Header

UZH-Logo

Maintenance Infos

Gating by induced Α-Γ asynchrony in selective attention


Pascucci, David; Hervais-Adelman, Alexis; Plomp, Gijs (2018). Gating by induced Α-Γ asynchrony in selective attention. Human Brain Mapping, 39(10):3854-3870.

Abstract

Visual selective attention operates through top-down mechanisms of signal enhancement and suppression, mediated by α-band oscillations. The effects of such top-down signals on local processing in primary visual cortex (V1) remain poorly understood. In this work, we characterize the interplay between large-scale interactions and local activity changes in V1 that orchestrates selective attention, using Granger-causality and phase-amplitude coupling (PAC) analysis of EEG source signals. The task required participants to either attend to or ignore oriented gratings. Results from time-varying, directed connectivity analysis revealed frequency-specific effects of attentional selection: bottom-up γ-band influences from visual areas increased rapidly in response to attended stimuli while distributed top-down α-band influences originated from parietal cortex in response to ignored stimuli. Importantly, the results revealed a critical interplay between top-down parietal signals and α-γ PAC in visual areas. Parietal α-band influences disrupted the α-γ coupling in visual cortex, which in turn reduced the amount of γ-band outflow from visual areas. Our results are a first demonstration of how directed interactions affect cross-frequency coupling in downstream areas depending on task demands. These findings suggest that parietal cortex realizes selective attention by disrupting cross-frequency coupling at target regions, which prevents them from propagating task-irrelevant information.

Abstract

Visual selective attention operates through top-down mechanisms of signal enhancement and suppression, mediated by α-band oscillations. The effects of such top-down signals on local processing in primary visual cortex (V1) remain poorly understood. In this work, we characterize the interplay between large-scale interactions and local activity changes in V1 that orchestrates selective attention, using Granger-causality and phase-amplitude coupling (PAC) analysis of EEG source signals. The task required participants to either attend to or ignore oriented gratings. Results from time-varying, directed connectivity analysis revealed frequency-specific effects of attentional selection: bottom-up γ-band influences from visual areas increased rapidly in response to attended stimuli while distributed top-down α-band influences originated from parietal cortex in response to ignored stimuli. Importantly, the results revealed a critical interplay between top-down parietal signals and α-γ PAC in visual areas. Parietal α-band influences disrupted the α-γ coupling in visual cortex, which in turn reduced the amount of γ-band outflow from visual areas. Our results are a first demonstration of how directed interactions affect cross-frequency coupling in downstream areas depending on task demands. These findings suggest that parietal cortex realizes selective attention by disrupting cross-frequency coupling at target regions, which prevents them from propagating task-irrelevant information.

Statistics

Citations

Dimensions.ai Metrics
2 citations in Web of Science®
3 citations in Scopus®
Google Scholar™

Altmetrics

Downloads

33 downloads since deposited on 20 Nov 2018
33 downloads since 12 months
Detailed statistics

Additional indexing

Item Type:Journal Article, refereed, original work
Communities & Collections:06 Faculty of Arts > Institute of Psychology
Dewey Decimal Classification:150 Psychology
Language:English
Date:October 2018
Deposited On:20 Nov 2018 09:44
Last Modified:19 Mar 2019 15:17
Publisher:Wiley-Blackwell Publishing, Inc.
ISSN:1065-9471
OA Status:Green
Publisher DOI:https://doi.org/10.1002/hbm.24216
Related URLs:https://www.biorxiv.org/content/early/2017/12/05/229526.full.pdf
PubMed ID:29797747
Other Identification Number:10.1101/229526
Project Information:
  • : FunderSNSF
  • : Grant IDPZ00P3_131731
  • : Project TitleFunctional brain networks: dynamics of directed information transfer in visual processes
  • : FunderSNSF
  • : Grant IDPP00P1_157420
  • : Project TitleDynamic Networks of Perception, Cognition and Action

Download

Download PDF  'Gating by induced Α-Γ asynchrony in selective attention'.
Preview
Content: Accepted Version
Language: English
Filetype: PDF
Size: 1MB
View at publisher
Licence: Creative Commons: Attribution 4.0 International (CC BY 4.0)