Abstract
Transcranial alternating current stimulation (tACS) at 10Hz has been shown to modulate spatial attention. However, the frequency-specificity and the oscillatory changes underlying this tACS effect are still largely unclear. Here, we applied high-definition tACS at 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 and offline alpha power (using electroencephalography, EEG). We revealed a behavioural and electrophysiological stimulation effect relative to sham for IAF but not control frequency stimulation conditions: there was a leftward lateralization of alpha power for IAF tACS, which differed from sham for the first out of three minutes following tACS. At a high value of this EEG effect (moderation effect), we observed a leftward attention bias relative to sham. This effect was task-specific, i.e. it could be found in an endogenous attention but not in a detection task. Only in the IAF tACS condition, we also found a correlation between the magnitude of the alpha lateralization and the attentional bias effect. Our results support a functional role of alpha oscillations in visuospatial attention and the potential of tACS to modulate it. The frequency-specificity of the effects suggests that an individualization of the stimulation frequency is necessary in heterogeneous target groups with a large variation in IAF.
Original language | English |
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Article number | 147834 |
Number of pages | 15 |
Journal | Brain Research |
Volume | 1782 |
Early online date | 14 Feb 2022 |
DOIs | |
Publication status | Published - 1 May 2022 |
Keywords
- <p>Transcranial alternating current stimulation & nbsp;(tACS)</p>
- ALTERNATING-CURRENT STIMULATION
- BETA-FREQUENCY
- BRAIN
- EEG
- MAGNETIC STIMULATION
- Non-invasive brain stimulation
- OSCILLATIONS
- Oscillations
- PARIETAL CORTEX
- PHASE
- Parietal cortex
- QUANTITATIVE EEG
- TACS
- VISUAL-SPATIAL ATTENTION
- individual alpha frequency (IAF)
- Transcranial alternating current stimulation (tACS)