Perceived Timing of Postural Instability Onset With and Without Vision

Background Vision can significantly impact both the perception and behaviour related to postural control. This study examines the influence of vision on the perception of postural instability onset. Previous research employing Temporal Order Judgment (TOJ) tasks to investigate the perceived timing of postural perturbation onset has not incorporated visual cues. Research question Does the presence of visual feedback affect the point of subjective simultaneity (PSS) between postural perturbation onset and an auditory reference stimulus and does this additional sensory cue increase TOJ precision? Methods Using a lean-and-release paradigm, 10 participants were exposed to postural perturbations in both eyes closed (EC) and eyes open (EO) conditions using a TOJ task where they indicated whether they perceived postural instability onset or sound onset as occurring first for each trial. Separate paired t-tests between EC and EO PSS and just noticeable difference (JND) values were used. One-sample t-tests were also used on PSS values for both conditions, comparing them to 0ms (true simultaneity). Results The EC condition demonstrated a perceived delay of postural instability onset by 25.78 ms, while the EO condition showed a perceived delay of the auditory stimulus by 12.33 ms. However, no significant differences were found between the conditions or in comparison to true simultaneity. Mean JND values for EC (39.88 ms) and EO (46.48 ms) were not significantly different, suggesting visual information does not affect response precision for this task under these conditions. Significance These findings indicate that visual information does not significantly affect the perception of postural instability onset. This suggests that visual information may play a limited role in the early perceptual stages of postural instability.