Non‐pathological associations – sleep and dreams, deprivation and bereavement

Hallucinations on demand: the utility of experimentally induced phenomena in hallucination research

“…Collectively, these methodological issues prevent the close examination of hallucination episodes that will yield important insights into underlying processes. Second, despite data demonstrating that hallucinations often occur in the absence of pathology [5][6][7], scientific study of hallucinations is still heavily biased toward those of pathological origin [5,18]. This continued focus is likely motivated by the manifest need to alleviate suffering caused by pathological hallucinations, coupled with a belief that the best (or only) avenue is to study them directly.…”

“…B 376: 20200233 perceptual phenomena often defy unequivocal classification [1,13,[16][17][18]. Some take a hard-line approach, defining hallucinations as involuntary false perceptions in the absence of any causative/corresponding stimulation of the relevant sensory organ [5,54,55]. Based on this definition, few if any of the above phenomena could be classified as hallucinations, perhaps with the exception of those induced by sensory deprivation.…”

“…However, the problem with this approach is that it inflexibly excludes any phenomena that interact with or are associated with external sensory information (e.g. hallucinated people that sit in veridically perceived chairs, or hallucinated filigree patterns that are seeded by veridically perceived visual contours), no matter how tenuous the link to internal conscious experience [1,5,13,[56][57][58].…”

“…Hallucinatory experiences are incredibly heterogeneous, and they can occur in a single sensory modality or in multiple modalities simultaneously, with content ranging from simple to complex, banal to bizarre, and amusing to harrowing, and insight into the unreal nature of these experiences might be present or absent. Hallucinations can occur in the absence of disease or disorder [5][6][7], are voluntarily sought out with psychedelic substances [8] and are considered sacred, privileged experiences of profound spiritual significance by many diverse cultures [9]. There is of course a dark side to hallucinations; when elicited recurrently by ongoing pathology, they can cause significant distress, disrupt normal functioning and attract considerable stigma [10][11][12].…”

Of Ghost Grandparents and Missing Limbs

“…Even though bereavement hallucinations are extremely common, people rarely refer to them openly, perhaps for fear of being looked upon as mentally disturbed. Consequently, a substantial proportion of widows and widowers never reveal their hallucinations (3).…”