FIG. 3.

Plots of the estimated d′ as a function of δ, the fractional change in f₀, as predicted by an optimal detector model. For sine-phase stimuli, slopes decrease with increasing f₀, while for random-phase stimuli, slopes increase with increasing f₀. Horizontal dotted lines indicate the arbitrary $d_0^{\prime }$ used to predict f₀ discrimination thresholds plotted in Fig. 1(b). The plots rarely cross, indicating that the predicted f₀ DL vs f₀ trend is independent of the chosen value of $d_0^{\prime }$.