Transcranial electric stimulation (tES) to early visual areas alters large-scale functional connectivity.

[摘要] Visual areas are functionally connected with higher cortical areas, and these connections with large-scale brain networks are known to shape visual perception. Recent research suggests that transcranial electric stimulation (tES) can induce changes in brain activity. To better understand how tES influences visual processing networks, we examined how tES modulated the connectivity of early visual areas both during and after stimulation. Ten participants took part in five fMRI sessions conducted on five different days, during which they received different stimulation protocols: transcranial direct current stimulation (tDCS), 10 Hz transcranial alternating current stimulation (tACS), high-frequency transcranial random noise stimulation (hf-tRNS), low-frequency transcranial random noise stimulation (lf-tRNS) and sham. The anodal electrode was placed over the scalp location Oz and the cathodal electrode was placed over Cz. In each session, participants underwent three 12 minute resting-state fMRI scans with their eyes open. tES was applied only during the second scan. Changes in functional connectivity with early visual areas during stimulation was defined as the contrast between the second and first scans, and changes in the connectivity after stimulation was defined as the contrast between the third and first scans. The results showed that (1) tDCS to the visual cortex induced an increase in functional connectivity with cerebellum and decreases in functional connectivity with right SMA and right inferior temporal gyrus during stimulation, (2) tDCS to the visual cortex induced a decrease in functional connectivity with right inferior temporal gyrus after stimulation and (3) tACS to the visual cortex induced an increase in functional connectivity with right-frontal pole after stimulation. These data suggest that tES changes the functional connections of visual processing areas, and that some of these effects are persistent after termination of the stimulation. We will further discuss implications of tES to visual cortex and its effects on the cortical networks.

[学科分类] 眼科学