MEMORY FOR PICTURES AND SOUNDS - INDEPENDENCE OF AUDITORY AND VISUAL CODES

Three experiments examined the mnemonic independence of auditory and v isual nonverbal stimuli in free recall. Stimulus lists consisted of (1 ) pictures, (2) the corresponding environmental sounds, or (3) picture -sound pairs. In Experiment 1, free recall was tested under three lear ning conditions: standard intentional, intentional with a rehearsal-in hibiting distracter task, or incidental with the distracter task. In a ll three groups, recall was best for the picture-sound items. In addit ion, recall for the picture-sound stimuli appeared to be additive rela tive to pictures or sounds alone when the distracter task was used. Ex periment 2 included two additional groups: In one, two copies of the s ame picture were shown simultaneously; in the other, two different pic tures of the same concept were shown. There was no difference in recal l among any of the picture groups; in contrast, recall in the picture- sound condition was greater than recall in either single-modality cond ition. However, doubling the exposure time in a third experiment resul ted in additively higher recall for repeated pictures with different e xemplars than ones with identical exemplars. The results are discussed in terms of dual coding theory and alternative conceptions of the mem ory trace.