Chapter 5 - Classical Conditioning: Underlying Process and Practical Applications

Stimulus-Substitution Theory

Coined by Pavlov, where the CS acts as a substitute for the US

-But if the CS acts as a substitute for the US, then the CR should always be the same or at least highly similar to the UR, but this is not the case

-Suggests that the purpose of the CR, rather than being a version of the UR, is to “ready” the organism for the occurrence of the US

Pavlov’s Neurological Connection to Conditioning

Believed that classical conditioning was a way to indirectly study neurological processes

-The US presentation activates an area in the cerebral cortex, which will then activate another area resulting in the response

Example: Food (US) → Activates food centre in CC → Activates salivation centre in CC → Salivation (UR)

-NS would also function in a similar way

Light (NS) → activates light centre → activates food center → activates salivation center

Pavlov’s neurological process idea was incorrect as it oversimplifies the process

Predatory-Response Theory

Proposes that the purpose of the CR is to prepare the organism for the presentation of the US

-Unlike the stimulus-substitution theory, it accounts for a situation where the CR/UR are different, such as when the UR and CR seem to be opposites

Heroin Example

A person who injects themselves in a particular environment (Heroin Cue)

Heroin Cue (NS); Heroin (US) → BP decrease (UR)

-But after conditioning, the heroin cue produces a CR that is the exact opposite as the UR

Heroin Cue (CS) → BP Increase (CR)

Compensatory-Response Model

A CS that has been repeatedly associated with the primary response (a-process) to a US will eventually come to elicit a compensatory response (b-process)

Compensatory Response and Heroin Example

During conditioning, the decrease in BP (an a process) acts as both the UR and as the US for the b-process (an increase in BP)

Heroin (US) → BP decrease (US/UR) → BP increase (UR)

So the actual conditioning in each trial is;

Heroin Cue (NS); BP decrease (US) → BP increases (UR)

Heroin Cue (CS) → BP increases (CR)

Compensatory Model and Substance Abuse

Explains how drugs can have a relaxing effect (b-process) which will then elicit agitation (perceived as withdrawal) in its absence

-Symptoms of withdrawal are stronger with drugs since they elicit compensatory response experienced as cravings

-For opiates, a single trial can result in significant compensatory conditioning

Compensatory Model and Drug Tolerance

Drinking and taking drugs in an unfamiliar environment results in much lower tolerance

-Can play a role in overdoses

Rescorla-Wagner Theory

Proposes that a given US can support only so much conditioning and that this amount of conditioning must be distributed among the various CSs that are present

-Assumes that the stronger stimuli (USs and CSs) support more conditioning than weaker stimuli

Helps explain the effect of each conditioning trial on the strength (associative value) of the CS in its relationship to the US

Diagraming Changes in Associative Value

V = Associative value of CS, at the start of conditioning V = 0

Max = Maximum associative value that can be supported by the US once conditioning is complete

Example:

Tone (V = 0); Food (max = 10) → Salivation

Tone (V = 10) → Salivation

Now with a compound stimulus…

[Tone + Light] (V = 0); Food (max = 10) → Salivation

[Tone + Light] (V = 10) → Salivation

Over-expectation Effect

Decrease in the conditioned response that occurs when two separately conditioned CSs are combined into a compound stimulus for further pairings with the US

-Each CS in the compound will lose some of its associative value

Example: Tone and Light both have a V = 10, but the US max is 10

-When we combine Tone and Light into a compound stimulus ([Tone + Light]) they will individually have a decrease in associative value because the total associative value cannot exceed 10

-So their associative values drop from 10 to 5, but still add up to the max value (5+5 = 10)

Phobias

Irrational fear reactions that often represent a process of overgeneralization

-Classical conditioning develops our fears and anxiety, which may become exagerrated;’ we become afraid of events that are not actually dangerous

Little Albert

Conditioned, with loud noise as the US and a rat as the NS, to have a fear response to rats but also to objects similar (rabbit, fur coat, dogs, etc)

Criticisms of the Experiment:

-No control for pseudo conditioning

-Required multiple conditioning trials, whereas real-life phobias require just one pairing of the NS/US to become a CS

-Albert’s fear was significantly weakened by sucking his thumb, but it should’ve caused a greater response

-Many behaviours of Albert (ie, his fear) were appropriate for his age (being afraid of unexpected events like the loud noise)

Additional Factors in Phobic Conditioning

1. Doesn’t have to stem from classical conditioning

• Many of those with phobias cannot recall particular event before development of their phobias

-Therefore, other factors may impact phobias such as:

1. Observational Learning

2. Temperament

3. Preparedness

4. Incubation

5. US revaluation

6. Selective Sensitization

Observational Learning

Phobias may be acquired when observing fearful reactions in others

-Tendency to acquire conditioned fear responses may be inherited

Example:

Snake (NS); Viewing fear in others (US) → Fear in yourself (UR)

Snake (CS) → Fear in yourself (CR)

Temperament

Individual’s level of emotional reactivity, including how quickly/strongly one reacts to external stimulation

-largely inherited, easily affects how easily a conditioned response is acquired

-People with certain temperaments may be more susceptible than others

-Focuses on how easily a certain person acquires a phobia

Preparedness

Innate tendency to learn certain behaviours or make certain types of associations more easily than others

-In general, people may have a certain inherited tendency to make aversive associations to certain events

Experiment: Participants developed signs of conditioned anxiety when exposed to subliminal stimuli that were paired with shocks

-Conditioned reaction occurred when the images were fear-relevant stimuli (snakes) rather than fear irrelevant

-Focuses on how easily people in general can acquire a certain phobia

Incubation

Strengthening of an already established conditioned fear response to an aversive CS as a result of repeated brief exposures to the CS by itself

Example: Child previously bitten by a dog always runs when a dog is near, but may have a worsening in their fear of dogs

-His moderate fear may evolve into severe fear

US Revaluation

Exposure to a US at a different intensity than during conditioning; can alter the strength of the response to a previously conditioned CS

Example:

-Skateboard; minor injury → Slight Anxiety

-Car; Severe injury → Strong Anxiety

Skateboarding → Strong anxiety

-US revaluation can occur through observational learning

-Can also occur through verbally transmitted information

• Individuals exposed to a traumatic event and are then given a psychological debriefing can develop PTSD as it may enhance effects of trauma

Selective Sensitization

Increase in one’s reactivity to a potentially fearful stimulus, following exposure to an unrelated stressful event

Ex; Those with agoraphobia (fear of public places) report that their disorders occurred when they were emotionally upset or experienced physical illness

Treatment of Phobias

Phobias can be treated through Systematic Desensitization and Flooding Therapies

Counterconditioning

Procedure whereby a CS that elicits one type of response is associated with an event that elicits an incompatible response

Reciprocal Inhibition

Process whereby the occurrence of a response can be inhibited by the simultaneous occurrence of an incompatible response

-Wolpe believed reciprocal inhibition is the underlying process in counterconditioning

Systematic Desensitization

Behaviour treatment for phobias that involves pairing relaxation with a succession of stimuli that elicit increasing levels of fear

Imaginal Desensitization

Involves three steps;

1. Training in Relaxation - Deep muscle relaxation is commonly used but meditation and hypnosis can also be used

2. Creation of a hierarchy of imaginary scenes that elicit progressively intense level of fear

• About 10-15 scenes are usually sufficient, starting with a scene that elicits a minor degree of fear and finishing with a scene that elicits a lot of fear/anxiety

3. Pairing of each item in the hierarchy with relaxation, starting with the least fearful scene

• Scene visualized for 10-30 seconds, then engage in a short period of relaxation, repeated until the scene no longer elicits anxiety

Disadvantage: Requires clients to visualize the feared event clearly, but many people cannot

In-Vivo Desensitiztion

Performing imaginal desensitization with real stimuli

Advantage: Certainty that the treatment will generalize to real life stimuli unlike imaginal desensitization, helpful for those who cannot clearly visualizer stimuli

-Most effective with patients that have few phobias that are specific to nature (doesn’t work well with those that have social phobias)

Mechanism behind Systematic Desensitization

Wolpe assumed systematic desensitization is a counter-conditioning procedure, but others (Eysenck) claim systematic desensitization is simply a matter of extinction

Evidence Against Counterconditioning - Relaxation is not always necessary for the treatment to be effective

Evidence for Counterconditioning - Relaxation seems to facilitate treatment when the phobia is severe

-Therefore, both aspects may play a role

Flooding Therapy

Behavioural treatment for phobias that involves prolonged exposure to a feared stimulus, thereby providing maximal opportunity for the conditioned fear response to be extinguished

-More based on the principle of extinction than counterconditioning

-Two types; Imaginal flooding and In-Vivo flooding

Imaginal Flooding

Client first visualizes the scenario in a therapist’s office, then practices visualizing it at home

-level of fear intially increases but will eventually decrease

-After fear response to one scenario of the phobia is extinguished, other scenarios can be similarily extinguished

-After extinction has occurred with several scenarios, person experiences less fear when encountering the feared event

In-vivo Flooding

Prolonged exposure to the actual feared event

-Can be highly aversive/can’t be used with some fears (ie, house fires) that are impossible to replicate in a therapy setting

-Clients with other psychiatric disorders may have an exacerbation of fears

-Flooding is a riskier procedure than systematic desensitization

Hybrid Approach to Phobia Treatment

Exposure therapies combine aspects of systematic desensitization and flooding along with additional processes like observational learning

-Treatment of choice for phobias

Ex; Ost’s single session procedure combines the gradualness of systematic desensitization (slowly approaching the feared stimulus), the prolonged exposure of flooding (standing near it until anxiety goes away) and uses participant modeling in which the therapist demonstrates how to interact with the feared object

Aversion Therapy

Treatment procedure that reduces that attractiveness of a desired event by associating it with an aversive stimulus

-Taste-aversion conditioning - client given a drug that induces nausea then drinks alcohol; more effective than shock-based treatments

Can be used to treat sex offenders by pairing pornographic material with nausea drugs

Covert Sensitization

Aversion therapy carried out with the use of imaginal stimuli, rather than real stimuli

Ex; visualize smoking cigarettes that have been smeared with feces

Less effective than aversion therapy which utilizes exposure to the real stimulus

Rapid Smoking

Highly effective procedure to reduce cigarette consumption where a high rate of smoking occurs until person cannot continue

-Very stressful, results in extreme increase in heartrate

Medical Application of Classical Conditioning

Bovberg; found that women who received chemo in a hospital displayed evidence of immunosuppression when they returned to the hospital

-Hospital became associated with the immunosuppressive effective of the chemotherapy and was now a CS for the immunosuppression (CR)

-Other studies indicate classical conditioning can be used to strengthen immune system functioning

Pairing sherbet with epinephrine (tends to increase activity of natural killer cells) resulted in sherbet eliciting an increase in natural killer cell activity

Placebo Effect

Placebo effect can be seen as the result of pairing the appearance of the drug (NS) with the active ingredients of the drug (US)

Example: White pill (NS): Acetylsalicylic Acid (US) → Headache removal (UR)

White pill (CS) → Headache removal (CR)

-Repeated presentation of the placebo reduces its effectiveness, suggests extinction is taking place