Neurophysiological oscillatory mechanisms underlying the effect of
mirror visual feedback-induced illusion of hand movements on nociception
and cortical activation
Abstract
Mirror Visual Feedback (MVF)-induced illusion of hand movements produces
beneficial effects in patients with chronic pain. However,
neurophysiological mechanisms underlying these effects are poorly known.
Here we hypothesized that such an MVF-induced movement illusion may
exert its effects by changing the activity in midline cortical areas of
the pain neural matrix. Electrical stimuli with individually fixed
intensity were applied to the left hand in healthy adults to produce
painful and non-painful sensations during unilateral right-hand
movements with such an MVF illusion and right and bilateral hand
movements without MVF. During these events, electroencephalographic
(EEG) activity was recorded from 64 scalp electrodes. Event-related
desynchronization (ERD) of EEG alpha rhythms (8-12 Hz) indexed the
neurophysiological oscillatory mechanisms inducing cortical activation.
As compared to the painful sensations, the non-painful sensations were
specifically characterized by (1) lower alpha ERD estimated in the
cortical midline, angular gyrus, and lateral parietal regions during the
experimental condition with MVF and (2) higher alpha ERD estimated in
the lateral prefrontal and parietal regions during the control
conditions without MVF. These core results suggest that the MVF-induced
movement illusion may affect nociception and neurophysiological
oscillatory mechanisms reducing the activation in cortical limbic and
default mode regions.