scholarly journals Top-down beta enhances bottom-up gamma

2016 ◽  
Author(s):  
Craig G. Richter ◽  
William H. Thompson ◽  
Conrado A. Bosman ◽  
Pascal Fries
Keyword(s):  
Gamma Band ◽  
Visual Area ◽  
Beta Band ◽  
Top Down ◽  
Bottom Up ◽  
Area V4 ◽  
Frequency Interaction ◽  
Area 7A ◽  
Alpha Beta ◽  
Band Activity

AbstractSeveral recent studies have demonstrated that the bottom-up signaling of a visual stimulus is subserved by interareal gamma-band synchronization, whereas top-down influences are mediated by alpha-beta band synchronization. These processes may implement top-down control of stimulus processing if top-down and bottom-up mediating rhythms are coupled via cross-frequency interaction. To test this possibility, we investigated Granger-causal influences among awake male macaque primary visual area V1, higher visual area V4 and parietal control area 7a during attentional task performance. Top-down 7a-to-V1 beta-band influences enhanced visually driven V1-to-V4 gamma-band influences. This enhancement was spatially specific and largest when beta-band activity preceded gamma-band activity by ∼0.1 s, suggesting a causal effect of top-down processes on bottom-up processes. We propose that this cross-frequency interaction mechanistically subserves the attentional control of stimulus selection.Significance StatementContemporary research indicates that the alpha-beta frequency band underlies top-down control, while the gamma-band mediates bottom-up stimulus processing. This arrangement inspires an attractive hypothesis, which posits that top-down beta-band influences directly modulate bottom-up gamma band influences via cross-frequency interaction. We evaluate this hypothesis determining that beta-band top-down influences from parietal area 7a to visual area V1 are correlated with bottom-up gamma frequency oscillations from V1 to area V4, in a spatially specific manner, and that this correlation is maximal when top-down activity precedes bottom-up activity. These results show that for top-down processes such as spatial attention, elevated top-down beta-band influences directly enhance feedforward stimulus induced gamma-band processing, leading to enhancement of the selected stimulus.

scholarly journals Top-down attentional processing enhances auditory evoked gamma band activity

Neuroreport ◽  
2003 ◽  
Vol 14 (5) ◽  
pp. 683-686 ◽  
Author(s):  
Stefan Debener ◽  
Christoph S. Herrmann ◽  
Cornelia Kranczioch ◽  
Daniel Gembris ◽  
Andreas K. Engel
Keyword(s):  
Gamma Band ◽  
Top Down ◽  
Attentional Processing ◽  
Gamma Band Activity ◽  
Band Activity

Dissociable Neural Mechanisms for Encoding Predictable and Unpredictable Events

2006 ◽  
Vol 18 (7) ◽  
pp. 1120-1132 ◽  
Author(s):  
Christopher Summerfield ◽  
Jennifer A. Mangels
Keyword(s):  
Necessary Condition ◽  
Study Phase ◽  
Neural Synchrony ◽  
Attentional Orienting ◽  
Top Down ◽  
Bottom Up ◽  
Episodic Memories ◽  
Gamma Band Activity ◽  
Band Activity ◽  
Attentional Mechanisms

Attention is a necessary condition for the formation of new episodic memories, yet little is known about how dissociable attentional mechanisms for “top-down” and “bottom-up” orienting contribute to encoding. Here, subjects performed an intentional encoding task in which to-be-learned items were interspersed with irrelevant stimuli such that subjects could anticipate the appearance of some study items but not others. Subjects were more likely to later remember stimuli whose appearance was predictable at encoding. Electroencephalographic data were acquired during the study phase of the experiment to assess how synchronous neural activity related to later memory for predictable stimuli (to which attention could be oriented in a top-down fashion) and unpredictable stimuli (which rely to a greater extent on bottom-up attentional orienting). Over left frontal regions, gamma-band activity (25–55 Hz) early (∼150 msec) in the epoch was a robust predictor of later memory for predictable items, consistent with an emerging view that links high-frequency neural synchrony to top-down attention. By contrast, later (∼400 msec) theta-band activity (4–8 Hz) over the left and midline frontal cortex predicted subsequent memory for unpredictable items, suggesting a role in bottom-up attentional orienting. These results reveal for the first time the contribution of dissociable attentional mechanisms to successful encoding and contribute to a growing literature dedicated to understanding the role of neural synchrony in cognition.

scholarly journals Does Muscle Fatigue Alter EEG Bands of Brain Hemispheres?

2017 ◽  
Author(s):  
Sh Taghizadeh ◽  
S Pirouzi ◽  
A Zamani ◽  
A Motealleh ◽  
Z Bagheri
Keyword(s):  
Muscle Contraction ◽  
Muscle Fatigue ◽  
Right Hemisphere ◽  
Voluntary Contraction ◽  
Gamma Band ◽  
Beta Band ◽  
Healthy Human ◽  
Gamma Rhythm ◽  
Band Activity ◽  
Three Phases

Background: Muscle fatigue has been known to influence brain activity, but very little is known about how cortical centers respond to muscle fatigue.Objective: This study was conducted to investigate the effects of muscle contraction and fatigue induced by two different percent of maximal voluntary contraction (MVC) on Electroencephalography (EEG) signals.Methods: EEG signals were recorded from twenty-one healthy human subjects during three phases (rest, pre fatigue and post fatigue) contraction of Adductor pollicis muscle (APM) at 30% and 70% MVC. The mean powers of EEG bands (alpha, beta and gamma) were computed offline in the frequency domain.Results: None of the three phases with each percent of MVC revealed significant differences for all bands (p>0.05). Comparison of two hemispheres showed right hemisphere gamma band activity was enhanced during pre-fatigue state at 30% MVC (p= 0.042) and post-fatigue state at 70% MVC (p= 0.028). Right hemisphere beta band activity also increased prominently at 70% MVC in post-fatigue condition (p = 0.030).Conclusion: These results suggest muscle contraction and fatigue at 30% and 70% MVC have no significant effect on EEG activity, but the trends of beta and gamma band activities are almost similar in each percent of 30% and 70% MVC. Right brain hemisphere shows more activity than left hemisphere in beta and gamma rhythm after fatigue state at 70% MVC.

scholarly journals Motion Coherence and Luminance Contrast Interact in Driving Visual Gamma-Band Activity

2020 ◽  
Author(s):  
Franziska Pellegrini ◽  
David J Hawellek ◽  
Anna-Antonia Pape ◽  
Joerg F Hipp ◽  
Markus Siegel
Keyword(s):  
Visual Motion ◽  
Human Subjects ◽  
Luminance Contrast ◽  
Gamma Band ◽  
Visual Features ◽  
Population Activity ◽  
Bottom Up ◽  
Motion Coherence ◽  
Gamma Band Activity ◽  
Band Activity

Abstract Synchronized neuronal population activity in the gamma-frequency range (>30 Hz) correlates with the bottom-up drive of various visual features. It has been hypothesized that gamma-band synchronization enhances the gain of neuronal representations, yet evidence remains sparse. We tested a critical prediction of the gain hypothesis, which is that features that drive synchronized gamma-band activity interact super-linearly. To test this prediction, we employed whole-head magnetencephalography in human subjects and investigated if the strength of visual motion (motion coherence) and luminance contrast interact in driving gamma-band activity in visual cortex. We found that gamma-band activity (64–128 Hz) monotonically increased with coherence and contrast, while lower frequency activity (8–32 Hz) decreased with both features. Furthermore, as predicted for a gain mechanism, we found a multiplicative interaction between motion coherence and contrast in their joint drive of gamma-band activity. The lower frequency activity did not show such an interaction. Our findings provide evidence that gamma-band activity acts as a cortical gain mechanism that nonlinearly combines the bottom-up drive of different visual features.

scholarly journals The ‘Narcissus Effect’: Top-down alpha-beta band modulation of face-related brain areas during self-face processing

NeuroImage ◽  
2020 ◽  
Vol 213 ◽  
pp. 116754 ◽  
Author(s):  
Elisabet Alzueta ◽  
María Melcón ◽  
Ole Jensen ◽  
Almudena Capilla
Keyword(s):  
Face Processing ◽  
Beta Band ◽  
Top Down ◽  
Brain Areas ◽  
Alpha Beta

scholarly journals Alpha-to-beta- and gamma-band activity reflect predictive coding in affective visual processing

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Andreas Strube ◽  
Michael Rose ◽  
Sepideh Fazeli ◽  
Christian Büchel
Keyword(s):  
Visual Processing ◽  
Predictive Coding ◽  
Stimulus Presentation ◽  
Gamma Band ◽  
Prediction Errors ◽  
Beta Band ◽  
Picture Processing ◽  
Gamma Band Activity ◽  
Spectral Patterns ◽  
Band Activity

AbstractProcessing of negative affective pictures typically leads to desynchronization of alpha-to-beta frequencies (ERD) and synchronization of gamma frequencies (ERS). Given that in predictive coding higher frequencies have been associated with prediction errors, while lower frequencies have been linked to expectations, we tested the hypothesis that alpha-to-beta ERD and gamma ERS induced by aversive pictures are associated with expectations and prediction errors, respectively. We recorded EEG while volunteers were involved in a probabilistically cued affective picture task using three different negative valences to produce expectations and prediction errors. Our data show that alpha-to-beta band activity after stimulus presentation was related to the expected valence of the stimulus as predicted by a cue. The absolute mismatch of the expected and actual valence, which denotes an absolute prediction error was related to increases in alpha, beta and gamma band activity. This demonstrates that top-down predictions and bottom-up prediction errors are represented in typical spectral patterns associated with affective picture processing. This study provides direct experimental evidence that negative affective picture processing can be described by neuronal predictive coding computations.

Early interaction between bottom-up and top-down processes in the beta-gamma band during ultra-rapid visual object detection

NeuroImage ◽  
2009 ◽  
Vol 47 ◽  
pp. S155
Author(s):  
A.V. Medvedev ◽  
S.B. Borisov ◽  
J. Kainerstorfer ◽  
J. VanMeter
Keyword(s):  
Object Detection ◽  
Gamma Band ◽  
Visual Object ◽  
Top Down ◽  
Bottom Up ◽  
Early Interaction

scholarly journals Negative covariation between task-related responses in alpha/beta-band activity and BOLD in human sensorimotor cortex: An EEG and fMRI study of motor imagery and movements

NeuroImage ◽  
2010 ◽  
Vol 49 (3) ◽  
pp. 2596-2606 ◽  
Author(s):  
Han Yuan ◽  
Tao Liu ◽  
Rebecca Szarkowski ◽  
Cristina Rios ◽  
James Ashe ◽  
...  
Keyword(s):  
Motor Imagery ◽  
Sensorimotor Cortex ◽  
Beta Band ◽  
Fmri Study ◽  
Alpha Beta ◽  
Band Activity

scholarly journals Motion Coherence and Luminance Contrast Interact in Driving Visual Gamma-Band Activity

2019 ◽  
Author(s):  
Franziska Pellegrini ◽  
David J Hawellek ◽  
Anna-Antonia Pape ◽  
Joerg F Hipp ◽  
Markus Siegel
Keyword(s):  
Visual Motion ◽  
Human Subjects ◽  
Luminance Contrast ◽  
Gamma Band ◽  
Visual Features ◽  
Population Activity ◽  
Bottom Up ◽  
Motion Coherence ◽  
Gamma Band Activity ◽  
Band Activity

AbstractSynchronized neuronal population activity in the gamma-frequency range (> 30 Hz) correlates with the bottom-up drive of various visual features. It has been hypothesized that gamma-band synchronization enhances the gain of neuronal representations, yet evidence remains sparse. We tested a critical prediction of the gain hypothesis, which is that features that drive synchronized gamma-band activity interact super-linearly. To test this prediction, we employed whole-head magnetencephalography (MEG) in human subjects and investigated if the strength of visual motion (motion coherence) and luminance contrast interact in driving gamma-band activity in visual cortex. We found that gamma-band activity (64 to 128 Hz) monotonically increased with coherence and contrast while lower frequency activity (8 to 32 Hz) decreased with both features. Furthermore, as predicted for a gain mechanism, we found a multiplicative interaction between motion coherence and contrast in their joint drive of gamma-band activity. The lower frequency activity did not show such an interaction. Our findings provide evidence, that gamma-band activity acts as a cortical gain mechanism that nonlinearly combines the bottom-up drive of different visual features in support of visually guided behavior.

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