The effect of interstimulus interval (ISI) variation on the acquisition of a classically conditioned emotional response was investigated using a one-trial conditioning procedure. The optimum ISI was found to be 10 s with a bidirectional gradient for conditioned suppression at ISI above and below 10 s. Control groups demonstrated that conditioning was not a function of either pseudoconditioning, sensitization or stimulus novelty.

The effects of intertrial interval (ITI) and foreperiod duration on the acquisition of a conditioned emotional response were investigated using a four-trial conditioning procedure. The optimum IT1 was found to be 60 s with a bidirectional gradient for conditioned suppression above and below 60 s. Conditioned supression was found to be directly related to foreperiod duration.

No abstract