Fig. 6: The detailed shape of statistically-driven gain is modulated by range, distribution, and sampling density.

See Fig. 1c for histograms of distributional regularities. Marker size scales with tone probability. In each panel, the darker color (dotted line) indicates behavior in the first half of the experiment; the lighter color (solid line) indicates behavior in the second half, when distributional regularities shift. Each panel plots mean detection accuracy as a function of acoustic frequency. Error bars indicate standard error of the mean. The top row shows Exp 7a,c,e for which the equiprobable distribution preceded the unimodal distribution. The bottom row shows Exp 7b,d,f for which a unimodal distribution preceded the switch to an equiprobable distribution. Panels (a) and (d) plot the narrow distribution (5.5 semitone range), Panels (b) and (e) plot the intermediate distribution (9.47 semitone range), and Panels (c) and (f) plot the wide distribution (11.36 semitone range). In each panel, the insets show detection accuracy for the high-probability tone (in the unimodal half of the experiment) and equiprobable low-probability tones near, intermediate, and far from the high-probability 1000-Hz tone.