The effects of music on auditory-motor integration for speech: a behavioral priming and interference study

Language and music are fundamentally entwined within human culture. The two domains share similar properties including rhythm, acoustic complexity, and hierarchical structure. Although language and music have commonalities, abilities in these two domains have been found to dissociate after brain damage, leaving unanswered questions about their interconnectedness, including can one domain support the other when damage occurs? Evidence supporting this question exists for speech production. Musical pitch and rhythm are employed in Melodic Intonation Therapy to improve expressive language recovery, but little is known about the effects of music on the recovery of speech perception and receptive language. This research is one of the first to address the effects of music on speech perception. Two groups of participants, an older adult group (n=24; M = 71.63 yrs) and a younger adult group (n=50; M = 21.88 yrs) took part in the study. A native female speaker of Standard American English created four different types of stimuli including pseudoword sentences of normal speech, simultaneous music-speech, rhythmic speech, and music-primed speech. The stimuli were presented binaurally and participants were instructed to repeat what they heard following a 15 second time delay. Results were analyzed using standard parametric techniques. It was found that musical priming of speech, but not simultaneous synchronized music and speech, facilitated speech perception in both the younger adult and older adult groups. This effect may be driven by rhythmic information. The younger adults outperformed the older adults in all conditions. The speech perception task relied heavily on working memory, and there is a known working memory decline associated with aging. Thus, participants completed a working memory task to be used as a covariate in analyses of differences across stimulus types and age groups. Working memory ability was found to correlate with speech perception performance, but that the age-related performance differences are still significant once working memory differences are taken into account. These results provide new avenues for facilitating speech perception in stroke patients and sheds light upon the underlying mechanisms of Melodic Intonation Therapy for speech production.