Music Cognition and Perceptual Facilitation: A Connectionist Framework

Abstract

The mind internalizes persistent structural regularities in music and recruits these internalized representations to facilitate subsequent perception. Facilitation underlies the generation of musical expectations and implications and the influence of a musical context on consonance and memory. Facilitation is demonstrated in experiments showing priming of chords: chords that are harmonically closely related to a preceding context are processed more quickly than chords that are harmonically distant from the context. A tonal context enhances intonational sensitivity for related chords and heightens their consonance. Facilitation occurs even when related chords don't share component tones with the context, and even when overlapping harmonics are eliminated. These results point to the indirect activation of representational units at a cognitive level. In a parallel study conducted in India, tones considered to play an important role in a rag but absent from the experimental rendition of that rag were facilitated in the same way. In a connectionist framework, facilitation is a consequence of activation spreading through a network of representational units whose pattern of connectivity encodes musical relationships. In a proposed connectionist model of harmony, each event in a musical sequence activates tone units, and activation spreads via connecting links to parent chord units and then to parent key units. Activation reverberates bidirectionally until the network settles into a state of equilibrium. The initial stages of the activation process constitute the bottom-up influence of the sounded tones, while the later, reverberatory stages constitute the top-down influence of learned, schematic structures internalized at the cognitive level. Computer simulations of the model show the same pattern of data as human subjects in experiments on relatedness judgments of chords and memory for chord sequences.