Recent studies suggest that lucid dreaming (awareness of dreaming while dreaming) might be associated with increased brain activity over frontal regions during rapid eye movement (REM) sleep. By applying transcranial direct current stimulation (tDCS), we aimed to manipulate the activation of the dorsolateral prefrontal cortex (DLPFC) during REM sleep to increase dream lucidity. Nineteen...
The subjective feeling of free choice is an important feature of human experience. Experimental tasks have typically studied free choice by contrasting free and instructed selection of response alternatives. These tasks have been criticised, and it remains unclear how they relate to the subjective feeling of freely choosing. We replicated previous findings of the fMRI correlates of free choice,...
This paper offers a comparative investigation of anomalous self-experiences common in schizophrenia (defined in Examination of Anomalous Self Experiences (EASE) instrument) and those of normal individuals in an intensely introspective orientation (early 20th-century "introspectionist" psychology). The latter represent a relatively pure manifestation of certain forms of exaggerated...
Research has increasingly focussed on the benefits of meditation in everyday life and performance. Mindfulness in particular improves attention, working memory capacity, and reading comprehension. Given its emphasis on moment-to-moment awareness, we hypothesised that mindfulness meditation would alter time perception. Using a within-subjects design, participants carried out a temporal bisection...
We present Activity Analysis as a new method for the quantification of subjective reports of altered states of consciousness with regard to the indicated level of simulated motor activity. Empirical linguistic activity analysis was conducted with dream reports conceived immediately after EEG-controlled periods of hypnagogic hallucinations and REM-sleep in the sleep laboratory. Reports of...
The relationship between dream content and waking life experiences remains difficult to decipher. However, some neurobiological findings suggest that dreaming can, at least in part, be considered epiphenomenal to ongoing memory consolidation processes in sleep. Both abnormalities in sleep architecture and impairment in memory consolidation mechanisms are thought to be involved in the...
Various forms of anomalous self-experience can be seen as central to schizophrenia and other psychiatric disorders. We examined similarities and differences between anomalous self-experiences common in schizophrenia-spectrum disorders, as listed in the EASE (Examination of Anomalous Self Experiences), and those described in published accounts of severe depersonalization. Our aims were to...
In this article, we present results from an interdisciplinary research project aimed at assessing consciousness in dreams. For this purpose, we compared lucid dreams with normal non-lucid dreams from REM sleep. Both lucid and non-lucid dreams are an important contrast condition for theories of waking consciousness, giving valuable insights into the structure of conscious experience and its...
We have previously found that attention to internal somatic sensations (interoceptive attention) during a heart beat perception task increases the misperception of external touch on a somatic signal detection task (SSDT), during which healthy participants erroneously report feeling near-threshold vibrations presented to their fingertip in the absence of a stimulus. However, it has been...
We introduce a new version of the perceptual retouch model. This model was used for explaining properties of temporal interaction of successive objects in reaching conscious representation. The new model incorporates two interactive binding operations - binding features for objects and binding the bound feature-objects with a large scale oscillatory system that corresponds to perceptual...
We argue that thought insertion primarily involves a disruption of the sense of ownership for thoughts and that the lack of a sense of agency is but a consequence of this disruption. We defend the hypothesis that this disruption of the sense of ownership stems from a failure in the online integration of the contextual information related to a thought, in particular contextual information...
Significant individual differences exist in dream recall frequency (DRF) but some variance is likely attributable to instrument choice in measuring DRF. Three hundred and fifty eight participants estimated their weekly DRF and recorded their dreams in either a narrative log (n = 165) or checklist log (n = 193) for 2-5 weeks. There was an early peak in DRF within the first week of both types of...
To test whether mental activities collected from non-REM sleep are influenced by REM sleep, we suppressed REM sleep using clomipramine 50mg (an antidepressant) or placebo in the evening, in a double blind cross-over design, in 11 healthy young men. Subjects were awakened every hour and asked about their mental activity. The marked (81%, range 39-98%) REM-sleep suppression induced by...
To test whether emotional empathy is linked to altered perceptions of self in relation to other and/or context, participants read one of two tragic news stories and then completed a self-report empathy measure, as well as an abridged version of Hood's (1975) Mysticism scale either before or after the article. Exposure to a needy other in the story tended to result in greater self-reported...
In lucid dreams the dreamer is aware of dreaming and often able to influence the ongoing dream content. Lucid dreaming is a learnable skill and a variety of techniques is suggested for lucid dreaming induction. This systematic review evaluated the evidence for the effectiveness of induction techniques. A comprehensive literature search was carried out in biomedical databases and specific...
Consciousness can be measured in various ways, but different measures often yield different conclusions about the extent to which awareness relates to performance. Here, we compare five different subjective measures of awareness in the context of an artificial grammar learning task. Participants (N=217) expressed their subjective awareness of rules using one of five different scales: confidence...
Clark and Chalmers (1998) claim that an external resource satisfying the following criteria counts as a memory: (1) the agent has constant access to the resource; (2) the information in the resource is directly available; (3) retrieved information is automatically endorsed; (4) information is stored as a consequence of past endorsement. Research on forgetting and metamemory shows that most of...
In two experiments and two different research paradigms, we tested the hypothesis that Zen meditation increases access to accessible but unconscious information. Zen practitioners who meditated in the lab performed better on the Remote Associate Test (RAT; Mednick, 1962) than Zen practitioners who did not meditate. In a new, second task, it was observed that Zen practitioners who meditated used...
This paper asks whether we can identify a neutral explanandum for theories of phenomenal consciousness, acceptable to all sides. The 'classic' conception of qualia, on which qualia are intrinsic, ineffable, and subjective, will not serve this purpose, but it is widely assumed that a watered-down 'diet' conception will. I argue that this is wrong and that the diet notion of qualia has no...
Recently, a number of philosophers have turned to folk intuitions about mental states for data about qualia and phenomenal consciousness. In this paper I argue that current research along these lines does not tell us about these subjects. I focus on a series of studies, performed by Justin Sytsma and Edouard Machery, to make my argument. Folk judgments studied by these researchers are mostly...
A zombie is a physical duplicates of a human being which lacks consciousness. A ghost is a phenomenal duplicate of a human being whose nature is exhausted by consciousness. Discussion of zombie arguments, that is anti-physicalist arguments which appeal to the conceivability of zombies, is familiar in the philosophy of mind literature, whilst ghostly arguments, that is, anti-physicalist...
In previous work, we presented evidence suggesting that ordinary people do not conceive of subjective experiences as having phenomenal qualities. We then argued that these findings undermine a common justification given for the reality of the hard problem of consciousness. In a thought-provoking article, Talbot has challenged our argument. In this article, we respond to his criticism.
It is widely accepted among philosophers that neuroscientists are conducting a search for the neural correlates of consciousness, or NCC. Chalmers (2000) conceptualized this research program as the attempt to correlate the contents of conscious experience with the contents of representations in specific neural populations. A notable claim on behalf of this interpretation is that the neutral...
Under normal circumstances, we experience that our center of awareness is located behind our eyes and inside our own body. To learn more about the perceptual processes that underlie this tight coupling between the spatial dimensions of our consciously perceived self and our physical body, we conducted a series of experiments using an 'out-of-body illusion'. In this illusion, the conscious sense...
The continual background awareness of duration is an essential structure of consciousness, conferring temporal extension to the many objects of awareness within the evanescent sensory present. Seeking the possible neural correlates of ubiquitous temporal awareness, this article reexamines fMRI data from off-task "default mode" (DM) periods in 25 healthy subjects studied by Grady et al....