Restricted vision increases sensorimotor cortex involvement in human
walking. J Neurophysiol 118: 1943–1951, 2017. First published July
5, 2017; doi:10.1152/jn.00926.2016.—This study aimed to determine
whether there is electrocortical evidence of augmented participation
of sensory brain areas in walking modulation during walking with
eyes closed. Healthy subjects (n 10) walked on a treadmill at 1 m/s
while alternating 5 min of walking with the eyes open or closed while
we recorded ground reaction forces (GRFs) and high-density scalp
electroencephalography (EEG). We applied independent component
analysis to parse EEG signals into maximally independent component
(IC) processes and then computed equivalent current dipoles for each
IC. We clustered cortical source ICs and analyzed event-related
spectral perturbations synchronized to gait events. Our results indicated
that walking with eyes closed reduced the first peak of the
vertical GRFs and induced shorter stride duration. Regarding the
EEG, we found that walking with eyes closed induced significantly
increased relative theta desynchronization in the frontal and premotor
cortex during stance, as well as greater desynchronization from theta
to beta bands during transition to single support for both left and right
somatosensory cortex. These results suggest a phase-specific increased
participation of brain areas dedicated to sensory processing
and integration when vision is not available for locomotor guidance.
Furthermore, the lack of vision demands higher neural processing
related to motor planning and execution. Our findings provide evidence
supporting the use of eyes-closed tasks in clinical practice, such
as gait rehabilitation and improvements in balance control, as there is
higher demand for additional sensory integration for achieving postural
control.
NEW & NOTEWORTHY We measured electrocortical dynamics in
sighted individuals while walking with eyes open and eyes closed to
induce the participation of other sensory systems in postural control.
Our findings show that walking with visual restriction increases the
participation of brain areas dedicated to sensory processing, motor
planning, and execution. These results confirm the essential participation
of supraspinal inputs to postural control in human locomotion,
supporting the use of eyes-closed tasks in clinical practice.