Fig. 3.

Experiment 1b: Discrimination of stimuli by amplitude difference. (A) Phase 1. (Left) Two frequencies (f = 37.5 Hz and 2f = 75 Hz) and two amplitudes (A = 13 μm and 2A = 26 μm) were combined to generate four vibrations. Stimuli that were presented together and had to be discriminated (paired stimuli) are connected by a shaded line (d₁ and d₂). S+ stimuli were defined by 2A. (Right) Performance is plotted for individual rats across all trials collected over 6 sessions. (B) Phase 2. (Left) Stimuli were identical to those in phase 1, but paired differently. The solid line indicates the pair in which both amplitude and frequency differed with the same sign (delta-Af) whereas the shaded line indicates the pair in which amplitude and frequency differed with opposite signs (iso-Af). (Right) Performance is plotted for individual rats across all trials collected over 10 sessions. Error bars indicate the 95% confidence interval (Wilson Score).