Abstract:

A fundamental mystery in music cognition concerns whether and how the human brain can develop expectations and preferences for events in the auditory environment. My thesis uses behavioral and electrophysiological methods to investigate the learning of a novel system of musical sounds. We design a new musical system based on the Bohlen-Pierce scale, a microtonal scale tuned differently from the traditional Western musical scale. Chord progressions and melodies were composed in this scale as legal exemplars of two finite-state grammars. In a series of behavioral studies, participants were presented with melodies in one of the two grammars, followed by several tests assessing grammar-learning, sensitivity to frequency of occurrence, and preference for melodies. Results demonstrate that given exposure to a small number of melodies, listeners recognized and preferred melodies they had heard, but when exposed to a sufficiently large set of melodies, listeners were able to learn the underlying statistical regularities of their given grammar. These effects were influenced by psychoacoustic and statistical properties of the exposure, and were replicable with transposed melodies and for scales with different harmonies. Electrophysiological recordings (Event-Related Potentials) in response to chords in the new musical system revealed two components of cortical activity which are sensitive to the probability of occurrence and the amount of exposure of sounds in the musical context. We conclude that the human brain can rapidly acquire various structural and statistical aspects of sounds, and that neural mechanisms subserving statistical learning may be vital to music as well as other cognitive and perceptual functions more generally.