Most people have at some point heard of Pavlov’s famous dog. Ivan Pavlov was a Russian psychologist famous for his study of conditioned stimuli. He took dog food (the natural stimulus) and paired it with a bell (the neutral stimulus). The bell would be rung, and the dog would be given food. After repeating this procedure for a while, even if there was no food present, the dog would begin to salivate after hearing the bell.
This experiment illustrated a concept called classical conditioning. Over time, previously neutral stimuli can be paired with natural, biological stimuli, becoming a conditioned stimulus. Pavlov’s experiment with the dog illustrated the concept of conditioning and laid the foundation for behaviorism.
Pavlov’s Research
Pavlov noticed during his research that the dogs began to react to stimuli associated with food, even before the food arrived. He noticed that the dogs would start to salivate when they saw the lab assistant or heard sounds linked to feeding time. The bell tone would be rung shortly before presenting food, and then the food would arrive. Pavlov observed that after repeating this procedure, the bell tone alone would eventually trigger the dog to salivate, even if there was no food present.
At first, the bell might only cause the dog to salivate slightly, but with repeated pairings, the bell would elicit salivation as a specific response to the conditioned stimulus. This process is known as stimulus substitution, where the conditioned stimulus (bell) comes to substitute for the unconditioned stimulus (food) in eliciting the response. The pairing process involves the neutral stimulus being paired with an unconditioned stimulus (presenting food), so that the conditioned stimulus can elicit the response on its own.
This experiment illustrated a concept called classical conditioning. Over time, previously neutral stimuli can be paired with natural, biological stimuli, becoming a conditioned stimulus or conditioned stimulus. The dogs’ salivating at the sound of the bell was the conditioned response observed by Pavlov. Stimulus discrimination was also demonstrated, as the dogs learned to respond only to the specific bell tone and not to other similar sounds.
Introduction to Classical Conditioning
Classical conditioning is one of the foundational concepts in psychology, offering insight into how both animals and humans learn to connect certain stimuli with specific responses. This process was first uncovered by Pavlov, whose groundbreaking experiments on the digestive response of dogs changed the way we understand learning and behavior. In classical conditioning, a previously neutral stimulus, something that would not naturally cause a reaction, can, through repeated pairing with an unconditioned stimulus, become a conditioned stimulus that elicits a learned response.
The process works through associative learning: by repeatedly pairing a neutral stimulus with an unconditioned stimulus, the neutral stimulus eventually triggers the same response as the unconditioned stimulus. The strength of this conditioned response can depend on factors like the intensity of the unconditioned stimulus, how often the pairing occurs, and the individual’s previous experience with similar stimuli.
Classical conditioning isn’t limited to Pavlov’s dogs. It plays a significant role in human behavior and mental health. For instance, the Little Albert experiment by John B. Watson and Rosalie Rayner demonstrated how a child could develop a conditioned fear. By pairing a white rat (neutral stimulus) with a loud noise (unconditioned stimulus), Little Albert learned to fear the rat, a clear example of how a previously neutral stimulus can become a conditioned stimulus that elicits a conditioned fear response (Watson & Rayner, 1920).
Beyond the laboratory, classical conditioning shapes our everyday experiences. Advertisers use pleasant music and appealing visuals to create positive associations with a particular product, hoping consumers will develop a favorable automatic response. In education, teachers reinforce desired behaviors with praise or rewards, helping students associate positive feelings with learning activities. Therapists use classical conditioning techniques, such as systematic desensitization, to help individuals overcome phobias by gradually exposing them to a feared stimulus in a safe environment.
Classical Conditioning Applied to Humans
How does the concept of conditioned stimuli look in the life of a regular person? Imagine you have a job where you are on call regularly for potential emergencies. These kinds of jobs could include doctors, counselors, veterinarians, firefighters, police officers, etc. After 6 months of working the job, you have been called out on 10 different occasions. On those occasions, you have dealt with different kinds of emergencies and crises that were stress-inducing and anxiety-provoking.
Now, every time your phone rings after hours, you notice your heart begins to race and your adrenaline begins pumping at the sound of your ringtone. Even if it is not a crisis, maybe it is just a call from your mom, you notice it takes a bit for your heart rate and blood pressure to return to normal. This is a conditioned stimulus. The ringtone now elicits a physiological response when it previously had not. The ringtone acts as a specific stimulus that triggers this reaction.
Over time, learning occurs as the ringtone is repeatedly paired with stressful events, leading to this automatic response. In some cases, the ringtone can become associated with a desired response, such as feeling alert and ready to help, or with an undesired response, like anxiety, depending on the context. Psychologists often use test trials in experimental settings to assess how well a conditioned stimulus, like a ringtone, elicits the conditioned response by presenting the stimulus alone after acquisition. Sometimes, after the conditioned response seems to fade, spontaneous recovery can occur, where the extinguished response reappears after a period of rest.
The example above may seem to only relate to certain people. However, conditioned stimuli can occur all the time for anyone and everyone. How it seems to manifest is through the associations people make. It happens more often than you think. If you need to wake up early for work and struggle to fall asleep because you are afraid you will sleep through your alarm, you might begin associating early mornings with the stress of trying to fall asleep.
If you suddenly have high blood pressure when you go to the doctor, you might associate the thought of going to the doctor with feeling nervous. If you have an anxiety attack when riding public transportation, you might find yourself associating riding a bus or subway with feeling anxious. Through repeated exposure to these situations, the associations can become stronger, but therapeutic approaches can use repeated exposure to help diminish phobias and anxieties. Even if those particular examples do not resonate with you, everyone likely has a certain song associated with a particular time of life or a certain smell associated with a specific memory, like the smell of a perfume your grandma used to wear. These are examples of how a familiar stimulus, such as a well-known song or scent, may take longer to become a conditioned stimulus compared to a novel stimulus, which can more quickly form new associations. New stimuli encountered in life can also become conditioned stimuli if they are paired with significant experiences. They are conditioned stimuli. They create almost an automatic response where there was no response previously, and people respond to these cues without conscious thought.
Fear conditioning is a specific type of classical conditioning where a neutral stimulus, like a tone, is paired with an aversive event, leading individuals to experience fear in response to the previously neutral cue. A common real-life example is the red light at a traffic intersection, which becomes a conditioned stimulus signaling drivers to stop, often evoking an automatic response.
It is also important to distinguish classical conditioning from instrumental conditioning and operant conditioning. While classical conditioning involves learning associations between stimuli and automatic responses, instrumental conditioning (also known as operant conditioning) focuses on modifying voluntary behaviors through reinforcement or punishment. In operant conditioning, behaviors are shaped by their consequences, whereas in classical conditioning, a specific stimulus is paired with another to elicit a response.
Final Thoughts
Classical conditioning and conditioned stimuli are important concepts in psychology that have many applications in day-to-day life. On the surface, they simply provide insights into connections and associations people maintain. On a deeper level, however, they delve into the roots of issues related to anxieties, fears, and insecurities. These concepts are invaluable to therapists looking to gain a broader context of the clients they are treating, as well as anyone looking to better their own behaviors and conditioned responses.
Sources
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- Eelen, P. (2018). Classical conditioning: Classical yet modern. Psychologica Belgica, 58(1), 196–211. https://doi.org/10.5334/pb.451
- Krapfl, J. E. (2016). Behaviorism and society. The Behavior Analyst, 39(1), 123–129. https://doi.org/10.1007/s40614-016-0063-8
- Rehman, I., Mahabadi, N., Sanvictores, T., & Rehman, C. I. (2023). Classical Conditioning. In StatPearls. StatPearls Publishing.
- Watson, J. B., & Rayner, R. (1920). Conditioned emotional reactions. Journal of Experimental Psychology, 3(1), 1–14. https://doi.org/10.1037/h0069608
Michelle is a Licensed Marriage & Family Therapist working as a counselor for students, faculty, and staff at Abilene Christian University in Texas. She works with athletes, bridging the gap between athletics and mental health at ACU. Michelle ran her own private practice in Austin, Texas where she worked with a diverse population, including couples and families.