Cl Conditioning and Exposure Flashcards
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Abstract
• Exposure therapy is an effective approach for treating anxiety disorders
- But many fail to benefit or see a return in fear after treatment
• Research suggests that anxious individuals show deficits in the mechanisms believed to underlie exposure therapy eg inhibitory learning
• Targeting these processes may help improve the efficacy of exposure-based
• Although evidence supports inhibitory learning model of extinction, there has been little discussion of how to implement this model in clinical practise
• The primary aim of the paper is to provide examples to clinicians for how to apply this model to optimise exposure therapy with anxious patients, in ways that distinguish it from a ‘fear habituation’ approach and ‘belief disconfirmation’ approach within standard cognitive-behaviour therapy
• Case studies illustrate methods of applying these techniques with a variety of anxiety disorders
- Including OCD, PTSD, social phobia, specific phobia, and panic disorder
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Exposure optimisation strategies
Exposure optimisation strategies include:
- Expectancy violation
- Deepened extinction
- Occasional reinforced extinction
- Removal of safety signals
- Variability
- Retrieval cues
- Multiple contexts
- Affect labelling
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Inhibitory learning model of extinction
Part 1
• Fear conditioning considered a valid model for many anxiety disorders
• One powerful way to reduce conditional fear re-actions is through extinction, in which the CS is repeatedly presented in the absence of the associated aversive event (the US).
- Led to Wolpe systematic desensitisation
- Inhibitory learning is essential
- Habituation also involved
• Within a Pavlovian conditioning approach, the inhibitory learning models mean that the original CS-US association learned during fear conditioning is not erased during extinction, but rather is left intact as new,
- secondary inhibitory learning about the CS-US develops specifically, that the CS no longer predicts the US
- amygdala ap-pears to be inhibited by cortical influences identified as occurring from the medial prefrontal cortex as a result of extinction learning
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Inhibitory learning model of extinction
Part 2
• First, conditional fear shows spontaneous recovery meaning that the strength of the CR increases in proportion to the amount of time since the end of extinction
- Thus, an individual whose fear of air travel significantly reduces by the end of exposure treatment is vulnerable to a return in fear of flying in the absence of repeated air travel following treatment completion.
• Second, renewal of conditional fear occurs if the surrounding context is changed between extinction and retest
- In other words, fear extinction appears to be specific to the context in which extinction occurs.
• Third, reinstatement of conditional fear occurs if unsignaled (or unpaired) US presentations occur in between extinction and retest
- Adverse events following exposure therapy may lead to a return of fear of the previously feared stimulus if it is encountered in an anxiety inducing context.
• Fourth, rapid reacquisition of the CR is seen if the CS-US pairings are repeated following extinction
- The clinical application is that fears that have subsided may be easily and rapidly reacquired with re-traumatization, as may occur in combat situations or other dangerous environments.
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Deficits in inhibition and anxiety disorders
- A substantial number of individuals fail to achieve clinically significant symptom relief from exposure-based therapies
- In other words, anxious individuals show deficits in the mechanisms that are believed to be central to extinction learning such deficits may not only contribute to poor response to exposure therapy but may also contribute to the development of excessive fear and anxiety in the first place
- An exposure model that takes elements of inhibitory learning into account has the potential to offset the negative effects of spontaneous recovery, renewal, reinstatement and reacquisition.
- The goal is to enhance inhibitory learning (and possibly underlying neural inhibitory regulation) during exposure therapy and to enhance its retrieval following completion of exposure therapy.
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Inhibitory learning versus habituation and behavioral testing approaches to exposure
• Notably, the strategies listed below are not always consistent with an habituation-based model of exposure therapy, which rests upon fear reduction during exposure trials as a critical index of therapeutic change
• Habituation models posit that fear reduction during an exposure trial is a necessary precursor to subsequent, longer lasting cognitive changes in the perceived harm associated with the phobic stimulus.
• The strategies that derive from inhibitory learning models do not emphasize fear reduction per se during exposure trials and instead sometimes use strategies designed to maintain elevated fear throughout exposure trials.
• Fear expressed at follow-up (as the critical index of the strength and consolidation of extinction learning) appears to be more likely to be influenced by factors such as passage of time, context shifts, adverse events or relearning
- Instead of Fear expressed at follow-up (as the critical index of the strength and consolidation of extinction learning) appears to be more likely to be influenced by factors such as passage of time, context shifts, adverse events or relearning
• Some aspects of the inhibitory learning model overlap with cognitive models that emphasize behavioral testing to disconfirm beliefs and assumptions
• However, the inhibitory learning model is not restricted to behavioral testing as a strategy for generating inhibitory associations, nor is it limited to testing of explicitly stated cognitions.
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Therapeutic strategies for enhancing inhibitory learning andits retrieval
- Expectancy violation
- Deepend extinction
- Occasional reinforcement extinction
- Removal of safety signals
- Variability
- Retrieval cues
- Multiple contexts
- Reconsolidation
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Expectancy violation
The first strategy is to design expo-sures that maximally violate expectancies regarding the frequency or intensity of aversive outcomes
- This strategy derives from thepremise that the mismatch between expectancy and outcome is critical for new learning
- and for thedevelopment of inhibitory expectancies that will compete withexcitatory expectancies.
- LT benefits
- Habituation approaches to exposure posit that exposure to agiven item continues for long enough for fear to decline and for thenumber of occasions necessary for fear to be significantly lessened
- In an inhibitory learning model, exposure continues for the lengthof time predetermined as an adequate test of a stated expectancy,and continues for the number of occasions necessary for expec-tancies to be lessened
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Deepened extinction
either multiple fearCSs arefirst extinguished separately before being combined duringextinction, or a previously extinguished cue is paired with a novelCS
- Wherever possible,we combine multiple cues (internal and/or external) duringexposure therapy, after initially conducting some exposure to eachcue in isolation.
- Eg Interoceptive exposure to feared bodily sensations(such as caffeine consumption), and in vivo exposure to feared external agoraphobic situations (such as shopping in a crowded mall) followed by inclusion of interoceptive exposure during in vivo exposure (drinking coffee whilst in the shopping mall) is anexample of deepened extinction for panic disorder and agora-phobia
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Occasional reinforcement extinction
Occasional reinforced extinction involves occa-sional CS-US pairings during extinction training
- The benefits may derive from an expectancy viola-tion effect in which the participant is less likely to expect thenextCS presentation to predict the US because CS-US pairings have beenassociated with both further CS-US pairingsandCS-no US pairings
- Or perhaps may increase salience of CS whixh in turn contributes to new learning about CS
- We routinely conduct such reinforcedexposure and even encourage clients to seek the opportunity foroccasional negative outcomes
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Removal of safety signals
Common safetysignals and behaviors for clients with anxiety are the presence ofanother person, therapists, cell phones, medications, or food ordrink.
- This effect is believed to derive in part frominterference with the development of inhibitory associations.
- Inphobic samples, the availability and use of safety signals and be-haviors has been shown to be detrimental to exposure therapy whereas instructions to refrain from usingsafety behaviors improved outcomes
- This has also been contradicted by research though
- However, the ability ofsafety behaviors to mitigate extinction learning likely variesdepending on the ratio of inhibition and excitation in a given trial.
- The impact ofinhibitory stimuli on extinction learning will therefore depend onthe number and strength of inhibitory stimuli versus the numberand strength of excitatory stimuli
- Gradual phasing is recommended only in order to reducetreatment attrition.
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Variability
- Afifth strategy involves stimulus variabilitythroughout exposure since varying the to-be-learned task en-hances retention of learned non-emotional material
- Variability isbelieved to enhance the storage capacity of newly learned infor-mation
- Exposure is con-ducted to items from the hierarchy in random order, without regardto fear levels or fear reduction, although usually beginning with theleast anxiety producing item to avoid treatment refusal.
- Thus, variation in fear levelthroughout exposure will offset context renewal once exposuretherapy is completed.
- We routinely encourage vari-ability in fear response during exposures, such as by conducting“unpredictable”lengths of exposures to phobic stimuli
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Retieval cues
One option for enhancing retrieval ofextinction learning and offsetting context renewal is to includeretrieval cues (of the CS-no US association) during extinctiontraining to be used in other contexts once extinction is over
- One risk of retrieval cues, however, is that they may acquire aninhibitory value and become a safety signal
- For example, a therapist’soffice where pre-vious exposure sessions were conducted can act as a retrieval cuefor a new exposure, whereas benzodiazepines (e.g., in the case ofpanic disorder) could act as a safety signal.
- However, these strate-gies are best employed as a relapse prevention skill.
- Using retrievalcues early in therapy, while the focus is on acquisition of extinctionlearning, may negatively impact progress as these cues can reducethe expectancy of the aversive event
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Multiple Contexts
Context renewal involves the return offear to a phobic stimulus when it is encountered in a context (in-ternal or external) that differs from the context in which exposuretherapy was conducted
- The clinical translation involves conductinginteroceptive, imaginal, and in vivo exposures in multiple differentcontexts, such as when alone, in unfamiliar places, or at varyingtimes of day or varying days of the week.
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Reconsolidation
A recent (re-)discovery is that retrieving already stored memories induces a process of reconsolidation, since the memory is written into long term memory again, requiring de novo neurochemical pro-cesses.
- Thus, it may be possible to change memories during thereconsolidation time frame upon retrieval.
- Thus, extinction during a reconsolidation win-dow may weaken the fear memory itself.
