Effects of Transcranial Alternating Current Stimulation on Cognitive Functions in Healthy Young and Older Adults

Figure 1

(a) Sample auditory (presented via headphones) and visual (presented on the screen) stimuli of the experiment. (b) Duration and composition of each trial (120 in total in each block). (c) Illustration of the electrode positions and experimental design. The two stimulation electrodes were placed over the left temporoparietal area (CP5; 5 × 7 cm²) and the right supraorbital area (10 × 10 cm²). L1–L5, learning blocks 1–5. R, retrieval testing.