Does post-movement beta synchronization reflect an idling motor cortex?

Abstract

After the completion of a voluntary movement, a synchronization of cortical beta rhythms is recorded over the contralateral central region, which is assumed to reflect the termination of the motor command. In order to test this hypothesis, we compared in eight healthy subjects the synchronization of EEG beta rhythms following active and passive index extension. The passive movement was also performed after deafferentation by ischaemic nerve block in three subjects. Beta synchronization was present in all subjects after both active and passive movements, and disappeared under ischaemia in all three subjects. Post-movement beta synchronization can not solely be explained by an idling motor cortex. It may also, at least in part, reflect a movement-related somatosensory processing.

Short-term learning of a visually guided power-grip task is associated with dynamic changes in EEG oscillatory activity

“…Among other functions, the SMA seems to be involved in movement control ( [Cunnington et al, 2002], [Floyer-Lea and Matthews, 2004], [Stephan et al, 1995] and [Vaillancourt et al, 2003]) which would support the idea of ERS reflecting a reset of cortical activity in brain regions involved in a motor task as expressed in the 'idling' hypothesis . On the other hand, the SMA receives proprioceptive input from sensory afferents stimulated by passive movements (Radovanovic et al, 2002), supporting the reafferent input hypothesis of ERS ( [Cassim et al, 2001] and [Labyt et al, 2003]). Another medial frontal structure, the anterior cingulate cortex (ACC), has been suggested to have a fundamental role in relating actions to their consequences (Rushworth et al, 2004).…”

Alpha and beta oscillatory activity during a sequence of two movements

“…A beta ERD/ERS pattern has also been described during and after negative movements (induced by muscle relaxation) in magnetoencephalographic (MEG) and EEG recordings (Toma et al, 2000;Alegre et al, 2003). Passive movements are also followed by an ERS (Cassim et al, 2001;Alegre et al, 2002). Moreover, a beta-ERS is present after either somatosensory or mechanical stimulation of the limbs, without any movement (Salenius et al, 1997;Pfurtscheller et al, 2001).…”

“…The exact significance of these changes has not been clearly established, though. Pre-movement changes (mainly in the beta band), have been related to motor preparation, while the post-movement ERS has been related either to sensory afferences (Cassim et al, 2001), the return of the motor cortex to a 'rest' state (Pfurtscheller et al, 1996), or to phenomena related to the closure of the motor process (Alegre et al, 2002).…”

Executed Movement Using EEG Signals through a Naive Bayes Classifier

“…Following an ERD that occurs shortly before and during the movement, an enhancement of β oscillations (β ERS) appears within a one-second interval after the movement offset [20]. Such a post-movement β ERS has been witnessed after voluntary hand movements [22][23][24], passive movements [25], imagined movements [26] and movements induced by functional electrical stimulation.…”