A systematic review and meta-analysis of the evidence for unaware fear conditioning

Gaetan Mertens*, Iris M. Engelhard

*Corresponding author for this work

Research output: Contribution to journalReview articleScientificpeer-review

Abstract

Whether fear conditioning can take place without contingency awareness is a topic of continuing debate and conflicting findings have been reported in the literature. This systematic review provides a critical assessment of the available evidence. Specifically, a search was conducted to identify articles reporting fear conditioning studies in which the contingency between conditioned stimuli (CS) and the unconditioned stimulus (US) was masked, and in which CS-US contingency awareness was assessed. A systematic assessment of the methodological quality of the included studies (k = 41) indicated that most studies suffered from methodological limitations (i.e., poor masking procedures, poor awareness measures, researcher degrees of freedom, and trial-order effects), and that higher quality predicted lower odds of studies concluding in favor of contingency unaware fear conditioning. Furthermore, meta-analytic moderation analyses indicated no evidence for a specific set of conditions under which contingency unaware fear conditioning can be observed. Finally, funnel plot asymmetry and p-curve analysis indicated evidence for publication bias. We conclude that there is no convincing evidence for contingency unaware fear conditioning.

Original languageEnglish
Pages (from-to)254-268
JournalNeuroscience and Biobehavioral Reviews
Volume108
DOIs
Publication statusPublished - Jan 2020

Keywords

  • Fear conditioning
  • Awareness
  • Meta-analysis
  • P-curve
  • SKIN-CONDUCTANCE RESPONSES
  • CS-UCS CONTINGENCY
  • ELECTRODERMAL RESPONSES
  • COGNITIVE-PROCESSES
  • POSITIVE FINDINGS
  • NEURAL RESPONSES
  • MEMORY-SYSTEMS
  • AWARENESS
  • ACQUISITION
  • EXTINCTION

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