Maintenance of memory for melodies: Articulation or attentional refreshing?

Past research on the effects of articulatory suppression on working memory for nonverbal sounds has been characterized by discrepant findings, which suggests that multiple mechanisms may be involved in the rehearsal of nonverbal sounds. In two experiments we examined the potential roles of two theoretical mechanisms of verbal working memory-articulatory rehearsal and attentional refreshing-in the maintenance of memory for short melodies. In both experiments, participants performed a same-different melody comparison task. During an 8-s retention interval, interference tasks were introduced to suppress articulatory rehearsal, attentional refreshing, or both. In Experiment 1, only the conditions that featured articulatory suppression resulted in worse memory performance than in a control condition, and the suppression of both attentional refreshing and articulatory rehearsal concurrently did not impair memory more than articulatory suppression alone. Experiment 2 reproduced these findings and also confirmed that the locus of interference was articulatory and not auditory (i.e., the interference was not attributable to the sound of participants' own voices during articulatory suppression). Both experiments suggested that articulatory rehearsal played a role in the maintenance of melodies in memory, whereas attentional refreshing did not. We discuss potential theoretical implications regarding the mechanisms used for the rehearsal of nonverbal sounds in working memory.