scholarly journals Beta band oscillations in motor cortex reflect neural population signals that delay movement onset

eLife ◽  
2017 ◽  
Vol 6 ◽  
Author(s):  
Preeya Khanna ◽  
Jose M Carmena

Motor cortical beta oscillations have been reported for decades, yet their behavioral correlates remain unresolved. Some studies link beta oscillations to changes in underlying neural activity, but the specific behavioral manifestations of these reported changes remain elusive. To investigate how changes in population neural activity, beta oscillations, and behavior are linked, we recorded multi-scale neural activity from motor cortex while three macaques performed a novel neurofeedback task. Subjects volitionally brought their beta oscillatory power to an instructed state and subsequently executed an arm reach. Reaches preceded by a reduction in beta power exhibited significantly faster movement onset times than reaches preceded by an increase in beta power. Further, population neural activity was found to shift farther from a movement onset state during beta oscillations that were neurofeedback-induced or naturally occurring during reaching tasks. This finding establishes a population neural basis for slowed movement onset following periods of beta oscillatory activity.

2020 ◽  
Author(s):  
L. Iskhakova ◽  
P. Rappel ◽  
G. Fonar ◽  
O. Marmor ◽  
R. Paz ◽  
...  

AbstractBeta oscillatory activity (13-30Hz) is pervasive within the cortico-basal ganglia (CBG) network. Studies in Parkinson’s disease (PD) patients and animal models suggested that beta-power increases with dopamine depletion. However, the exact relationship between oscillatory power, frequency and dopamine-tone remains unclear. We recorded neural activity in the CBG network of non-human-primates (NHP) while acutely up- and down-modulating dopamine levels. Further, we assessed changes in beta oscillations of PD patients following acute and chronic changes in dopamine-tone. Beta oscillation frequency was strongly coupled with dopamine-tone in both NHPs and human patients. In contrast, power, coherence between single-units and LFP, and spike-LFP phase-locking were not systematically regulated by dopamine levels. These results demonstrate via causal manipulations that frequency, rather than other properties, is the key property of pathological oscillations in the CBG networks. These insights can lead to improvements in understanding of CBG physiology, PD progression tracking and patient care.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
L. Iskhakova ◽  
P. Rappel ◽  
M. Deffains ◽  
G. Fonar ◽  
O. Marmor ◽  
...  

AbstractΒeta oscillatory activity (human: 13–35 Hz; primate: 8–24 Hz) is pervasive within the cortex and basal ganglia. Studies in Parkinson’s disease patients and animal models suggest that beta-power increases with dopamine depletion. However, the exact relationship between oscillatory power, frequency and dopamine tone remains unclear. We recorded neural activity in the cortex and basal ganglia of healthy non-human primates while acutely and chronically up- and down-modulating dopamine levels. We assessed changes in beta oscillations in patients with Parkinson’s following acute and chronic changes in dopamine tone. Here we show beta oscillation frequency is strongly coupled with dopamine tone in both monkeys and humans. Power, coherence between single-units and local field potentials (LFP), spike-LFP phase-locking, and phase-amplitude coupling are not systematically regulated by dopamine levels. These results demonstrate that beta frequency is a key property of pathological oscillations in cortical and basal ganglia networks.


Stroke ◽  
2021 ◽  
Author(s):  
Robert Schulz ◽  
Marlene Bönstrup ◽  
Stephanie Guder ◽  
Jingchun Liu ◽  
Benedikt Frey ◽  
...  

Background and Purpose: Cortical beta oscillations are reported to serve as robust measures of the integrity of the human motor system. Their alterations after stroke, such as reduced movement-related beta desynchronization in the primary motor cortex, have been repeatedly related to the level of impairment. However, there is only little data whether such measures of brain function might directly relate to structural brain changes after stroke. Methods: This multimodal study investigated 18 well-recovered patients with stroke (mean age 65 years, 12 males) by means of task-related EEG and diffusion-weighted structural MRI 3 months after stroke. Beta power at rest and movement-related beta desynchronization was assessed in 3 key motor areas of the ipsilesional hemisphere that are the primary motor cortex (M1), the ventral premotor area and the supplementary motor area. Template trajectories of corticospinal tracts (CST) originating from M1, premotor cortex, and supplementary motor area were used to quantify the microstructural state of CST subcomponents. Linear mixed-effects analyses were used to relate tract-related mean fractional anisotropy to EEG measures. Results: In the present cohort, we detected statistically significant reductions in ipsilesional CST fractional anisotropy but no alterations in EEG measures when compared with healthy controls. However, in patients with stroke, there was a significant association between both beta power at rest ( P =0.002) and movement-related beta desynchronization ( P =0.003) in M1 and fractional anisotropy of the CST specifically originating from M1. Similar structure-function relationships were neither evident for ventral premotor area and supplementary motor area, particularly with respect to their CST subcomponents originating from premotor cortex and supplementary motor area, in patients with stroke nor in controls. Conclusions: These data suggest there might be a link connecting microstructure of the CST originating from M1 pyramidal neurons and beta oscillatory activity, measures which have already been related to motor impairment in patients with stroke by previous reports.


2020 ◽  
Author(s):  
Inge Leunissen ◽  
Manon Van Steenkiste ◽  
Kirstin Heise ◽  
Thiago Santos Monteiro ◽  
Kyle Dunovan ◽  
...  

Voluntary movements are accompanied by an increase in gamma-band oscillatory activity (60-100Hz) and a strong desynchronization of beta-band activity (13-30Hz) in the motor system at both the cortical and subcortical level. Conversely, successful motor inhibition is associated with increased beta power in a fronto-basal-ganglia network. Intriguingly, gamma activity also increases in response to a stop-signal. In this study, we used transcranial alternating current stimulation to drive beta and gamma oscillations to investigate whether these frequencies are causally related to motor inhibition. We found that 20Hz stimulation targeted at the pre-supplementary motor area enhanced inhibition and increased beta oscillatory activity around the time of the stop-signal in trials directly following stimulation. In contrast, 70Hz stimulation seemed to slow down the braking process, and predominantly affected go task performance. These results demonstrate that the effects of tACS are state-dependent and that especially fronto-central beta activity is a functional marker for successful motor inhibition.


eLife ◽  
2015 ◽  
Vol 4 ◽  
Author(s):  
Chethan Pandarinath ◽  
Vikash Gilja ◽  
Christine H Blabe ◽  
Paul Nuyujukian ◽  
Anish A Sarma ◽  
...  

The prevailing view of motor cortex holds that motor cortical neural activity represents muscle or movement parameters. However, recent studies in non-human primates have shown that neural activity does not simply represent muscle or movement parameters; instead, its temporal structure is well-described by a dynamical system where activity during movement evolves lawfully from an initial pre-movement state. In this study, we analyze neuronal ensemble activity in motor cortex in two clinical trial participants diagnosed with Amyotrophic Lateral Sclerosis (ALS). We find that activity in human motor cortex has similar dynamical structure to that of non-human primates, indicating that human motor cortex contains a similar underlying dynamical system for movement generation.Clinical trial registration: NCT00912041.


2014 ◽  
Vol 112 (9) ◽  
pp. 2053-2058 ◽  
Author(s):  
Holly E. Rossiter ◽  
Marie-Hélène Boudrias ◽  
Nick S. Ward

Stroke is the most common cause of physical disability in the world today. While the key element of rehabilitative therapy is training, there is currently much interest in approaches that “prime” the primary motor cortex to be more excitable, thereby increasing the likelihood of experience-dependent plasticity. Cortical oscillations reflect the balance of excitation and inhibition, itself a key determinant of the potential for experience-dependent plasticity. In the motor system, beta-band oscillations are important and are thought to maintain the resting sensorimotor state. Here we examined motor cortex beta oscillations during rest and unimanual movement in a group of stroke patients and healthy control subjects, using magnetoencephalography. Movement-related beta desynchronization (MRBD) in contralateral primary motor cortex was found to be significantly reduced in patients compared with control subjects. Within the patient group, smaller MRBD was seen in those with more motor impairment. We speculate that impaired modulation of beta oscillations during affected hand grip is detrimental to motor control, highlighting this as a potential therapeutic target in neurorehabilitation.


2018 ◽  
Vol 30 (2) ◽  
pp. 174-187 ◽  
Author(s):  
Erika Nyhus

Evidence from fMRI has consistently located a widespread network of frontal, parietal, and temporal lobe regions during episodic retrieval. However, the temporal limitations of the fMRI methodology have made it difficult to assess the transient network dynamics by which these distributed regions coordinate activity. Recent evidence suggests that beta oscillations (17–20 Hz) are important for top–down control for memory suppression. However, the spatial limitations of the EEG methodology make it difficult to assess the relationship between these oscillatory signals and the distributed networks identified with fMRI. This study used simultaneous EEG/fMRI to identify networks related to beta oscillations during episodic retrieval. Participants studied adjectives and either imagined a scene (Place Task) or judged its pleasantness (Pleasant Task). During the recognition test, participants decided which task was performed with each word (“Old Place Task” or “Old Pleasant Task”) or “New.” EEG results revealed that posterior beta power was greater for new than old words. fMRI results revealed activity in a frontal, parietal network that was greater for old than new words, consistent with prior studies. Although overall beta power increases correlated with decreased activity within a predominantly parietal network, within the right dorsolateral and ventrolateral pFC, beta power correlated with BOLD activity more under conditions requiring more cognitive control and EEG/fMRI effects in the right frontal cortex correlated with BOLD activity in a frontoparietal network. Therefore, using simultaneous EEG and fMRI, the present results suggest that beta oscillations are related to postretrieval control operations in the right frontal cortex and act within a broader postretrieval control network.


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