Poster D108, Monday, March 27, 8:00 – 10:00 am, Pacific Concourse
Post-Stimulus Target Detection Modulation as Evidence for the Oscillatory Entrainment Model
Moran Aharoni1, Matthias M. Müller1, Erich Schröger1; 1Leipzig University, Germany
The importance of beat entrainment, i.e., the ability to perceive and synchronize to a regular beat, extends beyond musical context, hinting at general deductive and predictive mechanisms. The oscillatory model is commonly used to represent the mechanism behind beat entrainment. Supporting evidence for the model was found in many behavioural and neuroimaging studies. However, as most previous studies focused on the stimulation period, it is hard to disentangle their periodic results from evoked responses to the beat. It is, therefore, not yet clear whether oscillatory sources play a role in beat entrainment. Large’s non-linear oscillator model (2008) suggests an ongoing oscillatory activity following the beat‘s end. Such activity, manifest in either brain signal or behavioural response, would be crucial evidence for the model. Recently, Hickok et al (2015) found periodic modulation of target detection following 3 Hz modulated noise. To find whether such response modulation is stimulus independent, we used a similar target detection task. Participants listened to a discrete, varying-length sequence of drum sounds at 3 Hz, accompanied by background noise. A target tone followed half the sequences, appearing at one of four temporal positions by equally dividing the presentation frequency period. We ran the experiment in 3 variations (four target positions, six positions and target positions shifted forward by 25%). Using a repeated-measures analysis, we found a robust, harmonic modulation (6 Hz) of the target detection rate. That is, target detection was dependent on the period of the preceding drum sequence, hinting at an ongoing oscillatory activity.
Topic Area: PERCEPTION & ACTION: Audition