Figure 1.

AV stimuli and behavioral data. (A) AV stimuli consisted of combinations of gray-scale photographs (left column) and complex sounds of both natural (i.e., animals) and artificial material (i.e., so-called “fribbles”). AV combinations could be either congruent, that is, corresponding to the learnt associations between the artificial visual and auditory stimuli (upper row in A) or incongruent (lower row in A). Middle and right columns provide the amplitude waveforms and spectrograms for typical exemplars of artificial sounds. (B) Behavioral training data of 17 subjects and interindividual differences in AV learning speed. The dashed horizontal line indicates the criterion of 15 (out of a maximum of 16) correct responses which had to be reached in 4 successive training blocks in order to terminate the training session. AU, arbitrary units.