TY - JOUR
T1 - Functional neuroimaging of associative learning and generalization in specific phobia
AU - Lange, Iris
AU - Goossens, Liesbet
AU - Bakker, Jindra
AU - Michielse, Stijn
AU - Marcelis, Machteld
AU - Wichers, Marieke
AU - van Os, Jim
AU - van Amelsvoort, Therese
AU - Schruers, Koen
N1 - Publisher Copyright:
© 2018 Elsevier Inc.
PY - 2019/3/8
Y1 - 2019/3/8
N2 - Background: Theoretical models have implicated classical fear conditioning, fear generalization, and extinction learning in the development of anxiety disorders. To date, it is largely unknown to what extent these mechanisms and the underlying neurobiology may be altered in specific phobia, a disorder characterized by focal fears. The current study systematically examined fear conditioning, fear generalization, extinction learning, and extinction recall in a sample of individuals with a specific phobia. Methods: Participants with a specific phobia (SP) of spiders (n = 46) and healthy controls (HC) (n = 48) underwent a 3-day fMRI cue-conditioning protocol, including a fear acquisition and a fear generalization phase (day 1), an extinction learning phase (day 2), and an extinction recall phase (day 3). Stimuli were phobia-irrelevant, as geometrical shapes served as conditioned threat (CS+) and safety stimuli (CS-), and an electrical shock as the unconditioned stimulus (US). Self-reported fear, US expectancy, and blood-oxygen-level dependent responses were measured. Results: Behavioral results only revealed enhanced CS+/CS-differentiation in fear scores during acquisition retention in SP. Some neural differences were observed during other task phases. During early fear acquisition, SP showed enhanced differential activation in the angular gyrus and lateral occipital cortex, and during extinction recall, more precuneus deactivation was found in SP compared to HC. There were no clear indications of altered neural fear generalization or extinction learning mechanisms in the SP group. Conclusions: Results indicate that spider phobia may be characterized by enhanced differential fear retention and altered brain activation patterns during fear acquisition and extinction recall. The findings provide insight into the nature of fear learning alterations in specific phobia, and how these may differ from those found in disorders characterized by broad anxious distress.
AB - Background: Theoretical models have implicated classical fear conditioning, fear generalization, and extinction learning in the development of anxiety disorders. To date, it is largely unknown to what extent these mechanisms and the underlying neurobiology may be altered in specific phobia, a disorder characterized by focal fears. The current study systematically examined fear conditioning, fear generalization, extinction learning, and extinction recall in a sample of individuals with a specific phobia. Methods: Participants with a specific phobia (SP) of spiders (n = 46) and healthy controls (HC) (n = 48) underwent a 3-day fMRI cue-conditioning protocol, including a fear acquisition and a fear generalization phase (day 1), an extinction learning phase (day 2), and an extinction recall phase (day 3). Stimuli were phobia-irrelevant, as geometrical shapes served as conditioned threat (CS+) and safety stimuli (CS-), and an electrical shock as the unconditioned stimulus (US). Self-reported fear, US expectancy, and blood-oxygen-level dependent responses were measured. Results: Behavioral results only revealed enhanced CS+/CS-differentiation in fear scores during acquisition retention in SP. Some neural differences were observed during other task phases. During early fear acquisition, SP showed enhanced differential activation in the angular gyrus and lateral occipital cortex, and during extinction recall, more precuneus deactivation was found in SP compared to HC. There were no clear indications of altered neural fear generalization or extinction learning mechanisms in the SP group. Conclusions: Results indicate that spider phobia may be characterized by enhanced differential fear retention and altered brain activation patterns during fear acquisition and extinction recall. The findings provide insight into the nature of fear learning alterations in specific phobia, and how these may differ from those found in disorders characterized by broad anxious distress.
KW - Extinction learning
KW - Extinction recall
KW - Fear generalization
KW - Fear learning
KW - fMRI
KW - Specific phobia
UR - http://www.scopus.com/inward/record.url?scp=85054018215&partnerID=8YFLogxK
U2 - 10.1016/j.pnpbp.2018.09.008
DO - 10.1016/j.pnpbp.2018.09.008
M3 - Article
C2 - 30266438
SN - 0278-5846
VL - 89
SP - 275
EP - 285
JO - Progress in Neuro-Psychopharmacology & Biological Psychiatry
JF - Progress in Neuro-Psychopharmacology & Biological Psychiatry
ER -