Experimental set up. A, Experimental design. B, Electrode montage. C, PAL task protocol: Following initial presentation and testing (as shown in the diagram) if subjects scored > 30% correct, they progressed to the preparation stage (see Fig. 1A). If however, they scored <30% correct then they were presented the word list again at twice the presentation speed. Following representation they were again tested without feedback, as before. No subjects failed to score 30% following the second presentation.