2003; Umbricht et al., 2005). The present study was undertaken to further develop a model of mouse EROs using auditory stimuli. EROs were generated in a paradigm shown to produce P3-like ERP components (Ehlers & Somes, 2002). We previously demonstrated that changes in frequency and loudness of auditory stimuli modified N1 ERP components that occurred in the 50-100 msec range where as P3 components in the 200-400msec range were found to be sensitive to probability but not to tone frequency or loudness (Ehlers & Somes, 2002). The N1 component consists of the N1a component, a large negative component that peaks between 20 and 30 ms, and the N1b component, a broader negative component that peaks between 80 and 90 ms. The P3 component is a broad positive wave that peaks between 200 and 300 ms (Ehlers & Somes, 2002). The specific aim of this study was to evaluate the effects of changes in auditory stimulus probability, loudness, and frequency on mouse EROs.
