The impact of varying cursor latency on visuomotor tracking.

The visuomotor system compensates for sensory feedback delays, enabling the integration of visual information with motor commands to track moving objects with precision. However, when latency associated with a movement outcome becomes variable or noisy, this ability to compensate is tested. We aimed to identify the thresholds at which delays disrupt tracking to understand the limits of visuomotor prediction and error correction. Participants performed a visually guided pursuit task following a target along a curvilinear path, while eye and cursor movements were recorded under various latency conditions. Cursor position was recorded throughout each trial to quantify mouse-to-cursor latency, cursor velocity, and cursor-target error. In the first study, latency was constant within trials. Six latency magnitudes (0-300 ms) were tested and their impact on tracking performance analysed. Spectral analysis of cursor velocity showed that under high latency, pursuit submovements shifted to lower frequencies interspersed with high frequency corrective actions, whereas under low latency conditions, smoother tracking dominated. In the second study, abrupt changes in cursor latency were introduced mid-trial. Step increases in latency resulted in larger positional errors and increased corrective submovements, while decreases in latency led to rapid error reduction and a return to smoother tracking. These transitions highlight the visuomotor system's ability to recalibrate in response to latency variability. Together these results show that error correction mechanisms rapidly respond to changes in latency depending on its magnitude. These results may inform the design of assistive display technologies that maintain performance under challenging conditions and increase safety in high-risk environments.