The perceptual relevance of balance, evenness, and entropy in musical rhythms

Hierarchical syntax model of music predicts theta power during music listening

Linguistic research showed that the depth of syntactic embedding is reflected in brain theta power. Here, we test whether this also extends to non-linguistic stimuli, specifically music. We used a hierarchical model of musical syntax to continuously quantify two types of expert-annotated harmonic dependencies throughout a piece of Western classical music: prolongation and preparation. Prolongations can roughly be understood as a musical analogue to linguistic coordination between constituents that share the same function (e.g., 'pizza' and 'pasta' in 'I ate pizza and pasta'). Preparation refers to the dependency between two harmonies whereby the first implies a resolution towards the second (e.g., dominant towards tonic; similar to how the adjective implies the presence of a noun in 'I like spicy … '). Source reconstructed MEG data of sixty-five participants listening to the musical piece was then analysed. We used Bayesian Mixed Effects models to predict theta envelope in the brain, using the number of open prolongation and preparation dependencies as predictors whilst controlling for audio envelope. We observed that prolongation and preparation both carry independent and distinguishable predictive value for theta band fluctuation in key linguistic areas such as the Angular, Superior Temporal, and Heschl's Gyri, or their right-lateralised homologues, with preparation showing additional predictive value for areas associated with the reward system and prediction. Musical expertise further mediated these effects in language-related brain areas. Results show that predictions of precisely formalised music-theoretical models are reflected in the brain activity of listeners which furthers our understanding of the perception and cognition of musical structure.

Thematic Contents of Mental Imagery are Shaped by Concurrent Task-Irrelevant Music

Imagination plays a key role in evidence-based, cognitive therapies, and recent research highlights that music - a perceptual stimulus imbued with affective and social meaning - can influence some aspects of imagination, such as vividness and emotional tone. However, little is known about music's capability to facilitate specific imagery themes that may be relevant for therapy. Here, we examine whether the quantity and quality (related to themes of affect, social dynamics, and confidence) of people's imagery is affected by the presence of task-irrelevant background music. One hundred participants imagined the continuation of a figure's journey while listening to different musical excerpts or silence. Written reports of imagined journeys underwent linguistic analysis to reveal the number of words belonging to the themes of interest. Bayesian Mixed Effects models revealed that music (vs. silence) led to longer reports and predicted imagery characterised by affect, social dynamics, and confidence. Implications for therapy are discussed.

The effects of rhythmic structure on tapping accuracy

Prior investigations of simple rhythms in familiar time signatures have shown the importance of several mechanisms; notably, those related to metricization and grouping. But there has been limited study of complex rhythms, including those in unfamiliar time signatures, such as are found outside mainstream Western music. Here, we investigate how the structures of 91 rhythms with nonisochronous onsets (mostly complex, several in unfamiliar time signatures) influence the accuracy, velocity, and timing of taps made by participants attempting to synchronize with these onsets. The onsets were piano-tone cues sounded at a well-formed subset of isochronous cymbal pulses; the latter occurring every 234 ms. We modelled tapping at both the rhythm level and the pulse level; the latter provides insight into how rhythmic structure makes some cues easier to tap and why incorrect (uncued) taps may occur. In our models, we use a wide variety of quantifications of rhythmic features, several of which are novel and many of which are indicative of underlying mechanisms, strategies, or heuristics. The results show that, for these tricky rhythms, taps are disrupted by unfamiliar period lengths and are guided by crude encodings of each rhythm: the density of rhythmic cues, their circular mean and variance, and recognizing common small patterns and the approximate positions of groups of cues. These lossy encodings are often counterproductive for discriminating between cued and uncued pulses and are quite different to mechanisms-such as metricization and emphasizing group boundaries-thought to guide tapping behaviours in learned and familiar rhythms.

Emotional cherry picking: the role of personality and goal orientation in selective emotion regulation for musical practice

Introduction

Emotion regulation is an important part of optimising performance and successful goal pursuit in practice-based tasks such as making music. Musicians may regulate their own emotions during the course of their musical practice in order to improve their performance and ultimately attain their practice-related goals. The specific emotions they target may depend upon their personality traits but may also relate to the nature of their goal orientation, and the interaction between the two. This study investigates whether the emotions desired by musicians in their musical practice were dependent on their personality traits and Mastery goal orientation (the desire to master musical and technical skills).

Methods

Via an online questionnaire, 421 musicians completed a personality scale and answered questions relating to their mastery practice goals. They also completed emotion scales indicating how strongly they desired to increase or decrease the intensity of specific emotions when practicing.

Results

Overall, musicians preferred to up-regulate positive rather than negative emotions [paired t(420) = 58.13, p < 0.001]. Bayesian Mixed Effects models showed that personality traits affected musicians' desire to regulate specific emotions. For example, higher levels of Agreeableness predicted greater desire to increase positive but not negative emotions, whereas Extraversion predicted greater desire to increase anger [Est. = 0.05, SE = 0.03, Odds (Est. > 0) = 43.03] but not positive emotions. The inclusion of Mastery goal orientation either amplified or mitigated these effects in several cases, and also introduced new trait-emotion relationships. Findings confirm a general hedonic principle underlying the emotions musicians desired in their musical practice. However, predicted by personality traits, musicians also sometimes sought to increase the intensity of unpleasant emotions.

Discussion

These findings complement existing research that suggests that some Mastery-oriented musicians may seek an emotional state consisting of both positive and negative emotions. This and future studies on this topic may contribute to a better understanding of individual differences in emotion regulation ability as a potential aspect of individualised musical practice strategies.

Understanding preschoolers' word learning success in different scenarios: disambiguation meets statistical learning and eBook reading

Children's ability to learn new words during their preschool years is crucial for further academic success. Previous research suggests that children rely on different learning mechanisms to acquire new words depending on the available context and linguistic information. To date, there is limited research integrating different paradigms to provide a cohesive view of the mechanisms and processes involved in preschool children's word learning. We presented 4 year-old children (n = 47) with one of three different novel word-learning scenarios to test their ability to connect novel words to their correspondent referents without explicit instruction to do so. The scenarios were tested with three exposure conditions of different nature: (i) mutual exclusivity-target novel word-referent pair presented with a familiar referent, prompting fast-mapping via disambiguation, (ii) cross-situational-target novel word-referent pair presented next to an unfamiliar referent prompting statistically tracking the target pairs across trials, and (iii) eBook - target word-referent pairs presented within an audio-visual electronic storybook (eBook), prompting inferring meaning incidentally. Results show children succeed at learning the new words above chance in all three scenarios, with higher performance in eBook and mutual exclusivity than in cross-situational word learning. This illustrates children's astounding ability to learn while coping with uncertainty and varying degrees of ambiguity, which are common in real-world situations. Findings extend our understanding of how preschoolers learn new words more or less successfully depending on specific word learning scenarios, which should be taken into account when working on vocabulary development for school readiness in the preschool years.

Beautiful on the inside: Aesthetic preferences and the skeletal complexity of shapes

A plain, blank canvas does not look very beautiful; to make it aesthetically appealing requires adding structure and complexity. But how much structure is best? In other words, what is the relationship between beauty and complexity? It has long been hypothesized that complexity and beauty meet at a “sweet spot,” such that the most beautiful images are neither too simple nor too complex. Here, we take a novel experimental approach to this question, using an information-theoretic approach to object representation based on an internal “skeletal” structure. We algorithmically generated a library of two-dimensional polygons and manipulated their complexity by gradually smoothing out their features—essentially decreasing the amount of information in the objects. We then stylized these shapes as “paintings” by rendering them with artistic strokes, and “mounted” them on framed canvases hung in a virtual room. Participants were shown pairs of these mounted shapes (which possessed similar structures but varied in skeletal complexity) and chose which shape looked best by previewing each painting on the canvas. Experiment 1 revealed a “Goldilocks” effect: participants preferred paintings that were neither too simple nor too complex, such that moderately complex shapes were chosen as the most attractive paintings. Experiment 2 isolated the role of complexity per se: when the same shapes were scrambled (such that their structural complexity was undermined, while other visual features were preserved), the Goldilocks effect was dramatically diminished. These findings suggest a quadratic relationship between aesthetics and complexity in ways that go beyond previous measures of each and demonstrate the utility of information-theoretic approaches for exploring high-level aspects of visual experience.

Explaining L2 Lexical Learning in Multiple Scenarios: Cross-Situational Word Learning in L1 Mandarin L2 English Speakers

Adults commonly struggle with perceiving and recognizing the sounds and words of a second language (L2), especially when the L2 sounds do not have a counterpart in the learner's first language (L1). We examined how L1 Mandarin L2 English speakers learned pseudo English words within a cross-situational word learning (CSWL) task previously presented to monolingual English and bilingual Mandarin-English speakers. CSWL is ambiguous because participants are not provided with direct mappings of words and object referents. Rather, learners discern word-object correspondences through tracking multiple co-occurrences across learning trials. The monolinguals and bilinguals tested in previous studies showed lower performance for pseudo words that formed vowel minimal pairs (e.g., /dit/-/dɪt/) than pseudo word which formed consonant minimal pairs (e.g., /bɔn/-/pɔn/) or non-minimal pairs which differed in all segments (e.g., /bɔn/-/dit/). In contrast, L1 Mandarin L2 English listeners struggled to learn all word pairs. We explain this seemingly contradicting finding by considering the multiplicity of acoustic cues in the stimuli presented to all participant groups. Stimuli were produced in infant-directed-speech (IDS) in order to compare performance by children and adults and because previous research had shown that IDS enhances L1 and L2 acquisition. We propose that the suprasegmental pitch variation in the vowels typical of IDS stimuli might be perceived as lexical tone distinctions for tonal language speakers who cannot fully inhibit their L1 activation, resulting in high lexical competition and diminished learning during an ambiguous word learning task. Our results are in line with the Second Language Linguistic Perception (L2LP) model which proposes that fine-grained acoustic information from multiple sources and the ability to switch between language modes affects non-native phonetic and lexical development.

Musical Garden Paths: Evidence for Syntactic Revision Beyond the Linguistic Domain

While theoretical and empirical insights suggest that the capacity to represent and process complex syntax is crucial in language as well as other domains, it is still unclear whether specific parsing mechanisms are also shared across domains. Focusing on the musical domain, we developed a novel behavioral paradigm to investigate whether a phenomenon of syntactic revision occurs in the processing of tonal melodies under analogous conditions as in language. We present the first proof-of-existence for syntactic revision in a set of tonally ambiguous melodies, supporting the relevance of syntactic representations and parsing with language-like characteristics in a nonlinguistic domain. Furthermore, we find no evidence for a modulatory effect of musical training, suggesting that a general cognitive capacity, rather than explicit knowledge and strategies, may underlie the observed phenomenon in music.

Music Perception Abilities and Ambiguous Word Learning: Is There Cross-Domain Transfer in Nonmusicians?

Perception of music and speech is based on similar auditory skills, and it is often suggested that those with enhanced music perception skills may perceive and learn novel words more easily. The current study tested whether music perception abilities are associated with novel word learning in an ambiguous learning scenario. Using a cross-situational word learning (CSWL) task, nonmusician adults were exposed to word-object pairings between eight novel words and visual referents. Novel words were either non-minimal pairs differing in all sounds or minimal pairs differing in their initial consonant or vowel. In order to be successful in this task, learners need to be able to correctly encode the phonological details of the novel words and have sufficient auditory working memory to remember the correct word-object pairings. Using the Mistuning Perception Test (MPT) and the Melodic Discrimination Test (MDT), we measured learners’ pitch perception and auditory working memory. We predicted that those with higher MPT and MDT values would perform better in the CSWL task and in particular for novel words with high phonological overlap (i.e., minimal pairs). We found that higher musical perception skills led to higher accuracy for non-minimal pairs and minimal pairs differing in their initial consonant. Interestingly, this was not the case for vowel minimal pairs. We discuss the results in relation to theories of second language word learning such as the Second Language Perception model (L2LP).

Isochrony, vocal learning, and the acquisition of rhythm and melody

A cross-species perspective can extend and provide testable predictions for Savage et al.'s framework. Rhythm and melody, I argue, could bootstrap each other in the evolution of musicality. Isochrony may function as a temporal grid to support rehearsing and learning modulated, pitched vocalizations. Once this melodic plasticity is acquired, focus can shift back to refining rhythm processing and beat induction.

The influence of anodal transcranial direct current stimulation over the right auditory cortex on interference effects in memory for melodies

The study investigates how transcranial direct current stimulation (tDCS) over the auditory cortex (AC) modulates memory for melodies under different noise conditions, whilst also considering cumulative disruptive interference effects. Forty-one participants completed a continuous recognition melody task, as well as a visual control task, which included four noise conditions for which noise was either present only during encoding (N-C), only during retrieval (C-N), during both (N-N) or not at all (C-C) and completed the tasks after receiving anodal or sham tDCS over the right AC. The results of the sham session replicate previous findings by revealing that memory for melodies is worse when noise in added to the encoding phase (N-C) whereas the N-N condition shows good performance, highlighting a context effect, and that cumulative disruptive interference is not present in memory for melodies except in the N-C condition. After anodal stimulation the memory pattern differs such as that memory performance is best in the C-C condition and furthermore the cumulative disruptive interference effect in the N-C condition is diminished. In sum, the study highlights the involvement of the right AC for memory for melodies and the results indicate an association of the AC for creating context effects.

The effect of low-frequency equalisation on preference and sensorimotor synchronisation in music

Equalisation, a signal processing technique commonly used to shape the sound of music, is defined as the adjustment of the energy in specific frequency components of a signal. In this work, we investigate the effects of equalisation on preference and sensorimotor synchronisation in music. A total of 21 participants engaged in a goal-directed upper body movements in synchrony with stimuli equalised in three low-frequency sub-bands (0-50, 50-100, and 100-200 Hz). To quantify the effect of equalisation, music features including spectral flux, pulse clarity, and beat confidence were extracted from seven differently equalised versions of music tracks-one original and six manipulated versions for each music track. These music tracks were then used in a movement synchronisation task. Bayesian mixed-effects models revealed different synchronisation behaviours in response to the three sub-bands considered. Boosting energy in the 100-200 Hz sub-band reduced synchronisation performance irrespective of the sub-band energy of the original version. An energy boost in the 0-50 Hz band resulted in increased synchronisation performance only when the sub-band energy of the original version was high. An energy boost in the 50-100 Hz band increased synchronisation performance only when the sub-band energy of the original version was low. Boosting the energy in any of the three sub-bands increased preference regardless of the energy of the original version. Our results provide empirical support for the importance of low-frequency information for sensorimotor synchronisation and suggest that the effects of equalisation on preference and synchronisation are largely independent of one another.

Music influences vividness and content of imagined journeys in a directed visual imagery task

Directed, intentional imagination is pivotal for self-regulation in the form of escapism and therapies for a wide variety of mental health conditions, such anxiety and stress disorders, as well as phobias. Clinical application in particular benefits from increasing our understanding of imagination, as well as non-invasive means of influencing it. To investigate imagination, this study draws from the prior observation that music can influence the imagined content during non-directed mind-wandering, as well as the finding that relative orientation within time and space is retained in imagination. One hundred participants performed a directed imagination task that required watching a video of a figure travelling towards a barely visible landmark, and then closing their eyes and imagining a continuation of the journey. During each imagined journey, participants either listened to music or silence. After the imagined journeys, participants reported vividness, the imagined time passed and distance travelled, as well as the imagined content. Bayesian mixed effects models reveal strong evidence that vividness, sentiment, as well imagined time passed and distances travelled, are influenced by the music, and show that aspects of these effects can be modelled through features such as tempo. The results highlight music's potential to support therapies such as Exposure Therapy and Imagery Rescripting, which deploy directed imagination as a clinical tool.

Rhythm and groove as cognitive mechanisms of dance intervention in Parkinson's disease

Parkinson's disease (PD) is associated with a loss of internal cueing systems, affecting rhythmic motor tasks such as walking and speech production. Music and dance encourage spontaneous rhythmic coupling between sensory and motor systems; this has inspired the development of dance programs for PD. Here we assessed the therapeutic outcome and some underlying cognitive mechanisms of dance classes for PD, as measured by neuropsychological assessments of disease severity as well as quantitative assessments of rhythmic ability and sensorimotor experience. We assessed prior music and dance experience, beat perception (Beat Alignment Test), sensorimotor coupling (tapping to high- and low-groove songs), and disease severity (Unified Parkinson's Disease Rating Scale in PD individuals) before and after four months of weekly dance classes. PD individuals performed better on UPDRS after four months of weekly dance classes, suggesting efficacy of dance intervention. Greater post-intervention improvements in UPDRS were associated with the presence of prior dance experience and with more accurate sensorimotor coupling. Prior dance experience was additionally associated with enhanced sensorimotor coupling during tapping to both high-groove and low-groove songs. These results show that dance classes for PD improve both qualitative and quantitative assessments of disease symptoms. The association between these improvements and dance experience suggests that rhythmic motor training, a mechanism underlying dance training, impacts improvements in parkinsonian symptoms following a dance intervention.

Prefrontal High Gamma in ECoG Tags Periodicity of Musical Rhythms in Perception and Imagination

Rhythmic auditory stimuli are known to elicit matching activity patterns in neural populations. Furthermore, recent research has established the particular importance of high-gamma brain activity in auditory processing by showing its involvement in auditory phrase segmentation and envelope tracking. Here, we use electrocorticographic (ECoG) recordings from eight human listeners to see whether periodicities in high-gamma activity track the periodicities in the envelope of musical rhythms during rhythm perception and imagination. Rhythm imagination was elicited by instructing participants to imagine the rhythm to continue during pauses of several repetitions. To identify electrodes whose periodicities in high-gamma activity track the periodicities in the musical rhythms, we compute the correlation between the autocorrelations (ACCs) of both the musical rhythms and the neural signals. A condition in which participants listened to white noise was used to establish a baseline. High-gamma autocorrelations in auditory areas in the superior temporal gyrus and in frontal areas on both hemispheres significantly matched the autocorrelations of the musical rhythms. Overall, numerous significant electrodes are observed on the right hemisphere. Of particular interest is a large cluster of electrodes in the right prefrontal cortex that is active during both rhythm perception and imagination. This indicates conscious processing of the rhythms’ structure as opposed to mere auditory phenomena. The autocorrelation approach clearly highlights that high-gamma activity measured from cortical electrodes tracks both attended and imagined rhythms.