Temporal prediction and feedforward control in cerebellar ataxia during spontaneous, instructed, and adaptive auditory-motor coupling while walking.

Auditory-motor coupling, the entrainment of movement to an auditory stimulus, involves processes of temporal prediction and feedforward control. The cerebellum is central to these mechanisms, with deficits contributing to ataxia, characterized by incoordination and increased movement variability. Previous research investigated these mechanisms through perceptual or paced finger-tapping tasks. However, little is known about how these processes interact in complex motor tasks, such as walking, which require feedforward control and voluntary adaptability. Thus, the dynamic interplay between temporal prediction and feedforward control in persons with cerebellar ataxia (PwCA) during walking was assessed in three auditory-motor coupling paradigms (spontaneous, instructed and adaptive), involving walking to music and metronomes at different frequencies. The adaptive paradigm additionally incorporated real-time alignment algorithms. Sixteen PwCA (scale for the assessment and rating of ataxia 3.59 ± 2.92) and fourteen healthy controls (HCs) participated. Overall, patients showed spared temporal predictions assessed by synchronization accuracy. Yet reduced synchronization consistency and gait modulation was observed in PwCA as compared to HCs, consistent with deficits of feedforward control. The adaptive alignment algorithm may have compensated for feedforward impairments, thereby promoting enhanced synchronization and gait dynamics. This approach warrants further investigation and holds potential for integration into rehabilitation strategies for persons with mild ataxia.