Why would Musical Training Benefit the Neural Encoding of Speech? The OPERA Hypothesis

Abstract

Mounting evidence suggests that musical training benefits the neural encoding of speech. This paper offers a hypothesis specifying why such benefits occur. The “OPERA” hypothesis proposes that such benefits are driven by adaptive plasticity in speech-processing networks, and that this plasticity occurs when five conditions are met. These are: (1) Overlap: there is anatomical overlap in the brain networks that process an acoustic feature used in both music and speech (e.g., waveform periodicity, amplitude envelope), (2) Precision: music places higher demands on these shared networks than does speech, in terms of the precision of processing, (3) Emotion: the musical activities that engage this network elicit strong positive emotion, (4) Repetition: the musical activities that engage this network are frequently repeated, and (5) Attention: the musical activities that engage this network are associated with focused attention. According to the OPERA hypothesis, when these conditions are met neural plasticity drives the networks in question to function with higher precision than needed for ordinary speech communication. Yet since speech shares these networks with music, speech processing benefits. The OPERA hypothesis is used to account for the observed superior subcortical encoding of speech in musically trained individuals, and to suggest mechanisms by which musical training might improve linguistic reading abilities.

Generality and specificity in the effects of musical expertise on perception and cognition

“…Moreover, we did not find that our violinist cohort -who spent significantly greater time in ensembles (see ST 2) -performed any better than our pianist cohort. These results contrast with previous reports of enhanced musician performance under the demands of competing speech (Parbery-Clark et al, 2009a, 2009b, 2011Strait et al, 2012b), sources of informational masking (Oxenham et al, 2003; see footnote 10), backward masking (Strait et al, 2010), and detection of auditory objects (Zendel & Alain, 2009. Our findings also contrast with previous evidence that specific expertise with ensemble settings benefits selective attention to spatially segregated sounds (Nager et al, 2003).…”

“…Orchestral conductors -whose primary role is to analyze, interpret, and manipulate a colossal auditory sceneshow enhanced selectivity in attending to spatially segregated auditory signals (noise bursts), when compared to both pianists and non-musicians (Nager et al, 2003). Musicians' long experience in musically-based scene analysis may also be a causal factor in their enhanced ability to comprehend speech when the speech signal is masked by noise (classic 'energetic' masking) or multi-talker babble (energetic plus so-called 'informational masking' -see footnote 4; Parbery-Clark et al, 2009a, 2009b, 2011Strait & Kraus, 2011b;Strait et al, 2012b; but see also Patel, 2011). However, recent data suggest that musicians and non-musicians do not differ in susceptibility to informational and energetic masking during speech-in-noise perception (Ruggles et al, 2014).…”

From temporal processing to developmental language disorders: mind the gap

“…In sum, rise time discrimination (or 'beat perception' as it is often termed) has been demonstrated to be associated with phonological awareness and reading skills, much like rapid temporal processing was two decades ago. Proposals for interventions have also appeared, suggesting general musical [35,36] or specifically rhythmic [37] training.…”

Neural overlap in processing music and speech

“…The original OPERA hypothesis [51] focuses on acoustic features (e.g. waveform periodicity) rather than on cognitive demands (e.g.…”

“…Patel [28,51] has introduced the OPERA framework to explain why musical training may lead to enhanced speech processing. An essential condition of the OPERA hypothesis is neural overlap, a term used by Patel to refer to 'neural sharing'.…”