Refractory period effects are defined as a temporal decrement in neural response due to a previous activation of the same system. We varied the ISI and modality of a preceding stimulus to investigate overlapping and distinct neural systems processing auditory and tactile stimuli. Auditory stimuli and tactile stimuli were presented in a sequential, random manner with a duration of 50 ms and an ISI of 1000 or 2000 ms. The P1-N1-P2 complex of event-related potentials (ERP) was analyzed separately for auditory and tactile stimuli, as a function of preceding ISI and modality. Main effects of ISI and modality were found within the time-window of the P1 and P2 (auditory) and P1, N1 and P2(tactile). These results suggest an overlap in underlying neural systems when stimuli from different modalities are being processed.