Increased activation in the left ventrolateral prefrontal cortex and temporal pole during tonality change in music

© 2018 In human music, the tonality (key) may change to punctuate sectional structures and to produce emotional effects. A tonality change would sound “smoother” when it is supported by appropriate harmony. This functional magnetic resonance imaging study examined the neural substrates of the processing of tonality change. We used a 2 × 2 factorial design with factors tonality change (tonality changed versus tonality unchanged) and harmonization (harmonized versus unharmonized). Participants were asked to covertly sing the pitch names in the movable-do system along with the heard melody. Repetitions of this melody were associated with or without a tonality change, with equal probability in a pseudo-random order. Our result demonstrated that tonality changes elicited increased activation in the left ventrolateral prefrontal cortex and left temporal pole. When a tonality change occurred, the left ventrolateral prefrontal cortex might underpin the cognitive control for retrieving the pitch-naming rule of the new tonality, whereas the left temporal pole might integrate the melodic/harmonic context and emotional meanings of music. This study provides a new insight into the cognitive and emotional processing of music.