Change in anxiety-related behavior during stress task
Time frame: Baseline, day 4
Observer-rated participant behavior during the stress task using 6 items reflecting the anxiety-related behaviors commonly displayed during social-evaluative stress (e.g., fidget, appear tense or rigid). Items are rated on a 7-point scale (1 to 7) from not at all to very much. Higher scores reflect greater anxious behavior.
Change in Emotional Attention Bias
Time frame: Baseline, day 4
Attentional bias (AB) for positive (happy) and negative (disapproving) faces will be measured by computing response latency differences to identify a visual probe that replaces the emotional stimulus compared to a neutral stimulus. Higher scores reflect greater AB for the emotional stimuli.
Change in Emotion Recognition
Time frame: Baseline, day 4
A discriminability (d') index based on signal detection theory will be computed to measure subjects' ability to detect subtle emotion displays across varying intensities of six basic emotions (happiness, surprise, sadness, fear, anger and disgust), which are morphed between each prototype and a neutral face.
Change in behavior on a Driving task
Time frame: Baseline, day 4
A simulated 1-dimensional driving task. The position of a virtual car is controlled with a gaming joystick. In each trial, subjects are instructed to drive the car as quickly as possible and stop as close as possible to a stop sign without crossing the stop-line. Behavior on this task can be modelled according to continuous adjustments in response to both current error and predicted future error, and has been shown to be predictive of self-reported fear. There are two computed parameters for the driving task, Kp (a driving parameter) and Kd (a damping parameter).
Change in approach-avoidance motivations - Social Approach-Avoidance Paradigm (SAAP)
Time frame: Baseline, day 4
The SAAP measures the degree to which morphed facial expressions elicit motivation to approach and avoid another individual. On each trial in the SAAP, participants are presented with a single facial expression and asked to self-report the degree to which they would like to approach and avoid.
Change in safety behaviors during the stress task
Time frame: Baseline, day 4
Safety behavior change will be assessed using the Safety Behavior Questionnaire. Items are rated on a 9-point scale ranging from 0 (not at all) to 8 (all the time). Higher scores indicate greater use of safety behaviors during the stress task.
Change in cannabinoid metabolites collected pre-stress task
Time frame: Baseline, day 4
Blood plasma levels of 6-OH-CBD (6-hydroxy-cannabidiol), 7-OH-CBD (7-hydroxycannabidiol) and 7-COOH-CBD (7-carboxy-cannabidiol).
Change in 2-arachidonoylglycerol (2-AG) collected pre-stress task
Time frame: Baseline, day 4
Blood plasma levels of 2-arachidonoylglycerol (2-AG).
Change in N palmitoylethanolamide (PEA) collected pre-stress task
Time frame: Baseline, day 4
Blood plasma levels of N palmitoylethanolamide (PEA).
Change in N oleoylethanolamide (OEA) collected pre-stress task
Time frame: Baseline, day 4
Blood plasma levels of N oleoylethanolamide (OEA).
Change in blood plasma levels of cannabidiol collected pre-stress task
Time frame: Baseline, day 4
Blood plasma levels of cannabidiol (CBD).
Change in threat-related predictions collected before the stress task
Time frame: Baseline, day 4
Self-ratings of (a) the perceived probability and (b) the perceived cost (consequence) of participants' most feared outcome occurring during the stress task ranging from 0 (not at all likely/bad) to 100 (extremely likely/bad). Higher scores reflect greater threat-related expectancies.
Change in threat-related outcomes collected after the stress task
Time frame: Baseline, day 4
Self-ratings of (a) the perceived occurrence and (b) the perceived cost (consequence) of participants' most feared outcome occurring during the stress task ranging from 0 (not at all) to 100 (completely/extremely bad). Higher scores reflect greater threat-related outcome perceptions.
Global Rating of Change
Time frame: Day 4
Participant reported perceptions of change from baseline (day 0) in response to the stress task. Change is rated on a 7-point scale ranging from 'much worse' to 'much better'
Global Satisfaction with Change
Time frame: Day 4
Participant reported satisfaction with the amount of perceived change from baseline (day 0) in response to the stress task. Satisfaction is rated on a 7-point scale ranging from 'very dissatisfied' to 'very satisfied'