scholarly journals Nonuniform High-Gamma (60-500 Hz) Power Changes Dissociate Cognitive Task and Anatomy in Human Cortex

2011 ◽  
Vol 31 (6) ◽  
pp. 2091-2100 ◽  
Author(s):  
C. M. Gaona ◽  
M. Sharma ◽  
Z. V. Freudenburg ◽  
J. D. Breshears ◽  
D. T. Bundy ◽  
...  
2018 ◽  
Vol 15 (2) ◽  
pp. 026015 ◽  
Author(s):  
Leah Muller ◽  
John D Rolston ◽  
Neal P Fox ◽  
Robert Knowlton ◽  
Vikram R Rao ◽  
...  

2015 ◽  
Vol 114 (1) ◽  
pp. 505-519 ◽  
Author(s):  
Ella Podvalny ◽  
Niv Noy ◽  
Michal Harel ◽  
Stephan Bickel ◽  
Gal Chechik ◽  
...  

Electrophysiological mass potentials show complex spectral changes upon neuronal activation. However, it is unknown to what extent these complex band-limited changes are interrelated or, alternatively, reflect separate neuronal processes. To address this question, intracranial electrocorticograms (ECoG) responses were recorded in patients engaged in visuomotor tasks. We found that in the 10- to 100-Hz frequency range there was a significant reduction in the exponent χ of the 1/ fχ component of the spectrum associated with neuronal activation. In a minority of electrodes showing particularly high activations the exponent reduction was associated with specific band-limited power modulations: emergence of a high gamma (80–100 Hz) and a decrease in the alpha (9–12 Hz) peaks. Importantly, the peaks' height was correlated with the 1/ fχ exponent on activation. Control simulation ruled out the possibility that the change in 1/ fχ exponent was a consequence of the analysis procedure. These results reveal a new global, cross-frequency (10–100 Hz) neuronal process reflected in a significant reduction of the power spectrum slope of the ECoG signal.


2019 ◽  
Author(s):  
Jacques Pesnot Lerousseau ◽  
Agnès Trébuchon ◽  
Benjamin Morillon ◽  
Daniele Schön

AbstractRhythmic stimulation, either sensory or electrical, aiming at entraining oscillatory activity to reveal or optimize brain functions, relies on a critically untested hypothesis: it should produce a persistent effect, outlasting the stimulus duration. We tested this assumption by studying cortical neural oscillations during and after presentation of rhythmic auditory stimuli. Using intracranial and surface recordings in humans, we reveal consistent neural response properties throughout the cortex, with persistent entrainment being selective to high-gamma oscillations. Critically, during passive perception, neural oscillations do not outlast low-frequency acoustic dynamics. We further show that our data are well-captured by a model of damped harmonic oscillator and can be classified into three classes of neural dynamics, with distinct damping properties and eigenfrequencies. This model thus provides a mechanistic and quantitative explanation of the frequency selectivity of persistent neural entrainment in the human cortex.Highlights- Neural oscillatory activity does not outlast low-frequency (2.5 Hz) acoustic dynamics during passive perception.- High-gamma activity is entrained by periodic auditory stimuli, with persistent activity up to 10 cycles after stimulus offset.- This frequency following response (FFR) is present throughout the cortex, up to inferior frontal and motor regions.- The frequency selective nature of neural entrainment is well-captured by a model of damped harmonic oscillator.


2018 ◽  
Author(s):  
G Arnulfo ◽  
SH Wang ◽  
B Toselli ◽  
N Williams ◽  
J Hirvonen ◽  
...  

AbstractInter-areal synchronization of neuronal oscillations below 100 Hz is ubiquitous in cortical circuitry and thought to regulate neuronal communication. In contrast, faster activities are generally considered to be exclusively local-circuit phenomena. We show with human intracerebral recordings that 100–300 Hz high-gamma activity (HGA) may be synchronized between widely distributed regions. HGA synchronization was not attributable to artefacts or to epileptic pathophysiology. Instead, HGA synchronization exhibited a reliable cortical connectivity and community structures, and a laminar profile opposite to that of lower frequencies. Importantly, HGA synchronization among functional brain systems during non-REM sleep was distinct from that in resting state. Moreover, HGA synchronization was transiently enhanced for correctly inhibited responses in a Go/NoGo task. These findings show that HGA synchronization constitutes a new, functionally significant form of neuronal spike-timing relationships in brain activity. We suggest that HGA synchronization reflects the temporal microstructure of spiking-based neuronal communication per se in cortical circuits.


2020 ◽  
Vol 133 (1) ◽  
pp. 43-53
Author(s):  
Michael Kogan ◽  
David J. Caldwell ◽  
Shahin Hakimian ◽  
Kurt E. Weaver ◽  
Andrew L. Ko ◽  
...  

OBJECTIVEElectrocorticography is an indispensable tool in identifying the epileptogenic zone in the presurgical evaluation of many epilepsy patients. Traditional electrocorticographic features (spikes, ictal onset changes, and recently high-frequency oscillations [HFOs]) rely on the presence of transient features that occur within or near epileptogenic cortex. Here the authors report on a novel corticography feature of epileptogenic cortex—covariation of high-gamma and beta frequency band power profiles. Band-limited power was measured from each recording site based on native physiological signal differences without relying on clinical ictal or interictal epileptogenic features. In this preliminary analysis, frequency windowed power correlation appears to be a specific marker of the epileptogenic zone. The authors’ overall aim was to validate this observation with the location of the eventual resection and outcome.METHODSThe authors conducted a retrospective analysis of 13 adult patients who had undergone electrocorticography for surgical planning at their center. They quantified the correlation of high-gamma (70–200 Hz) and beta (12–18 Hz) band frequency power per electrode site during a cognitive task. They used a sliding window method to correlate the power of smoothed, Hilbert-transformed high-gamma and beta bands. They then compared positive and negative correlations between power in the high-gamma and beta bands in the setting of a hand versus a tongue motor task as well as within the resting state. Significant positive correlations were compared to surgically resected areas and outcomes based on reviewed records.RESULTSPositive high-gamma and beta correlations appeared to predict the area of eventual resection and, preliminarily, surgical outcome independent of spike detection. In general, patients with the best outcomes had well-localized positive correlations (high-gamma and beta activities) to areas of eventual resection, while those with poorer outcomes displayed more diffuse patterns.CONCLUSIONSData in this study suggest that positive high-gamma and beta correlations independent of any behavioral metric may have clinical applicability in surgical decision-making. Further studies are needed to evaluate the clinical potential of this methodology. Additional work is also needed to relate these results to other methods, such as HFO detection or connectivity with other cortical areas.


2001 ◽  
Vol 6 (1) ◽  
pp. 15-25 ◽  
Author(s):  
Harald Walach ◽  
Stefan Schmidt ◽  
Yvonne-Michelle Bihr ◽  
Susanne Wiesch

We studied the effect of experimenter expectations and different instructions in a balanced placebo design. 157 subjects were randomized into a 2 × 4 factorial design. Two experimenters were led to expect placebos either to produce physiological effects or not (pro- vs. antiplacebo). All subjects except a control group received a caffeine placebo. They were either made to expect coffee, no coffee, or were in a double-blind condition. Dependent measures were blood pressure, heart rate, well-being, and a cognitive task. There was one main effect on the instruction factor (p = 0.03) with the group “told no caffeine” reporting significantly better well-being. There was one main effect on the experimenter factor with subjects instructed by experimenter “proplacebo” having higher systolic blood pressure (p = 0.008). There was one interaction with subjects instructed by experimenter “proplacebo” to receive coffee doing worse in the cognitive task than the rest. Subjects instructed by experimenter “antiplacebo” were significantly less likely to believe the experimental instruction, and that mostly if they had been instructed to receive coffee. Contrary to the literature we could not show an effect of instruction, but there was an effect of experimenters. It is likely, however, that these experimenter effects were not due to experimental manipulations, but to the difference in personalities.


2019 ◽  
Vol 35 (6) ◽  
pp. 878-890 ◽  
Author(s):  
David Marcusson-Clavertz ◽  
Oscar N. E. Kjell

Abstract. Thinking about task-unrelated matters (mind wandering) is related to cognition and well-being. However, the relations between mind wandering and other psychological variables may depend on whether the former commence spontaneously or deliberately. The current two studies investigated the psychometric properties of the Spontaneous and Deliberate Mind Wandering Scales (SDMWS; Carriere, Seli, & Smilek, 2013 ). Study 1 evaluated the stability of the scales over 2 weeks ( N = 284 at Time 1), whereas Study 2 ( N = 323) evaluated their relations to Generalized anxiety disorder symptoms, Openness, Social desirability, and experience-sampling reports of intentional and unintentional mind wandering during an online cognitive task. The results indicated that the SDMWS were better fitted with a two-factor than a one-factor solution, although the fit was improved with the exclusion of one item. The scales exhibited strong measurement invariance across gender and time, and moderately high test-retest reliability. Spontaneous mind wandering predicted Generalized anxiety disorder and experience-sampling reports of unintentional mind wandering, whereas Deliberate mind wandering predicted Openness and experience-sampling reports of intentional mind wandering. Furthermore, Spontaneous mind wandering showed a negative association with social desirability of weak-to-medium strength. In sum, the scales generally showed favorable psychometric properties.


Author(s):  
Leonard Reinecke ◽  
Sabine Trepte

Abstract. This quasi-experimental study examined the effects of exposure to a computer game on arousal and subsequent task performance. After inducing a state of low arousal, participants were assigned to experimental or control conditions via self-selection. Members of the experimental group played a computer game for five minutes; subjects in the control group spent the same amount of time awaiting further instructions. Participants who were exposed to the computer game showed significantly higher levels of arousal and performed significantly better on a subsequent cognitive task. The pattern of results was not influenced by the participants' prior experience with the game. The findings indicate that mood-management processes associated with personal media use at the workplace go beyond the alteration of arousal and affect subsequent cognitive performance.


Author(s):  
Laura G. Militello ◽  
Robert J. B. Hutton ◽  
Rebecca M. Pliske ◽  
Betsy J. Knight ◽  
Gary Klein ◽  
...  

2001 ◽  
Author(s):  
Richard P. Fahey ◽  
Anna L. Rowe ◽  
Kendra L. Dunlap ◽  
Dan O. deBoom

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