Neurodynamics, tonality, and the auditory brainstem response

Tonal relationships are foundational in music, providing the basis upon which musical structures, such as melodies, are constructed and perceived. A recent dynamic theory of musical tonality predicts that networks of auditory neurons resonate nonlinearly to musical stimuli. Nonlinear resonance leads to stability and attraction relationships among neural frequencies, and these neural dynamics give rise to the perception of relationships among tones that we collectively refer to as tonal cognition. Because this model describes the dynamics of neural populations, it makes specific predictions about human auditory neurophysiology. Here, we show how predictions about the auditory brainstem response (ABR) are derived from the model. To illustrate, we derive a prediction about population responses to musical intervals that has been observed in the human brainstem. Our modeled ABR shows qualitative agreement with important features of the human ABR. This provides a source of evidence that fundamental principles of auditory neurodynamics might underlie the perception of tonal relationships, and forces reevaluation of the role of learning and enculturation in tonal cognition.     

Human Distributed Cognition from an Organism-in-Its-Environment Perspective

The organism-in-its-environment is recognized as the basic unit of analysis when dealing with living beings. This paper seeks to define the fundamental implications of the concept of the organism-in-its-environment in terms of the biosemiotic concept of human distributed cognition. Human distributed cognition in a biosemiotic context is defined as the ability of a self-referencing organism-in-its-environment to interact with its environment to satisfy its physiological (internal and external) and social needs to survive and sustain itself. The ontogenetic development of the organism-in-its-environment serves as the backdrop to discover the implications of distributed cognition that have general applicability in organisms, but in this paper, are made relevant to human beings.     

Music for a Brighter World: Brightness Judgment Bias by Musical Emotion

A prevalent conceptual metaphor is the association of the concepts of good and evil with brightness and darkness, respectively. Music cognition, like metaphor, is possibly embodied, yet no study has addressed the question whether musical emotion can modulate brightness judgment in a metaphor consistent fashion. In three separate experiments, participants judged the brightness of a grey square that was presented after a short excerpt of emotional music. The results of Experiment 1 showed that short musical excerpts are effective emotional primes that cross-modally influence brightness judgment of visual stimuli. Grey squares were consistently judged as brighter after listening to music with a positive valence, as compared to music with a negative valence. The results of Experiment 2 revealed that the bias in brightness judgment does not require an active evaluation of the emotional content of the music. By applying a different experimental procedure in Experiment 3, we showed that this brightness judgment bias is indeed a robust effect. Altogether, our findings demonstrate a powerful role of musical emotion in biasing brightness judgment and that this bias is aligned with the metaphor viewpoint.     

From Sound to Music: An Evolutionary Approach to Musical Semantics

This paper holds an evolutionary approach to musical semantics. Revolving around the nature/nurture dichotomy, it considers the role of the dispositional machinery to respond to sounding stimuli. Conceiving of music as organized sound, it stresses the dynamic tension between music as a collection of vibrational events and their potential of being structured. This structuring, however, is not gratuitous. It depends on levels of processing that rely on evolutionary older levels of reacting to the sounds as well as higher-level functions of the brain, which allow listeners to emancipate themselves from mere acoustic processing of sounds to the level of epistemic interactions with the sounding music. These interactions are partly autonomous and partly constrained, but they all stress the realization of systemic cognition in the context of a living system‘s interactions with the environment. As such, listeners can be conceived as adaptive devices, which can build up new semiotic linkages with the sounding world.     

The Concept of Umwelt Overlap and its Application to Cooperative Action in Multi-Agent Systems

The present paper stems from the biosemiotic modelling of individual artificial cognition proposed by Ferreira and Caldas (2012) but goes further by introducing the concept of Umwelt Overlap. The introduction of this concept is of fundamental importance making the present model closer to natural cognition. In fact cognition can only be viewed as a purely individual phenomenon for analytical purposes. In nature it always involves the crisscrossing of the spheres of action of those sharing the same environmental bubble. Plus, the incorporation of that concept is vital to understand the complex semiosis that sustains collective tissues, societies, regulating collective cognition and consequently cooperative action. The concept of Umwelt Overlap broadens the range of applicability of the previous model to several distinct domains allowing for example for its application to multi-agent cooperative autonomous systems. In this paper a Middle Size League RoboCup soccer team is used as an example of a possible application.     

Cross-cultural perspectives on music and musicality

Musical behaviours are universal across human populations and, at the same time, highly diverse in their structures, roles and cultural interpretations. Although laboratory studies of isolated listeners and music-makers have yielded important insights into sensorimotor and cognitive skills and their neural underpinnings, they have revealed little about the broader significance of music for individuals, peer groups and communities. This review presents a sampling of musical forms and coordinated musical activity across cultures, with the aim of highlighting key similarities and differences. The focus is on scholarly and everyday ideas about music—what it is and where it originates—as well the antiquity of music and the contribution of musical behaviour to ritual activity, social organization, caregiving and group cohesion. Synchronous arousal, action synchrony and imitative behaviours are among the means by which music facilitates social bonding. The commonalities and differences in musical forms and functions across cultures suggest new directions for ethnomusicology, music cognition and neuroscience, and a pivot away from the predominant scientific focus on instrumental music in the Western European tradition.     

Dynamic emotional and neural responses to music depend on performance expression and listener experience

Apart from its natural relevance to cognition, music provides a window into the intimate relationships between production, perception, experience, and emotion. Here, emotional responses and neural activity were observed as they evolved together with stimulus parameters over several minutes. Participants listened to a skilled music performance that included the natural fluctuations in timing and sound intensity that musicians use to evoke emotional responses. A mechanical performance of the same piece served as a control. Before and after fMRI scanning, participants reported real-time emotional responses on a 2-dimensional rating scale (arousal and valence) as they listened to each performance. During fMRI scanning, participants listened without reporting emotional responses. Limbic and paralimbic brain areas responded to the expressive dynamics of human music performance, and both emotion and reward related activations during music listening were dependent upon musical training. Moreover, dynamic changes in timing predicted ratings of emotional arousal, as well as real-time changes in neural activity. BOLD signal changes correlated with expressive timing fluctuations in cortical and subcortical motor areas consistent with pulse perception, and in a network consistent with the human mirror neuron system. These findings show that expressive music performance evokes emotion and reward related neural activations, and that music's affective impact on the brains of listeners is altered by musical training. Our observations are consistent with the idea that music performance evokes an emotional response through a form of empathy that is based, at least in part, on the perception of movement and on violations of pulse-based temporal expectancies.     

Making a Design Hold Together

The author examines early childhood music education in Taiwan through Bronfenbrenner's ecological systems theory. Factors in the microsystem level that influenced the musical development of children included adult perception of children, child-adult interactions, Taiwanese family structure, and the existing early childhood education system. The quality of child-parent-teacher relationships in mesosystem, the second level, had a noticeable impact on children's musical development. Exosystem, the next level, illustrated how insufficient early childhood teacher training in music influenced children's musical growth. The outermost level illustrated the educational policies and how the current practice affected Taiwanese children's music learning. The author gives recommendations to improve current practice of educational policies based on problems raised and discussed in the different levels.     

The perception of music.

A common but none the less remarkable human faculty is the ability to recognize and reproduce familiar pieces of music. No two performances of a given piece will ever be acoustically identical, but a listener can perceive, in both, the same rhythmic and tonal relationships, and can judge whether a particular note or phrase was played out of time or out of tune. The problem considered in this lecture is that of describing the conceptual structures by which we represent Western classical music and the processes by which these structures are created. Some new hypotheses about the perception of rhythm and tonality have been cast in the form of a computer program which will transcribe a live keyboard performance of a classical melody into the equivalent of standard musical notation.     

Activating and Relaxing Music Entrains the Speed of Beat Synchronized Walking

Inspired by a theory of embodied music cognition, we investigate whether music can entrain the speed of beat synchronized walking. If human walking is in synchrony with the beat and all musical stimuli have the same duration and the same tempo, then differences in walking speed can only be the result of music-induced differences in stride length, thus reflecting the vigor or physical strength of the movement. Participants walked in an open field in synchrony with the beat of 52 different musical stimuli all having a tempo of 130 beats per minute and a meter of 4 beats. The walking speed was measured as the walked distance during a time interval of 30 seconds. The results reveal that some music is ‘activating’ in the sense that it increases the speed, and some music is ‘relaxing’ in the sense that it decreases the speed, compared to the spontaneous walked speed in response to metronome stimuli. Participants are consistent in their observation of qualitative differences between the relaxing and activating musical stimuli. Using regression analysis, it was possible to set up a predictive model using only four sonic features that explain 60% of the variance. The sonic features capture variation in loudness and pitch patterns at periods of three, four and six beats, suggesting that expressive patterns in music are responsible for the effect. The mechanism may be attributed to an attentional shift, a subliminal audio-motor entrainment mechanism, or an arousal effect, but further study is needed to figure this out. Overall, the study supports the hypothesis that recurrent patterns of fluctuation affecting the binary meter strength of the music may entrain the vigor of the movement. The study opens up new perspectives for understanding the relationship between entrainment and expressiveness, with the possibility to develop applications that can be used in domains such as sports and physical rehabilitation.     

Neural substrates of processing syntax and semantics in music

Growing evidence indicates that syntax and semantics are basic aspects of music. After the onset of a chord, initial music-syntactic processing can be observed at about 150-400 ms and processing of musical semantics at about 300-500 ms. Processing of musical syntax activates inferior frontolateral cortex, ventrolateral premotor cortex and presumably the anterior part of the superior temporal gyrus. These brain structures have been implicated in sequencing of complex auditory information, identification of structural relationships, and serial prediction. Processing of musical semantics appears to activate posterior temporal regions. The processes and brain structures involved in the perception of syntax and semantics in music have considerable overlap with those involved in language perception, underlining intimate links between music and language in the human brain.     

Enhanced Syllable Discrimination Thresholds in Musicians

Speech processing inherently relies on the perception of specific, rapidly changing spectral and temporal acoustic features. Advanced acoustic perception is also integral to musical expertise, and accordingly several studies have demonstrated a significant relationship between musical training and superior processing of various aspects of speech. Speech and music appear to overlap in spectral and temporal features; however, it remains unclear which of these acoustic features, crucial for speech processing, are most closely associated with musical training. The present study examined the perceptual acuity of musicians to the acoustic components of speech necessary for intra-phonemic discrimination of synthetic syllables. We compared musicians and non-musicians on discrimination thresholds of three synthetic speech syllable continua that varied in their spectral and temporal discrimination demands, specifically voice onset time (VOT) and amplitude envelope cues in the temporal domain. Musicians demonstrated superior discrimination only for syllables that required resolution of temporal cues. Furthermore, performance on the temporal syllable continua positively correlated with the length and intensity of musical training. These findings support one potential mechanism by which musical training may selectively enhance speech perception, namely by reinforcing temporal acuity and/or perception of amplitude rise time, and implications for the translation of musical training to long-term linguistic abilities.     

Active Drumming Experience Increases Infants’ Sensitivity to Audiovisual Synchrony during Observed Drumming Actions

In the current study, we examined the role of active experience on sensitivity to multisensory synchrony in six-month-old infants in a musical context. In the first of two experiments, we trained infants to produce a novel multimodal effect (i.e., a drum beat) and assessed the effects of this training, relative to no training, on their later perception of the synchrony between audio and visual presentation of the drumming action. In a second experiment, we then contrasted this active experience with the observation of drumming in order to test whether observation of the audiovisual effect was as effective for sensitivity to multimodal synchrony as active experience. Our results indicated that active experience provided a unique benefit above and beyond observational experience, providing insights on the embodied roots of (early) music perception and cognition.     

Experience Changes How Emotion in Music Is Judged: Evidence from Children Listening with Bilateral Cochlear Implants,Bimodal Devices,and Normal Hearing

Children using unilateral cochlear implants abnormally rely on tempo rather than mode cues to distinguish whether a musical piece is happy or sad. This led us to question how this judgment is affected by the type of experience in early auditory development. We hypothesized that judgments of the emotional content of music would vary by the type and duration of access to sound in early life due to deafness, altered perception of musical cues through new ways of using auditory prostheses bilaterally, and formal music training during childhood. Seventy-five participants completed the Montreal Emotion Identification Test. Thirty-three had normal hearing (aged 6.6 to 40.0 years) and 42 children had hearing loss and used bilateral auditory prostheses (31 bilaterally implanted and 11 unilaterally implanted with contralateral hearing aid use). Reaction time and accuracy were measured. Accurate judgment of emotion in music was achieved across ages and musical experience. Musical training accentuated the reliance on mode cues which developed with age in the normal hearing group. Degrading pitch cues through cochlear implant-mediated hearing induced greater reliance on tempo cues, but mode cues grew in salience when at least partial acoustic information was available through some residual hearing in the contralateral ear. Finally, when pitch cues were experimentally distorted to represent cochlear implant hearing, individuals with normal hearing (including those with musical training) switched to an abnormal dependence on tempo cues. The data indicate that, in a western culture, access to acoustic hearing in early life promotes a preference for mode rather than tempo cues which is enhanced by musical training. The challenge to these preferred strategies during cochlear implant hearing (simulated and real), regardless of musical training, suggests that access to pitch cues for children with hearing loss must be improved by preservation of residual hearing and improvements in cochlear implant technology.     

Precursors of Dancing and Singing to Music in Three- to Four-Months-Old Infants

Dancing and singing to music involve auditory-motor coordination and have been essential to our human culture since ancient times. Although scholars have been trying to understand the evolutionary and developmental origin of music, early human developmental manifestations of auditory-motor interactions in music have not been fully investigated. Here we report limb movements and vocalizations in three- to four-months-old infants while they listened to music and were in silence. In the group analysis, we found no significant increase in the amount of movement or in the relative power spectrum density around the musical tempo in the music condition compared to the silent condition. Intriguingly, however, there were two infants who demonstrated striking increases in the rhythmic movements via kicking or arm-waving around the musical tempo during listening to music. Monte-Carlo statistics with phase-randomized surrogate data revealed that the limb movements of these individuals were significantly synchronized to the musical beat. Moreover, we found a clear increase in the formant variability of vocalizations in the group during music perception. These results suggest that infants at this age are already primed with their bodies to interact with music via limb movements and vocalizations.     

The origins of music in auditory scene analysis and the roles of evolution and culture in musical creation

Whether music was an evolutionary adaptation that conferred survival advantages or a cultural creation has generated much debate. Consistent with an evolutionary hypothesis, music is unique to humans, emerges early in development and is universal across societies. However, the adaptive benefit of music is far from obvious. Music is highly flexible, generative and changes rapidly over time, consistent with a cultural creation hypothesis. In this paper, it is proposed that much of musical pitch and timing structure adapted to preexisting features of auditory processing that evolved for auditory scene analysis (ASA). Thus, music may have emerged initially as a cultural creation made possible by preexisting adaptations for ASA. However, some aspects of music, such as its emotional and social power, may have subsequently proved beneficial for survival and led to adaptations that enhanced musical behaviour. Ontogenetic and phylogenetic evidence is considered in this regard. In particular, enhanced auditory–motor pathways in humans that enable movement entrainment to music and consequent increases in social cohesion, and pathways enabling music to affect reward centres in the brain should be investigated as possible musical adaptations. It is concluded that the origins of music are complex and probably involved exaptation, cultural creation and evolutionary adaptation.