Psychology for Dummies (26 page)
Read Psychology for Dummies Online
Authors: Adam Cash
Tags: #Psychology, #General, #Body; Mind & Spirit, #Spirituality
The power of classical conditioning is pretty impressive. Just think — if you appropriately pair two stimuli together, the CS will eventually get the job done alone. But when the pairing stops and the CS is producing the response by itself, the power of the CS eventually fades. If a CS is presented enough times without the US, the CS eventually will cease to elicit the CR. This phenomenon is called
extinction,
and it is a way to reverse the process of classical conditioning. For example, Pavlov’s dogs learned to salivate at the sound of a bell. But if the bell kept getting presented without any delivery of food, the dogs would eventually stop slobbering to the bell.
But wait, there’s more! Something even more interesting happens if the US is reintroduced sometime after extinction —
spontaneous recovery.
At this point, the CS’s ability to elicit the response comes bouncing back, and once again the CS is capable of eliciting the CR. So, you can use classical conditioning to teach an old dog new tricks, and you can reverse the process through extinction. With this skill, you’ll never be the boring guy at the party sitting in the corner. You can dazzle your newfound friends with classical conditioning tricks.
Here’s a little something to try, just in case you’re thinking about testing out classical conditioning for yourself.
1. Gather a few people together — family, friends, coworker, whoever. Get some packets of powdered, lemonade drink mix. This stuff is really sour without sugar. Give one pack to each participant.
2. Ask the crowd that you’ve gathered to dip their fingers in the lemonade and take a lick. (This is the US.) Ask them to observe if their mouths watered. They should have. If not, get yourself some better droolers.
3. Then choose a CS (a bell, a light, a whistle, whatever). Go through the process of pairing the bell (or any other CS that you choose) with tasting the lemonade (CS → US → UR over and over again). After 10 to 20 trials, go through a couple of trials where you present just the CS and ask the participants to observe if their mouths watered. They should have! That’s classical conditioning. You can also play around with extinction and spontaneous recovery if you want.
One more way to reverse the effects of classical conditioning is worth mentioning. You’ve conducted the lemonade test, and you’ve successfully taught your Pavlovian subjects to drool at the sound of a bell ringing. If you want to reverse the effect, choose another US that produces some other response (UR) and classically condition the bell (CS) with the new US. This process is called
counterconditioning.
Counterconditioning works especially well if the new US produces a response that is incompatible with the old CR. If the old CR was a watering mouth, maybe you could pick a new US that produces a dry mouth. I don’t know what — maybe eating sand. I guarantee that, if you classically condition the bell with the eating of sand, the bell will have a very hard time producing the old CR, watering of the mouth, from that point on. Unless, of course, you reverse the process all over again. Remember though, you’ve got to give your subjects a break from time to time, and I wouldn’t recommend the sand-eating demonstration as a parlor game.
You may be thinking, “Big deal. We can teach dogs to salivate to a bell, so what?” Classical conditioning is actually a very important phenomenon in terms of human survival. It helps us learn things simply by association, without effort, and this can be very beneficial. After we’ve associated a CS with a US to the point where the CS produces the CR, we can expand automatically on that learning through a process known as
generalization.
Generalization happens when we respond to something similar to the CS, I’ll call it CS-2, and a CR is produced, even if we’ve never learned to associate CS-2 with the original US. For instance, if you learn to associate certain facial gestures, like a snarl or a sneer, with eventual violence, then the snarl or sneer (CS) produces fear (CR) whereas only a flying fist or a verbal threat (US) elicited fear (UR) in the past. You might then generalize from the CS-snarl and experience fear in connection with direct and non-adverted eye contact (CS-2). This generalization could save your tail. Generalization helps us adapt, because we apply what we’ve learned to new situations.
Generalization can backfire though. If, for example, I was attacked by a black-colored pit bull, I might then get scared every time I see a black-colored dog of any type, even a Chihuahua. Another example comes from the traumatic experiences of war veterans who suffer from post-traumatic stress. If they’ve experienced loud explosions and heavy gunfire and developed a strong fear reaction to these events, these individuals may react the same way when they hear a car backfire or some other loud noise. This can make life pretty difficult, considering that a lot of people live in urban areas with a lot of loud noises.
When we begin to overgeneralize what we’ve learned, we are not engaging in a process known as
discrimination.
We need to know how to
discriminate,
or tell the difference, between stimuli — between a gunshot and a car backfire, for example. Discrimination is learned when a CS-2 (or 3, or 4, and so on) is presented enough times without eliciting a response. We then learn that only the CS, and not the CS-2, is necessarily going to produce the CR.
All of this seems easy, doesn’t it? You pair a couple of things together, and one eventually starts doing the job of the other. So far, the process is pretty straightforward, but some specific rules must be abided by in order to prevent this relatively simple procedure of conditioning from turning into an impossible task.
Contiguity
is absolutely required in order for classical conditioning to occur. What if Pavlov had presented the bell (CS) after he presented the food (US)? What if he had presented the bell 15 minutes before the food? The CS must come before the US in order for the association to form.
Each of these questions represents a type of conditioning that isn’t actually a very good conditioning technique at all. If Pavlov presented the US before the CS, a process known as
backward conditioning,
the dogs would have either made no association at all or an extremely weak one. If he presented the bell well in advance of the food, a process known as
trace conditioning,
the dogs again would have formed a weak association, if any.
The best way to ensure that a strong association is formed is to
Present the CS just before the US and keep the CS “on” or “around” until the US appears. This way, the CS is seen as contiguous with the US.
Conduct a lot of trials with the CS and US paired frequently. The strength of the association is a direct product of the frequency of the pairing.
Select a strong or intense CS. A bright light conditions easier than a dim one. A loud bell conditions easier than a faint one. If you want your CS to produce the CR, give it some oomph.
Again, I don’t want to mislead you into thinking that all you have to do is frequently present an intense CS before a US and you get hassle-free classical conditioning.
The rule of contiguity states that if two stimuli are contiguous, an association will form. It actually might have been that simple, if it wasn’t for a pesky graduate student named Robert Rescorla.
Rescorla questioned whether contiguity was enough. Maybe he thought that it all seemed too simple. He proposed that another rule be added to the list, the rule of
contingency.
Rescorla’s idea was that a CS not only has to be contiguous with a US, it also has to be an accurate predictor of the US. If the CS is presented at random times (at 1 minute, 7 minutes, 2 minutes, 12 minutes, and so on for example) with the US, the CS wouldn’t be a very good predictor of the US. The learner (animal or human) would gain no predictive power from experiencing the CS. The CS has to be presented with the US in a way that the learner can anticipate, with a fair degree of certainty, that the US is soon to come.
Adding another rule to the necessities of classical conditioning is quite the accomplishment for a graduate student. But Rescorla wasn’t finished. Later, he and another psychologist, Allan Wagner, made another huge contribution to learning theory. The Rescorla-Wagner model (1972) simply states that in order for a CS to be maximally effective, it must be unexpected. The learning process is dependent on the element of surprise. If we expect the US every time we see the CS, we’ll learn to associate it properly, but eventually, the strength of the association will reach a maximum. The strength will increase dramatically at first and then level off as the novelty of the CS wears off, and it becomes more “expectable.” Therefore, the power or strength of an association is a function of the amount of surprise. The more novel the CS, the stronger the association will be.