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According to virtual reality dream theory , while dreaming, brains generate a dream world similar to a virtual reality environment, and this world uses the same predictive self/world modeling capacity as that used during wakefulness. The theory proposes that phenomenology of dreaming experience is based on the waking experience, a view widely accepted by dream researchers. In the current research, we argued that individuals with different intensities of dissociative experiences during waking, will report corresponding differences in the profoundness of sensory modality experiences, such as touching in dreams. To test this hypothesis, first, we developed a novel Bodily Self-Consciousness in Dreams Questionnaire, that was completed by 414 participants. The questionnaire measured the intensity of different sensory modality experiences in past dreams. The results showed that a four-factor solution explains 64% of the total variance, and yielded sufficient reliability with McDonald's v ranging from .62 to .84, and Cronbach's a ranged from .61 to .84. Along with the Bodily Self-Consciousness in Dreams Questionnaire, we administered the Dissociation Questionnaire (Vanderlinden et al., 1993), which showed a significant positive correlation between the bodily self-consciousness in dreams and dissociative experiences during waking. In conclusion, the results showed that all of the modalities pertain to bodily self-consciousness in dreams and are significantly correlated with waking state dissociative experiences.

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According to virtual reality dream theory (Hobson & Friston, 2014) while dreaming, brains generate a dream world similar to a virtual reality environment, and this world utilizes the same predictive self/world modelling capacity as that used during wakefulness. The theory proposes that phenomenology of dreaming experience is based on the waking experience, a view widely accepted by dream researchers. In the current research, we argued that individuals with different bodily experiences, eg those with different intensities of dissociative experiences during waking, will report corresponding differences in the profoundness of sensory modality experiences, such as that of somatosensory (i.e., touching in dreams). In order to test this hypothesis, firstly, we developed a novel bodily self-consciousness in dreams questionnaire (BSD-Q), that was completed by 414 participants. The questionnaire measured the intensity of different sensory modality experiences in past dreams. The results showed that a four factor solution explains 64% of the total variance, and yielded sufficient reliability with McDonald’s ω ranging from .62 to .84, and Cronbach’s α ranged from .61 to .84. Along with the BSD-Q, we administered the Dissociation Questionnaire (DIS-Q) (Vanderlinden, Van Dyck, Vandereycken, Vertommen, & Jan Verkes, 1993), which showed a significant positive correlation between the bodily self-consciousness in dreams and dissociative experiences during waking. In conclusion, the results showed that all of the modalities pertain to bodily self-consciousness in dreams and are significantly correlated with waking state dissociative experiences.

Out-of-body experiences (OBEs) provide fascinating insights into our understanding of bodily self-consciousness and the workings of the brain. Studies that examined individuals with brain lesions reported that OBEs are generally characterized by participants experiencing themselves outside their physical body (i.e., disembodied feeling) (Blanke and Arzy, 2005). Based on such a characterization, it has been shown that it is possible to create virtual OBEs in immersive virtual environments (Ehrsson, 2007; Ionta et al., 2011b; Bourdin et al., 2017). However, the extent to which body-orientation influences virtual OBEs is not well-understood. Thus, in the present study, 30 participants (within group design) experienced a full-body ownership illusion (synchronous visuo-tactile stimulation only) induced with a gender-matched full-body virtual avatar seen from the first-person perspective (1PP). At the beginning of the experiment, participants performed a mental ball dropping (MBD) task, seen from the location of their virtual avatar, to provide a baseline measurement. After this, a full-body ownership illusion (embodiment phase) was induced in all participants. This was followed by the virtual OBE illusion phase of the experiment (disembodiment phase) in which the first-person viewpoint was switched to a third-person perspective (3PP), and participants' disembodied viewpoint was gradually raised to 14 m above the virtual avatar, from which altitude they repeated the MBD task. During the experiment, this procedure was conducted twice, and the participants were allocated first to the supine or the standing body position at random. Results of the MBD task showed that the participants experienced increased MBD durations during the supine condition compared to the standing condition. Furthermore, although the findings from the subjective reports confirmed the previous findings of virtual OBEs, no significant difference between the two postures was found for body ownership. Taken together, the findings of the current study make further contributions to our understanding of both the vestibular system and time perception during OBEs.