Poster Presentation

Poster A in Poster Session A: Tuesday, August 4, 9:30 – 11:15 am, Kimmel Center, Shorin & Rosenthal Rooms

Internal noise, not error correction, limits the development of synchronization and adaptation

Michal Dobner¹, Gal Vishne², Merav Ahissar¹; ¹Hebrew University of Jerusalem, ²Columbia University

Presenter: Michal Dobner

Sensorimotor synchronization improves with development (Vorberg & Schulze, 2002; Jacoby & Keller, 2015), yet the mechanisms underlying this trajectory remain poorly understood. We tested whether developmental changes reflect improvements in error correction or reductions in internal variability. 198 children aged 5.5–13 and 68 adults performed a paced tapping task with fixed and changing tempos. In the fixed-tempo condition, synchronization precision improved with age, though not reaching adult levels. A computational model decomposed performance into three components: error correction, timekeeper noise (interval memory precision), and motor noise. Error correction did not change with age, whereas timekeeper noise decreased substantially and motor noise showed weaker changes. In a tempo-change condition, participants adapted to sudden tempo shifts. Some maintained alignment with the metronome throughout ("aligners"), while others showed breakdowns with missing or extra taps ("non-aligners"). Non-aligners exhibited higher timekeeper noise in the fixed-tempo condition even after controlling for age, while motor noise and error correction did not differ. These results show that developmental improvements in synchronization and adaptation are constrained by timekeeper noise rather than error-correction mechanisms, which appear adult-like by early childhood.

Topic Area: Development, Individual Differences & Clinical Populations