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Lecture 1: The acquisition of phobias

C83MLP Mechanisms of Learning and Psychopathology. Lecture 1: The acquisition of phobias. Dr. Mark Haselgrove. Content of Lecture. (1) Introduction and Overview of module. (2) Reminder of Conditioning terminology/procedures. (3) The acquisition of Phobias. What is a phobia?.

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Lecture 1: The acquisition of phobias

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  1. C83MLP Mechanisms of Learning and Psychopathology Lecture 1: The acquisition of phobias Dr. Mark Haselgrove

  2. Content of Lecture (1) Introduction and Overview of module (2) Reminder of Conditioning terminology/procedures (3) The acquisition of Phobias What is a phobia? How do we treat them What causes a phobia? - Traditional Conditioning account - Rachman’s challenge - Contemporary learning theory view Retrospective studies of Phobia acquisition

  3. C83MLP Introduction and Overview

  4. C83MLP Introduction and Overview Autumn Term

  5. C83MLP Introduction and Overview Spring Term HAND IN DISSERTATIONS BY Tuesday 7th MAY 2013

  6. Brilliant reading Out Now! Chapters relevant to lectures on: Phobias ANV Depressive realism Also chapters on: Schizophrenia Drug addiction Relapse Potential use for C83CLI??

  7. Conditioning and Learning A reminder of some terminology and facts… Unconditioned Stimulus (US): Biologically significant event (e.g. food, pain) Unconditioned Response (UR): The response evoked by the US Conditioned stimulus (CS): Previously neutral stimulus (e.g. tone) that acquires a response by being paired with a US Conditioned response (CR): The response evoked by the CS Clicker → Shock Jumping → Jumping (US) → (UR) (CS) → (CR)

  8. Fear Reality of Danger What is a phobia? “Irrational” fear of an “objectively harmless” stimulus D B A: Accountant at work B: Oil rig worker in North sea C: Bomb disposal worker D:Phobia! C A

  9. What is a phobia? DSM-IV categories: Agoraphobia - Public places outside home, e.g. shops trains Social Phobia - Being watched/appraised by other people Specific Phobia - Grouped into: - Animals and insects - Blood/injury/medical (e.g. dentist) - Situational (e.g. driving, crowds, enclosure, air travel) - Natural Environment (e.g. heights, water)

  10. What causes a phobia? Associative learning (Conditioning) account: Acquired through experience of phobic stimulus (CS) being paired with a really frightening or painful event (traumatic US) e.g. Dental phobia Potential phobic stimuli PAIN Street....Waiting room….Dentist’s chair….sight of drill/needle Aversive US CS (First order) Higher-order CSs Dentist’s waiting room (e.g.) associated with aversive US (pain) - thus evokes anxiety/avoidance

  11. How do we treat it? e.g. Dental phobia Potential phobic stimuli Relaxation PAIN Street....Waiting room….Dentist’s chair….sight of drill/needle e.g. Systematic desensitization • Teach relaxation techniques (e.g. slow breathing) • Establish hierarchy of fear (low-high) • Work up hierarchy, pairing each level with relaxation Monitor success with fear ratings

  12. What causes a phobia? Rachman (1990) – Need to revise conditioning model • Phobics can’t always recall an experience where • phobic stimulus paired with traumatic event (2) People who experience Stimulus → Trauma don’t always go on to develop a phobia of that stimulus (3) Incidence of phobias ≠ likelihood of experiencing Stimulus → Trauma (4) People can have phobias of things never experienced (e.g. snake phobia in town dwellers) Rachman proposed 3 pathways to fear… • Conditioning (as on previous slide) • Vicarious (observing another person expressing fear of a stimulus) • Information/Instruction (stories/warnings) N.B. All pathways propose an associative experience, But not necessarily “real” stimulus or “real” trauma

  13. What causes a phobia? Contemporary learning theory can address some of Rachman’s problems… (i) Prevention of associative learning (Davey, 1989) Despite CS-US pairings, associative learning may not take place… (A) Latent inhibition (B) Overshadowing, Blocking Discussion point: What are these?

  14. What causes a phobia? Contemporary learning theory can address some of Rachman’s problems… (ii) Experience after original associative learning (Davey et al. 1993) Associative learning will only give rise to a fear CR, if the US is evaluated as aversive Evaluation of US can ↑ or ↓ and alter the CR e.g. Dentists waiting room → Drill (not painful) Association formed, but drill is not aversive, thus no fear of waiting room. - Later a friend reports traumatic experience with drill…person evaluates drill as aversive….waiting room evokes fear

  15. What causes a phobia? Contemporary learning theory can address some of Rachman’s problems… (iii) Selective associations Some CS-US associations are predisposed to be learned, others not. Biases present in people, monkeys and rats e.g. Cook & Mineka (1990) – Monkeys readily associate sight of snake, but not flowers, with fear in another monkey. e.g. Garcia & Koelling (1966) - Flavour → Illness Light → Shock Flavour →Shock Light → Illness Easy to Learn Hard to Learn Might explain why some phobias are very common, despite few opportunities to learn

  16. What causes a phobia? Contemporary learning theory can address some of Rachman’s problems… (iv) S-R associations - Phobic stimulus may not be associated with a painful/aversive US (S-S learning) - But with fear of threat (S-R learning) S-S e.g. Dentists waiting room Drill (not painful) S-R Belief that drill will cause pain (Anxiety) Some phobic learning (e.g. agoraphobia) may result from “false alarm” experiences - including panic attacks rather than true harm/danger.

  17. What causes a phobia? All foregoing accounts imply some form of associative experience is important for acquisition of phobia (not necessarily 1st order conditioning though) Menzies & Clarke (1995) – Suggest experience is not necessary for phobia - Many fears develop without learning (fear of heights, water, strangers) - Selective associations taken as evidence for this (unlearned tendency for fear …… not for prepared learning) - Learning is important for loss of fear not acquisition Merckelbach, de Jong et al (1996) – Disagree. Evidence for learning origin is convincing. So, we need research on what experiences people with phobias have had (and ask whether these are different from experiences of non-phobics)….

  18. Retrospective studies • Best if research could be Prospective (i.e. look at what happened before phobia) • Nearly all research retrospective – Done with people who already have phobia • Reports of experience potentially inaccurate/distorted Öst (1991) – review of retrospective studies in clinical phobics Used Öst/Hugdah POQ – Phobic Origins Questionnaire 9 Questions (Did you have this type of experience - Yes/No Answers) Conditioning (2 qs) Experienced phobic stim +real aversive event Vicarious (4 qs) Observed other person showing fear of aversive event Instruction (3 qs) Given information that phobic stimulus is harmful Focused on how people believe phobia started – responses classified in above types (or no recall of experience) 80%-90% of people came into one of the categories (conditioning most common) e.g. animal phobia - 48%, social phobia - 51%, agoraphobia - 81%

  19. Retrospective studies McNally & Steketee (1985) 22 severe animal phobics (incl. 10 snake phobics) Structured interview focussing on experiences round the start of phobia - 15 (68%) could provide no information re onset of phobia - of 7 who could recall, 5 reported conditioning-like experiences Also asked what they feared would happen if did encounter phobic animal.. 41% - feared harm from animal 91% feared panic or similar (c.f. S-R model) Results linked to concept of “anxiety sensitivity”, common in many anxiety disorders. Afraid of being afraid….

  20. Retrospective studies Himle et al (1991) reviewed case records of 89 simple phobics. 4 phobia subtypes: animal/insect blood/injury situational choking/vomit Raters classified “onset events” into 5 types. 96% agreement between independent raters. Only 5/89 could not be classified • Realistic, e.g. attack or bite by animal; car crash (S-S) • Spontaneous, e.g. uncued anxiety attack while driving (S-R?) • Vicarious/observational learning, e.g. fearful parent • Gradual onset, no identifiable event • Lifelong fear, can never remember not having it. Mode of Onset (%)

  21. Retrospective studies None of the previous studies showed experience is critical for phobia acquisition - no non-phobic controls. Need to show experiences of 2 groups are different. Doogan & Thomas (1992) – Fear of dogs in adults and children Follow-up of study by DiNardo et al (1988), who found no diffs in frequency of aversive (S-S or S-R) experiences in high and low dog fearers. D &T replicated and looked a children to get around “Memory problem” 100 students & 30 children (8-9 yr olds) classified as high or low on fear of dogs (self report). 9 children dropped because of inconsistent responses Asked by questionnaire/interview if they had had any of the following experiences:

  22. Retrospective studies % saying yes Doogan & Thomas (1992) continued… * = sig diff between high/low group Discussion points: Evidence for S-R learning? Why are data in red interesting?

  23. Further reading…

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