Fig. 3.

Average ability of rats to discriminate between upward and downward FM sweep direction in logarithmic FM tones depending on sweep speed. The averaged psychometric function is based on data from five animals, individual variability is indicated by 95%-confidence intervals. Two values for threshold sweep speed were determined from the data and are given in the panel: threshold at 0.75 hit rate (upper value) and the threshold at the inflection point of the average psychometric function (i.e., the middle between minimum and maximum hit rate; lower value).