scholarly journals Functional brain plasticity during L1 training on complex sentences: Changes in gamma‐band oscillatory activity

2021 ◽  
Author(s):  
Peng Wang ◽  
Thomas R. Knösche ◽  
Luyao Chen ◽  
Jens Brauer ◽  
Angela D. Friederici ◽  
...  
Keyword(s):  
Brain Plasticity ◽  
Gamma Band ◽  
Oscillatory Activity ◽  
Functional Brain ◽  
Complex Sentences

scholarly journals The Rapid Extraction of Gist—Early Neural Correlates of High-level Visual Processing

2012 ◽  
Vol 24 (2) ◽  
pp. 521-529 ◽  
Author(s):  
Frank Oppermann ◽  
Uwe Hassler ◽  
Jörg D. Jescheniak ◽  
Thomas Gruber
Keyword(s):  
Visual Processing ◽  
Time Course ◽  
Occipital Cortex ◽  
Stimulus Onset ◽  
Gamma Band ◽  
Oscillatory Activity ◽  
Rapid Extraction ◽  
The Right ◽  
High Level ◽  
Individual Objects

The human cognitive system is highly efficient in extracting information from our visual environment. This efficiency is based on acquired knowledge that guides our attention toward relevant events and promotes the recognition of individual objects as they appear in visual scenes. The experience-based representation of such knowledge contains not only information about the individual objects but also about relations between them, such as the typical context in which individual objects co-occur. The present EEG study aimed at exploring the availability of such relational knowledge in the time course of visual scene processing, using oscillatory evoked gamma-band responses as a neural correlate for a currently activated cortical stimulus representation. Participants decided whether two simultaneously presented objects were conceptually coherent (e.g., mouse–cheese) or not (e.g., crown–mushroom). We obtained increased evoked gamma-band responses for coherent scenes compared with incoherent scenes beginning as early as 70 msec after stimulus onset within a distributed cortical network, including the right temporal, the right frontal, and the bilateral occipital cortex. This finding provides empirical evidence for the functional importance of evoked oscillatory activity in high-level vision beyond the visual cortex and, thus, gives new insights into the functional relevance of neuronal interactions. It also indicates the very early availability of experience-based knowledge that might be regarded as a fundamental mechanism for the rapid extraction of the gist of a scene.

scholarly journals Selective sensory deafferentation induces structural and functional brain plasticity

2019 ◽  
Vol 21 ◽  
pp. 101633 ◽  
Author(s):  
Raphael F. Casseb ◽  
Brunno M. de Campos ◽  
Alberto R.M. Martinez ◽  
Gabriela Castellano ◽  
Marcondes C. França Junior
Keyword(s):  
Brain Plasticity ◽  
Functional Brain

scholarly journals Induced gamma band activity from EEG as a possible index of training-related brain plasticity in motor tasks

PLoS ONE ◽  
2017 ◽  
Vol 12 (10) ◽  
pp. e0186008 ◽  
Author(s):  
Carlos Amo ◽  
Luis De Santiago ◽  
Daniel Zarza Luciáñez ◽  
José Miguel León Alonso-Cortés ◽  
Miguel Alonso-Alonso ◽  
...  
Keyword(s):  
Brain Plasticity ◽  
Gamma Band ◽  
Motor Tasks ◽  
Gamma Band Activity ◽  
Band Activity

scholarly journals Effects of beta- and gamma-band rhythmic stimulation on motor inhibition

2020 ◽  
Author(s):  
Inge Leunissen ◽  
Manon Van Steenkiste ◽  
Kirstin Heise ◽  
Thiago Santos Monteiro ◽  
Kyle Dunovan ◽  
...  
Keyword(s):  
Gamma Oscillations ◽  
Gamma Band ◽  
Stop Signal ◽  
Gamma Activity ◽  
Oscillatory Activity ◽  
Beta Activity ◽  
Motor Inhibition ◽  
Beta Band ◽  
Beta Power ◽  
Transcranial Alternating Current Stimulation

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.

scholarly journals Brain–Heart Interaction During Transcutaneous Auricular Vagus Nerve Stimulation

2021 ◽  
Vol 15 ◽  
Author(s):  
Kathrin Machetanz ◽  
Levan Berelidze ◽  
Robert Guggenberger ◽  
Alireza Gharabaghi
Keyword(s):  
Vagus Nerve ◽  
Nerve Stimulation ◽  
Vagus Nerve Stimulation ◽  
Heart Function ◽  
Brain Activity ◽  
Gamma Band ◽  
Cortical Activation ◽  
Oscillatory Activity ◽  
Beta Band ◽  
Rr Intervals

ObjectivesTranscutaneous auricular vagus nerve stimulation (taVNS) modulates brain activity and heart function. The induced parasympathetic predominance leads to an increase of heart rate variability (HRV). Knowledge on the corresponding cortical activation pattern is, however, scarce. We hypothesized taVNS-induced HRV increases to be related to modulation of cortical activity that regulates the autonomic outflow to the heart.Materials and MethodsIn thirteen healthy subjects, we simultaneously recorded 64-channel electroencephalography and electrocardiography during taVNS. Two taVNS stimulation targets were investigated, i.e., the cymba conchae and inner tragus, and compared to active control stimulation in the anatomical vicinity, i.e., at the crus helicis and outer tragus. We used intermitted stimulation bursts of 25 Hz applied at a periodicity of 1 Hz. HRV was estimated with different time-domain methodologies: standard deviation of RR (SDNN), the root mean squares of successive differences (RMSSD), the percentage of RR-intervals with at least 50 ms deviation from the preceding RR-interval (pNN50), and the difference of consecutive RR intervals weighted by their mean (rrHRV).ResultsThe stimulation-induced HRV increases corresponded to frequency-specific oscillatory modulation of different cortical areas. All stimulation targets induced power modulations that were proportional to the HRV elevation. The most prominent changes that corresponded to HRV increases across all parameters and stimulation locations were frontal elevations in the theta-band. In the delta-band, there were frontal increases (RMSSD, pNN50, rrHRV, SDNN) and decreases (SDNN) across stimulation sites. In higher frequencies, there was a more divers activity pattern: Outer tragus/crus helicis stimulation increased oscillatory activity with the most prominent changes for the SDNN in frontal (alpha-band, beta-band) and fronto-parietal (gamma-band) areas. During inner tragus/cymba conchae stimulation the predominant pattern was a distributed power decrease, particularly in the fronto-parietal gamma-band.ConclusionNeuro–cardiac interactions can be modulated by electrical stimulation at different auricular locations. Increased HRV during stimulation is correlated with frequency-specific increases and decreases of oscillatory activity in different brain areas. When applying specific HRV measures, cortical patterns related to parasympathetic (RMSSD, pNN50, rrHRV) and sympathetic (SDNN) modulation can be identified. Thus, cortical oscillations may be used to define stimulation locations and parameters for research and therapeutic purposes.

scholarly journals The Effect of Alterations of Schizophrenia-Associated Genes on Gamma Band Oscillations

2020 ◽  
Author(s):  
Christoph Metzner ◽  
Tuomo Mäki-Marttunen ◽  
Gili Karni ◽  
Hana McMahon-Cole ◽  
Volker Steuber
Keyword(s):  
Genetic Variants ◽  
Association Studies ◽  
Primary Auditory Cortex ◽  
Gamma Band ◽  
Oscillatory Activity ◽  
Genome Wide Association Studies ◽  
Genome Wide ◽  
Common Genetic Variants ◽  
Gamma Power ◽  
Response Task

Abnormalities in the synchronized oscillatory activity of neurons in general and, specifically in the gamma band, might play a crucial role in the pathophysiology of schizophrenia. While these changes in oscillatory activity have traditionally been linked to alterations at the synaptic level, we demonstrate here, using computational modeling, that common genetic variants of ion channels can contribute strongly to this effect. Our model of primary auditory cortex highlights multiple schizophrenia-associated genetic variants that reduce gamma power in an auditory steady-state response task. Furthermore, we show that combinations of several of these schizophrenia-associated variants can produce similar effects as the more traditionally considered synaptic changes. Overall, our study provides a mechanistic link between schizophrenia-associated common genetic variants, as identified by genome-wide association studies, and one of the most robust neurophysiological endophenotypes of schizophrenia.

scholarly journals Pallidal Thermolesion Unleashes Gamma Oscillations in the Motor Cortex in Parkinson's Disease

Neurosurgery ◽  
2019 ◽  
Vol 66 (Supplement_1) ◽  
Author(s):  
Doris D Wang ◽  
Coralie de Hemptinne ◽  
Svjetlana Miocinovic ◽  
Witney Chen ◽  
Jill L Ostrem ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Motor Cortex ◽  
Essential Tremor ◽  
Primary Motor Cortex ◽  
Gamma Oscillations ◽  
Gamma Band ◽  
Motor Dysfunction ◽  
Oscillatory Activity ◽  
Motor Network

Abstract INTRODUCTION In Parkinson's disease, the emergence of motor dysfunction is thought to be related to an imbalance between antikinetic and prokinetic patterns of oscillatory activity in the motor network. Invasive recordings from the basal ganglia and cortex in surgical patients have suggested that levodopa and therapeutic deep brain stimulation can suppress antikinetic beta band (13-30 Hz) rhythms while promoting prokinetic gamma band (60-90 Hz) rhythms. Surgical ablation of the globus pallidus internus is one of the oldest effective therapies for Parkinson's disease and gives a remarkable immediate relief from rigidity and bradykinesia, but its effects on oscillatory activity in the motor network have not been studied. We characterize the effects of pallidotomy on cortical oscillatory activity in Parkinson's disease patients. METHODS Using a temporary 6-contact lead placed over the sensorimotor cortex in the subdural space, we recorded acute changes in cortical oscillatory activities in 3 Parkinson's disease patients undergoing pallidotomy and compared the results to that of 3 essential tremor patients undergoing thalamotomy. RESULTS In all 3 Parkinson's disease patients, we observed the emergence of an approximately 70 to 80 Hz narrow-band oscillation with effective thermolesion of the pallidum. This gamma oscillatory activity was spatially localized over the primary motor cortex, was minimally affected by voluntary movements, and was not found in the motor cortex of essential tremor patients undergoing thalamotomy. CONCLUSION Our finding suggests that acute lesioning of the pallidum promotes cortical gamma band oscillations. This may represent an important mechanism for alleviating bradykinesia in Parkinson's disease.

Applications of Magnetoencephalography to Autism Spectrum Disorder

2020 ◽  
pp. 317-346
Author(s):  
Kristina Safar ◽  
Margot J. Taylor ◽  
Junko Matsuzaki ◽  
Timothy P. L. Roberts
Keyword(s):  
Autism Spectrum Disorder ◽  
Face Processing ◽  
Autism Spectrum ◽  
Gamma Band ◽  
Spectrum Disorder ◽  
Social Impairment ◽  
Oscillatory Activity ◽  
Sensory Sensitivity ◽  
Neural Signals ◽  
Auditory Responses

Magnetoencephalography (MEG) has a unique combination of attributes allowing the probing of brain function, with resolution of space, time, and spectral content. These attributes lend themselves to the study of disorders characterized by no conspicuous structural brain anomalies, but rather anomalies of neural signals and communication. This chapter reviews the use of diverse MEG techniques and paradigms to study one such disorder, autism spectrum disorder (ASD). The authors focus on MEG as a probe of auditory and face processing anomalies in ASD. Impairments in auditory processing in ASD have been identified as objective markers of language and communication ability, general cognitive ability, and abnormal sensory sensitivity. Most MEG studies have observed that atypical auditory responses such as components of the early auditory evoked field (i.e., M50, M100), mismatch fields, or gamma-band oscillatory activity occur in individuals with ASD compared with typically developing children. Maturational trajectories of such measures also deviate from neurotypical patterns. Similarly, impairments in face perception are characteristic of ASD and have been a large focus of MEG studies, as a model probe for the social impairment phenotype. MEG research has demonstrated atypical source localization of activity during face processing in children through adults as well as in executive functions, including working memory and inhibition. Interregional differences in synchrony of neural oscillations have been elaborated by MEG in emotional face processing tasks, with visual perceptual processing underscoring gamma-band atypicalities in ASD. We highlight MEG as a promising approach for establishing clinical biomarkers of ASD and informing mechanistic neuroscience.

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