Poster F3, Tuesday, March 28, 8:00 – 10:00 am, Pacific Concourse
The effects of alpha-band electrical stimulation of a fronto-parietal network on spatial attention.
Martine R. van Schouwenburg1, Lynn Sörensen1, Raza de Klerk1, Leon C. Reteig1, Heleen A. Slagter1; 1Brain & Cognition, Department of Psychology, University of Amsterdam
Recent studies suggests that communication between distant brain regions might be facilitated through neuronal coherence, such that two regions that oscillate in-phase show increased information exchange, while two regions that oscillate out-of-phase are not able to communicate effectively. In a previous study using transcranial alternating current (tACS) stimulation, we found preliminary evidence that the fronto-parietal network, which has been shown to play a pivotal role in the top-down control of spatial attention, might communicate through coherence in the alpha-band (8-12 Hz). Specifically, simultaneous (in-phase) alpha-band stimulation over the right frontal and parietal cortex was associated with changes in performance and fronto-parietal coherence during a spatial attention task as compared to sham stimulation. In the current study, we aimed to test if the observed changes were specific for in-phase stimulation (0⁰ phase difference) of the two regions or if similar results were obtained if the two regions received the same amount of stimulation but out-of-phase (180⁰ phase difference). Participants were tested in three different sessions in which they received either in-phase, out-of-phase, or sham stimulation to the right frontal and parietal cortex. In contrast to our previous study, we found no effect of stimulation on behavior or coherence from either the in-phase or out-of-phase condition compared to sham. These results might challenge the reproducibility of tACS effects. We will highlight some of the differences in study design that may have contributed to the discrepancy in findings between the two studies and more generally, may determine the effectiveness of tACS.
Topic Area: ATTENTION: Spatial