Know safety, no fear

NEUROSCIENCE AND BIOBEHAVIORAL REVIEWS

卷:108

Review

Sangha, Susan^1,2  Diehl, Maria M.³  Bergstrom, Hadley C.⁴  Drew, Michael R.^5,6 

[1] Purdue Univ, Dept Psychol Sci, W Lafayette, IN 47907 USA

[2] Purdue Univ, Purdue Inst Integrat Neurosci, W Lafayette, IN 47907 USA

[3] Kansas State Univ, Dept Psychol Sci, Manhattan, KS 66506 USA

[4] Vassar Coll, Dept Psychol Sci, Program Neurosci & Behav, Poughkeepsie, NY 12601 USA

[5] Univ Texas Austin, Ctr Learning & Memory, Austin, TX 78712 USA

[6] Univ Texas Austin, Dept Neurosci, Austin, TX 78712 USA

关键词: Safety;    Fear;    Discrimination;    Generalization;    Extinction;    Avoidance;    Amygdala;    Hippocampus;    Cortex;   

DOI  :  10.1016/j.neubiorev.2019.11.006

来源: Elsevier

【 摘 要 】

Every day we are bombarded by stimuli that must be assessed for their potential for harm or benefit. Once a stimulus is learned to predict harm, it can elicit fear responses. Such learning can last a lifetime but is not always beneficial for an organism. For an organism to thrive in its environment, it must know when to engage in defensive, avoidance behaviors and when to engage in non-defensive, approach behaviors. Fear should be suppressed in situations that are not dangerous: when a novel, innocuous stimulus resembles a feared stimulus, when a feared stimulus no longer predicts harm, or when there is an option to avoid harm. A cardinal feature of anxiety disorders is the inability to suppress fear adaptively. In PTSD, for instance, learned fear is expressed inappropriately in safe situations and is resistant to extinction. In this review, we discuss mechanisms of suppressing fear responses during stimulus discrimination, fear extinction, and active avoidance, focusing on the well-studied tripartite circuit consisting of the amygdala, medial prefrontal cortex and hippocampus.

【 授权许可】

Free