Contingency awareness and fear inhibition in a human fear-potentiated startle paradigm.
Fear-potentiated startle is defined as an increase in the magnitude of the startle reflex in the presence of a stimulus that was previously paired with an aversive event. It has been proposed that a subject's awareness of the contingencies in the experiment may affect fear-potentiated startle. The authors adapted a conditional discrimination procedure (AX+/BX-), previously validated in animals, to a human fear-potentiated startle paradigm in 50 healthy volunteers. This paradigm allows for an assessment of fear-potentiated startle during threat conditions as well as inhibition of fear-potentiated startle during safety conditions. A response keypad was used to assess contingency awareness on a trial-by-trial basis. Both aware and unaware subjects showed fear-potentiated startle. However, awareness was related to stimulus discrimination and fear inhibition.
Jovanovic
Tanja
T
Mental Health Service/116A, Atlanta Veterans Affairs Medical Center, Decatur, GA 30033, USA. tjovano@emory.edu
Norrholm
Seth D
SD
Keyes
Megan
M
Fiallos
Ana
A
Jovanovic
Sasa
S
Myers
Karyn M
KM
Davis
Michael
M
Duncan
Erica J
EJ
D000161:Acoustic Stimulation; D000328:Adult; D000368:Aged; D001143:Arousal; D001245:Association Learning; D001288:Attention; D001364:Awareness; D001767:Blinking; D003214:Conditioning, Classical; D003463:Cues; D004576:Electromyography; D005239:Fear; D005260:Female; D006801:Humans; D007266:Inhibition, Psychological; D008297:Male; D008875:Middle Aged; D010775:Photic Stimulation; D011597:Psychomotor Performance; D013216:Reflex, Startle