How Classical Conditioning Can Cause Chronic Pain

Classical conditioning is a type of learning that can result in learned associations. One of those learned associations can be pain. Classical conditioning can create pain but there are strategies that can be used to loosen the associations learned by classical conditioning.

What is Classical Conditioning?

Classical conditioning is a type of learning that comes from forming an association between two stimuli, resulting in a learned response. There are three main phases of this process.

Phase 1: Before Conditioning

Before conditioning can happen there needs to be a naturally occurring stimulus that will automatically elicit a response. An example of this is a person salivating to the smell of food.

The naturally occurring stimulus is referred to as the unconditioned stimulus (UCS) and the response it results in is an unconditioned response (UCR). During this phase, there is also a neutral stimulus (NS) that produces no effect.

Phase 2: Acquisition

During conditioning, the previously neutral (NS) is repeatedly paired with the unconditioned stimulus (UCS). This creates an association between the previously neutral stimulus and the unconditioned stimulus. The neutral stimulus is now known as the conditioned stimulus (CS), and the subject has been conditioned to respond to this stimulus. Essentially, a conditioned stimulus is a previously neutral stimulus that, after becoming associated with the unconditioned stimulus, eventually comes to trigger a conditioned response.

Phase 3: After Conditioning

Now that the association has been made between the unconditioned stimulus (UCS) and the conditioned stimulus (CS), presenting the conditioned stimulus alone will evoke a response, even without the unconditioned stimulus (UCS). This response is called the conditioned response (CR). The conditioned response is the learned response to the previously neutral stimulus.

Pavlov’s Dogs

Russian physiologist Ivan Pavlov was the one who discovered classical conditioning. The experiments involving dogs were his most well-known. In his experiments, he noticed that the dogs would salivate (UCR) to the smell of food (UCS). He started to pair the food with a tone (NS). Eventually, the dogs would salivate (CR) to the tone (CS) even when it was not paired with the food.

Other Terms Associated with Classical Conditioning

Extinction

When a conditioned stimulus is no longer paired with an unconditioned stimulus, the occurrences of a conditioned response may decrease or disappear in a process called extinction.

Spontaneous Recovery

There are times when a learned response can suddenly reemerge after a period of extinction in a process called spontaneous recovery. However, if the conditioned stimulus and unconditioned stimulus are no longer associated extinction will return very soon after a spontaneous recovery.

Generalization

After a response has been conditioned, stimulus generalization may occur. Stimulus generalization occurs when a conditioned stimulus evokes similar responses. For example, a person with a conditioned fear of a white rat may experience a fear of similar objects, such as other white fuzzy objects.

Discrimination

Discrimination is another thing that may occur with classical conditioning. It is the ability to differentiate between a conditioned stimulus (CS) and other similar stimuli.

Fear Response

Phobias and fears can form through classical conditioning when a neutral stimulus is paired with a frightening stimulus.

Taste Aversions

Taste aversions can occur from the pairing of the conditioned stimulus (taste of the food) and an unconditioned stimulus (something distasteful or disgusting like nausea).

How Classical Conditioning Can Cause Chronic Pain

Classical conditioning can cause chronic pain when there’s a learned association involving pain to a neutral sensation in the body or common body position.

How Pain Can Be a Conditioned Response

Unfortunately, pain can be a conditioned response. Your brain may be making an association between neutral stimuli and protective mechanisms like pain. For example, if you have an injury to a muscle in your glutes that causes pain (UCR) when sitting (NS), your brain may start to associate pain with sitting. After your injury has healed, you may still feel pain (CR) while sitting (CS) because the pain has become a conditioned response to the conditioned stimulus of sitting.

Conditioned responses that involve things like pain and nausea are strategies that your brain uses to keep you safe. For example, if you eat a poisonous mushroom and fall ill, your brain may learn to trigger nausea when you look at the same or similar mushrooms, even if they are not poisonous.  The symptom of nausea is not from the mushroom but the brain’s fear of the mushroom and your brain’s prediction that you will get sick. Whenever you respond to the symptom (nausea, pain, etc.) with fear, annoyance, preoccupation, or frustration, you unintentionally reinforce the association.

With Chronic pain, it is more complicated. Classical conditioning is part of a complex picture of chronic pain. Some aspects reinforce the pain to a stronger and weaker extent. For example, a pain association can be connected to trauma.

How Can Classical Conditioning Be Used to Reduce Chronic Pain

In the same way, when pain becomes a conditioned response there are patterns that reinforce the association. When we remove or change the patterns that reinforce the association, we can weaken the association of the conditioned stimulus to the pain (CR), eventually achieving extinction.

Brain Retraining to Unlearn Pain

The reason why pain associations are often so strong is because the brain is interpreting threat, harm, and danger. Associations connected to survival mechanisms are harder to change than ones that aren’t, because your brain is focused on survival. If we can retrain our brain so it no longer interprets the conditioned stimulus as harmful or dangerous, the association can weaken to a point where the brain no longer holds it as tightly because it is no longer associated with survival.

Correcting Associations

When an association involves movements, the key to breaking free from conditioned responses is not to avoid movement; it is to reintroduce it gradually in a way that feels authentically safe. Gentle, mindful movement paired with psychoeducation and anxiety regulation has the ability to retrain the brain’s pain pathways, shifting the body from a state of fear to one of confidence and ease.

What Therapies Can We Use to Correct Pain Associations Learned with Classical Conditioning?

Pain Reprocessing Therapy

With pain recovery therapies like pain reprocessing therapy, the goal is to interrupt the pain-fear cycle by changing your response to symptoms. When you change your response, the association will weaken and eventually disappear.

Have you ever hesitated before moving because you expected pain? You’re not alone. When movement has caused pain in the past, the brain starts anticipating pain before it even happens.

To generate pain, the brain integrates sensory input and internal predictions. Sensory input refers to bottom-up processing – from the nerve endings in our body to the brain. Internal predictions refer to top-down processing. This is what we expect to feel before performing an activity. It is our brain’s prediction about what it feels like to move in a certain way because of a past experience. And the pain produced is the combination of the two.

If someone feels pain every time they bend down, the fear of bending alone will amplify their pain experience beyond what makes sense for the signals produced by the nerve ending in their back.

This is called a conditioned response, and over time, it will reinforce the pain-fear cycle, causing even safe, neutral movement to feel threatening.

Perhaps you once hurt your knee while jogging. Now, you might tense up every time you try running again, even if your knee has healed. Your brain, trying to protect you, has learned that this movement equals danger, so it sends out pain signals as a warning even when no harm is present.

This protective response is common, but it is not always accurate. The good news? Just as your brain learned to fear movement, it can unlearn fear and learn a sense of safety.

Cognitive Behaviour Therapy

Cognitive Behaviour Therapy (CBT) can be used to reframe reinforcing thoughts, desensitize fears, and build a sense of safety through safety messages.

EMDR

There are situations when pain associations are created during traumatic or extremely stressful experiences. Often, when the trauma is processed the association can be released, but it can be stuck with the trauma. EMDR and Flash can help process the trauma connected to the pain association which can release the stuck association.

Conclusion

Classical conditioning can both cause chronic pain and be used to unlearn conditioned responses.