Potentiation or diminution of discrete motor unconditioned responses (rabbit eyeblink) to an aversive pavlovian unconditioned stimulus by two associative processes: conditioned fear and a conditioned diminution of unconditioned stimulus processing.
In two experiments using the rabbit conditioned eyeblink preparation, the conditions under which a Pavlovian conditioned stimulus (CS) potentiates or diminishes the unconditioned response (UR) were examined. The results indicated that, after discrimination training (CS+ vs. CS-), the CS+ diminished UR amplitude at the training interstimulus interval (ISI). When CS+ trials were segregated into trials on which a conditioned response (CR) did or did not occur, the CS+ diminished the UR when it elicited a CR, but not when a CR failed to occur. When the CS-unconditioned stimulus (US) interval was lengthened to 10 s, the CS+ reliably potentiated the eyeblink UR on CR trials but did not potentiate responding on trials on which a CR was absent. The results are discussed in terms of the modulatory effects and temporal properties of conditioned fear and an associatively produced decrement in US processing.
Canli
T
T
Yale University, New Haven, Connecticut 06520.
Detmer
W M
WM
Donegan
N H
NH
D000818:Animals; D001143:Arousal / Q000502:physiology; D001245:Association Learning / Q000502:physiology*; D001288:Attention / Q000502:physiology; D001307:Auditory Perception / Q000502:physiology; D001767:Blinking / Q000502:physiology*; D001921:Brain / Q000502:physiology; D003214:Conditioning, Classical / Q000502:physiology*; D003215:Conditioning, Eyelid / Q000502:physiology*; D005239:Fear / Q000502:physiology*; D008297:Male; D009433:Neural Inhibition / Q000502:physiology; D009434:Neural Pathways / Q000502:physiology; D011817:Rabbits; D014796:Visual Perception / Q000502:physiology