Modulation of event-related desynchronization in robot-assisted hand performance: brain oscillatory changes in active, passive and imagined movements

Abstract

BackgroundRobot-assisted therapy in patients with neurological disease is an attempt to improve function in a moderate to severe hemiparetic arm. A better understanding of cortical modifications after robot-assisted training could aid in refining rehabilitation therapy protocols for stroke patients. Modifications of cortical activity in healthy subjects were evaluated during voluntary active movement, passive robot-assisted motor movement, and motor imagery tasks performed under unimanual and bimanual protocols.MethodsTwenty-one channel electroencephalography (EEG) was recorded with a video EEG system in 8 subjects. The subjects performed robot-assisted tasks using the Bi-Manu Track robot-assisted arm trainer. The motor paradigm was executed during one-day experimental sessions under eleven unimanual and bimanual protocols of active, passive and imaged movements. The event-related-synchronization/desynchronization (ERS/ERD) approach to the EEG data was applied to investigate where movement-related decreases in alpha and beta power were localized.ResultsVoluntary active unilateral hand movement was observed to significantly activate the contralateral side; however, bilateral activation was noted in all subjects on both the unilateral and bilateral active tasks, as well as desynchronization of alpha and beta brain oscillations during the passive robot-assisted motor tasks. During active-passive movement when the right hand drove the left one, there was predominant activation in the contralateral side. Conversely, when the left hand drove the right one, activation was bilateral, especially in the alpha range. Finally, significant contralateral EEG desynchronization was observed during the unilateral task and bilateral ERD during the bimanual task.ConclusionsThis study suggests new perspectives for the assessment of patients with neurological disease. The findings may be relevant for defining a baseline for future studies investigating the neural correlates of behavioral changes after robot-assisted training in stroke patients.

Electrocorticography reveals beta desynchronization in the basal ganglia-cortical loop during rest tremor in Parkinson's disease

“…This has been shown for self-paced voluntary movement (Crone et al, 1998b) passive movement (Alegre et al 2006; Formaggio et al, 2013), and imagined movement (Formaggio et al, 2013). Alpha-beta ERD is typically represented broadly across the sensorimotor cortex (Pfurtscheller et al, 2003), occurs prior to movement initiation, and is thought to represent a “pro-kinetic” state of increased cortical responsiveness (Crone et al, 1998b).…”

Effect of instructive visual stimuli on neurofeedback training for motor imagery-based brain–computer interface

“…Online adjustment of the timing and speed of instructive visual stimulation could further improve BCI training on the ERD production. Third, the current study focused only on visual information, while somatic sensation is also known to evoke ERD even when limbs are moved passively by a human experimenter (Alegre et al, 2002), a robot (Formaggio et al, 2013), or by functional electrical stimulation (Müller et al, 2003). Therefore, combining visual and somatosensory stimulation for MI-based BCI training may be worth to investigate if multisensory integration is more effective, although concurrent presentation of multimodal sensory stimuli sometimes disturbs ERD production (Takata et al, 2012).…”

A Brain-Machine Interface Based on ERD/ERS for an Upper-Limb Exoskeleton Control

“…One reason is that, when wearing the exoskeleton, the right arm will move following the exoskeleton, which causes some problems in practical use because the movement of the right arm would produce ERD/ERS patterns over the hand area and this can result in false decisions of the system [27], especially an effect on the classification of left hand movement. Even if the right arm movement is a passive movement, it can also result in the ERD/ERS patterns similar to those in voluntary movements [40]. A related work [41] about passive movement effect found that the ERD/ERS patterns associated with upper limb movements are not significantly changed by periodic lower limb passive movements, which is similar to our results (the right hand movement mainly affects the classification of left hand movement, but not foot movement, as shown in Figure 7).…”