In all paradigms, rare tones were interspersed with standard tones such that no two rare tones occurred successively. The digitizing epoch for each trial was one second and a .5 - 1 second intertrial interval was used (to reduce habituation). In the 3 paradigms, 2 tones (standard, rare) were presented and the total number of trials in a recording session was 150. Animals were only tested on a single paradigm per test day and at least 24 hours lapsed between testing sessions. The order of presentation of each paradigm over time as well as which paradigm each mouse participated in was randomized. There were equivalent numbers of DBA’s and C57’s in all paradigms. Each mouse participated over a 4-week period. Mice were between 10 and 14 weeks of age at the time of the electrophysiological recordings.
