1 00:00:14,216 --> 00:00:15,704 When we think about learning, 2 00:00:15,704 --> 00:00:18,365 we often picture students in a classroom or lecture hall, 3 00:00:18,365 --> 00:00:19,673 books open on their desks, 4 00:00:19,673 --> 00:00:21,941 listening intently to a teacher or professor 5 00:00:21,941 --> 00:00:23,599 in the front of the room. 6 00:00:23,599 --> 00:00:26,511 But in psychology, learning means something else. 7 00:00:26,511 --> 00:00:30,152 To psychologists, learning is a long-term change in behavior 8 00:00:30,152 --> 00:00:32,283 that's based on experience. 9 00:00:32,283 --> 00:00:34,379 Two of the main types of learning are called 10 00:00:34,379 --> 00:00:36,021 classical conditioning 11 00:00:36,021 --> 00:00:39,066 and operant, or instrumental, conditioning. 12 00:00:39,066 --> 00:00:41,969 Let's talk about classical conditioning first. 13 00:00:41,969 --> 00:00:45,505 In the 1890's, a Russian physiologist named Ivan Pavlov 14 00:00:45,505 --> 00:00:48,404 did some really famous experiments on dogs. 15 00:00:48,404 --> 00:00:49,736 He showed dogs some food 16 00:00:49,736 --> 00:00:51,780 and rang a bell at the same time. 17 00:00:51,780 --> 00:00:55,290 After a while, the dogs would associate the bell with the food. 18 00:00:55,290 --> 00:00:56,942 They would learn that when they heard the bell, 19 00:00:56,942 --> 00:00:58,420 they would get fed. 20 00:00:58,420 --> 00:01:00,454 Eventually, just ringing the bell 21 00:01:00,454 --> 00:01:01,915 made the dogs salivate. 22 00:01:01,915 --> 00:01:05,461 They learned to expect food at the sound of a bell. 23 00:01:05,461 --> 00:01:07,564 You see, under normal conditions, 24 00:01:07,564 --> 00:01:11,015 the sight and smell of food causes a dog to salivate. 25 00:01:11,015 --> 00:01:13,565 We call the food an unconditioned stimulus, 26 00:01:13,565 --> 00:01:17,564 and we call salivation the unconditioned response. 27 00:01:17,564 --> 00:01:21,032 Nobody trains a dog to salivate over some steak. 28 00:01:21,032 --> 00:01:24,313 However, when we pair an unconditioned stimulus like food 29 00:01:24,313 --> 00:01:26,634 with something that was previously neutral, 30 00:01:26,634 --> 00:01:28,202 like the sound of a bell, 31 00:01:28,202 --> 00:01:31,458 that neutral stimulus becomes a conditioned stimulus. 32 00:01:31,458 --> 00:01:35,086 And so classical conditioning was discovered. 33 00:01:35,086 --> 00:01:37,463 We see how this works with animals, 34 00:01:37,463 --> 00:01:39,588 but how does it work with humans? 35 00:01:39,588 --> 00:01:41,405 In exactly the same way. 36 00:01:41,405 --> 00:01:44,811 Let's say that one day you go to the doctor to get a shot. 37 00:01:44,811 --> 00:01:47,766 She says, "Don't worry, this won't hurt a bit," 38 00:01:47,766 --> 00:01:51,935 and then gives you the most painful shot you've ever had. 39 00:01:51,935 --> 00:01:54,856 A few weeks later you go to the dentist for a check-up. 40 00:01:54,856 --> 00:01:56,408 He starts to put a mirror in your mouth 41 00:01:56,408 --> 00:01:57,859 to examine your teeth, 42 00:01:57,859 --> 00:02:01,324 and he says, "Don't worry, this won't hurt a bit." 43 00:02:01,324 --> 00:02:03,747 Even though you know the mirror won't hurt, 44 00:02:03,747 --> 00:02:05,195 you jump out of the chair and run, 45 00:02:05,195 --> 00:02:06,924 screaming from the room. 46 00:02:06,924 --> 00:02:08,604 When you went to get a shot, 47 00:02:08,604 --> 00:02:10,852 the words, "This won't hurt a bit," 48 00:02:10,852 --> 00:02:12,467 became a conditioned stimulus 49 00:02:12,467 --> 00:02:14,628 when they were paired with pain of the shot, 50 00:02:14,628 --> 00:02:16,637 the unconditioned stimulus, 51 00:02:16,637 --> 00:02:18,798 which was followed by your conditioned response 52 00:02:18,798 --> 00:02:21,270 of getting the heck out of there. 53 00:02:21,270 --> 00:02:24,008 Classical conditioning in action. 54 00:02:24,008 --> 00:02:26,267 Operant conditioning explains how consequences 55 00:02:26,267 --> 00:02:29,142 lead to changes in voluntary behavior. 56 00:02:29,142 --> 00:02:31,478 So how does operant conditioning work? 57 00:02:31,478 --> 00:02:34,730 There are two main components in operant conditioning: 58 00:02:34,730 --> 00:02:36,989 reinforcement and punishment. 59 00:02:36,989 --> 00:02:38,777 Reinforcers make it more likely 60 00:02:38,777 --> 00:02:40,525 that you'll do something again, 61 00:02:40,525 --> 00:02:42,708 while punishers make it less likely. 62 00:02:42,708 --> 00:02:45,869 Reinforcement and punishment can be positive or negative, 63 00:02:45,869 --> 00:02:48,134 but this doesn't mean good and bad. 64 00:02:48,134 --> 00:02:50,490 Positive means the addition of a stimulus, 65 00:02:50,490 --> 00:02:52,951 like getting dessert after you finish your veggies, 66 00:02:52,951 --> 00:02:55,264 and negative means the removal of a stimulus, 67 00:02:55,264 --> 00:02:56,965 like getting a night of no homework 68 00:02:56,965 --> 00:02:59,469 because you did well on an exam. 69 00:02:59,469 --> 00:03:02,176 Let's look at an example of operant conditioning. 70 00:03:02,176 --> 00:03:03,995 After eating dinner with your family, 71 00:03:03,995 --> 00:03:06,522 you clear the table and wash the dishes. 72 00:03:06,522 --> 00:03:08,724 When you're done, your mom gives you a big hug 73 00:03:08,724 --> 00:03:11,108 and says, "Thank you for helping me." 74 00:03:11,108 --> 00:03:13,267 In this situation, your mom's response 75 00:03:13,267 --> 00:03:15,896 is positive reinforcement if it makes you more likely 76 00:03:15,896 --> 00:03:17,689 to repeat the operant response, 77 00:03:17,689 --> 00:03:20,611 which is to clear the table and wash the dishes. 78 00:03:20,611 --> 00:03:24,038 Operant conditioning is everywhere in our daily lives. 79 00:03:24,038 --> 00:03:25,533 There aren't many things we do 80 00:03:25,533 --> 00:03:27,473 that haven't been influenced at some point 81 00:03:27,473 --> 00:03:29,308 by operant conditioning. 82 00:03:29,308 --> 00:03:31,080 We even see operant conditioning 83 00:03:31,080 --> 00:03:34,121 in some extraordinary situations. 84 00:03:34,121 --> 00:03:36,461 One group of scientists showed the power 85 00:03:36,461 --> 00:03:37,501 of operant conditioning 86 00:03:37,501 --> 00:03:40,390 by teaching pigeons to be art connoisseurs. 87 00:03:40,390 --> 00:03:42,725 Using food as a positive reinforcer, 88 00:03:42,725 --> 00:03:44,142 scientists have taught pigeons 89 00:03:44,142 --> 00:03:46,392 to select paintings by Monet 90 00:03:46,392 --> 00:03:48,388 over those by Picasso. 91 00:03:48,388 --> 00:03:50,644 When showed works of other artists, 92 00:03:50,644 --> 00:03:53,436 scientists observed stimulus generalization 93 00:03:53,436 --> 00:03:55,229 as the pigeons chose the Impressionists 94 00:03:55,229 --> 00:03:56,754 over the Cubists. 95 00:03:56,754 --> 00:03:58,609 Maybe next they'll condition the pigeons 96 00:03:58,609 --> 00:04:00,535 to paint their own masterpieces.