Figure 7. Structural discrimination learning. Left: Mean performance of the perirhinal lesion (PRh, square) and sham control (Sham, circle) groups on Stage 6 across all three concurrent, structural discriminations. Right: Stage 7 (probe). Mean performance when the compound stimuli were re-paired to give novel combinations of S+ with S– stimuli. Performance of both groups remained above chance. The vertical bars show the standard error of the mean (although when small, they are obscured by the symbols).