Response trajectories and autonomic reactivity during adaptive human–computer interaction

Adaptive computerized tasks alter subsequent response conditions, complicating the interpretation of slowing and errors. We examined autonomic reactivity and response trajectories in 31 participants completing an adaptive cognitive task; photoplethysmography-derived pulse rate variability (PRV) passed final quality control (QC) in 26. Heart-rate (HR) change correlated positively with reaction-time (RT) slope (r = 0.452, 95% CI [0.116, 0.695]), but the permutation result did not meet the five-test Holm criterion (p = 0.070). PRV indices RMSSD and SDNN decreased from baseline to task by 8.82 and 18.98 ms, respectively. No association between PRV change and RT slope was detected (both Holm-adjusted p = 0.974). In a separate eight-test family, greater RMSSD reduction was associated with higher accuracy (r = − 0.560, 95% CI [− 0.779, − 0.221], Holm-adjusted p = 0.029); strict QC retained a similar estimate (n = 22, r = − 0.498) without meeting the corrected threshold. For local slowing, both primary empirical-logit models had Holm-adjusted p = 0.060; grouped-binomial sensitivities indicated lower failure and omission odds (adjusted p = 0.021 and 0.029). PRV analyses were post hoc.