The Influence of Auditory Cueing and Movement Tempo on Heel-Tapping Sensorimotor Dynamics and Synchronization in Sighted and Blind/Low-Vision Individuals

This study evaluated the main and interaction effects of Visual Status (Blind/Low-Vision, BLV vs. Sighted), Auditory Cueing (Self-paced vs. Rhythmic Auditory Stimulation, RAS) and Movement Tempo (Natural, Slowest, Fastest) on heel kinematics and tapping sensorimotor synchronization. While extensive research has examined sighted populations, comparative data regarding individuals with complete visual impairment remain limited. BLV (N = 15; total blindness or severe low vision of various etiologies) and Sighted (N = 15; normal visual acuity or corrected-to-normal visual acuity) individuals performed heel tapping tasks across three distinct preferred Tapping Tempo levels (Natural, Slowest, and Fastest), each under two auditory cueing conditions (self-paced and RAS-via metronome). Linear acceleration (Acc) time series were recorded in synchronization with strike impact (Strike) time series (both sampled at 1000 Hz), all synchronized to the metronome’s signal (Met) in the RAS condition. Statistical analysis (2 × 2 × 3 mixed ANOVA, SPSS 30.0, p ≤ 0.05) aimed to assess how auditory rhythmic cueing and movement tempo modulate the magnitude and individual variability (%CVind) of the heel-tapping kinematic and sensorimotor synchronization variables across the two visual groups. The aggregated BLV group exhibited significantly degraded timing stability compared to Sighted controls, though clinical heterogeneity within the BLV cohort may mask subgroup-specific patterns (highly elevated %CVind of BLV in tcycle, dt Acc-Strike, dt Acc-Met, and dt Strike-Met, p ranging from ≤0.001 to 0.042). Conversely, RAS elicited a robust main effect that suppressed macro-level %CVind of tcycle (p < 0.001). The Fastest tempo forced significant increases in Acc (p < 0.01) and Jerk (p < 0.001), whereas the Slowest tempo exposed an entrainment constraint, causing synchronization delays (p < 0.001). RAS significantly reduced macroscopic cycle-timing variability (%CVind of tcycle) in both groups, with a larger reduction in the BLV group. In contrast, the findings do not provide clear evidence that RAS significantly modified global kinematic smoothness, as measured by Jerk magnitude. Auditory cues appear to successfully serve as automated, feedforward timing anchors for BLV when the movement task is executed at fast movement tempo, though condition-specific within-group facilitation under rapid execution warrants cautious.