• Global external assessment of performance in an in vivo public speech test [ Time Frame: Assessing change between baseline and predefined follow-up time points during 11 weeks ]
  The global external assessment of performance is done by averaging VAS-ratings (range from 0 = very bad performance to 100 = very good performance) of the PST from three independent members of a committee (experimenters) and a forth experimenter that will rate the performances using a video and audio recording from the speeches.
• Total time of eye contact during an in vivo public speech test [ Time Frame: Assessing change between baseline and predefined follow-up time points during 11 weeks ]
  Total time of eye contact is measured by a mobile eye tracking device from Pupil Labs and operationalized by the number of frames the gaze is in predefined regions of interest comprising the eyes of the committee members.
• Fear of eye contact (SUDS, eye contact) [ Time Frame: Assessing change between baseline and predefined follow-up time points during 11 weeks ]
  Fear of public speaking is quantified by means of SUDS-ratings during a Public Speaking Test (PST) in vivo.
• Global self-assessment of performance in an in vivo public speech test [ Time Frame: Assessing change between baseline and predefined follow-up time points during 11 weeks ]
  The global self-assessment of performance is done by a VAS-ratings (range from 0 = very bad performance to 100 = very good performance) of the PST
• Global subjectively perceived improvement of fear, eye contact and performance after single VR-exposure/waitlist [ Time Frame: Assessed at visit 1 after completing the second PST ]
  Global subjectively perceived improvement of fear, eye contact and performance by the VR eye contact training App will be done by VAS-ratings
• Global subjectively perceived improvement of fear, eye contact and performance after VR-training/waitlist [ Time Frame: Assessed at visit 2 after completing the PST ]
  Global subjectively perceived improvement of fear, eye contact and performance by the VR eye contact training App will be done by VAS-ratings
• Questionnaire for social anxiety (Soziale-Phobie-Inventar; SPIN) [ Time Frame: Assessing change between baseline and predefined follow-up time points during 11 weeks ]
  The SPIN is a 17-item questionnaire developed by the Psychiatry and Behavioral Sciences Department at Duke University. It is effective in screening for, and measuring the severity of fear related to the negative evaluation by others. The 17 items cover different aspects of the anxiety such as fear, avoidance, and physiological symptoms on 5-point Likert scales. The statements of the SPIN items indicate the particular signs of public speaking anxiety (e.g. "I am bothered by blushing in front of people"). The SPIN demonstrates solid psychometric properties and is valid as a measurement for the severity and clinical relevance of fear related symptoms (Connor et al., 2000).
• Questionnaire for fear of negative evaluation (The Furcht vor negativer Evaluation - Kurzskala; FNE-K) [ Time Frame: Assessing change between baseline and predefined follow-up time points during 11 weeks ]
  The FNE-K is a frequently used, valid, and reliable self-report questionnaire consisting of 12 items measuring fear and distress related to negative evaluation by others (e.g. "I am afraid that people will find fault with me") on 4-point Likert scales. The FNE-K has demonstrated good reliability and validity (Reichenberger et al., 2016).
• Eye-tracking measures [ Time Frame: Assessing change between baseline and predefined follow-up time points during 11 weeks ]
  Gaze behaviour (fixation frequency and location, scan path characteristics) and pupil size
• Physiological measures [ Time Frame: Assessing change between baseline and predefined follow-up time points during 11 weeks ]
  Salivary cortisol levels

• Feature-specific external and self-assessment of performance in an in vivo public speech test (VAS-ratings) [ Time Frame: Assessing change between baseline and predefined follow-up time points during 11 weeks ]
  Feature-specific assessment of the participants performance in the in vivo PST is measured by VAS-ratings (from 0 = very bad to 100 = very good) from three independent members of a committee. A forth experimenter will rate the performances using a video and audio recording from the speeches. 8 specific VAS-ratings covering nonverbal aspects of performances (e.g. facial expression, gestures etc.) are divided into two subscales with 4 VAS-ratings each (1 = speech, 2 = appearance).
• Vocal indices of stress [ Time Frame: Assessing change between baseline and predefined follow-up time points during 11 weeks ]
  Vocal indices of stress comprise f.e. level and variability of the fundamental frequency or the active speech duration. They will be measured by analysing the audio recordings during the PST.
• Simulation sickness in VR [ Time Frame: Assessing change between baseline and predefined follow-up time points during 11 weeks ]
  Safety outcome, assessed by the Simulator Sickness Questionnaire (SSQ)

The study will be conducted as a randomized controlled single-blind study in a parallel groups design.

Participants will be divided into groups afraid of public speaking with and without fulfilling the criteria of social anxiety (according to DSM-V), which can represent a clinically relevant and more generalized form of public speaking anxiety. The treatment for the participants solely differs in terms of whether they receive (1) the VR exposure or (2) a fear-unrelated VR task (study phase 1) or no treatment at all (study phase 2), resulting in the following 2 groups:

• Group 1 (treatment group) consists of individuals with fear of public speaking that will (in study phase 1) receive a three-session VR exposure and undergo (in study phase 2) a 2-week treatment period with the same VR scenarios, each repeated three times.
• Group 2 (control group) consists of individuals with fear of public speaking that will not receive any active treatment but complete a distractor task in VR in study phase 1 and no treatment in study phase 2.

In study phase 1, the treatment group receives three VR exposure sessions each lasting for 20 minutes, whereas the control group completes three virtual distractor tasks (e.g. virtual tours) of identical duration. In study phase 2, the treatment group completes a home training spanning two weeks (9 x 20-minutes sessions), whereas the control group does not receive any treatment (untreated comparison group).

In study phase 1, before and after the virtual exposure session, participants undergo an in vivo PST to assess the acute effects of the VR exposure-based eye contact training App.

In study phase 2, the participants undergo a third in vivo PST to assess the training effects of the VR exposure-based eye contact training after two weeks of home training.

This design allows a direct isolation and comparison of acute effects (study phase 1) and of training effects (study phase 2) and therefore enables an overall estimation of the effectiveness of the VR exposure-based eye contact training.

Approximately 96 participants between 18 and 40 years with fear of public speaking will take part in the study. Approximately 1 to 5 weeks after having finished the first study phase, all participants that have not dropped out will take part in the second study phase.

• Experimental: Exposure
  Phase 1 (visit 1): 60 minutes exposure-based eye contact training in VR Phase 2 (home training): 9 blocks of 20 minutes exposure-based eye contact training in VR, distributed over a total duration of maximally 2 weeks
  Intervention: Other: Exposure-based eye contact training in Virtual Reality (VR)
• No Intervention: Control

  Phase 1 (visit 1): waitlist. In order to prevent systematic preparation for the subsequent PST, a 60 minutes virtual reality games with fear-unrelated content will serve as the control intervention.

  Phase 2 (home training): waitlist

Inclusion Criteria:

• Fear of public speaking, assessed by two separate aspects:
• High fear in social situations including the potential of being evaluated by others
• Social situations can only be withstood under high fear or are avoided
• Aged between 18-40
• Fluent in German

Exclusion Criteria:

• BDI-II sumscore >= 20
• Suicidal ideation (BDI-II item 9 > 0)
• Serious medical or psychological condition, other than social anxiety (including Depression, Epilepsy and Migraine)
• Concurrent psychotherapy
• Previous exposure-based therapy for social anxiety (including public speaking anxiety) or other anxiety disorders
• Parallel participation in another psychological or medical study
• Chronic medication intake (except oral contraceptives)
• Chronic drug intake (i.e. LSD, mushrooms, Ecstasy, MDMA, amphetamines etc.)
• Medication intake before visits (less than 24 h)
• Alcohol intake before visits (less than 12 h)
• Cannabis or other psychoactive substances (including benzodiazepines) intake before visits (less than 5 days)
• Restricted 3D sight
• For women: Current pregnancy