The cloud of unknowing: Cognitive dedifferentiation in whole-body perceptual deprivation.

An altered sensory environment, especially a homogeneous one like a ganzfeld, can induce a wide range of experiences in people immersed in it. The ganzfeld of our current focus is the OVO Whole-Body Perceptual Deprivation chamber (OVO-WBPD). Previous literature has found this specific immersive environment to be capable of softening and dissolving perception of boundaries across time and sensory modalities, among other domains. Since recent published electrophysiological results demonstrated that immersion in the OVO-WBPD significantly increased delta and beta activity, in the left inferior frontal cortex and in the left insula, we sought to better understand the subjective experiences of participants utilizing this altered sensory environment via semi-qualitative methodology. Consequently, semi-structured interviews of participants were analyzed by three independent evaluators focusing on several domains of experience often reported in perceptual deprivation environments. We found a significantly shared consensus on the presence of experiences belonging to semantic domains of altered experience, demonstrating that the OVO-WBPD chamber consistently elicits positively connotated, bodily-oriented and cognitively dedifferentiated subjective states of consciousness in the majority of 32 examined participants.

Fully immersed: State absorption and electrophysiological effects of the OVO Whole-Body Perceptual Deprivation chamber.

Absorption, the ability to highly focus attention, as well as openness to self-altering experiences, is an important psychological construct, closely related to deep-meditation states and other altered states of consciousness. Yet, little is known about the electrophysiological profile of states of absorption, possibly due to the difficulty to induce this state in the lab. While most studies have used a visual Ganzfeld (homogeneous perceptual field), here we use a novel technique of full immersion-the OVO Whole-Body Perceptual Deprivation (OVO-WBPD) chamber, which is an altered sensory environment in the form of a human-sized egg. Consequently, the aims of the current study were to investigate whether the OVO-WBPD chamber induces state absorption, using first-person reports, as well as to examine electrophysiological change following immersion in this altered sensory environment. Fourteen participants volunteered to participate in the study. Trait absorption was measured using the Tellegen Absorption Scale (TAS). State absorption was assessed by analyzing the content of the subjective reports, using sub-categories of the absorption construct (e.g., synesthesia). EEG was measured before and during a 20-min OVO-WBPD experience. Using exact low-resolution brain electromagnetic tomography (eLORETA), we analyzed change in oscillatory EEG activity and localized the generators of the scalp EEG power spectra following the OVO-WBPD. Our results show that OVO-WBPD immersion leads to a state of absorption in all participants. We also report significant increased oscillatory activity in the delta and beta bands, in the left inferior frontal cortex, with a peak in the sub-lobar of the left insula. In addition, a positive correlation was found between change in delta activity and trait absorption. The results are discussed in light of other meditative practices and altered states of consciousness.

Individual EEG alpha profiles are gender-dependent and indicate subjective experiences in Whole-Body Perceptual Deprivation.

We use a unique environment of Whole Body Perceptual Deprivation (WBPD) to induce an altered state of consciousness (ASC) in our participants, and employ online EEG recording. We present individual EEG alpha profiles, and show how these data can be analyzed at the individual level. Our goal is to investigate to what degree subjective experience matches EEG alpha profile, and in particular, the various alpha hemispheric asymmetries observed in the frontal, parietal, and occipital lobes. Specifically, we consider positive (frontal L < R) or negative (frontal L > R) affect; a more verbal (L > R) or a more imagistic (R > L) mode of thinking; and a more trancelike (frontal > parietal) or more reflective (frontal < parietal) state of consciousness. Our results indicate that the individual alpha profiles are reflected in individual differences in subjective experience. However, the alpha profiles are confounded with the gender of the participant. Specifically, there is a predominant R > L asymmetry found for male participants, and a predominant L > R asymmetry found for female participants.

Time Perception and the Experience of Time When Immersed in an Altered Sensory Environment.

The notion that exposure to a monotonous sensory environment could elicit reports indicating aberrant subjective experience and altered time perception is the impetus for the present report. Research has looked at the influence of exposure to such environments on time perception, reporting that the greater the environmental variation, the shorter is the time estimation obtained by the method of production. Most conditions for creating an altered sensory environment, however, have not facilitated an immersive experience, one that directly impacts both time perception and subjective experience. In this study, we invited our participants to enter a whole-body altered sensory environment for a 20-min session, wherein they were asked to relax without falling asleep. The session included white-colored illumination of the chamber with eyes closed (5 min), followed by 10 min of illuminating the room with color, after which a short report of subjective experience was collected using a brief questionnaire; this was followed by an additional 5 min of immersion in white light with closed eyes. The participants were then interviewed regarding their subjective experience, including their experience of time within the chamber. Prior to entering the chamber, the participants completed a time-production (TP) task. One group of participants then repeated the task within the chamber, at the end of the session; a second group of participants repeated the task after exiting the chamber. We shall report on changes in TP, and present data indicating that when produced time is plotted as a function of target duration, using a log-log plot, the major influence of sensory environment is on the intercept of the psychophysical function. We shall further present data indicating that for those participants reporting a marked change in time experience, such as "the sensation of time disappeared," their TP data could not be linearized using a log-log plot, hence indicating that for these individuals there might be a "break" in the psychophysical function.