Task-set control, chunking, and hierarchical timing in rhythm production

Perceptual grouping in complex rhythmic patterns

Perception of simple temporal patterns has been shown to rely on accentuations in terms of intensity, pitch, or timbre, but also on grouping according to runs of the same events (intervals between successive sounds or light flashes) or significant gaps between them (Garner in The processing of information and structure. Lawrence Erlbaum, 1974; Preusser et al. in Am J Psychol 83(2):151-170 in 1970; Royer and Garner in Percept Psychophys 1(1):41-47, 1966; Royer and Garner in Percept Psychophys 7(2):115-120, 1970; Yu et al. in Atten Percept Psychophys 77(8):2728-2739, 2015). Here we investigate whether the run and gap principles can also account for participants' perceived start of complex rhythmic patterns. We also investigated the role of participants' musical training. Sixteen novices and 16 amateur musicians listened to rhythmic patterns and indicated perceived starting points by a single tap with a drumstick on electronic pads. Auditory patterns contained prominent gaps, runs, or a combination of the two for target intervals. We systematically varied task complexity in terms of the target durations of intervals constituting the patterns and overall tempos. Overall, run and gap principles proved to be useful grouping principles accounting for a large proportion (59.2%) of the selected starting positions underlining the universal relevance of these principles. Grouping principles were not as successful in predicting the perceived start of a rhythmic pattern compared to previous studies. Results indicate that additional grouping principles must be at play. Predictive power of the grouping principles varied depending on the structure of rhythmic patterns. For rhythmic patterns including longer intervals (i.e., longer gaps) the gap principle alone or in combination with the run principle showed the strongest predictive power. Novices and amateur musicians were similar in their usage of grouping principles suggesting that the underlying principles might be equally at the dispositions of performers and listeners.

Beat Patterns Determine Inter-Hand Differences in Synchronization Error in a Bimanual Coordination Tapping Task

A previous study reported the unique finding that people tapping a beat pattern with the right hand produce larger negative synchronization error than when tapping with the left hand or other effectors, in contrast to previous studies that have shown that the hands tap patterns simultaneously without any synchronization errors. We examined whether the inter-hand difference in synchronization error occurred due to handedness or to a specificity of the beat pattern employed in that study. Two experiments manipulated the hand–beat assignments. A comparison between the identical beat to the pacing signal and a beat with a longer interval excluded the handedness hypothesis and demonstrated that beat patterns with relatively shorter intervals were tapped earlier (Experiment 1). These synchronization errors were not local but occurred consistently throughout the beat patterns. Experiment 2 excluded alternative explanations. These results indicate that the apparent inconsistency in previous studies was due to the specificity of the beat patterns, suggesting that a beat pattern with a relatively shorter interval between hands is tapped earlier than beats with longer intervals. Our finding that the bimanual tapping of different beat patterns produced different synchronization errors suggests that the notion of a central timing system may need to be revised.