Sleep onset is associated with marked changes in behavioral, physiological, and subjective phenomena. In daily life though subjective experience is the main criterion in terms of which we identify it. But very few studies have focused on these experiences. This study seeks to identify the subjective variables that reflect sleep onset. Twenty young subjects took an afternoon nap in the laboratory while polysomnographic recordings were made. They were awakened four times in order to assess subjective experiences that correlate with the (...) (1) appearance of slow eye movement, (2) initiation of stage 1 sleep, (3) initiation of stage 2 sleep, and (4) 5 min after the start of stage 2 sleep. A logistic regression identified control over and logic of thought as the two variables that predict the perception of having fallen asleep. For sleep perception, these two variables accurately classified 91.7% of the cases; for the waking state, 84.1%. (shrink)

In the current hypothesis paper, we propose that focusing attention on silence can be used as a paradigm conceptually similar to sensory deprivation, to study consciousness without content. We briefly overview recent influential models of consciousness and consider how they assess the relationship between consciousness and contents. After discussing the strengths and weaknesses of current models, we suggest an extension based on the Sphere Model of Consciousness (SMC) and introduce new definitions for identification and self-awareness as states of consciousness. We (...) further compare Paoletti’s theoretical model for the development of self with other influential models, highlighting similarities and differences. We conclude with a discussion of how attentional focus on silence can be empirically tested. (shrink)

Consciousness alterations can be experienced during unstructured, monotonous stimuli. These effects have not been linked to particular cognitive operations; individual differences in response to such stimulation remain poorly understood. We examined the role of hypnotizability and dissociative tendencies in mind-wandering during a sensory homogenization procedure . We expected that the influence of ganzfeld on MW would be more pronounced among highly hypnotizable individuals , particularly those high in dissociative tendencies. High and low hypnotizables, also stratified by dissociation, completed the sustained (...) attention to response task during ganzfeld and control conditions. High dissociative highs made more commission errors during ganzfeld, suggesting increased MW, whereas the other groups displayed the opposite pattern. Increases in commission errors from the control condition to ganzfeld were associated with more alterations in consciousness and negative affect, but only among highs. Sensory homogenization had opposite effects on MW depending on the interaction of hypnotizability and dissociation. (shrink)

Previous studies have shown that misperceptions and illusory experiences can occur if sensory stimulation is withdrawn or becomes invariant even for short periods of time. Using a perceptual deprivation paradigm, we created a monotonous audiovisual environment and asked participants to verbally report any auditory, visual or body-related phenomena they experienced. The data (analysed using a variant of interpretative phenomenological analysis) revealed two main themes: (1) reported sensory phenomena have different spatial characteristics ranging from simple percepts to the feeling of immersion (...) in a complex multisensory environment and (2) the active contribution of the perceiver where participants report engaging in exploratory processes even when there is nothing to find. Detailed analysis of the qualitative data further showed that participants who reported more perceptual phenomena were more likely to report internal bodily sensations, move more during the experiment and score higher on the Revised Hallucination Scale than those reporting fewer percepts explicitly linking perceptual deprivation to somatic phenomena. The results demonstrate how the variety of sensory experiences induced by perceptual deprivation can give further insight into the factors mediating conscious awareness and may suggest ways in which the brain imposes meaning on the environment under invariant sensory conditions. (shrink)