title: Generalization of Contextual Fear in Humans.
abstract: Enhanced fear responses to cues, which were not associated with the threat but share perceptual characteristics with the threat signal, indicate generalization of conditioned fear. Here, we investigated for the first time generalization processes in contextual fear conditioning. Thirty-two participants were guided through two virtual offices (acquisition phases). Mildly painful electric shocks (unconditioned stimulus, US) were unpredictably delivered in one office (anxiety context, CTX+), but never in the other office (safety context, CTX-). During the generalization test, participants were guided through CTX+, CTX-, and the generalization context (G-CTX), which contained features of both the CTX+ and the CTX-, but no US was delivered. We found successful contextual fear conditioning (i.e., the CTX+ compared to the CTX- elicited potentiated startle responses and was rated with more negative valence, higher arousal and higher anxiety). Importantly, implicit and explicit responses dissociated in the generalization test. Thus, participants rated the G-CTX as more arousing and anxiogenic than the CTX- indicating anxiety generalization, but they showed enhanced startle responses to the CTX+ only, while the G-CTX and the CTX- did not differ. In summary, healthy participants on an explicit level responded to the generalization context like to the anxiety context, but on an implicit level responded to the generalization context like to the safety context. Possibly, this dissociation suggests distinct and specific generalization processes underlying contextual fear.
authors.affiliation: University of Würzburg. Electronic address: marta.andreatta@mail.uni-wuerzburg.de.
authors.forename: Marta
authors.initials: M
authors.lastname: Andreatta
authors.affiliation: University of Padova.
authors.forename: Estelle
authors.initials: E
authors.lastname: Leombruni
authors.affiliation: University of Würzburg; Seoul National University College of Medicine.
authors.forename: Evelyn
authors.initials: E
authors.lastname: Glotzbach-Schoon
authors.affiliation: University of Würzburg.
authors.forename: Paul
authors.initials: P
authors.lastname: Pauli
authors.affiliation: University of Regensburg.
authors.forename: Andreas
authors.initials: A
authors.lastname: Mühlberger
mesh_terms: D000328:Adult; D001007:Anxiety / Q000523:psychology*; D001143:Arousal; D003214:Conditioning, Classical; D003463:Cues; D004597:Electroshock; D005239:Fear / Q000502:physiology / Q000523:psychology*; D005260:Female; D006801:Humans; D008297:Male; D013216:Reflex, Startle; D055815:Young Adult
keywords: conditioned anxiety generalization; contextual fear conditioning; startle response