Figure 3.

Performance of three ferrets on baseline and probe sessions of experiment. Several training sessions occurred prior to the first session indicated on the abscissa of the figure for each of the ferrets. All three ferrets attained proficiency at the baseline task of distinguishing pure-tone targets from inharmonic complex tone references, as indicated by the hit rate exceeding 70% and the false-alarm rate not exceeding 20%. Two ferrets (top two panels) had probe hit rates that were significantly greater than the false-alarm rate during probe sessions (statistically significantly greater probe hit rates are indicated with a filled symbol), indicating that they sometimes heard harmonic complex tones as being different from inharmonic complex tones.