HUMAN BLINK STARTLE DURING AVERSIVE AND NONAVERSIVE PAVLOVIAN CONDITIONING

Potentiation of blink startle during aversive and nonaversive Pavlovia n single-cue conditioning was assessed in human Ss. In Experiment 1 (N = 89), the conditioning group received paired presentations of a visu al conditioned stimulus (CS) and an unconditioned stimulus (US), where as the control group was presented with a random sequence. The US was an electric shock for half the Ss and a nonaversive reaction time task for the other half. Electrodermal conditioning was evident regardless of the nature of the US, but blink potentiation was found only in the conditioning group that had been trained with the aversive US. These results were replicated in Experiment 2 (N = 65), in which a nonaversi ve US of increased motivational significance was used. Thus, only aver sive conditioning seems to affect the affective valence of the CS, at least as reflected by changes in a skeletal reflex.