The incidence and determinants of visual phenomenology during out-of-body experiences.
The visual content of out-of-body experiences (OBEs) has received little attention but a number of theories of OBEs include implicit predictions regarding the determinants of this phenomenological feature. Hypnagogic imagery and unusual sleep experiences, weak synaesthesia and preference for employing object and spatial visual imagic cognitive styles were psychometrically measured along with the incidence of self-reported OBEs and the absence or presence of visual content therein, in a sample of individuals drawn from the general population. Seventy percent of individuals who had experienced an OBE reported that the experience included some form of visual content. These individuals exhibited greater scores on the measures of preference for object visual imagic cognition and weak synaesthesia than those who reported an absence of visual content during their OBE. Subsequent analysis revealed that the measure of weak synaesthesia was the stronger discriminator of the two cohorts. The results are discussed within the context of the synaesthetic model of visual phenomenology during OBEs (Brugger, 2000; Irwin, 2000). This account proposes that visual content appears during these experiences through a process of cognitive dedifferentiation in which visual hallucinations are derived from available non-visual sensory cues and that such dedifferentiation is made possible through an underlying characteristic hyperconnectivity of cortical structures regulating vestibular and visual representations of the body and those responsible for the rotation of environmental objects. Predictions derived from this account and suggestions for future research are proffered.