3 Respondent vs. operant RespondentOperant --------------------------------------------------------------- UtløstAvgitt S RR S Refleksiv“Intensjonal” NedarvetForming av ny atferd Mål på refleksstyrke:Mål på operant styrke: terskelfrekvens (R/t) latens magnitude
12 Cued ”tolerance” Conditioned “anticipatory” responses attenuate the drug effects and contribute to tolerance
13 A failure of tolerance A failure of tolerance should occur if the drug is administered in an environment that has not, in the past, been associated with the drug
14 Absence of a compensatory reponse One contributing factor in death from the so-called opiate overdose might be the absence of a conditioned compensatory pharmacological response
15 An animal model: The contribution of contextual stimuli to tolerance
16 Procedures Two environments: 1. The colony – where rats were individually housed. (Animal removed from the cage and put back.) 2. Different room with ”white noise” (injection 15 min. after transfer and kept for 2 hours).
17 Training (heroin injections) Experimental groups: One location: Increasing doses of heroin Trial 1: 1 mg/kg Trials 2-3:2 mg/kg Trials 4-7: 4 mg/kg Trials 8-15:8 mg/kg Other location: Dexterose Control group: Both locations: Dexterose
18 3 groups I.ST (similarly tested) II.DT (differently tested) III.Control (no drug history) Test (heroin - 15mg/kg)
21 Results (cont.) Both groups with pretest experience with sublethal doses of heroin were more likely to survive the higher dose than control animals Tolerance was highest when the potential lethal dose of heroin was administered in a setting that had preceded lower-dose heroin injection
22 Extrapolation Respondent conditioning contributes to tolerance: Typical pre-drug stimuli function as conditioned stimuli for responses that counteract the effects of the drug Respondent-conditioned tolerance may fail to occur when the drug is administered in an unusual setting Hence, some “overdose” deaths among heroin addicts may occur because the drug is administered in unusual settings
33 Thorndike (1911) ’The Law of Effect’ Of several responses made to the same situation, those which are accompanied or closely followed by satisfaction to the animal will, other things being equal, be more firmly connected with the situation, so that, when it recurs, they will be more likely to recur; discomfort ! less likely to occur By a satisfying state of affairs is meant one which the animal does nothing to avoid, often doing such things as attain and preserve it. By a discomforting or annoying state of affairs is meant one which the animal commonly avoids and abandons.
37 Forming Eksempel (Haugton & Ayllon, 1965) Kasus: Ei femti-fire år gml. Institusjonalisert dame beskrevet som ”schizofren” og ”lat.” Mål: Å få henne til å utføre enkelt arbeid i avdelingen. Prosedyre: * Forming av Å BÆRE LANGKOSTEN * Intermitterende forsterkning, tokens Resultat: ”Tvangsmessig (compulsive) atferd.
45 Lært Hjelpeløshet - et syndrom Abulia, anhedonia Vansker med å lære ny atferd Emosjonelle forstyrrelser Fysiologiske endringer (økt sykelighet og dødelighet) Mindre aggresjon Appetittløshet og mindre seksuell aktivitet
46 Lært Hjelpeløshet - prinsippet Ekstinksjon – manglende sammenheng (kontingens) mellom atferd og forsterkende konsekvenser. (Kfr. Seligmans kognitive forklaring) Forhindring og kur: Flukt-trening.