The multimodal Ganzfeld-induced altered state of consciousness induces decreased thalamo-cortical coupling

Different pharmacologic agents have been used to investigate the neuronal underpinnings of alterations in consciousness states, such as psychedelic substances. Special attention has been drawn to the role of thalamic filtering of cortical input. Here, we investigate the neuronal mechanisms underlying an altered state of consciousness (ASC) induced by a non-pharmacological procedure. During fMRI scanning, N = 19 human participants were exposed to multimodal Ganzfeld stimulation, a technique of perceptual deprivation where participants are exposed to intense, unstructured, homogenous visual and auditory stimulation. Compared to pre- and post-resting-state scans, the Ganzfeld data displayed a progressive decoupling of the thalamus from the cortex. Furthermore, the Ganzfeld-induced ASC was characterized by increased eigenvector centrality in core regions of the default mode network (DMN). Together, these findings can be interpreted as an imbalance of sensory bottom-up signaling and internally-generated top-down signaling. This imbalance is antithetical to psychedelic-induced ASCs, where increased thalamo-cortical coupling and reduced DMN activity were observed.

Using Angels and Devils: A Board Game Developed for Play in Nursing Homes

The incidence of perceptual deprivation and social isolation effects, possible correlates of such effects, and the potential for remediation of effects was studied for thirty-two nursing home residents through playing a discussion-stimulating board game called Angels and Devils. Results indicate a high incidence of sensory deprivation and social isolation effects in the population, as measured by resident response to questionnaire items. These do not correlate with length of institutionalization, amount of social contact, or degree of medical restriction, and may be reduced by stimulating resident-staff discussion. Findings are interpreted as indicating the need for more research in application of board games to ameliorate negative effects emerging in institutional environments.

Effects of Hypnosis and Perceptual Deprivation on Vigilance in a Simulated Radar Target-Detection Task

Detection efficiency of humans deteriorates rapidly in a variety of monotonous monitoring tasks. The experiment was performed to determine whether or not superior vigilance performance could be obtained through hypnosis in the context of perceptual deprivation. Subjects, forty U.S. Navy personnel, were divided into four groups. Subjects worked on a simulated radar target-detection task before and after one of four treatments. Those given post-hypnotic suggestions for increased alertness made significantly fewer errors in target detection while those exposed to suggestions for decreased performance or perceptual deprivation only showed significant increases in errors. Controls showed no significant changes in errors. Change scores were significantly related to Stanford Hypnotic Clinical Scale hypnotizability scores for subjects in the hypnosis-augment performance group but not for other groups.