Increased motor cortex excitability during motor imagery in brain-computer interface trained subjects

Abstract

Background: Motor imagery (MI) is the mental performance of movement without muscle activity. It is generally accepted that MI and motor performance have similar physiological mechanisms.Purpose: To investigate the activity and excitability of cortical motor areas during MI in subjects who were previously trained with an MI-based brain-computer interface (BCI).Subjects and Methods: Eleven healthy volunteers without neurological impairments (mean age, 36 years; range: 24–68 years) were either trained with an MI-based BCI (BCI-trained, n = 5) or received no BCI training (n = 6, controls). Subjects imagined grasping in a blocked paradigm task with alternating rest and task periods. For evaluating the activity and excitability of cortical motor areas we used functional MRI and navigated transcranial magnetic stimulation (nTMS).Results: fMRI revealed activation in Brodmann areas 3 and 6, the cerebellum, and the thalamus during MI in all subjects. The primary motor cortex was activated only in BCI-trained subjects. The associative zones of activation were larger in non-trained subjects. During MI, motor evoked potentials recorded from two of the three targeted muscles were significantly higher only in BCI-trained subjects. The motor threshold decreased (median = 17%) during MI, which was also observed only in BCI-trained subjects.Conclusion: Previous BCI training increased motor cortex excitability during MI. These data may help to improve BCI applications, including rehabilitation of patients with cerebral palsy.

Mu-Beta event-related (de)synchronization and EEG classification of left-right foot dorsiflexion kinaesthetic motor imagery for BCI

“…BCIs that use EEG features such as oscillatory/sensorimotor rhythm (SMR) are recorded over the somatic sensorimotor cortex. SMR are concentrated in the alpha (mu) (7)(8)(9)(10)(11)(12), beta , and gamma (>36 Hz) frequency bands [8,9]. BCIs have successfully deployed SMR to identify any changes related to the physical movement (motor execution, ME) or imagination of movement (motor imagery, MI) of any limb [10].…”

Clinical usefulness of brain-computer interface-controlled functional electrical stimulation for improving brain activity in children with spastic cerebral palsy: a pilot randomized controlled trial

“…These increases in concentration, improvement of wrist movement from muscle contraction, and joint ROM increase might have resulted in the improvements in upper extremity function. Researchers have also observed activation in the somatosensory and contralateral premotor areas—regions associated with knowledge acquisition and learning—when patients attend to movements on the BCI screen19 ) . Brain activity in the frontal lobe while attending to and focusing on movement may therefore be regarded as a process of practice by which movement can be acquired.…”

Motor Cortex Hyperexcitability, Neuroplasticity, and Degeneration in Amyotrophic Lateral Sclerosis

“…According to Perez et al (2004), a 32-minute training causes statistically significant increase in the slope ratio of the amplitudeintensity curve and a decrease in intracortical inhibition [81]. Increased motor cortex excitability presenting as increased MER amplitude and reduced motor threshold is observed in healthy volunteers not only after actual training but also after they had imagined the movements [82]. Professional sportsmen and musicians were found to have increased motor cortex excitability and increased ability of the motor cortex to undergo plastic alterations [83,84].…”