The Perruchet Effect In Electrodermal Responses To Pictures

Currently the two primary explanations for classical conditioning are an automatic (unconscious) link between the two stimuli or a propositional (conscious) understanding of the contingency. One design, known as the Perruchet design, uses probabilistic fallacies to produce a difference in prediction between the two models. The Perruchet effect has almost exclusively been studied using eyeblink conditioning. The present study tested the generalizability of this design to visual stimuli. The setup of the Perruchet design entails pairing the conditioned stimulus (CS) and the unconditioned Stimulus (UCS) on 50% of trials in a pseudo-random order. On each trial we recorded a verbal report of (conscious) expectation of the UCS, as well as (unconscious) skin-conductance responses to the CS. Based on previous findings on the Perruchet effect, we predicted that we would observe changes in expectation and skin conductance response across consecutive trials of the same type. Due to data loss errors, we were able to analyze only paired trials. We observed the expected decrease in verbal expectation across paired trials, but we did not find a significant difference in skin conductance response strength between paired trials. This means that we were unable to replicate the Perruchet effect.