Lucid Dreamless Sleep

As part of my PhD, I’m investigating a special sort of conscious experience during deep sleep. This experience has been largely described by contemplative philosophical traditions, as an awareness had during dreamless sleep that is objectless and contentless (that’s it, that it lacks any object or content of awareness).

The Indian school of the Advaita Vedanta refers to this state under the name of sushupti (Sanskrit: सुषुप्ति); one of the four states of consciousness.   (Mandukya Upanishad, Olivelle, 1998: 475). Sushupti is considered for this school as a state in which there is no awareness of anything – not of oneself, not of a lack of an object, not of an absence. This state has also received the name of ‘witnessing-sleep’ (Fort, 1980; Chatterje, 1982; Gupta, 1998).

Similar reports of this experience are also found in the Tibetan Buddhist tradition accompanying the practice of ‘Yoga Nidra’ or ‘Sleep Yoga’. Yoga Nidra is a meditative practice that aims to acquire a lucid state during deep sleep (Norbu, 1983; Wangyal Tenzin, 1998; Gyatrul, Khandro, & Wallace, 2002). The goal for their practitioners is to reach a state in which one is aware during the threshold of dreams – the transition between sleeping and dreaming. Individuals trained in this practice describe this experience as an awareness of the ‘light’; a self-luminous experience.

Following the practice of Yoga Nidra, the experience of contentless awareness during dreamless sleep has recently been coined under the name of ‘lucid dreamless sleep’ (Windt, Nielsen and Thompson, 2016). In turn, lucid dreamless sleep is described as “a state in which awareness is luminous and without an object (free of thoughts and images)” (Thompson 2015:15).

My PhD project aims to develop a philosophical account on lucid dreamless sleep. As such, I’m currently working on two strands:

Conceptual work: In here I’m focusing on the philosophical side of a lucid dreamless sleep by asking questions such as: how should we better describe this experience? Should we understand lucid dreamless sleep as a sort of awareness devoid of content? And, if we do, which implications can this conception have to other accounts on the nature of consciousness? Can we explain consciousness without alluding to an ‘object’ of awareness?

Empirical work: As part of my research, I’m also collecting new evidence on the experience of lucid dreamless sleep. With that purpose, I’ve already carried out a qualitative study where I’ve interviewed participants reporting awareness during dreamless sleep. You can check the information on this study to find out more.

In addition, I’m currently preparing a new experimental study in collaboration with Dr Martin Dresler (Donders Institute, Nijmegen).


Chatterjee, T. (1982). The Concept of Saksin. Journal of Indian Philosophy,10, 339-356

Gupta, B. (1998). The Disinterested Witness: A Fragment of The Advaita Vedanta Phenomenology. Illinois: Northwestern University Press

Gyatrul, R, Khandro, S and Wallace, A (Trans) (2002). Meditation, Transformation and Dream yoga. Snow Lion, 91, 399-404.

Fort, A. (1984). The Concept of Saksin in Advaita Vedanta. Journal of Indian Philosophy, 12, 277-290.

Namkhai Norbu. (1983). Dream yoga and the practice of natural light. Ithaca, New York: Snow Lion Publications.

Olivelle, P. (1998). The Early Upanishads: Annotated Text and Translation. New York; Oxford:: Oxford University Press.

Thompson, E. (2015). Dreamless Sleep, the Embodied Mind, and Consciousness. Open MIND, 37.

Wangyal Tenzin, R., (1998). The Tibetan Yogas of Dream and Sleep. Ithaca, NY: Snow Lion.

Windt, J., Nielsen, T., & Thompson, E. (2016). Does Consciousness Disappear in Dreamless Sleep? Trends in Cognitive Sciences, 20(12), 871-882