The neurocognitive basis of creativity: enhancing creative cognition with neurostimulation and inspiration

The ability to think creatively is uniquely human. The capacity to generate ideas that are both original and applicable to any situation is a fundamental and biologically adaptive skill. How do humans think creatively? Is everyone capable of creativity? Can creativity be increased? The aim of this thesis is to illuminate the neural mechanisms underlying creativity, with a focus on musical creativity. The experiments contained within this thesis explore brain areas that have received little attention in creativity research, and yet have surprising relevance for musical creativity. The role of inspiration in the generation of creative ideas is also addressed. Finally, the thesis introduces a novel, multilevel model of creativity that can act as a framework for interpreting past research results and for planning future studies in the field. In Chapter 1, I outline the most influential theoretical models of creativity and describe how they have shaped current understandings. My review also scrutinises the most prominent creativity tasks that are currently in use, and what those tasks can and cannot reveal about creative processes. Next, landmark research findings in the area are described that reveal how various brain regions may contribute to creative thinking, and how they interconnect. The most recent technologies used to investigate the creative brain are also reviewed (e.g., functional magnetic resonance imaging), along with an assessment of what such methods have revealed about the activation and deactivation of brain regions during creative thinking. The experiments reported in this thesis were designed to test important features of the model, focusing especially on the motor and memory systems of the brain and how they contribute to creative thinking. The experiments focused on piano musical improvisation (a measure of real-world creativity) as a model case. This approach was coupled with neuromodulation technology to determine whether distinct motor and memory regions of the brain contribute to musical creativity. In addition to neuromodulation technology, I also investigated the role of inspiration in the generation and evaluation of creative ideas in both musical improvisation and for creativity more generally (the Alternate Uses task). The focus of these experiments was to determine whether creativity can be induced by listening to self-selected inspirational music. The research was designed to assess both the mechanisms that underlie creativity as well as effective strategies for increasing creativity. The dissertation revealed several findings. First, when the primary motor cortex was excited with transcranial direct current stimulation (tDCS), musical creativity increased, but not technical fluency (Chapter 2). Second, when the posterior parietal cortex was stimulated with tDCS, there was no effect was for creativity or technical fluency (Chapter 3). Third, when listening to self-selected inspirational music compared to mundane piano scales, creativity levels were not affected in the Alternate Uses task (Experiment 1), but musical improvisations were judged to be more creative. These results show there is considerable scientific value in researching the psychological and neural markers of creativity. Understanding creativity at the level of the brain provides insight into how the brain works and helps us uncover how populations of neurons have the ability to generate an original thought in real time. Wider implications include the realm of artificial intelligence, given that creativity is vastly distinct from other modes of cognition but critical for decision making. The human brain is one of the most complex entities in our Universe, in part from the highly flexible computational capacities that arise from creativity. The goal of this thesis is to unravel the complexity of the creative brain, shedding light on what makes us human.