Poster F86, Tuesday, March 27, 8:00-10:00 am, Exhibit Hall C
Dissociating the functions of delta and beta oscillatory entrainments: from intrapersonal and interpersonal perspectives
Andrew Chang1, Dan Bosnyak1, Laurel Trainor1,2; 1McMaster University, 2Rotman Research Institute
Prior studies showed that sensory systems proactively predict upcoming information to optimize perceptual and sensorimotor processing. In particular, both the phase of delta oscillations (1-3 Hz) and the power of induced beta oscillations (15-25 Hz) entrain to the temporal regularity of external tone sequence. However, it remains unclear if these two entrainment activities are associated with different functions of temporal entrainment. We aimed to investigate this topic from intrapersonal and interpersonal perspectives. In the first study, we investigated how oscillatory neural activity intrapersonally entrains to an external auditory sequence, and how it relates to perceptual processing. By combining EEG and psychophysical techniques, participants were asked to discriminate a target pitch embedded in rhythmic versus arrhythmic tone sequences. The behavioral results showed that pitch discrimination sensitivity was higher when target tones were embedded in rhythmic than arrhythmic sequences. The EEG-behavioral trial-by-trial analyses showed that the size of pre-target beta entrainment predicted pitch discriminative sensitivity, and the level of delta-beta phase-amplitude coupling predicted reaction time. In the second study, we investigated dynamic sensorimotor processing in a real-world interpersonal interaction, using professional string quartets as a model for interpersonal coordination. We experimentally manipulated leadership roles during performances, and employed causal analyses to investigate the directional coupling among musicians. Analyses on body movements revealed that directional coupling followed assigned leadership (Chang et al., 2017, PNAS), as predicted. Ongoing analyses are examining EEG dynamics, especially in delta and beta band, to investigate oscillatory synchronization and information flow between brains.
Topic Area: PERCEPTION & ACTION: Audition