Supplemental Material for Overlapping Brain Network and Alpha Power Changes Suggest Visuospatial Attention Effects on Driving Performance

Fatigue is one problem with driving as it can lead to difficulties with sustaining attention, behavioral lapses, and a tendency to ignore vital information or operations. In this research, we explore multimodal physiological phenomena in response to driving fatigue through simultaneous functional near-infrared spectroscopy (fNIRS) and electroencephalography (EEG) recordings with the aim of investigating the relationships between hemodynamic and electrical features and driving performance. Sixteen subjects participated in an event-related lane-deviation driving task while measuring their brain dynamics through fNIRS and EEGs. Three performance groups, classified as Optimal, Suboptimal, and Poor, were defined for comparison. From our analysis, we find that tonic variations occur before a deviation, and phasic variations occur afterward. The tonic results show an increased concentration of oxygenated hemoglobin (HbO2) and power changes in the EEG theta, alpha, and beta bands. Both dynamics are significantly correlated with deteriorated driving performance. The phasic EEG results demonstrate event-related desynchronization associated with the onset of steering vehicle in all power bands. The concentration of phasic HbO2 decreased as performance worsened. Further, the negative correlations between tonic EEG delta and alpha power and HbO2 oscillations suggest that activations in HbO2 are related to mental fatigue. In summary, combined hemodynamic and electrodynamic activities can provide complete knowledge of the brain’s responses as evidence of state changes during fatigue driving.

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Electroencephalogram (EEG) Alpha Power as a Marker of Visuospatial Attention Orienting and Suppression in Normoxia and Hypoxia. An Exploratory Study

Brain Sciences ◽

10.3390/brainsci10030140 ◽

2020 ◽

Vol 10 (3) ◽

pp. 140 ◽

Cited By ~ 1

Author(s):

Alberto Zani ◽

Clara Tumminelli ◽

Alice Mado Proverbio

Keyword(s):

Exploratory Study ◽

Visuospatial Attention ◽

Alpha Power ◽

Control Networks ◽

Attention Orienting ◽

Oxygenation Condition ◽

Eeg Alpha ◽

The Right ◽

And Control ◽

Electroencephalogram Eeg

While electroencephalogram (EEG) alpha desynchronization has been related to anticipatory orienting of visuospatial attention, an increase in alpha power has been associated to its inhibition. A separate line of findings indicated that alpha is affected by a deficient oxygenation of the brain or hypoxia, although leaving unclear whether the latter increases or decreases alpha synchronization. Here, we carried out an exploratory study on these issues by monitoring attention alerting, orienting, and control networks functionality by means of EEG recorded both in normoxia and hypoxia in college students engaged in four attentional cue-target conditions induced by a redesigned Attention Network Test. Alpha power was computed through Fast Fourier Transform. Regardless of brain oxygenation condition, alpha desynchronization was the highest during exogenous, uncued orienting of spatial attention, the lowest during alerting but spatially unpredictable, cued exogenous orienting of attention, and of intermediate level during validly cued endogenous orienting of attention, no matter the motor response workload demanded by the latter, especially over the left hemisphere. Hypoxia induced an increase in alpha power over the right-sided occipital and parietal scalp areas independent of attention cueing and conflict conditions. All in all, these findings prove that attention orienting is undergirded by alpha desynchronization and that alpha right-sided synchronization in hypoxia might sub-serve either the effort to sustain attention over time or an overall suppression of attention networks functionality.

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Signatures of Brain Network Alteration in Psychogenic Non-Epileptic Seizures: A Rest-EEG Study Based on Power Spectral Density and Phase Lag Index

10.1101/2021.10.20.464353 ◽

2021 ◽

Author(s):

Giuseppe Varone ◽

Wadii Boulila ◽

Michele Lo Giudice ◽

Bilel Benjdira ◽

Nadia Mammone ◽

...

Keyword(s):

Power Spectrum ◽

Epileptic Seizures ◽

Brain Regions ◽

Brain Network ◽

Oscillatory Activity ◽

Alpha Power ◽

Phase Lag ◽

Distributed Information ◽

Main Challenge ◽

Large Populations

The main challenge in the clinical assessment of Psychogenic Non-Epileptic Seizures (PNES) is the lack of an electroencephalographic marker in the electroencephalography (EEG) readout. Although decades of EEG studies have focused on detecting cortical brain function underlying PNES, the principle of PNES remains poorly understood. To address this problem, electric potentials generated by large populations of neurons were collected during the resting state to be processed after that by Power Spectrum Density (PSD) for possible analysis of PNES signatures. Additionally, the integration of distributed information of regular and synchronized multi-scale communication within and across inter-regional brain areas has been observed using functional connectivity tools like Phase Lag Index (PLI) and graph-derived metrics. A cohort study of 20 PNES and 19 Healthy Control subjects (HC) were enrolled. The major finding is that PNES patients exhibited significant differences in alpha-power spectrum in brain regions related to cognitive operations, attention, working memory, and movement regulation. Noticeably, we observed that there exists an altered oscillatory activity and a widespread inter-regional phase desynchronization. This indicates changes in global efficiency, node betweenness, shortest path length, and small worldness in the delta, theta, alpha, and beta frequency bands. Finally, our findings look into new evidence of the intrinsic organization of functional brain networks that reflects a dysfunctional level of integration of local activity across brain regions, which can provide new insights into the pathophysiological mechanisms of PNES.

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Frequency-specific transcranial neuromodulation of oscillatory alpha power alters and predicts human visuospatial attention performance

10.1101/2020.08.04.236109 ◽

2020 ◽

Author(s):

S. K. Kemmerer ◽

A.T. Sack ◽

T.A. de Graaf ◽

S. ten Oever ◽

P. De Weerd ◽

...

Keyword(s):

Spatial Attention ◽

Posterior Parietal Cortex ◽

Attention Bias ◽

Visuospatial Attention ◽

Alpha Power ◽

High Definition ◽

Alpha Frequency ◽

Transcranial Alternating Current Stimulation ◽

Attention Performance ◽

The Individual

AbstractUnilateral transcranial alternating current stimulation (tACS) at alpha frequency modulates the locus of spatial attention. However, the neural mechanisms by which tACS influences spatial attention remain poorly understood. Here, we applied high-definition tACS at the individual alpha frequency (IAF), two control frequencies (IAF+/-2Hz) and sham to the left posterior parietal cortex and measured its effects on visuospatial attention performance as well as alpha power (using electroencephalography, EEG). Our results revealed a leftward lateralization of alpha power relative to sham. At a high value of leftward alpha lateralization, we also observed a leftward attention bias, which differed from sham. Moreover, the magnitude of the alpha lateralization effect predicted the attention bias. These effects occurred for tACS at IAF but not for the control frequencies. This suggests that tACS operates through oscillatory interactions with ongoing brain rhythms in line with the synchronization theory. Our results also highlight the importance of personalized stimulation protocols, especially in potential clinical settings.

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Relating alpha power modulations to competing visuospatial attention theories

NeuroImage ◽

10.1016/j.neuroimage.2019.116429 ◽

2020 ◽

Vol 207 ◽

pp. 116429 ◽

Cited By ~ 1

Author(s):

Stefano Gallotto ◽

Felix Duecker ◽

Sanne ten Oever ◽

Teresa Schuhmann ◽

Tom A. de Graaf ◽

...

Keyword(s):

Visuospatial Attention ◽

Alpha Power

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Faculty Opinions recommendation of A lateralized brain network for visuospatial attention.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.13357152.14726479 ◽

2011 ◽

Author(s):

Peter König ◽

Jose Ossandon

Keyword(s):

Brain Network ◽

Visuospatial Attention

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Left parietal tACS at alpha frequency induces a shift of visuospatial attention

10.1101/644237 ◽

2019 ◽

Cited By ~ 2

Author(s):

T. Schuhmann ◽

S. K. Kemmerer ◽

F. Duecker ◽

T.A. de Graaf ◽

S. ten Oever ◽

...

Keyword(s):

Spatial Attention ◽

Parietal Cortex ◽

Visuospatial Attention ◽

High Density ◽

Exogenous Attention ◽

Alpha Power ◽

Endogenous Attention ◽

Alpha Frequency ◽

Stimulus Detection ◽

Left Parietal Cortex

AbstractBackgroundVoluntary shifts of visuospatial attention are associated with a lateralization of occipitoparietal alpha power (7-13Hz), i.e. higher power in the hemisphere ipsilateral and lower power contralateral to the locus of attention. Recent noninvasive neuromodulation studies demonstrated that alpha power can be experimentally increased using transcranial alternating current stimulation (tACS).Objective/HypothesisWe hypothesized that tACS at alpha frequency over the left parietal cortex induces shifts of attention to the left hemifield. However, spatial attention shifts not only occur voluntarily (endogenous), but also stimulus-driven (exogenous). In order to study the task-specificity of the potential effects of tACS on attentional processes, we administered three conceptually different spatial attention tasks.Methods36 healthy volunteers were recruited from an academic environment. In two seperate sessions, we applied either high-density tACS at 10Hz, or sham tACS, for 35-40 minutes to their left parietal cortex. We systematically compared performance on endogenous attention, exogenous attention, and stimulus detection tasks.ResultsIn the Endogenous attention task, we found a greater leftward bias in reaction times during left parietal 10Hz tACS as compared to sham. There were no stimulation effects in the exogenous attention or stimulus detection task.ConclusionThe study shows that high-density tACS at 10Hz can be used to modulate visuospatial attention performance. The tACS effect is task-specific, indicating that not all forms of attention are equally susceptible to the stimulation.

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Parietal alpha tACS shows inconsistent effects on visuospatial attention

PLoS ONE ◽

10.1371/journal.pone.0255424 ◽

2021 ◽

Vol 16 (8) ◽

pp. e0255424

Author(s):

Andra Coldea ◽

Stephanie Morand ◽

Domenica Veniero ◽

Monika Harvey ◽

Gregor Thut

Keyword(s):

Visual Processing ◽

Visuospatial Attention ◽

Alpha Power ◽

Attention Task ◽

Replication Studies ◽

Positive Effects ◽

Promising Tool ◽

Visual Hemifield ◽

Transcranial Alternating Current Stimulation ◽

Resting Electroencephalography

Transcranial alternating current stimulation (tACS) is a popular technique that has been used for manipulating brain oscillations and inferring causality regarding the brain-behaviour relationship. Although it is a promising tool, the variability of tACS results has raised questions regarding the robustness and reproducibility of its effects. Building on recent research using tACS to modulate visuospatial attention, we here attempted to replicate findings of lateralized parietal tACS at alpha frequency to induce a change in attention bias away from the contra- towards the ipsilateral visual hemifield. 40 healthy participants underwent tACS in two separate sessions where either 10 Hz tACS or sham was applied via a high-density montage over the left parietal cortex at 1.5 mA for 20 min, while performance was assessed in an endogenous attention task. Task and tACS parameters were chosen to match those of previous studies reporting positive effects. Unlike these studies, we did not observe lateralized parietal alpha tACS to affect attention deployment or visual processing across the hemifields as compared to sham. Likewise, additional resting electroencephalography immediately offline to tACS did not reveal any notable effects on individual alpha power or frequency. Our study emphasizes the need for more replication studies and systematic investigations of the factors that drive tACS effects.

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