The Neuroscience of Musical Improvisation

Researchers have recently begun to examine the neural basis of musical improvisation, one of the most complex forms of creative behavior. The emerging field of improvisation neuroscience has implications not only for the study of artistic expertise, but also for understanding the neural underpinnings of domain-general processes such as motor control and language production. This review synthesizes functional magnetic resonance imagining (fMRI) studies of musical improvisation, including vocal and instrumental improvisation, with samples of jazz pianists, classical musicians, freestyle rap artists, and non-musicians. A network of prefrontal brain regions commonly linked to improvisatory behavior is highlighted, including the pre-supplementary motor area, medial prefrontal cortex, inferior frontal gyrus, dorsolateral prefrontal cortex, and dorsal premotor cortex. Activation of premotor and lateral prefrontal regions suggests that a seemingly unconstrained behavior may actually benefit from motor planning and cognitive control. Yet activation of cortical midline regions points to a role of spontaneous cognition characteristic of the default network. Together, such results may reflect cooperation between large-scale brain networks associated with cognitive control and spontaneous thought. The improvisation literature is integrated with Pressing’s theoretical model, and discussed within the broader context of research on the brain basis of creative cognition

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

Neural Substrates of Spontaneous Musical Performance: An fMRI Study of Jazz Improvisation

To investigate the neural substrates that underlie spontaneous musical performance, we examined improvisation in professional jazz pianists using functional MRI. By employing two paradigms that differed widely in musical complexity, we found that improvisation (compared to production of over-learned musical sequences) was consistently characterized by a dissociated pattern of activity in the prefrontal cortex: extensive deactivation of dorsolateral prefrontal and lateral orbital regions with focal activation of the medial prefrontal (frontal polar) cortex. Such a pattern may reflect a combination of psychological processes required for spontaneous improvisation, in which internally motivated, stimulus-independent behaviors unfold in the absence of central processes that typically mediate self-monitoring and conscious volitional control of ongoing performance. Changes in prefrontal activity during improvisation were accompanied by widespread activation of neocortical sensorimotor areas (that mediate the organization and execution of musical performance) as well as deactivation of limbic structures (that regulate motivation and emotional tone). This distributed neural pattern may provide a cognitive context that enables the emergence of spontaneous creative activity

Where do bright ideas occur in our brain? Meta-analytic evidence from neuroimaging studies of domain-specific creativity

Many studies have assessed the neural underpinnings of creativity, failing to find a clear anatomical localization. We aimed to provide evidence for a multi-componential neural system for creativity. We applied a general activation likelihood estimation (ALE) meta-analysis to 45 fMRI studies. Three individual ALE analyses were performed to assess creativity in different cognitive domains (Musical, Verbal, and Visuo-spatial). The general ALE revealed that creativity relies on clusters of activations in the bilateral occipital, parietal, frontal, and temporal lobes. The individual ALE revealed different maximal activation in different domains. Musical creativity yields activations in the bilateral medial frontal gyrus, in the left cingulate gyrus, middle frontal gyrus, and inferior parietal lobule and in the right postcentral and fusiform gyri. Verbal creativity yields activations mainly located in the left hemisphere, in the prefrontal cortex, middle and superior temporal gyri, inferior parietal lobule, postcentral and supramarginal gyri, middle occipital gyrus, and insula. The right inferior frontal gyrus and the lingual gyrus were also activated. Visuo-spatial creativity activates the right middle and inferior frontal gyri, the bilateral thalamus and the left precentral gyrus. This evidence suggests that creativity relies on multi-componential neural networks and that different creativity domains depend on different brain regions

The Perception of Musical Spontaneity in Improvised and Imitated Jazz Performances

The ability to evaluate spontaneity in human behavior is called upon in the esthetic appreciation of dramatic arts and music. The current study addresses the behavioral and brain mechanisms that mediate the perception of spontaneity in music performance. In a functional magnetic resonance imaging experiment, 22 jazz musicians listened to piano melodies and judged whether they were improvised or imitated. Judgment accuracy (mean 55%; range 44–65%), which was low but above chance, was positively correlated with musical experience and empathy. Analysis of listeners’ hemodynamic responses revealed that amygdala activation was stronger for improvisations than imitations. This activation correlated with the variability of performance timing and intensity (loudness) in the melodies, suggesting that the amygdala is involved in the detection of behavioral uncertainty. An analysis based on the subjective classification of melodies according to listeners’ judgments revealed that a network including the pre-supplementary motor area, frontal operculum, and anterior insula was most strongly activated for melodies judged to be improvised. This may reflect the increased engagement of an action simulation network when melodic predictions are rendered challenging due to perceived instability in the performer's actions. Taken together, our results suggest that, while certain brain regions in skilled individuals may be generally sensitive to objective cues to spontaneity in human behavior, the ability to evaluate spontaneity accurately depends upon whether an individual's action-related experience and perspective taking skills enable faithful internal simulation of the given behavior

Brain Functional and Structural Networks Underpinning Musical Creativity

Musical improvisation is one of the most complex forms of creative behavior, which offers a realistic task paradigm for the investigation of real-time creativity. Despite previous studies on the topics of musical improvisation, brain activations, and creativity, the main questions about the neural mechanisms for musical improvisation in efforts to unlocking the mystery of human creativity remain unanswered. What are the brain regions that are activated during the improvised performances of music? How do these brain areas coordinate activity among themselves and others during such performances? Whether and how does the brain connectivity structure encapsulate such creative skills? In attempts to contribute to answering these questions, this dissertation examines the brain activity dynamics during musical improvisation, explores white matter fiber architecture in advanced jazz improvisers using functional and structural magnetic resonance imaging (MRI) techniques. A group of advanced jazz musicians underwent functional and structural magnetic resonance brain imaging. While the functional MRI (fMRI) of their brains were collected, these expert improvisers performed vocalization and imagery improvisation and pre-learned melody tasks. The activation and connectivity analysis of the fMRI data showed that musical improvisation is characterized by higher brain activity with less functional connectivity compared to pre-learned melody in the brain network consisting of the dorsolateral prefrontal cortex (dlPFC), supplementary motor area (SMA), lateral premotor cortex (lPMC), Cerebellum (Cb) and Broca’s Area (BCA). SMA received a dominant causal information flow from dlPFC during improvisation and prelearned melody tasks. The deterministic fiber tractography analysis also revealed that the underlying white matter structure and fiber pathways in advanced jazz improvisers were enhanced in advanced jazz improvisers compared to the control group of nonmusicians, specifically the dlPFC - SMA network. These results point to the notion that an expert\u27s performance under real-time constraints is an internally directed behavior controlled primarily by a specific brain network, that has enhanced task-supportive structural connectivity. Overall, these findings suggest that a creative act of an expert is functionally controlled by a specific cortical network as in any internally directed attention and is encapsulated by the long-timescale brain structural network changes in support of the related cognitive underpinnings

The improviser and the improvised: The relationship between neural and musical structures, and the role of improvisation

This paper investigates the intersection of well-formed structures in music with neurocognitive structures and responses in expert musicians. As musicology has explored musical structures to great length, and neuroscience has begun exploring the neural structures that underscore musical experiences, little research has been done to investigate how functional differences in music structure relate to neural structure. As the overwhelming majority of professional performing musicians have regular contact with music structures in applied and theoretical contexts, it is of interest to understand how the functions of these music structures correlate with neurocognitive structures when listening to or performing music. Furthermore, this work aims to explore how experience with improvisation drives the relationship between the function of musical structures and its neural correlates. This work is motivated by the idea that improvising musicians regularly employ techniques to change the prescribed music structure to fit the dynamics of the musical environment. This implies that expert improvising musicians may view the function of musical structures differently from musicians who do not interact with music structure in such a way. As such, an EEG experiment was conducted to investigate this relationship. Forty-one musicians performed an oddball task where they listened to 3-chord chord progressions, responding to any and all oddball chord progressions on a computer keyboard. The middle chord could be an exemplar oddball (an inversion of standard chord) or a functional oddball (a different class from the standard chord). The results found that musicians with more improvisational experience produced a greater response to functional deviants, indicating that improvisation experience plays a role in what category of structural information is more prevalent to the musician. These results were consistent across behavioral and neural measures, which were also correlated with one another. Chapters 1 and 2 provide background on music structure, improvisation, neuroscience, and the intersection of the three. Chapters 3 and 4 explain the experiment and the results. Chapter 5 integrates these results into the larger questions regarding improvisation, creativity research, and considers the pragmatic applications of improvisation training. Finally, this paper proposes another study that addresses deeper questions about neural and music structural correlations

The neuroscience of musical improvisation

Abstract: Researchers have recently begun to examine the neural basis of musical improvisation, one of the most complex forms of creative behavior. The emerging field of improvisation neuroscience has implications not only for the study of artistic expertise, but also for understanding the neural underpinnings of domain-general processes such as motor control and language production. This review synthesizes functional magnetic resonance imagining (fMRI) studies of musical improvisation, including vocal and instrumental improvisation, with samples of jazz pianists, classical musicians, freestyle rap artists, and non-musicians. A network of prefrontal brain regions commonly linked to improvisatory behavior is highlighted, including the presupplementary motor area, medial prefrontal cortex, inferior frontal gyrus, dorsolateral prefrontal cortex, and dorsal premotor cortex. Activation of premotor and lateral prefrontal regions suggests that a seemingly unconstrained behavior may actually benefit from motor planning and cognitive control. Yet activation of cortical midline regions points to a role of spontaneous cognition characteristic of the default network. Together, such results may reflect cooperation between large-scale brain networks associated with cognitive control and spontaneous thought. The improvisation literature is integrated with Pressing's theoretical model, and discussed within the broader context of research on the brain basis of creative cognition