Auditory working and reference memory can be tested in a single situation of stimuli for the rat

The comparison of working and reference memory is one of the most valuable research angles for revealing the precise neural mechanisms of memory. The present study introduces a method to test both auditory working and reference memory during a short period in the rat. The apparatus and stimuli are identical for both memory tasks. High and low tones, between which lies a 5-s interval, are continuously presented. The task for working memory is a continuous nonmatching-to-sample. The rat makes go and no-go responses to indicate whether the current tone is the same as (match) or different from (nonmatch) the preceding tone. The task for reference memory is a continuous discrimination. The rat makes go responses on high-tone trials and no-go responses on low-tone trials. With alternate training in these tasks, the rat comes to perform well in both tasks. The rat can only know which task is employed in a given session from its own response-reward contingency during the early trials of each session.