Name:Ciara Ritchie

School/Affiliation:McMaster University

Co-Authors:Daniel J. Cameron, Laurel J. Trainor

Virtual or In-person:In-person

Abstract:

Music contains a large range of pitches and rhythms, but why is it that the bass sounds tend to carry the beat? Previous research (Hove et al., 2014) showed superior timing for lower-pitched tones compared to higher-pitched tones in adults’ behaviour and neural responses. Using electroencephalography (EEG), we are investigating whether neural responses in 7-month-old infants have the same timing bias for low pitches. Two tones were presented to the infants; either simultaneously, or with either the low or high tone 50 ms earlier than the other, every 600 ms. Data collection is ongoing (n = 23 so far). Planned analyses include measuring the mismatch response (MMR) to early-occurring tones by subtracting the average response to early-occurring low and high tones when they are presented as the standard (expected) stimulus (a context of 50% low-tone early, 50% high-tone early) from the average response to those same stimuli when they are presented as the deviant (unexpected) stimulus (a context of 80% simultaneous tones, 10% low-tone early, 10% high-tone early). Comparing the MMR for low vs. early tones in infants will provide insight into auditory development. Finding that timing deviations in low tones elicit a stronger response than deviations in high tones, replicating what was found in adults, would suggest an innate or early-developing mechanism is behind the greater sensitivity to timing for lower tones. However, if there is no difference in responses to high and low tone timing deviants, further research should examine the factors that relate to development of low-tone superiority for timing in older children and adults.