2.4. Virtual Lab Visits
A virtual lab visit (approximately 90-min) consisted of the following. First, a study staff member greeted the participant on the video call, confirmed their current location in case of any emergencies, answered any urgent questions, and provided an overview of the session. Next, the staff member ensured the correct placement of the devices by asking the participant to demonstrate this by video camera, and made any necessary corrections (e.g., tightening the bands if they appeared loose). Then, the staff member instructed the participant to rest quietly for a 10-min baseline period. After this resting period, the study interventionist (M.R.G.) joined the video call to provide the 60-min training for their assigned intervention (see below for details). Next, the interventionist left the call and the study staff member managing the visit returned to guide the participant through the online Stroop test. Finally, the staff member answered any remaining questions and completed the call. Timestamps for each period of interest (resting baseline, intervention practice, and stress task) were tracked by the study staff to align with the ambulatory recording devices for the subsequent analysis.Stroop stress task: To also test the feasibility of probing the effects of the interventions on a simulated condition of daily stress, an online Stroop test was administered during each of the virtual laboratory visits, following the same procedure as Chin and Kales [