2017年第二届曲阜视觉科学会议知识库

Transcranial direct-current stimulation (tDCS) is a well-established noninvasive brain stimulation technique that has been widely applied to modulate cortical excitability in the human brain. Previous tDCS studies on modulating contrast sensitivity, one of the most fundamental visual function, were mixed. In the current study, we designed a single blind, sham-controlled with-subject study to investigate the effects of tDCS on contrast sensitivity functions (CSF), assessed with a quick procedure that accurately estimated CSF within minutes (Lesmes et al., 2010). Twenty-seven healthy adult subjects received three sets of 15-min tDCS (two 2-mA anodal and one sham), with CSF measured before and after tDCS stimulation. The tDCS were delivered at Oz and separated by at least twenty-four hours. The results indicated that one-session anodal tDCS didn’t alter the CSF’s significantly; an extra session of tDCS led to improved CSF, most around mid-frequency. These results were discussed within the measurement precision. Our findings also suggested that the cortical excitation elicited by external electrical stimulation might be cumulative.