Extinction in Human Fear Conditioning

Katholieke Universiteit Leuven, Leuven, Belgium.
Biological Psychiatry (Impact Factor: 10.26). 09/2006; 60(4):361-8. DOI: 10.1016/j.biopsych.2005.10.006
Source: PubMed


Although most extinction research is conducted in animal laboratories, the study of extinction learning in human fear conditioning has gained increasing attention over the last decade. The most important findings from human fear extinction are reviewed in this article. Specifically, we review experimental investigations of the impact of conditioned inhibitors, conditioned exciters, context renewal, and reinstatement on fear extinction in human samples. We discuss data from laboratory studies of the extinction of aversively conditioned stimuli, as well as results from experimental clinical work with fearful or anxious individuals. We present directions for future research, in particular the need for further investigation of differences between animal and human conditioning outcomes, and research examining the role of both automatic and higher-order cognitive processes in human conditioning and extinction.

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    • ". The experimental trials were divided into four phases : acquisition , extinction , reinstatement , and test ( see Table 1 ) ; these phases were run after four pre - experimental phases : preparation , practice and startle probe habituation and sound - US familiarization . This general design was consistent with past human reinstatement studies ( Hermans et al . , 2005 ; LaBar & Phelps , 2005 ; Norrholm et al . , 2006 ) ."

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    • "on this result we suggest that the reduction of the return of fear caused by GE is not restricted to animals but can also be seen at least partly in humans , too . This is an important issue when considering the transfer of results from laboratory research to clinical practice . Extinction serves as the laboratory counterpart of exposure therapy ( Hermans et al . , 2006 ) . Replication of this effect in further studies could have major implications for the practical treatment of fear related disorder . For example , in social phobia one method is exposure in which a patient is asked to hold a public speech in front of an audience ( Anderson et al . , 2005 ) . An incorporation of gradual exposure may su"
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    ABSTRACT: The current study investigated whether gradually reducing the frequency of aversive stimuli during extinction can prevent the return of fear. Thirty-one participants of a three-stage procedure (acquisition, extinction and a reinstatement test on day 2) were randomly assigned to a standard extinction (SE) and gradual extinction (GE) procedure. The two groups differed only in the extinction procedure. While the SE group ran through a regular extinction process without any negative events, the frequency of the aversive stimuli during the extinction phase was gradually reduced for the GE group. The unconditioned stimulus (US) was an air blast (5 bar, 10 ms). A spider and a scorpion were used as conditioned stimuli (CS). The outcome variables were contingency ratings and physiological measures (skin conductance response, SCR and startle response). There were no differences found between the two groups for the acquisition and extinction phases concerning contingency ratings, SCR, or startle response. GE compared to SE significantly reduced the return of fear in the reinstatement test for the startle response but not for SCR or contingency ratings. This study was successful in translating the findings in rodent to humans. The results suggest that the GE process is suitable for increasing the efficacy of fear extinction.
    Frontiers in Behavioral Neuroscience 09/2015; 9. DOI:10.3389/fnbeh.2015.00254 · 3.27 Impact Factor
    • "This study examines aspects of emotional memory, sleep timing and quality and trait anxiety that, in currently healthy individuals , could potentially interact in such a way as to lead to pathological anxiety. An emotional memory that is of particular importance to regulating normal anxiety is the extinction of conditioned fear, or learning that something that once signaled danger no longer does so (Hermans et al., 2006). For example, exposure therapy for anxiety disorders is based on the formation of therapeutic extinction memories (Craske et al., 2008). "
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    ABSTRACT: Poor ability to remember the extinction of conditioned fear, elevated trait anxiety, and delayed or disrupted nocturnal sleep are reported in anxiety disorders. The current study examines the interrelationship of these factors in healthy young-adult males. Skin-conductance response was conditioned to two differently colored lamps. One color but not the other was then extinguished. After varying delays, both colors were presented to determine extinction recall and generalization. Questionnaires measured sleep quality, morningness-eveningness, neuroticism and trait anxiety. A subset produced a mean 7.0 nights of actigraphy and sleep diaries. Median split of mean sleep midpoint defined early- and late-"sleep timers". Extinction was more rapidly learned in the morning than evening only in early timers who also better generalized extinction recall. Extinction recall was greater with higher sleep efficiency. Sleep efficiency and morningness were negatively associated with neuroticism and anxiety. However, neuroticism and anxiety did not predict extinction learning, recall or generalization. Therefore, neuroticism/anxiety and deficient fear extinction, although both associated with poor quality and late timing of sleep, are not directly associated with each other. Elevated trait anxiety, in addition to predisposing directly to anxiety disorders, may thus also indirectly promote such disorders by impairing sleep and, consequently, extinction memory. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.
    06/2015; 229(3). DOI:10.1016/j.psychres.2015.05.069
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