BA410 Unit 3 Pavlovian Conditioning Paper Example

The Click of the Pellet Dispenser: A BA410 Unit 3 Pavlovian Conditioning Paper

[Student Name]

Purdue University Global

BA410: Introduction to Experimental Analysis of Behavior

Unit 3 Pavlovian Conditioning Paper

[Instructor Name]

[Date]

The writer, the lab, its animals and the family examples are composite; the studies and books cited are real.

A Sound in the Chamber

In the rat lab where I work part time, every new animal starts with the same first step. When a new rat begins training, the first step is called magazine training. The rat is placed in the operant chamber, and the computer delivers food pellets into a food cup at irregular times, regardless of what the rat does. Each delivery is preceded by a sharp click from the pellet dispenser. At first the rat ignores the click and finds pellets by chance. Within a session or two, the rat turns toward the food cup as soon as it hears the click, often reaching it before the pellet lands.

Nothing the rat did produced the click or the food. The change happened because the click reliably came just before food. That is Pavlovian, or classical, conditioning, and this paper explains it using the lab and two studies with very different subjects.

Pavlov's Procedures

Pavlov (1927) studied digestion in dogs and noticed that they began to salivate before food reached their mouths, at the sight of the person who fed them or the sound of preparations. He developed procedures to study this systematically. A neutral stimulus, such as a metronome, was presented just before food. Food, the unconditioned stimulus, elicited salivation, the unconditioned response, without any training. After repeated pairings, the metronome alone elicited salivation, which Pavlov called a conditioned response, and the metronome had become a conditioned stimulus.

Pavlov also described the conditions that strengthen or weaken conditioning: the timing between the two stimuli, the number of pairings, extinction when the conditioned stimulus is presented without the unconditioned stimulus, and spontaneous recovery after a rest.

In the chamber, the click is the conditioned stimulus, food is the unconditioned stimulus, and orienting toward and approaching the food cup is the conditioned response. The rat's approach before the pellet lands is the same phenomenon Pavlov saw in dogs that salivated at footsteps.

The rat did not learn that pressing the lever brings food; it first learned that the click means food is coming, before it ever touched the lever.

Timing Matters: Infants and Eyeblinks

Pavlovian conditioning is not limited to animals or to salivation. Claflin et al. (2002) studied eyeblink conditioning in five-month-old infants. A tone was presented, followed by a gentle puff of air to the eye, which elicits a blink. Infants learned to blink to the tone before the puff arrived, and the researchers compared groups trained with different intervals between tone and puff to see how the delay affected learning. The interval mattered: how well the infants learned depended on the timing between the two stimuli.

The finding shows two things. First, Pavlovian conditioning occurs very early in human development. Second, the interval between the conditioned and unconditioned stimuli is critical, a principle Pavlov emphasized. In the lab, the pellet click precedes food by a fraction of a second, which is part of why magazine training works so quickly.

What the Click Predicts

Rescorla (1988) argued that Pavlovian conditioning is better understood as learning about relations between events than as a simple bond formed by pairing. A stimulus becomes a strong conditioned stimulus when it predicts the unconditioned stimulus, not merely when they occur together.

The lab provides a test. Early in training, graduate students sometimes run a few sessions in which the dispenser clicks without delivering a pellet because of a mechanical jam. Rats' approaches to the cup after the click decline over those sessions, respondent extinction, and recover when the dispenser is fixed. The click controls approach only as long as it continues to predict food.

From Conditioned Stimulus to Conditioned Reinforcer

The click does more than elicit approach. Once training moves to lever pressing, the click is delivered immediately after each press that earns food, and it now follows the response. Williams (1994) reviewed research on conditioned reinforcement, the process by which a stimulus paired with a primary reinforcer comes to strengthen behavior that produces it. He discussed how Pavlovian pairing is closely tied to a stimulus's ability to function as a conditioned reinforcer, and debated how best to explain the effect.

In practical terms, the click bridges the gap between the lever press and the arrival of food. Because it has been paired with food, it marks the exact moment of the correct response and strengthens it. The same logic underlies clicker training with dogs, where trainers first pair a click with treats and then use the click to mark desired behavior.

Second-Order Conditioning

Pavlov also showed that a conditioned stimulus can itself condition a new stimulus, without the unconditioned stimulus present, a process called second-order conditioning. A graduate student in the lab tested this in a short pilot. After the rats had learned the click, she presented a soft tone followed by the click alone, with the pellet dispenser empty, for a small number of trials. Several rats began moving toward the food cup when the tone sounded, although the tone had never been followed by food. The tone had acquired some of the click's effect through its pairing with the click. Because the click was no longer followed by food during those trials, the effect was brief, which is typical of second-order conditioning. Second-order conditioning helps explain how stimuli far removed from any primary reinforcer, such as a lab's door opening or a technician's footsteps, can come to influence behavior.

Conditioning at Home

I see the same process at home. My dog, Juniper, runs to the kitchen when she hears the can opener, because the sound has preceded her food for years. When I switched to a new brand that comes in pouches, her rush to the kitchen at the can opener weakened over a few weeks, unless I was opening a can of her food, which happens on weekends. She had learned what the sound predicted, and when the prediction changed, so did her behavior.

Conclusion

The click of a pellet dispenser shows Pavlovian conditioning at the heart of operant research. Pavlov's procedures name the elements, the infant eyeblink study shows that timing matters even in five-month-olds, Rescorla's account explains why the click works only while it predicts food, and research on conditioned reinforcement explains how the click goes on to strengthen lever pressing. Both kinds of learning are at work in every session in the chamber.

References

Claflin, D. I., Stanton, M. E., Herbert, J., Greer, J., & Eckerman, C. O. (2002). Effect of delay interval on classical eyeblink conditioning in 5-month-old human infants. Developmental Psychobiology, 41(4), 329-340. https://doi.org/10.1002/dev.10050

Pavlov, I. P. (1927). Conditioned reflexes: An investigation of the physiological activity of the cerebral cortex (G. V. Anrep, Trans.). Oxford University Press.

Rescorla, R. A. (1988). Pavlovian conditioning: It's not what you think it is. American Psychologist, 43(3), 151-160. https://doi.org/10.1037/0003-066X.43.3.151

Williams, B. A. (1994). Conditioned reinforcement: Neglected or outmoded explanatory construct? Psychonomic Bulletin & Review, 1(4), 457-475. https://doi.org/10.3758/BF03210950