17.564 and we call salivation the unconditioned response. 00:01:17.564 --> 00:01:21.032 Nobody trains a dog to salivate over some steak. 00:01:21.032 --> 00:01:24.313 However, when we pair an unconditioned stimulus like food 00:01:24.313 --> 00:01:26.634 with something that was previously neutral, 00:01:26.634 --> 00:01:28.202 like the sound of a bell, 00:01:28.202 --> 00:01:31.458 that neutral stimulus becomes a conditioned stimulus. 00:01:31.458 --> 00:01:35.086 And so classical conditioning was discovered. 00:01:35.086 --> 00:01:37.463 We see how this works with animals, 00:01:37.463 --> 00:01:39.588 but how does it work with humans? 00:01:39.588 --> 00:01:41.405 In exactly the same way. 00:01:41.405 --> 00:01:44.811 Let's say that one day you go to the doctor to get a shot. 00:01:44.811 --> 00:01:47.766 She says, "Don't worry, this won't hurt a bit," 00:01:47.766 --> 00:01:51.935 and then gives you the most painful shot you've ever had. 00:01:51.935 --> 00:01:54.856 A few weeks later you go to the dentist for a check-up. 00:01:54.856 --> 00:01:56.408 He starts to put a mirror in your mouth 00:01:56.408 --> 00:01:57.859 to examine your teeth, 00:01:57.859 --> 00:02:01.324 and he says, "Don't worry, this won't hurt a bit." 00:02:01.324 --> 00:02:03.747 Even though you know the mirror won't hurt, 00:02:03.747 --> 00:02:05.195 you jump out of the chair and run, 00:02:05.195 --> 00:02:06.924 screaming from the room. 00:02:06.924 --> 00:02:08.604 When you went to get a shot, 00:02:08.604 --> 00:02:10.852 the words, "This won't hurt a bit," 00:02:10.852 --> 00:02:12.467 became a conditioned stimulus 00:02:12.467 --> 00:02:14.628 when they were paired with pain of the shot, 00:02:14.628 --> 00:02:16.637 the unconditioned stimulus, 00:02:16.637 --> 00:02:18.798 which was followed by your conditioned response 00:02:18.798 --> 00:02:21.270 of getting the heck out of there. 00:02:21.270 --> 00:02:24.008 Classical conditioning in action. 00:02:24.008 --> 00:02:26.267 Operant conditioning explains how consequences 00:02:26.267 --> 00:02:29.142 lead to changes in voluntary behavior. 00:02:29.142 --> 00:02:31.478 So how does operant conditioning work? 00:02:31.478 --> 00:02:34.730 There are two main components in operant conditioning: 00:02:34.730 --> 00:02:36.989 reinforcement and punishment. 00:02:36.989 --> 00:02:38.777 Reinforcers make it more likely 00:02:38.777 --> 00:02:40.525 that you'll do something again, 00:02:40.525 --> 00:02:42.708 while punishers make it less likely. 00:02:42.708 --> 00:02:45.869 Reinforcement and punishment can be positive or negative, 00:02:45.869 --> 00:02:48.134 but this doesn't mean good and bad. 00:02:48.134 --> 00:02:50.490 Positive means the addition of a stimulus, 00:02:50.490 --> 00:02:52.951 like getting dessert after you finish your veggies, 00:02:52.951 --> 00:02:55.264 and negative means the removal of a stimulus, 00:02:55.264 --> 00:02:56.965 like getting a night of no homework 00:02:56.965 --> 00:02:59.469 because you did well on an exam. 00:02:59.469 --> 00:03:02.176 Let's look at an example of operant conditioning. 00:03:02.176 --> 00:03:03.995 After eating dinner with your family, 00:03:03.995 --> 00:03:06.522 you clear the table and wash the dishes. 00:03:06.522 --> 00:03:08.724 When you're done, your mom gives you a big hug 00:03:08.724 --> 00:03:11.108 and says, "Thank you for helping me." 00:03:11.108 --> 00:03:13.267 In this situation, your mom's response 00:03:13.267 --> 00:03:15.896 is positive reinforcement if it makes you more likely 00:03:15.896 --> 00:03:17.689 to repeat the operant response, 00:03:17.689 --> 00:03:20.611 which is to clear the table and wash the dishes. 00:03:20.611 --> 00:03:24.038 Operant conditioning is everywhere in our daily lives. 00:03:24.038 --> 00:03:25.533 There aren't many things we do 00:03:25.533 --> 00:03:27.473 that haven't been influenced at some point 00:03:27.473 --> 00:03:29.308 by operant conditioning. 00:03:29.308 --> 00:03:31.080 We even see operant conditioning 00:03:31.080 --> 00:03:34.121 in some extraordinary situations. 00:03:34.121 --> 00:03:36.461 One group of scientists showed the power 00:03:36.461 --> 00:03:37.501 of operant conditioning 00:03:37.501 --> 00:03:40.390 by teaching pigeons to be art connoisseurs. 00:03:40.390 --> 00:03:42.725 Using food as a positive reinforcer, 00:03:42.725 --> 00:03:44.142 scientists have taught pigeons 00:03:44.142 --> 00:03:46.392 to select paintings by Monet 00:03:46.392 --> 00:03:48.388 over those by Picasso. 00:03:48.388 --> 00:03:50.644 When showed works of other artists, 00:03:50.644 --> 00:03:53.436 scientists observed stimulus generalization 00:03:53.436 --> 00:03:55.229 as the pigeons chose the Impressionists 00:03:55.229 --> 00:03:56.754 over the Cubists. 00:03:56.754 --> 00:03:58.609 Maybe next they'll condition the pigeons 00:03:58.609 --> 00:04:00.535 to paint their own masterpieces.