Effects of “Below‐Zero” Habituation on the Electrodermal Orienting Response to a Test Stimulus

ABSTRACT Two experiments were designed to investigate the effect of below‐zero habituation training on skin conductance response (SCR) amplitude to a change in auditory stimulus frequency. In both experiments, subjects were trained with a 1000 Hz tone until zero responding and then received 5, 10, or IS further training trials. In Experiment 1 (N=45), subjects then received 1 presentation of a test stimulus of 1400 Hz, while in Experiment 2 (N=45), the test stimulus was a tone of 670 Hz. On the basis of dual‐process theory, it was hypothesized that response amplitude to the test stimulus would be inversely related to amount of below‐zero training. However, the results of both experiments indicate that SCR amplitude was positively related to amount of below‐zero training. These results suggest that in situations of extended habituation training, an expectancy or subjective probability of stimulus occurrence gradient is important in determining response amplitude to a test stimulus.