Event-related potential dynamics of unilateral lower limb movement with functional connectivity analysis

Locomotor lateralization represents a general evolutionary trait in primates and is particularly well documented in human upper limb movements. Whether a corresponding lateralization pattern exists in lower limb movements, however, has remained largely unexplored.

To address this question, electroencephalographic (EEG) signals were recorded from 15 healthy volunteers while they performed instructed foot‑lift tasks under both motor execution (ME) and motor imagery (MI) conditions. The study characterized the frequency‑domain network representation of lower limb movement by analyzing event‑related potential (ERP) components in conjunction with functional connectivity measures.

The results revealed that unilateral motor imagery of the lower limb elicits functionally opposing patterns, manifested as distinct alterations in the spatial distribution of lateralized neural activities across hemispheres.

By systematically comparing motor imagery and motor execution within the same paradigm, the study provides empirical evidence that the laterality hypothesis previously established for upper limb tasks extends universally to unilateral lower limb movements, thereby advancing beyond descriptive lateralization accounts.

These findings confirm that lower limb movements exhibit robust lateralization patterns, and the observed similarity between actual and imagined movements suggests a common neural substrate, providing insights into the neural network organization that may inform future brain computer interface research.