Efficacy of Transcranial Electrical Stimulation (tES) on Emotion Processing

Efficacy of Transcranial Electrical Stimulation (tES) of Dorsolateral- Prefrontal Cortex on Emotion Processing: A Randomized, Single-blind, Sham-controlled Trial

The aim of this study is to assess the efficacy of transcranial Electrical Stimulation (tES) on emotion processing of healthy participants. Meanwhile, the investigators evaluate the effect of tES on electroencephalography (EEG) of both resting and task-related signal. The hypothesis of this study is that tES can improve the cognitive function of emotion by modulating brain activity.

This is a randomized, single-blind, sham-controlled study using transcranial Electrical Stimulation (tES) for 7-day treatment. Participants were randomly assigned to transcranial alternating current stimulation (tACS) group, transcranial direct current stimulation (tDCS) group or sham-control group. Active tES comprised 20 min sessions of 1.5 mA peak-to-peak current delivered over the dorsolateral prefrontal cortex, for 7 consecutive days. Sham group was administered similarly, but with current turned off after 30s. Apart from studying the effects of tES on physiology signals, subjective scale assessments and behavioral data are performed before and after the treatment.

Inclusion Criteria:

• age between 18 and 35 years
• with normal or corrected to normal vision
• participant or guardian need to sign informed consent

Exclusion Criteria:

• reported neurological or psychiatric disorders
• history of any form of transcranial electrical stimulation experience
• use of mood stabilizer
• history of substance abuse or dependence
• severe somatic diseases that might interfere with regular antidepressant treatment including conditions such as kidney and liver failure, uncontrolled hypertension, cardiovascular, cerebrovascular and pulmonary disease, thyroid disease, diabetes, epilepsy and asthma
• use of anti-inflammatory medication for longer than 7 days in the last two months preceding the trial
• use of immunosuppressive medication such as oral steroid hormones women in pregnancy or lactation period