An unconditioned stimulus (US) is something that naturally triggers a reflexive response without prior learning or conditioning. For example, the smell of food causing hunger or a loud noise causing a startle response.
Unlike a conditioned stimulus (CS), you do not have to learn to respond to the unconditioned stimulus; rather, the response occurs automatically.
Examples of unconditioned stimulus
Pavlovs Dogs Experiment
Ivan Pavlov discovered the best-known and most thorough work on classical conditioning in the early 1900s in his experiments on the digestive response of dogs.
Pavlov greatly impacted the study of classical conditioning, which is often referred to as Pavlovian conditioning.
Ivan Pavlov was the first person to discover the process of classical conditioning. When conducting research on the digestion of dogs, Pavlov noticed that the dogs’ physical reactions to food changed over time.
While at first, the dogs would only salivate when the food was placed in front of them, they eventually began to salivate slightly before their food arrived.
He realized that the dogs were not salivating to the smell or sight of the food in front of them but rather the noises and sites that were consistently present before the food even arrived.
To test his theory further, Pavlov would ring a bell shortly before presenting food to the dogs. At first, this elicited no response from the dogs, but eventually, the dogs learned to associate the sound of the bell with the presentation of the food and they would begin to salivate at the sound of the bell alone.
As mentioned earlier, an unconditioned stimulus is a stimulus that leads to an automatic response. So in Pavlov’s experiment, the food is the unconditioned stimulus and the dogs salivating for food is the unconditioned response.
Salivation occurred automatically and without the dogs” conscious effort when they smelled the food. The food was the unconditioned stimulus because it prompted a reflexive response and required no learning.
Little Albert (Watson & Raynor) Experiment
Behaviorist John B. Watson and graduate student Rosalie Rayner were the first psychologists to apply the principles of classical conditioning to human behavior by showing that emotional reactions could be classically conditioned in people.
Their experiment, known as the case of Little Albert, involved conditioning a phobia in an emotionally stable child.
When Albert was just 9 months old, Watson and Rayner exposed him to a series of stimuli including a white rat, burning newspapers, a monkey, and masks.
At first, Alert showed no fear of any of the stimuli.
However, the next time Albert was exposed to each stimuli, Watson would make a loud noise by hitting a metal pipe with a hammer.
After repeatedly pairing one of the stimuli, the white rat for example, with the loud noise, Albert would begin to expect a loud noise whenever he saw the white rate.
Eventually, Albert would begin to cry from simply seeing the rat. In other words, he was classically conditioned to experience fear at the sight of the rat.
The loud noise is the unconditioned stimulus in this example. When Watson would make the loud noise, Albert would cry.
Watson used this unconditioned response to condition Little Albert to fear distinctive stimuli that normally would not be feared by a child (ie: the white rat or the monkey).
Advertising
Classical conditioning is an effective tool in marketing and advertising. The idea is to create an advertisement that has positive features such as catchy music, bright colors, cute babies, attractive models, or funny spokespeople so that the ad will create an enjoyable response in the person exposed to it.
Thus, when the consumer sees the particular product online or in the store, he/she should experience this positive feeling and be more likely to purchase the product.
In this example, the advertisement serves as the unconditioned stimulus (US), and the enjoyment from watching the advertisement serves as the unconditioned response (UR).
Because the product being advertised is mentioned in the advertisement, it becomes associated with the US, and then becomes the conditioned stimulus (CS).
One example of this kind of conditioning is seen in the “Drake Sprite: The Spark Commercial,” a Sprite commercial starring rapper Drake. In this one minute advertisement, Drake is not able to rap very well and is feeling uninspired.
But, when he takes a sip of a Sprite, he is reinvigorated and instantly able to rap again. The unconditioned stimulus is Drake and the conditioned stimulus is drinking Sprite. The conditioned response is thinking that by drinking Sprite you will be refreshed and inspired just like Drake.
Smoking
According to the theories of classical conditioning, drug-related stimuli can become associated with the rewarding aspects of using.
For example, drug paraphernalia, such as cigarette packets, bongs, and pipes, and environments where drug use occurs can invoke craving and drug-seeking responses in users. For smokers, just the sight of a cigarette packet can invoke the feeling of wanting to smoke.
This paraphernalia are considered the conditioned stimuli and nicotine would be the unconditioned stimulus .
Cue reactivity is the theory that people associate situations (e.g. meeting with friends)/ places (e.g. pub) with the rewarding effects of nicotine, and these cues can trigger a feeling of craving.
These factors become smoking-related cues. Prolonged use of nicotine creates association between these factors and smoking. This is based on classical conditioning. Nicotine is the unconditioned stimulus (UCS) and the pleasure caused by the sudden increase in dopamine levels is the unconditioned response (UCR).
In a 2012 study on associative learning in smokers, Marianne Littel found that smokers show pronounced associative learning during a higher-order conditioning experiment in response to neutral cues that are paired with smoking-related stimuli.
In other words, she conditioned smokers to associate smoking with an object that had previously been entirely neutral.
Learning Check
- Which of the following is an example of a conditioned response?
- Feeling hungry when smelling food.
- Jumping at the sound of a loud noise.
- Sweating when the temperature is high.
- Feeling anxious when hearing a dentist’s drill, after several dental visits.
2. Which of the following can be an unconditioned stimulus in classical conditioning?
- A bell that rings every time a dog gets food.
- A light that turns on every time a rat receives a shock.
- A piece of food that causes a dog to salivate.
- A tone that sounds every time a pigeon receives food.
3. What does an unconditioned response trigger automatically?
- A neutral response.
- A learned response.
- A reflexive or biological response.
- An unlearned response.
4. Which of the following is a conditioned stimulus?
- A sudden loud noise startles a person.
- The smell of food makes someone feel hungry.
- A bell sound that, after being associated with food, makes a dog salivate.
- The sensation of pain when touching something hot.
5. What is the difference between an unconditioned stimulus and a conditioned stimulus?
Absolutely, here are more multiple-choice questions in a similar format:
- Which of the following is an example of a conditioned response?
A) Feeling hungry when smelling food. B) Jumping at the sound of a loud noise. C) Sweating when the temperature is high. D) Feeling anxious when hearing a dentist’s drill, after several dental visits.
- Which of the following can serve as an unconditioned stimulus in classical conditioning?
A) A bell that rings every time a dog gets food. B) A light that turns on every time a rat receives a shock. C) A piece of food that causes a dog to salivate. D) A tone that sounds every time a pigeon receives food.
- What does an unconditioned response trigger automatically?
A) A neutral response. B) A learned response. C) A reflexive or biological response. D) An unlearned response.
- Which of the following is a conditioned stimulus?
A) A sudden loud noise that startles a person. B) The smell of food that makes someone feel hungry. C) A bell sound that, after being associated with food, makes a dog salivate. D) The sensation of pain when touching something hot.
5. What is the difference between an unconditioned stimulus and a conditioned stimulus?
- An unconditioned stimulus requires learning, while a conditioned stimulus does not.
- An unconditioned stimulus is always food, while a conditioned stimulus is always a bell.
- An unconditioned stimulus naturally triggers a response, while a conditioned stimulus triggers a response after being associated with the unconditioned stimulus.
- There is no difference between an unconditioned stimulus and a conditioned stimulus.
Answers:
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The correct answer is D) Feeling anxious when hearing a dentist’s drill, after several dental visits. This anxiety is a conditioned response, as it is learned through repeated association of the drill sound with the uncomfortable experience of dental work.
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The correct answer is C) A piece of food that causes a dog to salivate. The piece of food is an unconditioned stimulus because it naturally, without prior learning, causes the dog to salivate.
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The correct answer is C) A reflexive or biological response. An unconditioned response is automatic and does not require learning or conditioning.
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The correct answer is C) A bell sound that, after being associated with food, makes a dog salivate. The bell sound has become a conditioned stimulus because it causes salivation after repeated association with the unconditioned stimulus (food).
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The correct answer is C) An unconditioned stimulus naturally triggers a response, while a conditioned stimulus triggers a response after being associated with the unconditioned stimulus. The unconditioned stimulus is inherent and naturally induces a response, while the conditioned stimulus only causes a response after learning or conditioning.
References
Clark, R. E. (2004). The classical origins of Pavlov’s conditioning. Integrative Physiological & Behavioral Science, 39 (4), 279-294.
Gorn, G. J. (1982). The effects of music in advertising on choice behavior: A classical conditioning approach. Journal of marketing, 46 (1), 94-101.
Harris, B. (1979). Whatever happened to little Albert?. American psychologist, 34 (2), 151.
Hawkins, D., Best, R., & Coney, K. (1998.) Consumer Behavior: Building Marketing Strategy (7th ed.). Boston, MA: McGraw-Hill.
Littel, M., Franken, I.H. Electrophysiological correlates of associative learning in smokers: a higher-order conditioning experiment. BMC Neurosci 13, 8 (2012).
Pavlov, I. P. (1897/1902). The work of the digestive glands. London: Griffin.
Pavlov, I. P. (1928). Lectures on conditioned reflexes. (Translated by W.H. Gantt) London: Allen and Unwin.
Pavlov, I. P. (1927). Conditioned Reflexes: An Investigation of the Physiological Activity of the Cerebral Cortex . Translated and edited by Anrep, GV (Oxford University Press, London, 1927).
Pavlov, I. P. (1955). Selected works. Moscow: Foreign Languages Publishing House.
Rehman I, Mahabadi N, Rehman CI. Classical Conditioning . In: StatPearls[Internet]. Treasure Island (FL): StatPearls Publishing; 2020 Jan. Available from: https://www.ncbi.nlm.nih.gov/books/NBK470326/
Vladtv, YouTube(2010, November). Drake Sprite: The Spark Commercial. Retrieved December 15, 2019, from https://www.youtube.com/watch?v=mh6vHoyBs58 .
Watson, J.B. (1913). Psychology as the behaviorist Views It. Psychological Review, 20, 158-177.
Watson, J. B., & Rayner, R. (1920). Conditioned emotional reactions. Journal of experimental psychology, 3 (1), 1.
Unconditioned stimulus vs. conditioned stimulus?
An unconditioned stimulus naturally and automatically triggers a response without any learning. For example, food causes salivation in dogs.
On the other hand, a conditioned stimulus is a previously neutral stimulus that, after being repeatedly associated with the unconditioned stimulus, eventually triggers a similar response.
For example, if a bell is rung every time food is presented, the bell becomes a conditioned stimulus as it can cause salivation even without the food.
If you pair a neutral stimulus (NS) with an unconditioned stimulus (US) that already triggers an unconditioned response (UR), that neutral stimulus will become a conditioned stimulus (CS), triggering a conditioned response (CR) similar to the original unconditioned response.
What is the difference between the unconditioned stimulus and the discriminative stimulus?
A discriminative stimulus refers to something, like a person or an event, that precedes a behavioral response. So, the discriminative stimulus comes first and then, the behavior follows as a direct result of this stimulus.
A discriminative stimulus is created when the response is reinforced, whereas an unconditioned stimulus is a stimulus that leads to an automatic response without any reinforcement or prior learning.
What is the difference between the unconditioned stimulus and the neutral stimulus?
A neutral stimulus is a stimulus that does not produce an automatic response at first whereas an unconditioned stimulus is quite the opposite – an unconditioned stimulus is a stimulus that does produce an automatic response.
In classical conditioning, the neutral stimulus will become conditioned when consistently paired with an unconditioned stimulus.
When it is initially presented, the neutral stimulus does not affect behavior. However, as it is repeatedly paired with an unconditioned stimulus, it will begin to cause the same response as the unconditioned stimulus.
What is the difference between the unconditioned stimulus and the unconditioned response?
An unconditioned stimulus is a stimulus that leads to an automatic response. An unconditioned response is that automatic response to the stimulus. The dogs salivating for food is the unconditioned response in Pavlov’s experiment.
How does an unconditioned stimulus become a conditioned stimulus?
An unconditioned stimulus becomes a conditioned stimulus after the neutral stimulus becomes associated with the unconditioned stimulus and the subject has learned to associate the stimulus with a given outcome.
Is alcohol an unconditioned stimulus?
Yes, alcohol is an unconditioned stimulus in classical conditioning. The effects of alcohol (intoxication and inhibition) do not have to be learned. They are universal, consistent, and automatic.
