scholarly journals Top-down inhibition of irrelevant information indexed by alpha rhythms is disrupted in migraine

2021 ◽  
Author(s):  
Rémy Masson ◽  
Hesham A ElShafei ◽  
Geneviève Demarquay ◽  
Lesly Fornoni ◽  
Yohana Lévêque ◽  
...  
Keyword(s):  
Cognitive Processing ◽  
Gamma Activity ◽  
Auditory Target ◽  
Alpha Power ◽  
Top Down ◽  
Significant Group ◽  
Bottom Up ◽  
Power Increase ◽  
Visual Areas ◽  
Healthy Participants

There is growing evidence that migraine is associated with attentional abnormalities, both during and outside migraine attacks, which would impact the cognitive processing of sensory stimulation. However, these attention alterations are poorly characterized and their neurophysiological basis is still unclear. Nineteen migraineurs without aura and nineteen healthy participants were recruited to perform a task which used visually-cued auditory targets and distracting sounds to evaluate conjointly top-down and bottom-up attention mechanisms. Magnetoencephalography (MEG) signals were recorded. We investigated anticipatory alpha activity (power increase and decrease) and distractor-induced gamma activity as markers for top-down (inhibition and facilitation) and bottom-up attention, respectively. Compared to healthy participants, migraineurs presented a significantly less prominent alpha power increase in visual areas in anticipation of the auditory target, indexing a reduced inhibition of task-irrelevant visual areas. However, there was no significant group difference regarding the alpha power decrease in the relevant auditory cortices in anticipation of the target, nor regarding the distractor-induced gamma power increase in the ventral attention network. These results in the alpha band suggest that top-down inhibitory processes in the visual cortices are deficient in migraine but there is no clear evidence supporting a disruption of top-down facilitatory attentional processes. This relative inability to suppress irrelevant sensory information may be underlying the self-reported increased distractibility and contribute to sensory disturbances in migraine.

scholarly journals Top–Down Control of Alpha Phase Adjustment in Anticipation of Temporally Predictable Visual Stimuli

2018 ◽  
Vol 30 (8) ◽  
pp. 1157-1169 ◽  
Author(s):  
Rodolfo Solís-Vivanco ◽  
Ole Jensen ◽  
Mathilde Bonnefond
Keyword(s):  
Visual Processing ◽  
Visual Information ◽  
Alpha Phase ◽  
Stimulus Onset ◽  
Gamma Activity ◽  
Alpha Power ◽  
Top Down ◽  
Alpha Oscillations ◽  
Phase Adjustment ◽  
Visual Areas

Alpha oscillations (8–14 Hz) are proposed to represent an active mechanism of functional inhibition of neuronal processing. Specifically, alpha oscillations are associated with pulses of inhibition repeating every ∼100 msec. Whether alpha phase, similar to alpha power, is under top–down control remains unclear. Moreover, the sources of such putative top–down phase control are unknown. We designed a cross-modal (visual/auditory) attention study in which we used magnetoencephalography to record the brain activity from 34 healthy participants. In each trial, a somatosensory cue indicated whether to attend to either the visual or auditory domain. The timing of the stimulus onset was predictable across trials. We found that, when visual information was attended, anticipatory alpha power was reduced in visual areas, whereas the phase adjusted just before the stimulus onset. Performance in each modality was predicted by the phase of the alpha oscillations previous to stimulus onset. Alpha oscillations in the left pFC appeared to lead the adjustment of alpha phase in visual areas. Finally, alpha phase modulated stimulus-induced gamma activity. Our results confirm that alpha phase can be top–down adjusted in anticipation of predictable stimuli and improve performance. Phase adjustment of the alpha rhythm might serve as a neurophysiological resource for optimizing visual processing when temporal predictions are possible and there is considerable competition between target and distracting stimuli.

scholarly journals Attention and Temporal Expectations Modulate Power, Not Phase, of Ongoing Alpha Oscillations

2015 ◽  
Vol 27 (8) ◽  
pp. 1573-1586 ◽  
Author(s):  
Rosanne M. van Diepen ◽  
Michael X Cohen ◽  
Damiaan Denys ◽  
Ali Mazaheri
Keyword(s):  
Phase Angle ◽  
Phase Locking ◽  
Auditory Target ◽  
Alpha Power ◽  
Visual Condition ◽  
Top Down ◽  
Alpha Oscillations ◽  
Alpha Oscillation ◽  
Sensory Cortices ◽  
Phase Angles

The perception of near-threshold visual stimuli has been shown to depend in part on the phase (i.e., time in the cycle) of ongoing alpha (8–13 Hz) oscillations in the visual cortex relative to the onset of that stimulus. However, it is currently unknown whether the phase of the ongoing alpha activity can be manipulated by top–down factors such as attention or expectancy. Using three variants of a cross-modal attention paradigm with constant predictable stimulus onsets, we examined if cues signaling to attend to either the visual or the auditory domain influenced the phase of alpha oscillations in the associated sensory cortices. Importantly, intermixed in all three experiments, we included trials without a target to estimate the phase at target presentation without contamination from the early evoked responses. For these blank trials, at the time of expected target and distractor onset, we examined (1) the degree of the uniformity in phase angles across trials, (2) differences in phase angle uniformity compared with a pretarget baseline, and (3) phase angle differences between visual and auditory target conditions. Across all three experiments, we found that, although the cues induced a modulation in alpha power in occipital electrodes, neither the visual condition nor the auditory cue condition induced any significant phase-locking across trials during expected target or distractor presentation. These results suggest that, although alpha power can be modulated by top–down factors such as attention and expectation, the phase of the ongoing alpha oscillation is not under such control.

scholarly journals Characterizing the effects of feature salience and top-down attention in the early visual system

2017 ◽  
Vol 118 (1) ◽  
pp. 564-573 ◽  
Author(s):  
Sonia Poltoratski ◽  
Sam Ling ◽  
Devin McCormack ◽  
Frank Tong
Keyword(s):  
Visual System ◽  
Spatial Attention ◽  
Visual Processing ◽  
Visual Pathway ◽  
Additive Effects ◽  
Voluntary Attention ◽  
Top Down ◽  
Motion Direction ◽  
Bottom Up ◽  
Visual Areas

The visual system employs a sophisticated balance of attentional mechanisms: salient stimuli are prioritized for visual processing, yet observers can also ignore such stimuli when their goals require directing attention elsewhere. A powerful determinant of visual salience is local feature contrast: if a local region differs from its immediate surround along one or more feature dimensions, it will appear more salient. We used high-resolution functional MRI (fMRI) at 7T to characterize the modulatory effects of bottom-up salience and top-down voluntary attention within multiple sites along the early visual pathway, including visual areas V1–V4 and the lateral geniculate nucleus (LGN). Observers viewed arrays of spatially distributed gratings, where one of the gratings immediately to the left or right of fixation differed from all other items in orientation or motion direction, making it salient. To investigate the effects of directed attention, observers were cued to attend to the grating to the left or right of fixation, which was either salient or nonsalient. Results revealed reliable additive effects of top-down attention and stimulus-driven salience throughout visual areas V1–hV4. In comparison, the LGN exhibited significant attentional enhancement but was not reliably modulated by orientation- or motion-defined salience. Our findings indicate that top-down effects of spatial attention can influence visual processing at the earliest possible site along the visual pathway, including the LGN, whereas the processing of orientation- and motion-driven salience primarily involves feature-selective interactions that take place in early cortical visual areas. NEW & NOTEWORTHY While spatial attention allows for specific, goal-driven enhancement of stimuli, salient items outside of the current focus of attention must also be prioritized. We used 7T fMRI to compare salience and spatial attentional enhancement along the early visual hierarchy. We report additive effects of attention and bottom-up salience in early visual areas, suggesting that salience enhancement is not contingent on the observer’s attentional state.

scholarly journals Circular inference in bistable perception

2019 ◽  
Author(s):  
Pantelis Leptourgos ◽  
Charles-Edouard Notredame ◽  
Marion Eck ◽  
Renaud Jardri ◽  
Sophie Denève
Keyword(s):  
Prior Knowledge ◽  
Bayesian Approach ◽  
Necker Cube ◽  
Top Down ◽  
Inference Model ◽  
Bottom Up ◽  
Bistable Perception ◽  
Sensory Evidence ◽  
The Brain ◽  
Healthy Participants

AbstractWhen facing fully ambiguous images, the brain cannot commit to a single percept and instead switches between mutually exclusive interpretations every few seconds, a phenomenon known as bistable perception. Despite years of research, there is still no consensus on whether bistability, and perception in general, is driven primarily by bottom-up or top-down mechanisms. Here, we adopted a Bayesian approach in an effort to reconcile these two theories. Fifty-five healthy participants were exposed to an adaptation of the Necker cube paradigm, in which we manipulated sensory evidence (by shadowing the cube) and prior knowledge (e.g., by varying instructions about what participants should expect to see). We found that manipulations of both sensory evidence and priors significantly affected the way participants perceived the Necker cube. However, we observed an interaction between the effect of the cue and the effect of the instructions, a finding incompatible with Bayes-optimal integration. In contrast, the data were well predicted by a circular inference model. In this model, ambiguous sensory evidence is systematically biased in the direction of current expectations, ultimately resulting in a bistable percept.

scholarly journals Development of Frontal EEG Differences Between Eyes-Closed and Eyes-Open Resting Conditions in Children: Data From a Single-Channel Dry-Sensor Portable Device

2020 ◽  
pp. 155005942094664
Author(s):  
Stuart J. Johnstone ◽  
Han Jiang ◽  
Li Sun ◽  
Jeffrey M. Rogers ◽  
Joaquin Valderrama ◽  
...  
Keyword(s):  
Single Channel ◽  
Developmental Change ◽  
Alpha Power ◽  
Top Down ◽  
Bottom Up ◽  
Individual Level ◽  
Eyes Closed ◽  
Beta Power ◽  
Eyes Open ◽  
The Individual

Changes in EEG when moving from an eyes-closed to an eyes-open resting condition result from bottom-up sensory processing and have been referred to as activation. In children, activation is characterized by a global reduction in alpha, frontally present reductions for delta and theta, and a frontal increase for beta. The present study aimed to replicate frontal EEG activation effects using single-channel, dry-sensor EEG, and to extend current understanding by examining developmental change in children. Frontal EEG was recorded using a single-channel, dry-sensor EEG device while 182 children aged 7 to 12 years completed eyes-closed resting (EC), eyes-open resting (EO), and focus (FO) tasks. Results indicated that frontal delta, theta, and alpha power were reduced, and frontal beta power was increased, in the EO compared with the EC condition. Exploratory analysis of a form of top-down activation showed that frontal beta power was increased in the FO compared with to the EO condition, with no differences for other bands. The activation effects were robust at the individual level. The bottom-up activation effects reduced with age for frontal delta and theta, increased for frontal alpha, with no developmental change for top-down or bottom-up frontal beta activation. These findings contribute further to validation of the single-channel, dry-sensor, frontal EEG and provide support for use in a range of medical, therapeutic, and clinical domains.

scholarly journals Spatial thinking from a different view: Disentangling top-down and bottom-up processes using eye tracking

2020 ◽  
Vol 2 (1) ◽  
pp. 138-212
Author(s):  
Benedict C. O. F. Fehringer
Keyword(s):  
Eye Tracking ◽  
Cognitive Processing ◽  
Difficulty Level ◽  
Spatial Thinking ◽  
Short Version ◽  
Test Model ◽  
Top Down ◽  
Bottom Up ◽  
Gaze Fixation ◽  
Processing Steps

AbstractThe goal of the present study was to investigate the potential of gaze fixation patterns to reflect cognitive processing steps during test performance. Gaze movements, however, can reflect top-down and bottom-up processes. Top-down processes are the cognitive processing steps that are necessary to solve a certain test item. In contrast, bottom-up processes may be provoked by varying visual features that are not related to the item solution. To disentangle top-down and bottom-up processes in the context of spatial thinking, a new test (R-Cube-Vis Test) was developed and validated explicitly for the usage of eye tracking in three studies as long and short version. The R-Cube-Vis Test measures visualization and is conform to the linear logistic test model with six difficulty levels. All items of one level demand the same transformation steps to solve an item. The R-Cube-Vis Test was then utilized to investigate different gaze-fixation-based indicators to identify top-down and bottom-up processes. Some of the indicators were also able to predict the correctness of the answer of a single item. Gaze-related measures have a high potential to reveal cognitive processing steps during solving an item of a given difficulty level, if top-down and bottom-up processes can be segregated.

scholarly journals Bottom-up and top-down influences at untrained conditions determine perceptual learning specificity and transfer

eLife ◽  
2016 ◽  
Vol 5 ◽  
Author(s):  
Ying-Zi Xiong ◽  
Jun-Yun Zhang ◽  
Cong Yu
Keyword(s):  
Perceptual Learning ◽  
Top Down ◽  
Transfer Condition ◽  
Bottom Up ◽  
Visual Neurons ◽  
Continuous Flash Suppression ◽  
Visual Areas ◽  
Suppression Technique ◽  
High Level ◽  
Additional Exposure

Perceptual learning is often orientation and location specific, which may indicate neuronal plasticity in early visual areas. However, learning specificity diminishes with additional exposure of the transfer orientation or location via irrelevant tasks, suggesting that the specificity is related to untrained conditions, likely because neurons representing untrained conditions are neither bottom-up stimulated nor top-down attended during training. To demonstrate these top-down and bottom-up contributions, we applied a “continuous flash suppression” technique to suppress the exposure stimulus into sub-consciousness, and with additional manipulations to achieve pure bottom-up stimulation or top-down attention with the transfer condition. We found that either bottom-up or top-down influences enabled significant transfer of orientation and Vernier discrimination learning. These results suggest that learning specificity may result from under-activations of untrained visual neurons due to insufficient bottom-up stimulation and/or top-down attention during training. High-level perceptual learning thus may not functionally connect to these neurons for learning transfer.

scholarly journals Frontal and parietal alpha oscillations reflect attentional modulation of cross-modal matching

2018 ◽  
Author(s):  
Jonas Misselhorn ◽  
Uwe Friese ◽  
Andreas K. Engel
Keyword(s):  
Gamma Activity ◽  
Multisensory Perception ◽  
Top Down ◽  
Bottom Up ◽  
Alpha Oscillations ◽  
Sensory Inputs ◽  
Gamma Power ◽  
Sensory Cortices ◽  
Underlying Mechanisms ◽  
Selection Of

Multisensory perception is shaped by both attentional selection of relevant sensory inputs and exploitation of stimulus-driven factors that promote cross-modal binding. Underlying mechanisms of both top-down and bottom-up modulations have been linked to changes in alpha/gamma dynamics in primary sensory cortices and temporoparietal cortex. Accordingly, it has been proposed that alpha oscillations provide pulsed inhibition for gamma activity and thereby dynamically route cortical information flow. In this study, we employed a recently introduced multisensory paradigm incorporating both bottom-up and top-down aspects of cross-modal attention in an EEG study. The same trimodal stimuli were presented in two distinct attentional conditions, focused on visual-tactile or audio-visual components, for which cross-modal congruence of amplitude changes had to be evaluated. Neither top-down nor bottom-up cross-modal attention modulated alpha or gamma power in primary sensory cortices. Instead, we found alpha band effects in bilateral frontal and right parietal cortex. We propose that frontal alpha oscillations reflect the origin of top-down control regulating perceptual gains and that modulations of parietal alpha oscillations relates to intersensory re-orienting. Taken together, we suggest that the idea of selective cortical routing via alpha oscillations can be extended from sensory cortices to the frontoparietal attention network.

In the Game or in the Stands: A Top-Down and Bottom-Up Approach to the Processing and Experience of Sport Communication

2017 ◽  
Vol 10 (1) ◽  
pp. 85-104 ◽  
Author(s):  
Justin Robert Keene ◽  
Collin Berke ◽  
Brandon H. Nutting
Keyword(s):  
Cognitive Processing ◽  
Secondary Task ◽  
Reaction Times ◽  
Emotional Reactions ◽  
Top Down ◽  
Bottom Up ◽  
Sport Communication ◽  
Differential Effects ◽  
Camera Angle

This study, based on previous work, investigated the interaction of camera angle, arousing content, and an individual’s general and school-specific fanship on the cognitive processing of and emotional reactions to sport communication from a top-down and bottom-up perspective. Cognitive processing was defined as the resources available for encoding and was indexed using secondary-task reaction times, and self-reported positivity, negativity, and arousal were also measured as an index of emotional reactions. Results indicate that general and school-specific fanship have differential effects on cognitive processing and emotional reactions. In addition, in a replication of previous work, it would appear that different camera angles do not have different effects on cognitive processing. The implications of the top-down and bottom-up approach for the sport communication experience are discussed for both sport researchers and sport communication practitioners.

scholarly journals Functional dynamics underlying near-threshold perception of facial emotions: a magnetoencephalography investigation

2018 ◽  
Author(s):  
Diljit Singh Kajal ◽  
Chiara Fioravanti ◽  
Adham Elshahabi ◽  
Sergio Ruiz ◽  
Ranganatha Sitaram ◽  
...  
Keyword(s):  
Visual Stimulation ◽  
Gamma Band ◽  
Gamma Activity ◽  
Hemispheric Dominance ◽  
Conscious Perception ◽  
Backward Masking ◽  
Top Down ◽  
Bottom Up ◽  
Facial Emotions ◽  
Perceptual Threshold

AbstractConscious perception of emotional valence of faces has been proposed to involve top-down and bottom-up information processing. Yet, the underlying neuronal mechanisms of these two processes and the implementation of their cooperation is still unclear. We hypothesized that the networks activated during the interaction of top-down and bottom-up processes are the key substrates responsible for perception. We assessed the participation of neural networks involved in conscious perception of emotional stimuli near the perceptual threshold using a visual-backward-masking paradigm in 12 healthy individuals using magnetoencephalography. Providing visual stimulation near the perceptual threshold enabled us to compare correctly and incorrectly recognized facial emotions and assess differences in top-down modulation for these stimuli using coherence analysis. We found a fronto-parietal network oscillating in the lower gamma band and exerting top-down control as determined by the causality measure of phase slope index. We demonstrated that correct recognition of facial emotions involved high-beta and low-gamma activity in parietal networks, Incorrect recognition was associated with enhanced coupling in the gamma band between left frontal and right parietal regions. Our results indicate that fronto-parietal control of the perception of emotional face stimuli relies on the right-hemispheric dominance of synchronized gamma band activity.

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