en
Doctoral thesis
Open access
English

Modulation of EEG-Alpha oscillations during visual spatial attention

ContributorsRihs, Tonia
Defense date2008-09-26
Abstract

Voluntarily directing visual attention to a cued position in space leads to improved processing of forthcoming visual stimuli at this position, due to anticipatory tuning of visual cortex activity. Recent evidence points to a determining role of modulations of posterior alpha-band activity (8-14Hz) during attention orienting.This thesis investigates the modulation of EEG alpha-oscillations during anticipatory preparation for a visual target. The results show that the topography of alpha band power maps is found to correspond to a retinotopic organisation according to the direction of attention in the time prior to the expected target arrival. Moreover, the thesis presents evidence for a dynamic modulation of alpha amplitudes according to task demands by showing that both alpha power decreases and increases can occur at different times in the course of anticipation of a visual target stimulus. The findings presented here provide further support for an active facilitative versus inhibitory role of alpha-power decreases and increases during attention orienting, by showing retionotopic specificity and dynamic deployment of attentional resources to prepare versus maintain the cortex for optimal target processing.

eng
Keywords
  • Alpha frequency band
  • EEG map topography
  • Oscillatory brain activity
  • Retinotopy
  • Visual spatial attention
  • Transcranial magnetic stimulation
  • Visual cortex excitability
NoteDiplôme commun des univ. de Genève et Lausanne. Thèse en Neurosciences des universités de Genève et de Lausanne
Citation (ISO format)
RIHS, Tonia. Modulation of EEG-Alpha oscillations during visual spatial attention. 2008. doi: 10.13097/archive-ouverte/unige:40109
Main files (1)
Thesis
accessLevelPublic
Identifiers
619views
757downloads

Technical informations

Creation09/05/2014 6:03:00 PM
First validation09/05/2014 6:03:00 PM
Update time03/14/2023 9:45:10 PM
Status update03/14/2023 9:45:10 PM
Last indexation01/29/2024 8:13:29 PM
All rights reserved by Archive ouverte UNIGE and the University of GenevaunigeBlack