Abstract
Conventional keypress measurement reduces a continuous motor action to a discrete event, typically represented by reaction time (RT) and accuracy. The present study evaluated continuous analogue key-actuation as a method for characterising the unfolding response while retaining a conventional two-choice keypress format. Seventy-seven adults completed the Attention Network Test-Revised (ANT-R) while response-key depth was recorded continuously. We derived target- and press-locked waveforms together with pre-specified measures of response timing, morphology, variability, preparation, and bilateral coor-dination. Established ANT-R manipulations served as experimentally controlled tests of measurement sensitivity. Target-locked waveforms differentiated six of the seven planned ANT-R contrasts after Holm adjustment; location conflict was not significant, and the alerting effect was less robust in sensitivity analyses. No exploratory press-locked contrast survived mul-tiplicity correction. Initiation time and peak-actuation time showed reliable effects across multiple attentional contrasts, whereas ramp time (the initiation-to-peak interval) showed no reliable modulation. Effects in the morphology, coordination, and preparation/control families were more selective and were confined to flanker conflict. Exploratory models further showed that ramp, rise-to-maximum, and return durations and hold jitter predicted trial-level accuracy after controlling for RT, whereas initiation time did not. These findings show that continuous key-actuation can decompose when a speeded re-sponse begins and how it unfolds, while selected key-actuation measures provide response-quality information beyond con-ventional RT. Continuous key-actuation therefore provides an experimentally sensitive measurement approach for extending standard keypress responses, although reliability and cross-device generalisation remain to be established.