AUTHOR=Liu Shuang , Zhai Siyu , Guo Dongyue , Chen Sitong , He Yuchen , Ke Yufeng , Ming Dong 

TITLE=Transcranial Direct Current Stimulation Over the Left Dorsolateral Prefrontal Cortex Reduced Attention Bias Toward Negative Facial Expression: A Pilot Study in Healthy Subjects

JOURNAL=Frontiers in Neuroscience

VOLUME=Volume 16 - 2022

YEAR=2022

URL=https://www.frontiersin.org/journals/neuroscience/articles/10.3389/fnins.2022.894798

DOI=10.3389/fnins.2022.894798

ISSN=1662-453X

ABSTRACT=Research of cognitive neuroscience field has shown that individual with a stronger attention bias for negative information had higher depression risk, which may be the underlying pathogenesis of depression. This dysfunction of affect-biased attention also represents a decline in emotion regulation ability. Clinical studies have suggested that transcranial direct current stimulation (tDCS) treatment can improve the symptoms of depression, yet the neural mechanism behind this improvement was still veiled. This study aims to investigate the effects of tDCS on affect-biased attention. A sample of healthy participants received 20 min active (n=22) or sham tDCS (n=19) over the left DLPFC for seven consecutive days. Electroencephalographic (EEG) signals were recorded while performing rest task and emotional oddball task. The oddball task required response to pictures of target (positive or negative) emotional facial stimuli and neglecting distracter (negative or positive) or standard (neutral) stimuli. Welch power spectrum estimation algorithm was applied to calculate frontal alpha asymmetry (FAA) in rest task, and overlapping averaging method was used to extract event-related potentials (ERP) components in oddball task. Compared to sham tDCS, active tDCS caused an obvious increment in FAA in connection with emotion regulation (p<0.05). Also, participants in active tDCS group show greater P3 amplitudes following positive targets (p<0.05) and greater N2 amplitudes following negative distracters (p<0.05), reflecting emotion-related attention biases. These results offer valuable insights into the relationship between affect-biased attention and the effects of tDCS, which may be of assistance of exploring the neuropathological mechanism of depression and anxiety and new treatment strategies of tDCS