Role of expectancy in physiological responses to sound recognition of musical dissonance and timbral change

Abstract

Recently, it has been suggested that tonal violations produce greater skin conductance response (SCR) than timbral violations in music listening. However, it is unknown how people focus their attention during musical excerpts. The aim of this study is to replicate previous research considering two psychophysiological mechanisms: prediction error and brain stem reflex. Twenty-seven nonmusicians were instructed to listen six melodies and detect three altered conditions in one note: a dissonance (note out-of-key), a timbral change, and dissonance which changes in timbre and tone ( timdis). Amplitudes of SCR, heart rate (HR), and respiration rate (RSPR) were analyzed. In addition, the frequency of SCR and the percentage of musical events detection were measured. Results showed no significant differences either on amplitude of SCR or on respiratory rate. However, perception of timdis produced an increase in HR higher than dissonance ( p < .05) and the timbre condition had a higher frequency of SCR than dissonance ( p < .05). In addition, participants only detected 59.3% of dissonances but they were aware of 90% of notes in-key ( original melody). Finally, there was no significant correlation between percentage of detection and frequency of SCR. Results are discussed based on the prediction error mechanism, a theoretical model of expectation.