scholarly journals Task performance changes the amplitude and timing of the BOLD signal

2017 ◽  
Vol 8 (1) ◽  
Author(s):  
Atae Akhrif ◽  
Maximilian J. Geiger ◽  
Marcel Romanos ◽  
Katharina Domschke ◽  
Susanne Neufang
Keyword(s):  
Task Performance ◽  
Temporal Dynamics ◽  
Brain Activation ◽  
Bold Signal ◽  
Bold Response ◽  
Imaging Data ◽  
Neural Firing ◽  
Beta Band ◽  
Beta Power ◽  
Band Activity

AbstractTranslational studies comparing imaging data of animals and humans have gained increasing scientific interests. With this upcoming translational approach, however, identifying harmonized statistical analysis as well as shared data acquisition protocols and/or combined statistical approaches is necessary. Following this idea, we applied Bayesian Adaptive Regression Splines (BARS), which have until now mainly been used to model neural responses of electrophysiological recordings from rodent data, on human hemodynamic responses as measured via fMRI. Forty-seven healthy subjects were investigated while performing the Attention Network Task in the MRI scanner. Fluctuations in the amplitude and timing of the BOLD response were determined and validated externally with brain activation using GLM and also ecologically with the influence of task performance (i.e. good vs. bad performers). In terms of brain activation, bad performers presented reduced activation bilaterally in the parietal lobules, right prefrontal cortex (PFC) and striatum. This was accompanied by an enhanced left PFC recruitment. With regard to the amplitude of the BOLD-signal, bad performers showed enhanced values in the left PFC. In addition, in the regions of reduced activation such as the parietal and striatal regions, the temporal dynamics were higher in bad performers. Based on the relation between BOLD response and neural firing with the amplitude of the BOLD signal reflecting gamma power and timing dynamics beta power, we argue that in bad performers, an enhanced left PFC recruitment hints towards an enhanced functioning of gamma-band activity in a compensatory manner. This was accompanied by reduced parieto-striatal activity, associated with increased and potentially conflicting beta-band activity.

scholarly journals Bilaterally Reduced Rolandic Beta Band Activity in Minor Stroke Patients

2021 ◽  
Author(s):  
Joshua P Kulasingham ◽  
Christian Brodbeck ◽  
Sheena Khan ◽  
Elisabeth B Marsh ◽  
Jonathan Z Simon
Keyword(s):  
Sensorimotor Cortex ◽  
Reaction Times ◽  
Minor Stroke ◽  
Button Press ◽  
Beta Band ◽  
Stroke Patients ◽  
Potential Biomarker ◽  
Beta Power ◽  
Motor Dexterity ◽  
Band Activity

Objective: Stroke patients with hemiparesis display decreased beta band (13-25 Hz) rolandic activity, correlating to impaired motor function. However, patients without significant weakness, with small lesions far from sensorimotor cortex, nevertheless exhibit bilateral decreased motor dexterity and slowed reaction times. We investigate whether these minor stroke patients also display abnormal beta band activity. Methods: Magnetoencephalographic (MEG) data were collected from nine minor stroke patients (NIHSS < 4) without significant hemiparesis, at ~1 and ~6 months postinfarct, and eight age-similar controls. Rolandic relative beta power during matching tasks and resting state, and Beta Event Related (De)Synchronization (ERD/ERS) during button press responses were analyzed. Results: Regardless of lesion location, patients had significantly reduced relative beta power and ERS compared to controls. Abnormalities persisted over visits, and were present in both ipsi- and contra-lesional hemispheres, consistent with bilateral impairments in motor dexterity and speed. Conclusions: Minor stroke patients without severe weakness display reduced rolandic beta band activity in both hemispheres, which may be linked to bilaterally impaired dexterity and processing speed, implicating global connectivity dysfunction affecting sensorimotor cortex. Significance: Rolandic beta band activity may be a potential biomarker and treatment target, even for minor stroke patients with small lesions far from sensorimotor areas.

scholarly journals Adaptive Parameter Modulation of Deep Brain Stimulation Based on Improved Supervisory Algorithm

2021 ◽  
Vol 15 ◽  
Author(s):  
Yulin Zhu ◽  
Jiang Wang ◽  
Huiyan Li ◽  
Chen Liu ◽  
Warren M. Grill
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Supervisory Control ◽  
Control Algorithm ◽  
Beta Band ◽  
Rbf Network ◽  
Stimulation Parameters ◽  
Beta Power ◽  
Band Activity ◽  
Deep Brain

Clinically deployed deep brain stimulation (DBS) for the treatment of Parkinson’s disease operates in an open loop with fixed stimulation parameters, and this may result in high energy consumption and suboptimal therapy. The objective of this manuscript is to establish, through simulation in a computational model, a closed-loop control system that can automatically adjust the stimulation parameters to recover normal activity in model neurons. Exaggerated beta band activity is recognized as a hallmark of Parkinson’s disease and beta band activity in model neurons of the globus pallidus internus (GPi) was used as the feedback signal to control DBS of the GPi. Traditional proportional controller and proportional-integral controller were not effective in eliminating the error between the target level of beta power and the beta power under Parkinsonian conditions. To overcome the difficulties in tuning the controller parameters and improve tracking performance in the case of changes in the plant, a supervisory control algorithm was implemented by introducing a Radial Basis Function (RBF) network to build the inverse model of the plant. Simulation results show the successful tracking of target beta power in the presence of changes in Parkinsonian state as well as during dynamic changes in the target level of beta power. Our computational study suggests the feasibility of the RBF network-driven supervisory control algorithm for real-time modulation of DBS parameters for the treatment of Parkinson’s disease.

scholarly journals A novel approach for combining task-dependent gamma with alpha and beta power modulation for enhanced identification of eloquent cortical areas using ECoG in patients with medical-refractory epilepsy

2019 ◽  
Author(s):  
M.E. Archila-Meléndez ◽  
G. Valente ◽  
E. Gommer ◽  
R.P.W. Rouhl ◽  
O.E.M.G. Schijns ◽  
...  
Keyword(s):  
Refractory Epilepsy ◽  
Low Frequency ◽  
Cognitive Testing ◽  
Gamma Activity ◽  
Beta Band ◽  
Diagnostic Ability ◽  
Eloquent Areas ◽  
Cortical Areas ◽  
Beta Power ◽  
Band Activity

AbstractElectrical stimulation mapping (ESM) is the gold standard for identification of “eloquent” areas prior to resection of epileptogenic tissue, however, it is time consuming and may cause side effects, especially stimulation-induced seizures and after-discharges. Broadband gamma activity (55 – 200 Hz) recorded with subdural electrocorticography (ECoG) during cognitive tasks has been proposed as an attractive tool for mapping cortical areas with specific function but until now has not proven definitive clinical value. Fewer studies have addressed whether the alpha (8 – 12 Hz) and beta (15 – 25 Hz) band activity could also be used to improve eloquent cortex identification. We compared alpha, beta and broadband gamma activity, and their combination for the identification of eloquent cortical areas defined by ESM. Ten patients participated in a delayed-match-to-sample task, where syllable sounds were matched to visually presented letters and responses given by keyboard. We used a generalized linear model (GLM) approach to find the optimal weighting of low frequency bands and broadband gamma power to predict the ESM categories. Broadband gamma activity increased more in eloquent areas than in non-eloquent areas and this difference had a diagnostic ability (area under (AU) the receiving operating characteristic curve - AUROC) of ∼70%. Both alpha and beta power decreased more in eloquent areas. Alpha power had lower AUROC than broadband gamma while beta had similar AUROC. AUROC was enhanced by the combination of alpha and broadband gamma (3% improvement) and by the combination of beta and broadband gamma (7% improvement) over the use of broadband gamma alone. Further analysis showed that the relative performance of broadband gamma and low frequency bands depended on multiple factors including the time period of the cognitive task, the location of the electrodes and the patient’s attention to the stimulus. However, the combination of beta band and broadband gamma always gave the best performance. We show how ECoG power modulation from cognitive testing periods can be used to map the probability of eloquence by ESM and how this probability can be used as an aid for optimal ESM planning. We conclude that low frequency power during cognitive testing can contribute to the identification of eloquent areas in patients with focal refractory epilepsy improving its precision but does not replace the need of ESM.HighlightsGamma, alpha and beta band activity has significant diagnostic ability to identify ESM defined eloquent cortical areas.We present a novel method to combine gamma and low frequency activity for enhanced identification.We quantify how identification is dependent on analysis time window, cortical function, and patient’s attentional engagement.With further development, this approach may offer an alternative to ESM mapping with reduced burden for patients.

Neurofeedback Training Protocol Based on Selecting Distinctive Features to Treat or Reduce ADHD Symptoms

2021 ◽  
pp. 155005942110334
Author(s):  
Parham Jalali ◽  
Nasrin Sho’ouri
Keyword(s):  
Treatment Protocol ◽  
Adhd Symptoms ◽  
Eeg Signals ◽  
Beta Band ◽  
Distinctive Features ◽  
Children With Adhd ◽  
Hyperactivity Disorder ◽  
Distinguishing Features ◽  
Band Activity ◽  
Training Protocol

Resent research has shown that electroencephalography (EEG) theta/beta ratio (TBR) in cases with attention deficit hyperactivity disorder (ADHD) has thus far been reported lower than that in healthy individuals. Accordingly, utilizing EEG-TBR as a biomarker to diagnose ADHD has been called into question. Besides, employing known protocol to reduce EEG-TBR in the vertex (Cz) channel to treat ADHD via neurofeedback (NFB) has been doubted. The present study was to propose a new NFB treatment protocol to manage ADHD using EEG signals from 30 healthy controls and 30 children with ADHD through an attention-based task and to calculate relative power in their different frequency bands. Then, the most significant distinguishing features of EEG signals from both groups were determined via a genetic algorithm (GA). The results revealed that EEG-TBR values in children with ADHD were lower compared with those in healthy peers; however, such a difference was not statistically significant. Likewise, inhibiting alpha band activity and enhancing delta one in F7 or T5 channels was proposed as a new NFB treatment protocol for ADHD. No significant increase in EEG-TBR in the Cz channel among children with ADHD casts doubt on the effectiveness of using EEG-TBR inhibitory protocols in the Cz channel. Consequently, it was proposed to apply the new protocol along with reinforced beta-band activity to treat or reduce ADHD symptoms.

scholarly journals The relationship between hippocampal-dependent task performance and hippocampal grey matter myelination and iron content

2021 ◽  
Vol 5 ◽  
pp. 239821282110119
Author(s):  
Ian A. Clark ◽  
Martina F. Callaghan ◽  
Nikolaus Weiskopf ◽  
Eleanor A. Maguire
Keyword(s):  
Individual Differences ◽  
Autobiographical Memory ◽  
Task Performance ◽  
Iron Content ◽  
Grey Matter ◽  
Cognitive Task ◽  
Spatial Navigation ◽  
Imaging Data ◽  
Future Thinking

Individual differences in scene imagination, autobiographical memory recall, future thinking and spatial navigation have long been linked with hippocampal structure in healthy people, although evidence for such relationships is, in fact, mixed. Extant studies have predominantly concentrated on hippocampal volume. However, it is now possible to use quantitative neuroimaging techniques to model different properties of tissue microstructure in vivo such as myelination and iron. Previous work has linked such measures with cognitive task performance, particularly in older adults. Here we investigated whether performance on scene imagination, autobiographical memory, future thinking and spatial navigation tasks was associated with hippocampal grey matter myelination or iron content in young, healthy adult participants. Magnetic resonance imaging data were collected using a multi-parameter mapping protocol (0.8 mm isotropic voxels) from a large sample of 217 people with widely-varying cognitive task scores. We found little evidence that hippocampal grey matter myelination or iron content were related to task performance. This was the case using different analysis methods (voxel-based quantification, partial correlations), when whole brain, hippocampal regions of interest, and posterior:anterior hippocampal ratios were examined, and across different participant sub-groups (divided by gender and task performance). Variations in hippocampal grey matter myelin and iron levels may not, therefore, help to explain individual differences in performance on hippocampal-dependent tasks, at least in young, healthy individuals.

scholarly journals Cognitive Replay of Visuomotor Learning at Sleep Onset: Temporal Dynamics and Relationship to Task Performance

SLEEP ◽  
2010 ◽  
Vol 33 (1) ◽  
pp. 59-68 ◽  
Author(s):  
Erin J. Wamsley ◽  
Karen Perry ◽  
Ina Djonlagic ◽  
Laura Babkes Reaven ◽  
Robert Stickgold
Keyword(s):  
Task Performance ◽  
Temporal Dynamics ◽  
Sleep Onset ◽  
Visuomotor Learning

scholarly journals L-Theanine and Caffeine in Combination Affect Human Cognition as Evidenced by Oscillatory alpha-Band Activity and Attention Task Performance

2008 ◽  
Vol 138 (8) ◽  
pp. 1572S-1577S ◽  
Author(s):  
Simon P. Kelly ◽  
Manuel Gomez-Ramirez ◽  
Jennifer L. Montesi ◽  
John J. Foxe
Keyword(s):  
Task Performance ◽  
Human Cognition ◽  
Alpha Band ◽  
Attention Task ◽  
Band Activity

scholarly journals The Innate Alarm System and Subliminal Threat Presentation in Posttraumatic Stress Disorder: Neuroimaging of the Midbrain and Cerebellum

2019 ◽  
Vol 3 ◽  
pp. 247054701882149 ◽  
Author(s):  
Braeden A. Terpou ◽  
Maria Densmore ◽  
Janine Thome ◽  
Paul Frewen ◽  
Margaret C. McKinnon ◽  
...  
Keyword(s):  
Posttraumatic Stress Disorder ◽  
Posttraumatic Stress ◽  
Stress Disorder ◽  
Brain Activation ◽  
Stimulus Presentation ◽  
Neutral Stimulus ◽  
Alarm System ◽  
Imaging Data ◽  
The Right

Background The innate alarm system, a network of interconnected midbrain, other brainstem, and thalamic structures, serves to rapidly detect stimuli in the environment prior to the onset of conscious awareness. This system is sensitive to threatening stimuli and has evolved to process these stimuli subliminally for hastened responding. Despite the conscious unawareness, the presentation of subliminal threat stimuli generates increased activation of limbic structures, including the amygdala and insula, as well as emotionally evaluative structures, including the cerebellum and orbitofrontal cortex. Posttraumatic stress disorder (PTSD) is associated with an increased startle response and decreased extinction learning to conditioned threat. The role of the innate alarm system in the clinical presentation of PTSD, however, remains poorly understood. Methods Here, we compare midbrain, brainstem, and cerebellar activation in persons with PTSD (n = 26) and matched controls (n = 20) during subliminal threat presentation. Subjects were presented with masked trauma-related and neutral stimuli below conscious threshold. Contrasts of subliminal brain activation for the presentation of neutral stimuli were subtracted from trauma-related brain activation. Group differences in activation, as well as correlations between clinical scores and PTSD activation, were examined. Imaging data were preprocessed utilizing the spatially unbiased infratentorial template toolbox within SPM12. Results Analyses revealed increased midbrain activation in PTSD as compared to controls in the superior colliculus, periaqueductal gray, and midbrain reticular formation during subliminal threat as compared to neutral stimulus presentation. Controls showed increased activation in the right cerebellar lobule V during subliminal threat presentation as compared to PTSD. Finally, a negative correlation emerged between PTSD patient scores on the Multiscale Dissociation Inventory for the Depersonalization/Derealization subscale and activation in the right lobule V of the cerebellum during the presentation of subliminal threat as compared to neutral stimuli. Conclusion We interpret these findings as evidence of innate alarm system overactivation in PTSD and of the prominent role of the cerebellum in the undermodulation of emotion observed in PTSD.

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