Augmenting Exposure Therapy for Social Anxiety With Transcranial Direct Current Stimulation

This study will examine whether transcranial direct current stimulation (tDCS) can be used to improve outcomes from exposure therapy for social anxiety disorder, and facilitate extinction of fear responding toward individuals outside one's own ethnic group (i.e., ethnic out-group members).

Although exposure therapy is among the most powerful treatment techniques for social anxiety, many individuals do not achieve full remission. Furthermore, some research suggests that fear responding toward ethnic out-group members may be more resistant to extinction. Enhancing activation of the mPFC during exposure therapy may improve overall response to treatment, and also facilitate extinction of fear toward ethic out-groups. Researchers have found that greater mPFC activation during exposure therapy is associated with better outcomes, and that transcranial direct current stimulation (tDCS) can be used enhance learning and cognition with no known serious adverse effects. This study will therefore examine whether active/anodal (versus sham) tDCS targeting the mPFC (a) enhances overall reductions in social anxiety symptoms, and (b) facilitates extinction of fear responding toward ethnic/racial out-groups for both Latino and Caucasian/non-Latino participants. Participants will receive either active/anodal tDCS or sham tDCS during a brief exposure therapy intervention involving public speaking in a Virtual Reality (VR) environment. The public speaking audience in the VR environment will alternate between audiences that are either matched or unmatched to the participant's ethnicity (in a randomly assigned order). Participants' fear reactivity will be assessed with behavioral, physiological, and subjective measures at baseline, post-treatment, and follow-up.

Participants will be randomly assigned to receive either sham or anodal (2 mA) tDCS targeting the mPFC during exposure therapy for public speaking anxiety.

anodal transcranial direct current stimulation (2mA) will be applied over EEG coordinate FpZ to target mPFC activation during exposure therapy

sham transcranial direct current stimulation will be applied over EEG coordinate FpZ during exposure therapy at a level that provides the physical sensations of tDCS but which is non-therapeutic

participants will complete one session of exposure therapy for fear of public speaking, which will involve providing speeches to audiences in virtual reality

Participants will provide a speech to (a) an audience primarily matched to their ethnicity, and (b) an audience primarily un-matched to their ethnicity. The speech will be for up to 5 minutes in duration. During each BAT, we will assess fear response behaviorally (length of the speech, up to 5 min in duration), physiologically (heart rate and electrodermal activity), and subjectively (self reported levels of anticipated and peak fear).

Participants will complete the PSAS, a 17-item questionnaire that assesses self-reported behavioral, cognitive, and physiological manifestations of public speaking anxiety. The items are sum scored, and totals range from 17 to 85, with higher scores indicating higher levels of public speaking anxiety.

Participants will complete the BFNE-II, a 12-item questionnaire that assesses the extent to which one has concerns about negative evaluation in social settings. A sum score is calculated for the scale, with total scores ranging from 12 to 60, and higher scores indicating higher levels of fear of negative evaluation.

Participants will complete the SSPS, a 10-item questionnaire that asses both positive and negative self statements associated with public speaking. The items within each of the two subscales are summed, with total scores ranging from 0 to 25 for each subscale, and higher scores indicating higher levels of agreement with positive or negative self statements, respectively.

Inclusion Criteria: Age 18 or older (adult) Enrolled in higher education (post-high school) Elevated public speaking anxiety as indicated by self-report questions NOT currently receiving in exposure therapy for social anxiety Exclusion Criteria: History of seizure or any other neurological diagnosis Has any metal in their skull (plates, steel sutures, etc.) Participant is currently taking anti-convulsant, sedative/hypnotic, or antipsychotic medications Participant is pregnant Participant has already participated in a prior tDCS/tACS study on the same day as study visit 1 (which will involve either placebo or active/anodal tDCS stimulation)