Sensorimotor synchronization (SMS), the rhythmic coordination of perception and action, is a fundamental human skill that supports many behaviors, from repetitive daily routines to the highest forms of behavioural coordination, including music and dance (see Repp, 2005; Repp & Su, 2013, for reviews). Research SMS has been mostly conducted in the lab using finger tapping paradigms, where participants typically tap with their index finger to a rhythmic sequence of auditory stimuli. However, these experiments require equipment with high temporal fidelity to capture the asynchronies between the time of the tap and the corresponding cue event, often in the tens of milliseconds range. Thus, SMS poses a unique challenge to study with online research, where variability in participants’ hardware and software can introduce uncontrolled latency and jitter into the recorded timestamps. For example, rhythm production experiments performed online, such as tapping on the spacebar or mouse in synchronization to an external beat, can introduce delays in the order of 60 to 100 ms (Anwyl-Irvine et al., 2020). 

We have developed a novel technology to measure SMS in online-based experiments that achieves small latency and jitter (< 4 ms), while also being practical in terms of realistic data collection. We have successfully collected large tapping datasets this way (Niarchou et al. in prep) and validated the technology through a series of calibration and behavioural experiments. We found  that our technology reaches the quality levels of in-lab studies while massively increasing the scalability and speed of data collection,  making research on SMS more accessible and efficient.