Sleep deprivation disrupts postural balance and sensorimotor integration: A combined psychophysiological-behavioral...

Sleep is crucial for optimal sensorimotor integration, a fundamental process enabling coordinated motor responses to sensory inputs. However, the neurophysiological mechanisms through which acute sleep deprivation impairs this integration remain incompletely understood. This study investigates the impact of acute sleep deprivation on postural balance and elucidates the underlying multilayered mechanisms using a combination of behavioral, psychophysiological, and neuroimaging indicators.

Twenty-five healthy young participants underwent 36 h of total sleep deprivation. Before and after the deprivation period, data were collected on postural stability metrics, psychomotor vigilance (PVT), critical flicker fusion frequency (CFF), resting-state electroencephalography (EEG), and resting-state functional magnetic resonance imaging (fMRI). Correlation analyses were performed to examine the associations between changes in behavioral performance (postural balance, PVT, and CFF) and alterations in psychophysiological measures (EEG spectral power and fMRI resting-state activity).

Sleep deprivation significantly impaired balance, particularly with eyes closed, and was associated with reduced alertness and increased visual fatigue. EEG revealed elevated low-frequency power in occipital and frontal regions. fMRI showed altered activity in sensorimotor-related areas, especially the caudate nucleus, cerebellum, and thalamus.

Acute sleep deprivation impairs postural stability by disrupting key nodes and networks involved in sensorimotor integration. This disruption manifests as reduced visual cortical excitability (affecting sensory input), weakened cognitive regulation within the frontoparietal network (impairing sensory processing and motor planning), and altered functional status of subcortical sensorimotor hubs (compromising motor coordination and feedback). These findings demonstrate that sleep deprivation compromises the neural circuitry governing the transformation of sensory information into appropriate motor outputs for balance control. This study provides comprehensive multimodal neuroimaging evidence for the neurobiological mechanisms linking insufficient sleep to impaired sensorimotor function.