Effects of Olfactory Stimuli in Virtual Reality Cue Exposure on Craving and Attentional Bias in Alcohol Use Disorder

Sixty patients with AUD, treated in inpatient or outpatient psychiatric clinics, will be enrolled in the study. Participants will receive written and verbal information about the study, and written informed consent for participation will be obtained. A screening for eligibility will then be conducted. This will include, among other things, a history of craving and the confirmation of normosmia. Sociodemographic data, questionnaires on craving, AUD characteristics, and tendency for immersion, as well as potentially confounding variables and factors influencing physiological parameters, will be collected. Participants will then be asked to name a beverage of their choice (beer, red wine, white wine, vodka, or schnaps), which will be presented to them visually and olfactorily during the VR-CE.

Before exposure to the VR scenarios, participants will be familiarized with the VR headset. Eye tracking within the head-mounted display (HMD) will be calibrated, and participants will be allowed to acclimatize to the VR environment. Subsequently, participants will be exposed to each of the four VR-CE conditions for 5 minutes (neutral visual+no odor; neutral visual+alcohol-related odor; alcohol-related visual+no odor; and alcohol-related visual+alcohol-related odor) in randomized order. Randomization will be implemented such that the visual stimuli are presented in blocks (i.e., both neutral or both alcohol-related VR scenarios), while the olfactory stimuli (no odor vs. alcohol-related odor) are randomized within each visual block. Prior to each visual block, participants will undergo a 5-minute VR baseline session in a black virtual room with blue orientation lines, which will serve as the baseline for subjective and psychophysiological parameters.

During exposure, psychophysiological parameters and eye-tracking data will be recorded, self-reported craving will be assessed three times and sense of presence once during each VR-CE condition. After the exposure, questionnaires to assess self-reported craving, attentional bias, sense of presence, affective reaction and cybersickness will be administered.

• Psychophysiological craving index (heart rate variability, HRV) [Срок оценки: Day 1, continuously during both VR baseline sessions and each VR-CE condition.]
• Psychophysiological craving index (heart rate, HR) [Срок оценки: Day 1, continuously during both VR baseline sessions and each VR-CE condition.]
• Psychophysiological craving index (electrodermal activity, EDA) [Срок оценки: Day 1, continuously during both VR baseline sessions and each VR-CE condition.]
• Psychophysiological craving index (respiratory rate, RR) [Срок оценки: Day 1, continuously during both VR baseline sessions and each VR-CE condition.]
• Psychophysiological craving index (pupillometry) [Срок оценки: Day 1, continuously during both VR baseline sessions and each VR-CE condition.]
• Self-reported craving (AUQ) [Срок оценки: Day 1, after both VR baseline sessions and each VR-CE condition.]
• Self-reported attentional bias (AAS) [Срок оценки: Day 1, after each VR-CE condition, except for the combination of neutral VR scenario and no odor.]
• Pupillometry indices of attentional bias [Срок оценки: Day 1, during the alcohol-related VR scenario.]
• Sense of presence (VAS-P) [Срок оценки: Day one, during both VR baseline sessions and each VR-CE condition (minute 4:35).]
• Sense of presence (IPQ) [Срок оценки: Day 1, after both VR baseline sessions and each VR-CE condition.]
• Affective reaction (SAM) [Срок оценки: Day 1, after both VR baseline sessions and each VR-CE condition.]
• Cybersickness (FMS) [Срок оценки: Day 1, after both VR baseline sessions and each VR-CE condition.]