Cross-Frequency Brain Network Dynamics Support Pitch Change Detection.

Processing auditory sequences involves multiple brain networks and is crucial to complex perception associated with music appreciation and speech comprehension. We used time-resolved cortical imaging in a pitch change detection task to detail the underlying nature of human brain network activity, at the rapid time scales of neurophysiology. In response to tone sequence presentation to the participants, we observed slow inter-regional signaling at the pace of tone presentations (2-4 Hz) that was directed from auditory cortex toward both inferior frontal and motor cortices. Symmetrically, motor cortex manifested directed influence onto auditory and inferior frontal cortices via bursts of faster (15-35 Hz) activity. These bursts occurred precisely at the expected latencies of each tone in a sequence. This expression of interdependency between slow/fast neurophysiological activity yielded a form of local cross-frequency phase-amplitude coupling in auditory cortex, which strength varied dynamically and peaked when pitch changes were anticipated. We clarified the mechanistic relevance of these observations in relation to behavior by including a group of individuals afflicted by congenital amusia, as a model of altered function in processing sound sequences. In amusia, we found a depression of inter-regional slow signaling toward motor and inferior frontal cortices, and a chronic overexpression of slow/fast phase-amplitude coupling in auditory cortex. These observations are compatible with a misalignment between the respective neurophysiological mechanisms of stimulus encoding and internal predictive signaling, which was absent in controls. In summary, our study provides a functional and mechanistic account of neurophysiological activity for predictive, sequential timing of auditory inputs.SIGNIFICANCE STATEMENT Auditory sequences are processed by extensive brain networks, involving multiple systems. In particular, fronto-temporal brain connections participate in the encoding of sequential auditory events, but so far, their study was limited to static depictions. This study details the nature of oscillatory brain activity involved in these inter-regional interactions in human participants. It demonstrates how directed, polyrhythmic oscillatory interactions between auditory and motor cortical regions provide a functional account for predictive timing of incoming items in an auditory sequence. In addition, we show the functional relevance of these observations in relation to behavior, with data from both normal hearing participants and a rare cohort of individuals afflicted by congenital amusia, which we considered here as a model of altered function in processing sound sequences.

Cross-Cultural Work in Music Cognition: Challenges, Insights, and Recommendations.

Many foundational questions in the psychology of music require cross-cultural approaches, yet the vast majority of work in the field to date has been conducted with Western participants and Western music. For cross-cultural research to thrive, it will require collaboration between people from different disciplinary backgrounds, as well as strategies for overcoming differences in assumptions, methods, and terminology. This position paper surveys the current state of the field and offers a number of concrete recommendations focused on issues involving ethics, empirical methods, and definitions of "music" and "culture."

Specialized neural dynamics for verbal and tonal memory: fMRI evidence in congenital amusia.

Behavioral and neuropsychological studies have suggested that tonal and verbal short-term memory are supported by specialized neural networks. To date however, neuroimaging investigations have failed to confirm this hypothesis. In this study, we investigated the hypothesis of distinct neural resources for tonal and verbal memory by comparing typical nonmusician listeners to individuals with congenital amusia, who exhibit pitch memory impairments with preserved verbal memory. During fMRI, amusics and matched controls performed delayed-match-to-sample tasks with tones and words and perceptual control tasks with the same stimuli. For tonal maintenance, amusics showed decreased activity in the right auditory cortex, inferior frontal gyrus (IFG) and dorso-lateral-prefrontal cortex (DLPFC). Moreover, they exhibited reduced right-lateralized functional connectivity between the auditory cortex and the IFG during tonal encoding and between the IFG and the DLPFC during tonal maintenance. In contrasts, amusics showed no difference compared with the controls for verbal memory, with activation in the left IFG and left fronto-temporal connectivity. Critically, we observed a group-by-material interaction in right fronto-temporal regions: while amusics recruited these regions less strongly for tonal memory than verbal memory, control participants showed the reversed pattern (tonal > verbal). By benefitting from the rare condition of amusia, our findings suggest specialized cortical systems for tonal and verbal short-term memory in the human brain.

Comorbidity and cognitive overlap between developmental dyslexia and congenital amusia.

This study investigated whether there is a co-occurrence between developmental dyslexia and congenital amusia in adults. First, a database of online musical tests on 18,000 participants was analysed. Self-reported dyslexic participants performed significantly lower on melodic skills than matched controls, suggesting a possible link between reading and musical disorders. In order to test this relationship more directly, we evaluated 20 participants diagnosed with dyslexia, 16 participants diagnosed with amusia, and their matched controls, with a whole battery of literacy (reading, fluency, spelling), phonological (verbal working memory, phonological awareness) and musical tests (melody, rhythm and metre perception, incidental memory). Amusia was diagnosed in six (30%) dyslexic participants and reading difficulties were found in four (25%) amusic participants. Thus, the results point to a moderate comorbidity between amusia and dyslexia. Further research will be needed to determine what factors at the neural and/or cognitive levels are responsible for this co-occurrence.

Playing Super Mario increases oculomotor inhibition and frontal eye field grey matter in older adults.

Aging is associated with cognitive decline and decreased capacity to inhibit distracting information. Video game training holds promise to increase inhibitory mechanisms in older adults. In the current study, we tested the impact of 3D-platform video game training on performance in an antisaccade task and on related changes in grey matter within the frontal eye fields (FEFs) of older adults. An experimental group (VID group) engaged in 3D-platform video game training over a period of 6 months, while an active control group was trained on piano lessons (MUS group), and a no-contact control group did not participate in any intervention (CON group). Increased performance in oculomotor inhibition, as measured by the antisaccade task, and increased grey matter in the right FEF was observed uniquely in the VID group. These results demonstrate that 3D-platform video game training can improve inhibitory control known to decline with age.

Ability to process musical pitch is unrelated to the memory advantage for vocal music.

Listeners remember vocal melodies better than instrumental melodies, but the origins of the effect are unclear. One explanation for the 'voice advantage' is that general perceptual mechanisms enhance processing of conspecific signals. An alternative possibility is that the voice, by virtue of its expressiveness in pitch, simply provides more musical information to the listener. Individuals with congenital amusia provide a unique opportunity to disentangle the effects of conspecific status and vocal expressiveness because they cannot readily process subtleties in musical pitch. Forty-one participants whose musical pitch discrimination ability ranged from congenitally amusic to typical were tested. Participants heard vocal and instrumental melodies during an exposure phase, and heard the same melodies intermixed with timbre-matched foils in a recognition phase. Memory was better for vocal than instrumental melodies, but the magnitude of the advantage was unrelated to musical pitch discrimination or memory overall. The voice enhances melodic memory regardless of music perception ability, ruling out the role of pitch expressiveness in the voice advantage. More importantly, listeners across a wide range of musical ability can benefit from the privileged status of the voice.

The effects of short-term musical training on the neural processing of speech-in-noise in older adults.

Experienced musicians outperform non-musicians in understanding speech-in-noise (SPIN). The benefits of lifelong musicianship endure into older age, where musicians experience smaller declines in their ability to understand speech in noisy environments. However, it is presently unknown whether commencing musical training in old age can also counteract age-related decline in speech perception, and whether such training induces changes in neural processing of speech. Here, we recruited older adult non-musicians and assigned them to receive a short course of piano or videogame training, or no training. Participants completed two sessions of functional Magnetic Resonance Imaging where they performed a SPIN task prior to and following training. While we found no direct benefit of musical training upon SPIN perception, an exploratory Region of Interest analysis revealed increased cortical responses to speech in left Middle Frontal and Supramarginal Gyri which correlated with changes in SPIN task performance in the group which received music training. These results suggest that short-term musical training in older adults may enhance neural encoding of speech, with the potential to reduce age-related decline in speech perception.

Decreased risk of falls in patients attending music sessions on an acute geriatric ward: results from a retrospective cohort study.

BACKGROUND: Music has been shown to improve health and quality of life. It was suggested that music may also have an impact on gait stability and fall risk. Yet, few studies have exploited music in the hospital setting, and even less so in the geriatric population. Our objective was to examine the influence of music listening on the risk of falls by comparing the Morse Fall Scale score in patients admitted to a Geriatric Assessment Unit (GAU) who attended music listening sessions and in patients who did not attend music sessions. METHODS: This was a retrospective cohort study (mean follow-up 13.3 ± 6.8 days) which took place in a GAU, St. Mary's Hospital Center, Montreal. A total of 152 charts of participants, with a mean age of 85.7 ± 6.4 years and 88.2% female were reviewed and included. There were 61 participants exposed to the music listening sessions group and 91 in the non-exposed group matched for age, sex, cause and season of admission, and living situation. One-hour music sessions were provided to the patients by volunteer musicians. The Morse Fall Scale score upon admission and discharge as well as its variation (change from before to after exposure) were used as outcomes. Age, sex, living situation, reason for admission, season of admission, Mini Mental Status Examination score, number of therapeutic classes taken daily upon admission, use of psychoactive drugs upon admission and length of stay were used as covariates. RESULTS: The Morse Fall Scale score decreased significantly in the exposed group compared to the non-exposed group (p = 0.025) and represented a small to medium-sized effect, d = 0.395. The multiple linear regression model showed a significant association between the decrease of the Morse Fall Scale score and music exposure (B = - 17.1, p = 0.043). CONCLUSION: Participating in music listening sessions was associated with a decreased risk of falls in patients admitted to a GAU. Further controlled research is necessary to confirm these findings and to determine the mechanisms by which music listening impacts fall risk. TRIAL REGISTRATION: Clinical trial registry: ClinicalTrials.gov . Registration number: NCT03348657 (November 17th, 2017). Retrospectively registered.

Benefits of Music Training for Perception of Emotional Speech Prosody in Deaf Children With Cochlear Implants.

OBJECTIVES: Children who use cochlear implants (CIs) have characteristic pitch processing deficits leading to impairments in music perception and in understanding emotional intention in spoken language. Music training for normal-hearing children has previously been shown to benefit perception of emotional prosody. The purpose of the present study was to assess whether deaf children who use CIs obtain similar benefits from music training. We hypothesized that music training would lead to gains in auditory processing and that these gains would transfer to emotional speech prosody perception. DESIGN: Study participants were 18 child CI users (ages 6 to 15). Participants received either 6 months of music training (i.e., individualized piano lessons) or 6 months of visual art training (i.e., individualized painting lessons). Measures of music perception and emotional speech prosody perception were obtained pre-, mid-, and post-training. The Montreal Battery for Evaluation of Musical Abilities was used to measure five different aspects of music perception (scale, contour, interval, rhythm, and incidental memory). The emotional speech prosody task required participants to identify the emotional intention of a semantically neutral sentence under audio-only and audiovisual conditions. RESULTS: Music training led to improved performance on tasks requiring the discrimination of melodic contour and rhythm, as well as incidental memory for melodies. These improvements were predominantly found from mid- to post-training. Critically, music training also improved emotional speech prosody perception. Music training was most advantageous in audio-only conditions. Art training did not lead to the same improvements. CONCLUSIONS: Music training can lead to improvements in perception of music and emotional speech prosody, and thus may be an effective supplementary technique for supporting auditory rehabilitation following cochlear implantation.

Emotional recognition from dynamic facial, vocal and musical expressions following traumatic brain injury.

OBJECTIVES: To assess emotion recognition from dynamic facial, vocal and musical expressions in sub-groups of adults with traumatic brain injuries (TBI) of different severities and identify possible common underlying mechanisms across domains. METHODS: Forty-one adults participated in this study: 10 with moderate-severe TBI, nine with complicated mild TBI, 11 with uncomplicated mild TBI and 11 healthy controls, who were administered experimental (emotional recognition, valence-arousal) and control tasks (emotional and structural discrimination) for each domain. RESULTS: Recognition of fearful faces was significantly impaired in moderate-severe and in complicated mild TBI sub-groups, as compared to those with uncomplicated mild TBI and controls. Effect sizes were medium-large. Participants with lower GCS scores performed more poorly when recognizing fearful dynamic facial expressions. Emotion recognition from auditory domains was preserved following TBI, irrespective of severity. All groups performed equally on control tasks, indicating no perceptual disorders. Although emotional recognition from vocal and musical expressions was preserved, no correlation was found across auditory domains. CONCLUSIONS: This preliminary study may contribute to improving comprehension of emotional recognition following TBI. Future studies of larger samples could usefully include measures of functional impacts of recognition deficits for fearful facial expressions. These could help refine interventions for emotional recognition following a brain injury.

Effect of Age on Attentional Control in Dual-Tasking.

Background/Study Context: The age-related differences in divided attention and attentional control have been associated with several negative outcomes later in life. However, numerous questions remain unanswered regarding the nature of these age differences and the role of attentional control abilities in dual-tasking. The aim of this study was to evaluate the sources for age differences in dual-tasking and more specifically: (1) whether they occur because of differences in attentional control skills, or (2) whether the age-related decrement in dual-tasking is due to a general resource reduction that would affect the ability to complete any demanding task. METHODS: In two experiments, young and older adults were required to combine an auditory digit span task and a visuospatial tracking task, for which performance was individually adjusted on each task. In Experiment 1, attentional control skills were measured by instructing participants to deliberately vary attentional priority between the two tasks. In Experiment 2, resource availability was measured by varying the level of difficulty of the visuospatial tracking task in a parametric manner by increasing the speed of the target to be tracked. RESULTS: Both experiments confirmed the presence of a larger dual-task cost in older adults than in young adults. In Experiment 1, older participants were unable to vary their performance according to task instructions compared with younger adults. Experiment 2 showed that the age-related difference in dual-task cost was not amplified by a variation in difficulty. CONCLUSION: A marked age-related difference was found in the ability to control attentional focus in response to task instructions. However, increasing resource demand in a parametric manner does not increase the age-related differences in dual-tasking, suggesting that the difficulties experienced by older adults cannot be entirely accounted for by an increased competition for resources. A reduction in attentional control skills is proposed to account for the divided attention deficit reported in aging.

Attending to pitch information inhibits processing of pitch information: the curious case of amusia.

In normal listeners, the tonal rules of music guide musical expectancy. In a minority of individuals, known as amusics, the processing of tonality is disordered, which results in severe musical deficits. It has been shown that the tonal rules of music are neurally encoded, but not consciously available in amusics. Previous neurophysiological studies have not explicitly controlled the level of attention in tasks where participants ignored the tonal structure of the stimuli. Here, we test whether access to tonal knowledge can be demonstrated in congenital amusia when attention is controlled. Electric brain responses were recorded while asking participants to detect an individually adjusted near-threshold click in a melody. In half the melodies, a note was inserted that violated the tonal rules of music. In a second task, participants were presented with the same melodies but were required to detect the tonal deviation. Both tasks required sustained attention, thus conscious access to the rules of tonality was manipulated. In the click-detection task, the pitch deviants evoked an early right anterior negativity (ERAN) in both groups. In the pitch-detection task, the pitch deviants evoked an ERAN and P600 in controls but not in amusics. These results indicate that pitch regularities are represented in the cortex of amusics, but are not consciously available. Moreover, performing a pitch-judgment task eliminated the ERAN in amusics, suggesting that attending to pitch information interferes with perception of pitch. We propose that an impaired top-down frontotemporal projection is responsible for this disorder.

The Nature and Nurture of Melody: A Twin Study of Musical Pitch and Rhythm Perception.

Both genetic and environmental factors are known to play a role in our ability to perceive music, but the degree to which they influence different aspects of music cognition is still unclear. We investigated the relative contribution of genetic and environmental effects on melody perception in 384 young adult twins [69 full monozygotic (MZ) twin pairs, 44 full dizygotic (DZ) twin pairs, 70 MZ twins without a co-twin, and 88 DZ twins without a co-twin]. The participants performed three online music tests requiring the detection of pitch changes in a two-melody comparison task (Scale) and key and rhythm incongruities in single-melody perception tasks (Out-of-key, Off-beat). The results showed predominantly additive genetic effects in the Scale task (58 %, 95 % CI 42-70 %), shared environmental effects in the Out-of-key task (61 %, 49-70 %), and non-shared environmental effects in the Off-beat task (82 %, 61-100 %). This highly different pattern of effects suggests that the contribution of genetic and environmental factors on music perception depends on the degree to which it calls for acquired knowledge of musical tonal and metric structures.

Effects of vocal training in a musicophile with congenital amusia.

Congenital amusia is a condition in which an individual suffers from a deficit of musical pitch perception and production. Individuals suffering from congenital amusia generally tend to abstain from musical activities. Here, we present the unique case of Tim Falconer, a self-described musicophile who also suffers from congenital amusia. We describe and assess Tim's attempts to train himself out of amusia through a self-imposed 18-month program of formal vocal training and practice. We tested Tim with respect to music perception and vocal production across seven sessions including pre- and post-training assessments. We also obtained diffusion-weighted images of his brain to assess connectivity between auditory and motor planning areas via the arcuate fasciculus (AF). Tim's behavioral and brain data were compared to that of normal and amusic controls. While Tim showed temporary gains in his singing ability, he did not reach normal levels, and these gains faded when he was not engaged in regular lessons and practice. Tim did show some sustained gains with respect to the perception of musical rhythm and meter. We propose that Tim's lack of improvement in pitch perception and production tasks is due to long-standing and likely irreversible reduction in connectivity along the AF fiber tract.

Capturing with EEG the neural entrainment and coupling underlying sensorimotor synchronization to the beat.

Synchronizing movements with rhythmic inputs requires tight coupling of sensory and motor neural processes. Here, using a novel approach based on the recording of steady-state-evoked potentials (SS-EPs), we examine how distant brain areas supporting these processes coordinate their dynamics. The electroencephalogram was recorded while subjects listened to a 2.4-Hz auditory beat and tapped their hand on every second beat. When subjects tapped to the beat, the EEG was characterized by a 2.4-Hz SS-EP compatible with beat-related entrainment and a 1.2-Hz SS-EP compatible with movement-related entrainment, based on the results of source analysis. Most importantly, when compared with passive listening of the beat, we found evidence suggesting an interaction between sensory- and motor-related activities when subjects tapped to the beat, in the form of (1) additional SS-EP appearing at 3.6 Hz, compatible with a nonlinear product of sensorimotor integration; (2) phase coupling of beat- and movement-related activities; and (3) selective enhancement of beat-related activities over the hemisphere contralateral to the tapping, suggesting a top-down effect of movement-related activities on auditory beat processing. Taken together, our results are compatible with the view that rhythmic sensorimotor synchronization is supported by a dynamic coupling of sensory and motor related activities.

Pitch perception and production in congenital amusia: Evidence from Cantonese speakers.

This study investigated pitch perception and production in speech and music in individuals with congenital amusia (a disorder of musical pitch processing) who are native speakers of Cantonese, a tone language with a highly complex tonal system. Sixteen Cantonese-speaking congenital amusics and 16 controls performed a set of lexical tone perception, production, singing, and psychophysical pitch threshold tasks. Their tone production accuracy and singing proficiency were subsequently judged by independent listeners, and subjected to acoustic analyses. Relative to controls, amusics showed impaired discrimination of lexical tones in both speech and non-speech conditions. They also received lower ratings for singing proficiency, producing larger pitch interval deviations and making more pitch interval errors compared to controls. Demonstrating higher pitch direction identification thresholds than controls for both speech syllables and piano tones, amusics nevertheless produced native lexical tones with comparable pitch trajectories and intelligibility as controls. Significant correlations were found between pitch threshold and lexical tone perception, music perception and production, but not between lexical tone perception and production for amusics. These findings provide further evidence that congenital amusia is a domain-general language-independent pitch-processing deficit that is associated with severely impaired music perception and production, mildly impaired speech perception, and largely intact speech production.

The impact of musicianship on the cortical mechanisms related to separating speech from background noise.

Musicians have enhanced auditory processing abilities. In some studies, these abilities are paralleled by an improved understanding of speech in noisy environments, partially due to more robust encoding of speech signals in noise at the level of the brainstem. Little is known about the impact of musicianship on attention-dependent cortical activity related to lexical access during a speech-in-noise task. To address this issue, we presented musicians and nonmusicians with single words mixed with three levels of background noise, across two conditions, while monitoring electrical brain activity. In the active condition, listeners repeated the words aloud, and in the passive condition, they ignored the words and watched a silent film. When background noise was most intense, musicians repeated more words correctly compared with nonmusicians. Auditory evoked responses were attenuated and delayed with the addition of background noise. In musicians, P1 amplitude was marginally enhanced during active listening and was related to task performance in the most difficult listening condition. By comparing ERPs from the active and passive conditions, we isolated an N400 related to lexical access. The amplitude of the N400 was not influenced by the level of background noise in musicians, whereas N400 amplitude increased with the level of background noise in nonmusicians. In nonmusicians, the increase in N400 amplitude was related to a reduction in task performance. In musicians only, there was a rightward shift of the sources contributing to the N400 as the level of background noise increased. This pattern of results supports the hypothesis that encoding of speech in noise is more robust in musicians and suggests that this facilitates lexical access. Moreover, the shift in sources suggests that musicians, to a greater extent than nonmusicians, may increasingly rely on acoustic cues to understand speech in noise.

Impairments in musical abilities reflected in the auditory brainstem: evidence from congenital amusia.

Congenital amusia is a neurogenetic condition, characterized by a deficit in music perception and production, not explained by hearing loss, brain damage or lack of exposure to music. Despite inferior musical performance, amusics exhibit normal auditory cortical responses, with abnormal neural correlates suggested to lie beyond auditory cortices. Here we show, using auditory brainstem responses to complex sounds in humans, that fine-grained automatic processing of sounds is impoverished in amusia. Compared with matched non-musician controls, spectral amplitude was decreased in amusics for higher harmonic components of the auditory brainstem response. We also found a delayed response to the early transient aspects of the auditory stimulus in amusics. Neural measures of spectral amplitude and response timing correlated with participants' behavioral assessments of music processing. We demonstrate, for the first time, that amusia affects how complex acoustic signals are processed in the auditory brainstem. This neural signature of amusia mirrors what is observed in musicians, such that the aspects of the auditory brainstem responses that are enhanced in musicians are degraded in amusics. By showing that gradients of music abilities are reflected in the auditory brainstem, our findings have implications not only for current models of amusia but also for auditory functioning in general.

The basis of musical consonance as revealed by congenital amusia.

Some combinations of musical notes sound pleasing and are termed "consonant," but others sound unpleasant and are termed "dissonant." The distinction between consonance and dissonance plays a central role in Western music, and its origins have posed one of the oldest and most debated problems in perception. In modern times, dissonance has been widely believed to be the product of "beating": interference between frequency components in the cochlea that has been believed to be more pronounced in dissonant than consonant sounds. However, harmonic frequency relations, a higher-order sound attribute closely related to pitch perception, has also been proposed to account for consonance. To tease apart theories of musical consonance, we tested sound preferences in individuals with congenital amusia, a neurogenetic disorder characterized by abnormal pitch perception. We assessed amusics' preferences for musical chords as well as for the isolated acoustic properties of beating and harmonicity. In contrast to control subjects, amusic listeners showed no preference for consonance, rating the pleasantness of consonant chords no higher than that of dissonant chords. Amusics also failed to exhibit the normally observed preference for harmonic over inharmonic tones, nor could they discriminate such tones from each other. Despite these abnormalities, amusics exhibited normal preferences and discrimination for stimuli with and without beating. This dissociation indicates that, contrary to classic theories, beating is unlikely to underlie consonance. Our results instead suggest the need to integrate harmonicity as a foundation of music preferences, and illustrate how amusia may be used to investigate normal auditory function.