A RT investigation of the Perruchet effect

This study aimed to determine whether the conditioned stimulus (CS) in the reaction time (RT) version of the Perruchet effect is instrumental to the production of said effect. In the Perruchet effect a single stimulus (the conditioned stimulus, CS) is paired with a second stimulus (the unconditioned stimulus, US) on half the trials and on the other half the trials the US is not presented. Conditioned responding to the CS is typically found to dissociate from conscious expectancy for the US. In this experiment there were two USs, one requiring participants to make a speeded left RT response and another a speeded right RT response (no expectancy ratings were recorded). Importantly, there was also no CS in this experiment. If the CS is important in the production of the Perruchet effect then removal of the CS in this experiment should distort RT responses, whereas if the CS is not important then a similar RT pattern should be produced to that seen in previous Perruchet experiments.