Figure 6.  Learning curves for two groups during classification training with these stimuli.  Lines fitted to the data plot the hyperbolic equation rho-0.5 + n (k-0.5)/(n+R), a convenient description of negatively accelerated learning curves (see Mazur & Hastie, 1978).  n = session number, k = performance asymptote, R = learning rate.  Huber et al. (submitted.).