scholarly journals Intracranial-EEG evidence for medial temporal pole driving amygdala activity induced by multi-modal emotional stimuli

2020 ◽  
Author(s):  
Saurabh Sonkusare ◽  
Vinh Thai Nguyen ◽  
Rosalyn Moran ◽  
Johan van der Meer ◽  
Yudan Ren ◽  
...  
Keyword(s):  
Low Frequency ◽  
Gamma Activity ◽  
Cortical Region ◽  
Frequency Range ◽  
Intracranial Eeg ◽  
Social And Emotional ◽  
Temporal Pole ◽  
High Gamma ◽  
Amygdala Activity ◽  
Computational Analyses

AbstractThe temporal pole (TP) is an associative cortical region required for complex cognitive functions such as social and emotional cognition. However, functional mapping of the TP with functional magnetic resonance imaging is technically challenging and thus understanding of its interaction with other key emotional circuitry, such as the amygdala, remain elusive. We exploited the unique advantages of stereo-electroencephalography (SEEG) to assess the responses of the TP and the amygdala during the perception of emotionally salient stimuli of pictures, music and movies. These stimuli consistently elicited high gamma responses (70-140 Hz) in both the TP and the amygdala, accompanied by functional connectivity in the low frequency range (2-12 Hz). Computational analyses suggested the TP driving this effect in the theta-alpha frequency range and which was modulated by the emotional salience of the stimuli. Of note, cross-frequency analysis indicated the phase of theta-alpha oscillations in the TP modulated the amplitude of high gamma activity in the amygdala. These results were reproducible with three types of stimuli including naturalistic stimuli suggesting a hierarchical influence of the TP over the amygdala in non-threatening stimuli.

scholarly journals Untangling cortico-striatal connectivity and cross-frequency coupling in L-DOPA-induced dyskinesia

2015 ◽  
Author(s):  
Jovana Belic ◽  
Per Halje ◽  
Ulrike Richter ◽  
Per Petersson ◽  
Jeanette Hellgren Kotaleski
Keyword(s):  
Primary Motor Cortex ◽  
Effective Connectivity ◽  
Spectral Characteristics ◽  
Low Frequency ◽  
Frequency Range ◽  
Gamma Frequency ◽  
High Gamma ◽  
Freely Behaving ◽  
Beta Frequency ◽  
Cross Frequency Coupling

We simultaneously recorded local field potentials in the primary motor cortex and sensorimotor striatum in awake, freely behaving, 6-OHDA lesioned hemi-parkinsonian rats in order to study the features directly related to pathological states such as parkinsonian state and levodopa-induced dyskinesia. We analysed the spectral characteristics of the obtained signals and observed that during dyskinesia the most prominent feature was a relative power increase in the high gamma frequency range at around 80 Hz, while for the parkinsonian state it was in the beta frequency range. Here we show that during both pathological states effective connectivity in terms of Granger causality is bidirectional with an accent on the striatal influence on the cortex. In the case of dyskinesia, we also found a high increase in effective connectivity at 80 Hz. In order to further understand the 80- Hz phenomenon, we performed cross-frequency analysis and observed characteristic patterns in the case of dyskinesia but not in the case of the parkinsonian state or the control state. We noted a large decrease in the modulation of the amplitude at 80 Hz by the phase of low frequency oscillations (up to ~10 Hz) across both structures in the case of dyskinesia. This may suggest a lack of coupling between the low frequency activity of the recorded network and the group of neurons active at ~80 Hz.

scholarly journals The dynamics of error processing in the human brain as reflected by high-gamma activity in noninvasive and intracranial EEG

NeuroImage ◽  
2018 ◽  
Vol 173 ◽  
pp. 564-579 ◽  
Author(s):  
Martin Völker ◽  
Lukas D.J. Fiederer ◽  
Sofie Berberich ◽  
Jiří Hammer ◽  
Joos Behncke ◽  
...  
Keyword(s):  
Human Brain ◽  
Gamma Activity ◽  
Error Processing ◽  
Intracranial Eeg ◽  
High Gamma

Dynamic Spectral Imaging: Online and Offline Functional Brain Mapping Using High-Frequency Activity [50–150 Hz] in SEEG

2018 ◽  
pp. 453-464
Author(s):  
Jean-Philippe Lachaux
Keyword(s):  
High Frequency ◽  
Large Scale ◽  
Human Cognition ◽  
Gamma Activity ◽  
Intracranial Eeg ◽  
Cortical Dynamics ◽  
Functional Brain Mapping ◽  
High Gamma ◽  
High Frequency Activity ◽  
Eeg Recordings

At the end of the twentieth century, a handful of research groups discovered that neural processing leaves a characteristic signature in intracranial EEG recordings: an increase of power in a broad frequency range above 50 Hz, dubbed ‘high-gamma’ of high-frequency activity ([50–150 Hz]). Since then, intracranial EEG research on human cognition has focused primarily on high-gamma activity to reveal the large-scale cortical dynamics of most major cognitive functions, not only offline in well-controlled paradigms, but also online, while patients freely interact with their environment. This chapter introduces that approach, including its recent extension to task-induced neural activity suppressions and functional connectivity mapping, and its clinical application to minimize cognitive deficits induced by epilepsy surgery.

scholarly journals Intracranial EEG Biomarkers for Seizure Lateralization in Rapidly-Bisynchronous Epilepsy After Laser Corpus Callosotomy

2021 ◽  
Vol 12 ◽  
Author(s):  
Simon Khuvis ◽  
Sean T. Hwang ◽  
Ashesh D. Mehta
Keyword(s):  
High Frequency ◽  
Detection Threshold ◽  
Low Frequency ◽  
Ground Truth ◽  
Line Length ◽  
High Frequency Oscillation ◽  
Corpus Callosotomy ◽  
Intracranial Eeg ◽  
Interictal Epileptiform Discharge ◽  
High Gamma

Objective: It has been asserted that high-frequency analysis of intracranial EEG (iEEG) data may yield information useful in localizing epileptogenic foci.Methods: We tested whether proposed biomarkers could predict lateralization based on iEEG data collected prior to corpus callosotomy (CC) in three patients with bisynchronous epilepsy, whose seizures lateralized definitively post-CC. Lateralization data derived from algorithmically-computed ictal phase-locked high gamma (PLHG), high gamma amplitude (HGA), and low-frequency (filtered) line length (LFLL), as well as interictal high-frequency oscillation (HFO) and interictal epileptiform discharge (IED) rate metrics were compared against ground-truth lateralization from post-CC ictal iEEG.Results: Pre-CC unilateral IEDs were more frequent on the more-pathologic side in all subjects. HFO rate predicted lateralization in one subject, but was sensitive to detection threshold. On pre-CC data, no ictal metric showed better predictive power than any other. All post-corpus callosotomy seizures lateralized to the pathological hemisphere using PLHG, HGA, and LFLL metrics.Conclusions: While quantitative metrics of IED rate and ictal HGA, PHLG, and LFLL all accurately lateralize based on post-CC iEEG, only IED rate consistently did so based on pre-CC data.Significance: Quantitative analysis of IEDs may be useful in lateralizing seizure pathology. More work is needed to develop reliable techniques for high-frequency iEEG analysis.

scholarly journals Neural Oscillatory Characteristics of Feedback Associated Activity in Globus Pallidus Interna

2021 ◽  
Author(s):  
Hadi Choubdar ◽  
Mahdi Mahdavi ◽  
Zahra Rostami ◽  
Erfan Zabeh ◽  
Martin J Gillies ◽  
...  
Keyword(s):  
Globus Pallidus ◽  
High Frequency ◽  
Low Frequency ◽  
Gamma Activity ◽  
Cognitive Tasks ◽  
Feedback Processing ◽  
Feedback Information ◽  
Disease States ◽  
High Gamma

Neural oscillatory activities in basal ganglia have prominent roles in cognitive processes on local and global scales. However, the characteristics of high frequency oscillatory activities during cognitive tasks have not been extensively explored in human Globus Pallidus internus (GPi). This study aimed to investigate amplitude and interhemispheric coupling of bilateral GPi high gamma bursts in dystonia and Parkinson's Disease (PD) patients, in on and off medication states, after feedback during the Intra-Extra-Dimension shift (IED) task. Bilateral GPi Local Field Potentials (LFP) activity was recorded via externalized DBS electrodes during the IED task. Inter hemisphere phase synchrony was assessed using Inter-Site Phase Clustering (ISPC). Transient high gamma activity (~100-150Hz) was observed immediately after feedback in the dystonia patient. Moreover, these bursts were phase synchronous between left and right GPis with an antiphase clustering of phase differences. In contrast, no synchronous high gamma activity was detected in the PD patient with or without dopamine administration. The off-med PD patient displayed enhanced low frequency clusters ameliorated by medication in the on-med state. Furthermore, an increased low frequency activity was observed after feedback of incorrect trials in both disease states. The current study provides a rare report of antiphase homotopic synchrony in human GPi, potentially related to incorporating and processing feedback information. The absence of these activities in off and on-med PD indicates the potential presence of impaired medication independent circuits related to feedback processing. Together, these findings are helpful in pointing to the potential role of GPi's synchronized high frequency activity in cognitive tasks and feedback information processing.

scholarly journals Intracranial-EEG evidence for medial temporal pole driving amygdala activity induced by multi-modal emotional stimuli

Cortex ◽  
2020 ◽  
Vol 130 ◽  
pp. 32-48
Author(s):  
Saurabh Sonkusare ◽  
Vinh T. Nguyen ◽  
Rosalyn Moran ◽  
Johan van der Meer ◽  
Yudan Ren ◽  
...  
Keyword(s):  
Emotional Stimuli ◽  
Intracranial Eeg ◽  
Temporal Pole ◽  
Amygdala Activity

Evaluation of Special Hearing Aids for Deaf Children

1971 ◽  
Vol 36 (4) ◽  
pp. 527-537 ◽  
Author(s):  
Norman P. Erber
Keyword(s):  
Hearing Aids ◽  
High Frequency ◽  
Hearing Aid ◽  
Low Frequency ◽  
Acoustic Stimulation ◽  
Deaf Children ◽  
Frequency Range ◽  
Frequency Limit ◽  
Unpublished Studies ◽  
Published Research

Two types of special hearing aid have been developed recently to improve the reception of speech by profoundly deaf children. In a different way, each special system provides greater low-frequency acoustic stimulation to deaf ears than does a conventional hearing aid. One of the devices extends the low-frequency limit of amplification; the other shifts high-frequency energy to a lower frequency range. In general, previous evaluations of these special hearing aids have obtained inconsistent or inconclusive results. This paper reviews most of the published research on the use of special hearing aids by deaf children, summarizes several unpublished studies, and suggests a set of guidelines for future evaluations of special and conventional amplification systems.

Dynamic Damping and Stiffness Characteristics of the Rolling Tire

2001 ◽  
Vol 29 (4) ◽  
pp. 258-268 ◽  
Author(s):  
G. Jianmin ◽  
R. Gall ◽  
W. Zuomin
Keyword(s):  
Dynamic Behavior ◽  
Variable Parameter ◽  
Low Frequency ◽  
Vertical Load ◽  
Frequency Range ◽  
Inflation Pressure ◽  
Vehicle Simulation ◽  
Dynamic Damping ◽  
Speed Range ◽  
Stiffness Characteristics

Abstract A variable parameter model to study dynamic tire responses is presented. A modified device to measure terrain roughness is used to measure dynamic damping and stiffness characteristics of rolling tires. The device was used to examine the dynamic behavior of a tire in the speed range from 0 to 10 km/h. The inflation pressure during the tests was adjusted to 160, 240, and 320 kPa. The vertical load was 5.2 kN. The results indicate that the damping and stiffness decrease with velocity. Regression formulas for the non-linear experimental damping and stiffness are obtained. These results can be used as input parameters for vehicle simulation to evaluate the vehicle's driving and comfort performance in the medium-low frequency range (0–100 Hz). This way it can be important for tire design and the forecasting of the dynamic behavior of tires.

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