Fig. 3.

Observers are poor generalizers. a Generalization experimenters (GENEXP) undergo the same training phase as EXP (training set of stimuli, S, top), after which they are exposed to the generalization set of stimuli S’ during the testing phase (bottom left). Generalization observers (GENOBS) first observe the training set of stimuli (S, top) and then are tested on the generalization set (S’, bottom right). b Scatter plot of dPesc on the generalization set as a function of block number (100 trials per block) in all birds (n = 9 GENEXP, blue dots; n = 9 GENOBS, green diamonds), the criterion block is represented by larger solid symbol. c GENEXP discriminated stimuli in the generalization set better than GENOBS (GENEXP ≠ GENOBS; p = 0.019, Wilcoxon ranksum). Symbols indicate dPesc averaged across the first 3 blocks of the testing phase, bars represent medians across animals. d GENEXP reached the criterion faster than GENOBS (GENEXP ≠ GENOBS; p = 0.006, Wilcoxon ranksum). Symbols indicate trials to criterion, bars represent medians