LAUSR

The intriguing experience that somebody is nearby when no one is actually present and cannot be seen or heard has been reported in many different contexts and has been referred to as the sense of presence, feeling of a presence, invisible presences, or presence hallucination (PH) (James, 1902; Critchley, 1979). PHs are often vivid experiences, have a clear location in space—with people frequently turning around to search for the invisible presence—and some even offering it a chair or food (Jaspers, 1913; Nightingale, 1982). PHs are a common theme in fiction, having been alluded to in the literature of divinity, occultism, and parapsychology (Green and McCreery, 1975; Critchley, 1979) and studied in history and anthropology (Solomonova et al., 2011; Wyatt et al., 2016). Following reports of PHs in extrememountaineering (Smythe, 1935; Messner, 2003), long-distance solo-biking (Davie, 2013), solo-sailing (Suedfeld and Mocellin, 1987) and in shipwreck survivors (Critchley, 1943), PHs have also been investigated in psychology and medicine (Critchley, 1979; Brugger et al., 1996; Arzy et al., 2006). Initially described in psychiatry (Jaspers, 1913; Llorca et al., 2016), PHs have more recently been mostly investigated in neurological patients with epilepsy, stroke, neoplasia, and Parkinson’s disease (PD) (Brugger et al., 1996; Fénelon et al., 2011). However, despite its intriguing experiential characteristics and the broad academic and clinical interest, scientific studies and experimental data on PHs continue to be sparse. This is likely due to difficulties in investigating a spontaneously occurring phenomenon, the absence of experimental procedures able to induce PHs reliably in real time, and to their occurrence in the large majority of cases in situations not prone to empirical investigations (far from laboratories). Here we provide an overview of recent investigations in clinical neuroscience on PH and in neuroscience using methods to induce PH experimentally, linking them to altered self-monitoring and sensorimotor processing. We analyze selected spiritual-religious experiences associated with PH and propose a new extended account of PH, by integrating and extending the altered self-monitoring account with the prominent agent detection theory in spiritual-religious experiences (Guthrie, 1989; Barrett and Lanman, 2008). We conclude by proposing that the mechanism and the controlled induction of invisible presences will likely have an impact in clinical and fundamental neurosciences and may provide a powerful experimental approach in biological anthropology and the cognitive science of religion.