One contribution of 12 to a theme issue 'Biology, cognition and origins of musicality'. Neural overlap in processing music and speech, as measured by the coactivation of brain regions in neuroimaging studies, may suggest that parts of the neural circuitries established for language may have been recycled during evolution for musicality, or vice versa that musicality served as a springboard for language emergence. Such a perspective has important implications for several topics of general interest besides evolutionary origins. For instance, neural overlap is an important premise for the possibility of music training to influence language acquisition and literacy. However, neural overlap in processing music and speech does not entail sharing neural circuitries. Neural separability between music and speech may occur in overlapping brain regions. In this paper, we review the evidence and outline the issues faced in interpreting such neural data, and argue that converging evidence from several methodologies is needed before neural overlap is taken as evidence of sharing.

Congenital amusia (commonly known as tone deafness) is a lifelong musical disorder that affects 4% of the population according to a single estimate based on a single test from 1980. Here we present the first large-based measure of prevalence with a sample of 20 000 participants, which does not rely on self-referral. On the basis of three objective tests and a questionnaire, we show that (a) the prevalence of congenital amusia is only 1.5%, with slightly more females than males, unlike other developmental disorders where males often predominate; (b) self-disclosure is a reliable index of congenital amusia, which suggests that congenital amusia is hereditary, with 46% first-degree relatives similarly affected; (c) the deficit is not attenuated by musical training and (d) it emerges in relative isolation from other cognitive disorder, except for spatial orientation problems. Hence, we suggest that congenital amusia is likely to result from genetic variations that affect musical abilities specifically.

The vast majority of humans move in time with a musical beat. This behaviour has been mostly studied through finger-tapping synchronization. Here, we evaluate naturalistic synchronization responses to music–bouncing and clapping–in 100 university students. Their ability to match the period of their bounces and claps to those of a metronome and musical clips varying in beat saliency was assessed. In general, clapping was better synchronized with the beat than bouncing, suggesting that the choice of a specific movement type is an important factor to consider in the study of sensorimotor synchronization processes. Performance improved as a function of beat saliency, indicating that beat abstraction plays a significant role in synchronization. Fourteen percent of the population exhibited marked difficulties with matching the beat. Yet, at a group level, poor synchronizers showed similar sensitivity to movement type and beat saliency as normal synchronizers. These results suggest the presence of quantitative rather than qualitative variations when losing the beat.

Although the relation between tonality and musical memory has been fairly well-studied, less is known regarding the contribution of tonal-schematic expectancies to this relation. Three experiments investigated the influence of tonal expectancies on memory for single tones in a tonal melodic context. In the first experiment, listener responses indicated superior recognition of both expected and unexpected targets in a major tonal context than for moderately expected targets. Importantly, and in support of previous work on false memories, listener responses also revealed a higher false alarm rate for expected than unexpected targets. These results indicate roles for tonal schematic congruency as well as distinctiveness in memory for melodic tones. The second experiment utilized minor melodies, which weakened tonal expectancies since the minor tonality can be represented in three forms simultaneously. Finally, tonal expectancies were abolished entirely in the third experiment through the use of atonal melodies. Accordingly, the expectancy-based results observed in the first experiment were disrupted in the second experiment, and disappeared in the third experiment. These results are discussed in light of schema theory, musical expectancy, and classic memory work on the availability and distinctiveness heuristics.

A major theme driving research in congenital amusia is related to the modularity of this musical disorder, with two possible sources of the amusic pitch perception deficit. The first possibility is that the amusic deficit is due to a broad disorder of acoustic pitch processing that has the effect of disrupting downstream musical pitch processing, and the second is that amusia is specific to a musical pitch processing module. To interrogate these hypotheses, we performed a meta-analysis on two types of effect sizes contained within 42 studies in the amusia literature: the performance gap between amusics and controls on tasks of pitch discrimination, broadly defined, and the correlation between specifically acoustic pitch perception and musical pitch perception. To augment the correlation database, we also calculated this correlation using data from 106 participants tested by our own research group. We found strong evidence for the acoustic account of amusia. The magnitude of the performance gap was moderated by the size of pitch change, but not by whether the stimuli were composed of tones or speech. Furthermore, there was a significant correlation between an individual's acoustic and musical pitch perception. However, individual cases show a double dissociation between acoustic and musical processing, which suggests that although most amusic cases are probably explainable by an acoustic deficit, there is heterogeneity within the disorder. Finally, we found that tonal language fluency does not influence the performance gap between amusics and controls, and that there was no evidence that amusics fare worse with pitch direction tasks than pitch discrimination tasks. These results constitute a quantitative review of the current literature of congenital amusia, and suggest several new directions for research, including the experimental induction of amusic behaviour through transcranial magnetic stimulation (TMS) and the systematic exploration of the developmental trajectory of this disorder.

Recently, Bowling, Purves, and Gill (2018a), found that individuals perceive chords with spectra resembling a harmonic series as more consonant. This is consistent with their vocal similarity hypothesis (VSH), the notion that the experience of consonance is based on an evolved preference for sounds that resemble human vocalizations. To rule out confounding between harmonicity and familiarity, we extended Bowling et al.’s (2018a) procedure to chords from the unconventional Bohlen-Pierce chromatic just (BPCJ) scale. We also assessed whether the association between harmonicity and consonance was moderated by timbre by presenting chords generated from either piano or clarinet samples. Results failed to straightforwardly replicate this association; however, evidence of a positive correlation between harmonicity and consonance did emerge across timbres following post hoc exclusion of chords containing intervals that were particularly similar to conventional equal-tempered dyads. Supplementary regression analyses using a more comprehensive measure of harmonicity confirmed its positive association with consonance ratings of BPCJ chords, yet also showed that spectral interference independently contributed to these ratings. In sum, our results are consistent with the VSH; however, they also suggest that a composite model, incorporating both harmonicity as well as spectral interference as predictors, would best account for variance in consonance judgments.

The Montreal Battery for the Evaluation of Amusia (MBEA; Peretz, Champod, & Hyde Annals of the New York Academy of Sciences, 999, 58-75, 2003) is an empirically grounded quantitative tool that is widely used to identify individuals with congenital amusia. The use of such a standardized measure ensures that the individuals tested will conform to a specific neuropsychological profile, allowing for comparisons across studies and research groups. Recently, a number of researchers have published credible critiques of the usefulness of the MBEA as a diagnostic tool for amusia. Here we argue that the MBEA and its online counterpart, the AMUSIA tests (Peretz et al. Music Perception, 25, 331-343, 2008), should be considered steps in a screening process for amusia, rather than standalone diagnostic tools. The goal of this article is to present, in detailed and easily replicable format, the full protocol through which congenital amusics should be identified. In providing information that has often gone unreported in published articles, we aim to clarify the strengths and limitations of the MBEA and to make recommendations for its continued use by the research community as part of the Montreal Protocol for Identification of Amusia.

Minor Tonal Hierarchies 461Music Perception vo lu m e 28, issue 5, pp. 461-472, issn 0730-7829, electronic issn 1533-8312 © 2011 by t h e regents o f t h e university o f california. all rights reserved. please d i r e c t all requests f o r permission to p h oto c o p y o r r e p ro d u c e a rt i c l e c o n t e n t t h ro u g h t h e university o f california press's rights a n d permissions w e b s i t e , h t t p ://www.ucpressjournals.com/reprintinfo.asp.