Selective Enhancement of Frontal-Posterior Functional Connectivity by Anodal tDCS Over the Right Posterior Parietal Cortex During Temporal Attention.

Temporal attention is the concentration of perceptual resources at a specific point in time, which can help individuals get prepared to improve their behavioral performance, whereas the neural mechanism of temporal attention is yet to be well understood. In this study, behavioral measurement, transcranial direct current stimulation (tDCS), and electroencephalography (EEG) were combined to explore the effects of task performance and whole-brain functional connectivities (FCs) during temporal attention with different time intervals after applying anodal and sham tDCS over the right posterior parietal cortex (PPC). Although anodal tDCS, compared with sham tDCS, did not induce a significant effect on the task performance of temporal attention, it could effectively increase long-range FCs of gamma rhythms between the right frontal and parieto-occipital regions during temporal attention, and most of the increased FCs were in the right hemisphere with certain hemispheric laterality. Meanwhile, there were intensively more increased long-range FCs at short-time intervals than those at long-time intervals, and the increased FCs at neutral long-time intervals were the least and mainly inter-hemispheric FCs. The current study not only further enriched the evidence on the key role of the right PPC during temporal attention but also proved that anodal tDCS could indeed enhance whole-brain functional connectivity architecture involving intra- and inter-hemispheric long-range FCs, which would provide ideas and references for subsequent studies of temporal attention as well as attention deficit disorder.