Costs or benefits of emotional conditioning on cognitive processing?

We report on two experiments using a transfer-of-control procedure in evaluating costs or benefits of emotionally relevant stimuli on the processing of a cognitive task. In differential conditioning the impact of Pavlovian conditioning usually is examined by contrasting instrumental responses in the presence of an excitatory conditioned stimulus (CS+) and an inhibitory conditioned stimulus (CS-). We expanded this comparison by introducing a neutral third condition. This additional neutral condition served as a within subject control for evaluating whether the CS+ increased responding and/or the CS- decreased responding. Both experiments yielded the same result; the CS- slowed down cognitive processing while the CS+ had no impact. Thus, the proposed transfer-of-control procedure may serve as a reliable and valid research tool in the evaluation of motivation and emotion in humans.