Investigating the Neural Systems That Support the Beneficial Effects of Positive Emotion on Stress Regulation
Phase: NA
Conditions: Behavior
Sponsor: University of Denver

CLINICAL TRIALS INFORMATION: 
 
Title: 
Investigating the Neural Systems That Support the Beneficial Effects of Positive 
Emotion on Stress Regulation 
 
Protocol ID: 1606445 
 
NCT Number: NCT04496258 
 
Date of Document: 06/29/2023 
 
ASSOCIATED PUBLICATION: The Future of Immersive Mood Induction in Affective 
Science: Using Virtual Reality to Test Effects of Mood Context on Task Performance 
• 
DOI: 10.1007/s42761-023-00213-1 

Procedures 
Participants came into the lab for one in-person session. Prior to starting the experimental 
procedures, participants completed informed consent. All procedures were approved by the University 
of Denver’s Institutional Review Board. Participants then completed task training, a practice run of the 
task in the VR headset, the task itself and then individual difference measures. Participants were then 
debriefed and compensated for their time. 
Materials 
Baseline and Post-Experiment Mood Ratings 
Before putting on the VR headset and at the end of the experiment, participants used the 
modified Differential Emotions Scale (mDES; Fredrickson, 2013; Izard, 1977) to rate their current mood. 
We defined the mDES as a mood measure because it was intended to measure participants’ current 
mood absent of a stimulus intended to evoke an emotional response (Rosenberg,1998). The mDES 
consists of 20 questions and is comprised of two sub-scales for positive and negative emotions with 10 
questions for each subscale respectively. Scales are comprised of summing all positive scores together 
and all negative scores together. In our study, participants were asked to rate their current experience 
of all 20 emotions on a five-point Likert Scale (1 – not at all to 5 – Extremely). 
Mood Induction via VR 
The virtual environments consisted of a beach scene and an office scene, which were shown to 
elicit incidental positive and neutral states respectively in our previous studies (see Song et al., 2019). 
The virtual environments and task were programmed with WebVR (an HTML framework) and JavaScript 
and displayed with a mounted VR headset (Oculus Rift) that included audio. Participants were instructed 
to explore the VR for approximately three minutes before the task started. Participants completed the 
task while still in the VR and while the virtual environments continued to play in the background. The 
task was programmed such that the images and instructions would appear in the center of the 
participant’s vision regardless of their position in the VR environment. 
Post Mood Induction Mood Ratings 
After the three minutes of exploring the VR environment, a mood rating scale appeared in front 
of the participants while still immersed in the environment. Participants were told they would be using a 
joystick similar to a laser pointer while immersed in the VR environment. Examiners showed the 
participants the joystick prior to entering the VR and explained how to hold the joystick and make 
ratings. They were instructed to point at the rating when it appeared in front of them and use their index 
finger to press a trigger on the joystick to make the rating they wanted. Participants rated how positive 
(1: not positive at all – 9: very positive) and negative they felt (1: not negative at all – 9: very negative). 
The mood ratings were displayed for 5s each to account for a potential delay in participants’ ratings after 
exploring the VR environment. 
Reappraisal Task and Emotion Ratings 
At the beginning of the experiment, participants were trained on the reappraisal task and given 
instructions about the various trial types (i.e., the look and decrease instructions), and the emotion 
ratings. During the look instruction, they were told to view the image in front of them and “let yourself 
react naturally.” When given the decrease instruction, they were told to “change your emotions to 
decrease how negatively you feel about the picture … reinterpret, or re-frame, or reconsider the 
meaning of the picture so that it makes you feel a lot more positively or a lot less negatively.” The 
experimenter provided participants with feedback and examples of reappraisals for the decrease 
instruction. Participants were also instructed on the timing and method for making their emotion ratings 
inside the VR headset. We defined the ratings participants made after viewing the images as emotions 
ratings, given we were asking them to rate their emotional response to a stimulus (Rosenberg, 1998). At 
the end of training, participants were asked to repeat the task instructions in their own words to ensure 

they fully comprehended the task. Participants then completed practice trials within the VR headset. 
Practice trials were intended to give participants experience with the pacing of the task within the VR 
headset, and practice using the joystick to make ratings. 
For the task, participants first saw a cue (2s) then an instruction (3s each) and then the target 
neutral or negative image (7s each). Participants then rated their positive and negative emotion (3s each) 
on a scale from 1 (not at all positive/negative) to 9 (very positive/negative). For analyses the positive and 
negative ratings were (separately) averaged within each trial type for each participant. Therefore, the 
task constituted a 3 × 2 mixed factorial design: positive mood context: look-negative, look-neutral, 
decrease-negative – neutral mood context – look-negative, look-neutral, decrease negative. 
The trials were organized into a single block which included a total of 54 images. The images 
were selected from the International Affective Picture System (IAPS; Lang et al., 2008). Neutral and 
negative pictures were selected based on the normative ratings available with the stimulus set, which 
include ratings of valence and arousal on nine-point scales of “1” (low pleasure, i.e., negative) to “9” 
(high pleasure, i.e., positive) and “1” (low arousal) to “9” (high arousal), respectively. The following 
distribution was used across condition type: one third look-negative, one third look-neutral, and one 
third decrease-negative. The images were counterbalanced with instruction type to control for the 
possibility that certain pictures might have had a greater impact on affect than others. Thus, participants 
were randomly assigned both to the positive or neutral VR mood context as well as image set. The entire 
task including the three-minute mood induction was completed in approximately 23 minutes. 
Post-Task Individual Difference Measures and Mood Ratings 
After the reappraisal task was completed, participants completed a battery of individual 
difference measures, including general demographics (e.g., age, gender, race) and other individual 
difference measures of emotion, well-being, and mental health symptoms. Participants also completed 
the Igroup Presence Questionnaire (IPQ)(Schubert et al., 2001) which is a measure of one’s sense of 
presence while experiencing a VR environment. The measure consists of 14 items intended to assess 
various aspects of sense of presence while in VR and includes three subscales: spatial-presence, realness, 
and involvement. The IPQ asks participants to rate various questions on Likert scales such as “In the 
computer-generated world I had a sense of ‘being there’” from not at all to very much. Participants also 
were asked to define each instruction (e.g., look and decrease) and how difficult it was to follow the 
reappraisal instructions, and what percentage of time they were able to follow the instruction. Lastly, 
participants completed a final mDES measure of their current mood. 
Timing of Mood and Emotion Ratings 
Participants rated their mood at several time points. The mDES was used to measure 
participants’ mood prior to entering the VR and at the very end of the entire experiment once they had 
completed other post-task individual difference measures. Mood ratings using the positive and negative 
scales (e.g., “1 not at all positive/negative to 9 very positive/negative”) were also collected after the 
three-minute VR mood induction. Emotions ratings using the positive/negative Likert scales were 
collected after each trial of the reappraisal task. 
Data Analysis 
All analyses were interpreted as significant if they crossed the p < .05 threshold and all follow-up 
t-test analyses were two-tailed. 
Several pre-registered exclusion criteria were applied prior to data analysis including: lack of 
understanding of the task (N = 5), missing more than 25% of trial level data (N = 8). Additional 
participants were excluded due to a corrupted data file (N =1) and mixing up the positive and negative 
ratings (N = 1). Lastly, one additional participant was excluded due to outlier scores on several measures 
including the VR task ratings and most individual difference measures as indicated by scores that were 

greater than 3 standard deviations from the mean. This left usable data for a total of 80 participants, 
which reflects the desired sample indicated in our power analysis for this study (see our preregistration 
at the Clinical Trials website for more information).