The Electrophysiological Correlates of Rhythm and Syntax in Music and Langauge

Music and language are human cognitive and neural functions that have been shown to share neural resources in syntax processing (Patel, 2003) as well as temporal processing (Large & Jones, 1999). Although recent studies have investigated the sharing of neural resources for music and language, little is known about how music and language processing might interact as syntax unfolds over time. The current electroencephalography (EEG) study investigates the relationship between rhythmic expectancy and musical and linguistic syntax by presenting sentences, broken down into segments, paired with musical chords (adapted from Slevc et al., 2009). Linguistic syntax violations appeared in a garden-path design, and musical expectation violations, presented as out-of-key chords, and rhythmic expectancy violations, through early and late temporal perturbations, were manipulated at the critical region. Participants read sentence segments and listened to the musical chords, and answered questions about the sentences while their EEGs were recorded. Results show that musically irregular chords and linguistically unexpected garden-path sentences elicited an early anterior negativity (EAN), but tend to diverge over time, with a posterior positivity for musically irregular chords (P3a) and a late positive component (LPC) for linguistically unexpected sentences. Results also show that the N400 decreases in amplitude between pre-critical, critical, and post-critical time regions, suggesting re-analysis of semantic content throughout the course of reading sentence segments. Together, results suggest that the interaction of music and language syntax processing depends on rhythmic expectancy, which in turn affects attentional entrainment.