Frontal brain asymmetries as effective parameters to assess the quality of audiovisual stimuli perception in adult and young cochlear implant users

How is music perceived by cochlear implant (CI) users? This question arises as "the next step" given the impressive performance obtained by these patients in language perception. Furthermore, how can music perception be evaluated beyond self-report rating, in order to obtain measurable data? To address this question, estimation of the frontal electroencephalographic (EEG) alpha activity imbalance, acquired through a 19-channel EEG cap, appears to be a suitable instrument to measure the approach/withdrawal (AW index) reaction to external stimuli. Specifically, a greater value of AW indicates an increased propensity to stimulus approach, and vice versa a lower one a tendency to withdraw from the stimulus. Additionally, due to prelingually and postlingually deafened pathology acquisition, children and adults, respectively, would probably differ in music perception. The aim of the present study was to investigate children and adult CI users, in unilateral (UCI) and bilateral (BCI) implantation conditions, during three experimental situations of music exposure (normal, distorted and mute). Additionally, a study of functional connectivity patterns within cerebral networks was performed to investigate functioning patterns in different experimental populations. As a general result, congruency among patterns between BCI patients and control (CTRL) subjects was seen, characterised by lowest values for the distorted condition (vs. normal and mute conditions) in the AW index and in the connectivity analysis. Additionally, the normal and distorted conditions were significantly different in CI and CTRL adults, and in CTRL children, but not in CI children. These results suggest a higher capacity of discrimination and approach motivation towards normal music in CTRL and BCI subjects, but not for UCI patients. Therefore, for perception of music CTRL and BCI participants appear more similar than UCI subjects, as estimated by measurable and not self-reported parameters

The Neural Mechanisms of Musical Rhythm Processing: Cross-Cultural Differences and the Stages of Beat Perception

Music is a universal human behaviour, is fundamentally temporal, and has unique temporal properties. This thesis presents research on the cognitive neuroscience of the temporal aspects of music: rhythm, beat, and metre. Specifically, this work investigates how cultural experience influences behavioural and neural measures of rhythm processing, and the different neural mechanisms (with particular interest in the role of the striatum) that underlie different stages of beat perception, as musical rhythms unfold. Chapter 1 presents an overview of the existing literature on the perceptual, cognitive, and neural processing of rhythm, including the entrainment of neural oscillations to rhythm and the neuroanatomical substrates of rhythm perception. Chapter 2 presents research on cross-cultural differences in the perception and production of musical rhythm and beat. Here, East African and North American participants performed three tasks (beat tapping, rhythm discrimination, and rhythm reproduction) using rhythms from East African and Western music. The results indicate an influence of culture on beat tapping and rhythm reproduction, but not rhythm discrimination. Chapter 3 presents electroencephalographic (EEG) research on cross-cultural differences in neural entrainment to rhythm and beat. The degree to which neural oscillations entrained to the different regular ‘metrical levels’ of rhythms differed between groups, suggesting an influence of culture. Moreover, across all participants, the proportion of trials in which different rates were tapped was correlated with the degree of neural entrainment to those rates. Chapter 4 presents functional magnetic resonance imaging (fMRI) research on the different neural mechanisms that underlie the different stages of beat perception (finding, continuation, and adjustment). Distinct regions of the striatum (dorsal vs. ventral putamen) were active to different extents in beat finding and adjustment, respectively. Activity in other regions (including the cerebellum, parietal cortex, supplementary motor area, and insula) also differed between stages. Additionally, when rhythms were metrically incongruent (polyrhythmic), additional activity was found in superior temporal gyri and the insula. Chapter 5 presents a general discussion of Chapters 2-4 in the context of the existing literature, limitations, and broader interpretations of how these results relate to future directions in the field

Not Cure But Heal: Music and Medicine

Despite evidence for music-specific mechanisms at the level of pitch-pattern representations, the most fascinating aspect of music is its transmodality. Recent psychological and neuroscientific evidence suggests that music is unique in the coupling of perception, cognition, action, and emotion. This potentially explains why music has been since time immemorial almost inextricably linked to healing processes and should continue to be

Investigating brain responses to section endings in tonal, classical and rhythmic music : an fMRI study

Our overall aim was to examine brain responses to different experiences of time in music with a particular focus on the question of how we experience large-scale music form. The present experiment was aimed at investigating the neural correlates to experiencing section endings in teleological (goal-directed) music as well as in rhythmic (groove-based) music. We used functional magnetic resonance imaging (fMRI) on 14 human participants. Comparing transition points to continuous sections of the music we found that there was more neural activity in both musical genres at the transition points. Additionally we saw stronger blood-oxygen-level dependent (BOLD) fMRI activations at transition points in the rhythmical piece than in the classical piece. We did four region-of-interest (ROI) analyses, based on a priori expectations about the likely involvement of different brain areas in our task; the ventrolateral prefrontal cortex (VLPFC), the posterior temporal cortex (PTC), the dorsolateral prefrontal cortex (DLPFC) and the posterior parietal cortex (PPC). PTC was the only region that showed activations strong enough to survive the correction for multiple comparisons

Affective Brain-Computer Interfaces Neuroscientific Approaches to Affect Detection

The brain is involved in the registration, evaluation, and representation of emotional events, and in the subsequent planning and execution of adequate actions. Novel interface technologies – so-called affective brain-computer interfaces (aBCI) - can use this rich neural information, occurring in response to affective stimulation, for the detection of the affective state of the user. This chapter gives an overview of the promises and challenges that arise from the possibility of neurophysiology-based affect detection, with a special focus on electrophysiological signals. After outlining the potential of aBCI relative to other sensing modalities, the reader is introduced to the neurophysiological and neurotechnological background of this interface technology. Potential application scenarios are situated in a general framework of brain-computer interfaces. Finally, the main scientific and technological challenges that have to be solved on the way toward reliable affective brain-computer interfaces are discussed

The neuroscience of musical creativity using complexity tools

This project is heavily experimental and draws on a wide variety of disciplines from musicology and music psychology to cognitive neuroscience and (neuro)philosophy. The objective is to explore and characterise brain activity during the process of creativity and corroborating this with self-assessments from participants and external assessments from professional “judges”. This three-way experimental design bypasses the semantically difficult task of defining and assessing creativity by asking both participants and judges to rate ‘How creative did you think that was?’. Characterising creativity is pertinent to complexity as it is an opportunity to comprehensively investigate a neural and cognitive system from multiple experimental and analytical facets. This thesis explores the anatomical and functional system underlying the creative cognitive state by analysing the concurrent time series recorded from the brain and furthermore, investigates a model in the stages of creativity using a behavioural experiment, in more detail than hitherto done in this domain. Experimentally, the investigation is done in the domain of music and the time series is the recorded Electroencephalogram (EEG) of a pianist’s whilst performing the two creative musical tasks of ‘Interpretation’ and ‘Improvisation’ manipulations of musical extracts. An initial pilot study consisted of 5 participants being shown 30 musical extracts spanning the Classical soundworld across different rhythms, keys and tonalities. The study was then refined to only 20 extracts and modified to include 10 Jazz extracts and 8 participants from a roughly equal spread of Classical and Jazz backgrounds and gender. 5 external assessors had a roughly even spread of expertise in Jazz and Classical music. Source localisation was performed on the experimental EEG data collected using a software called sLORETA that allows a linear inverse mapping of the electrical activity recorded at the scalp surface onto deeper cortical structures as the source of the recorded activity. Broadman Area (BA) 37 which has previously been linked to semantic processing, was robustly related to participants from a Classical background and BA 7 which has previously been linked to altered states of consciousness such as hypnagogia and sleep, was robustly related to participants from a Jazz background whilst Improvising. Analyses exploring the spread, agreement and biases of ratings across the different judges and self-ratings revealed a judge and participant inter-rater reliability at participant level. There was also an equal agreement between judges when rating the different genres Jazz or Classical, across the different tasks of ‘Improvisation’ and ‘Interpretation’, increasing confidence in inter-genre rating reliability for further analyses on the EEG of the extracts themselves. Furthermore, based on the ratings alone, it was possible to partition participants into either Jazz or Classical, which agreed with phenomenological interview information taken from the participants themselves. With the added conditions of extracts that were deemed creative by objective judge assessment, source localisation analyses pinpointed BA 32 as a robust indicator of Creativity within the participants’ brain. It is an area that is particularly well connected and allows an integration of motoric and emotional communication with a maintenance of executive control. Network analysis was performed using the PLV index (Phase Locking Value) between the 64 electrodes, as the strength of the links in an adjacency matrix of a complex network. This revealed the brain network is significantly more efficient and more strongly synchronised and clustered when participants’ are playing Classical extracts compared to Jazz extracts, in the fronto-central region with a clear right hemispheric lateralization. A behavioural study explored the role of distraction in the ‘Incubation’ period for both interpretation and improvisation using a 2-back number exercise occupying working memory, as the distractor. Analysis shows that a distractor has no significant effect on ‘Improvisation’ but significantly impairs ‘Interpretation’ based on the self-assessments by the participants.Open Acces

Music in Research and Rehabilitation of Disorders of Consciousness: Psychological and Neurophysiological Foundations

According to a prevailing view, the visual system works by dissecting stimuli into primitives, whereas the auditory system processes simple and complex stimuli with their corresponding features in parallel. This makes musical stimulation particularly suitable for patients with disorders of consciousness (DoC), because the processing pathways related to complex stimulus features can be preserved even when those related to simple features are no longer available. An additional factor speaking in favor of musical stimulation in DoC is the low efficiency of visual stimulation due to prevalent maladies of vision or gaze fixation in DoC patients. Hearing disorders, in contrast, are much less frequent in DoC, which allows us to use auditory stimulation at various levels of complexity. The current paper overviews empirical data concerning the four main domains of brain functioning in DoC patients that musical stimulation can address: perception (e.g., pitch, timbre, and harmony), cognition (e.g., musical syntax and meaning), emotions, and motor functions. Music can approach basic levels of patients’ self-consciousness, which may even exist when all higher-level cognitions are lost, whereas music induced emotions and rhythmic stimulation can affect the dopaminergic reward-system and activity in the motor system respectively, thus serving as a starting point for rehabilitation

A multicomponential examination of tennis players’ emotional responses to music

This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University.The principal aim of this research programme was to examine multiple components of competitive tennis players’ emotional responses to pre-performance music. To this end, four objectives were defined: First, to develop a grounded theory (Glaser & Strauss, 1967) of players’ use of music to manipulate emotional state; second, to examine the impact of altering music tempo and intensity on players’ affective and behavioural responses; third, to identify neural origins for these phenomena; and fourth, to elucidate the role of motoneuron excitability in behavioural responses observed. These objectives were realised in four interrelated studies. First, 14 players provided quantitative and qualitative interview, questionnaire, and diary data to detail their use of personally emotive music; a grounded theory and associated model were consequently developed to facilitate future research and practice. Participants used music to attain five broad emotional states, including psyched-up; this was associated with faster tempi and louder intensities (volumes). Study 2 was conceived to examine the effects of manipulating these variables on 54 players’ affective and behavioural states, using measures based on Russell’s (1980) affective circumplex and reaction times (RTs). Faster tempi elicited higher valence and arousal, loud intensity yielded higher arousal and shorter RTs; and higher arousal was associated with shorter RTs. Functional magnetic resonance imaging was utilised in Study 3 to identify neural bases for 12 participants’ emotional responses to the same music manipulations; emotion-processing, visuomotor and sensorimotor structures were activated under high-arousal conditions. Transcranial magnetic stimulation and electromyography were used in Study 4 to investigate changes in 10 participants’ corticospinal excitability as a result of listening to purposively selected music; optimised music elicited higher arousal and reduced corticospinal response latencies. The foremost contribution of this thesis is to show that music variables may be carefully selected and/or manipulated to maximise performance-facilitating emotional responses to music in tennis