Sensitivity to masked conditioned stimuli predicts conditioned response magnitude under masked conditions.
Expression of conditioned fear has been reported to be independent of perceptual awareness of conditioned stimuli (CSs). Previous studies have been criticized, however, for not adequately assessing perceptual awareness. We fear-conditioned participants to one of two symbols and measured skin conductance responses to dichoptically masked and unmasked CSs. Participants also performed a target detection task and sensitivity (d') to the masked conditioned stimuli (CS+, CS-) was measured. Results showed that sensitivity under masking conditions was related to conditioned responses to masked CSs but not unmasked CSs. Thus, a strong relationship between expression of conditioned fear and awareness of the CS+ emerges when the latter is assessed by signal detection methods. Without consensus on how awareness should be defined, these findings bring balance to previous studies that have typically used less sensitive assessments of awareness.
Cornwell
Brian R
BR
National Institute of Mental Health, National Institutes of Health, 15K North Drive, Bethesda, MD 20892, USA. cornwellb@mail.nih.gov
Echiverri
Aileen M
AM
Grillon
Christian
C
D000293:Adolescent; D000328:Adult; D001143:Arousal / Q000502:physiology*; D001245:Association Learning / Q000502:physiology; D001341:Autonomic Nervous System / Q000502:physiology; D001364:Awareness / Q000502:physiology; D003118:Color Perception / Q000502:physiology; D003214:Conditioning, Classical / Q000502:physiology*; D005239:Fear / Q000502:physiology*; D005260:Female; D005712:Galvanic Skin Response / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D010364:Pattern Recognition, Visual / Q000502:physiology; D010470:Perceptual Masking / Q000502:physiology*; D017603:Signal Detection, Psychological / Q000502:physiology