The role of trust in psychophysiological adaptation during split-belt treadmill training: a multimodal study

Trust is a key factor in motor learning, but its psychophysiological correlates remain poorly understood. This study examined how trust relates to neural, muscular, and behavioural adaptation during split-belt treadmill training. Twenty-five healthy adults (12 males, 13 females) underwent gait training with unilateral knee/ankle restrictions and weight-bearing. Electroencephalographic, electromyographic, and inertial signals, gait kinematics, and subjective trust were recorded. Variance decomposition characterised variability across signals, and multi-block partial least squares (MB-PLS) extracted latent components linking signals to trust. These analyses identified three distinct adaptation patterns combining neural, muscular, postural, and gait responses. Patterns marked by efficient neural-motor coordination and stable gait were positively associated with trust. A compensatory pattern reflecting sensorimotor conflict was negatively associated, and pattern prevalence shifted across training targets. Trust is embedded in neuromuscular adaptation signatures, supporting trust-aware rehabilitation robots and exoskeletons inferring confidence from multimodal sensing.