Those who momentarily shuffled off this mortal coil returned with positive perceptions of what they discovered on the other side – a finding that encourages researchers to dig deeper into the ways people describe near-death experiences, according to a joint study between Western and the University of Liège (Belgium).
In their written testaments of the great beyond, individuals who had a near-death experience offered positive-toned words like “see” and “light” far more frequently than negative-toned ones like “fear” and “dead,” according to the study.
Researchers are celebrating this quantitative scientific proof that most people respond positively to near death experiences
The study, Characterization of near death experiences using text mining analyses: A preliminary study, was published today in the journal PLOS ONE.
Unlike previous work, this study utilized text mining and artificial intelligence to provide an objective, unbiased approach to understanding human consciousness following these life-altering encounters that are predominantly studied elsewhere as subjective, individual phenomenon.
Physics and Astronomy professor Andrea Soddu, a Brain and Mind Institute member, collaborated with Belgian neurologist Steven Laureys and colleagues at Western and ULiège for the study.
Traditionally, near-death experiences are explored using standardized questionnaires like the Greyson scale, which includes queries like “Did you have a feeling of peace and pleasantness?” or “Did you feel separated from your body?”
This is a potentially biased approach, which may skew recollections and subsequent discoveries.
“There is no bias with text mining, which is contrary to behavioral studies like Greyson scaling when individuals are asked specific questions,” Soddu explained. “Text mining is completely unbiased. It is fully automatic and we, as researchers, don’t make any assumptions.”
In this study, researchers investigated 158 participants by analyzing first-person, text narratives shared by the individuals following their near-death experiences.
This text mining model allows for unbiased evaluation and also provides valuable and measurable data like frequency and correlation of key words like “see,” “light,” “dead” and “fear.”
Once the data was retrieved, the neuroscientists developed visual representations of the findings like graphs and dendrograms to illustrate the proximity of specific words as they relate to positive and negative connotations towards near-death experiences.
Western graduate student Demetrius Ribeiro De Paula, co-first author of the study with Vanessa Charland from ULiège, says this text mining approach will only increase in validity as more and more narratives are collected.
“In the future, when there will be a huge volume of these text narratives, it will be much easier to handle the data using text mining as opposed to the questionnaire approach,” De Paula said.
Many experiences, ranging from an altered perception of time to a sensation of separation from the body, may reflect cases of dissociative state as they involve mental separation of components (such as consciousness, memory, perception, and identity) that would ordinarily be processed together as an experience.
Some of these non-ordinary states of consciousness seem closely related to the emergence of potential pathways for regulating awareness in crisis situations1,2.
After having experienced situations of intense physical or emotional danger (e.g., severe trauma), some individuals may report dissociative states as well as vivid extra-ordinary and mystical perceptions, such as out-of-body experiences (OBEs), encountering with deceased relatives, or an intense feeling of peacefulness3–5.
These phenomenological experiences are commonly referred to as “near-death experience” (NDE). It has been assumed that these subjective experiences are psychological responses to trauma in order to cope with it, which benefits the individual at that time6.
A few decades ago, the prevalence of NDEs seemed difficult to apprehend. Most recently, studies have estimated their recall to be between 4–8% in the overall population7–9 and 10–23% when only considering cardiac arrest survivors10–12.
Since the first descriptions of the phenomenon by Albert Heim13 and Victor Egger14, different sets of specific phenomenological features have been identified (e.g.15–17), ordered18, and quantified by standardized scales (e.g.19).
Recent research has led to the hypothesis that disruptions in information processing underlying dissociative detachment may be associated with reduced fronto-parietal synchronization20–22. Available scientific literature raises the hypothesis that dissociation may be related to decreased functional connectivity among brain areas, as measured by electroencephalography (EEG)20,23,24.
Although dissociative states and their underlying mechanisms are attracting increasing interest due to significant theoretical and clinical implications, they are still poorly understood and have been under-studied in non-clinical samples.
Hypnosis could be a great tool for producing modified states of consciousness that can yield dissociative states in order to contribute to a better understanding of the phenomenon25–27. Rooted in the psychodynamic tradition, hypnosis is characterized by a change in baseline mental activity through an induction procedure (notably reducing activity of the extrinsic brain network involved in the environment and sensory perception28).
Hypnosis can be experienced subjectively as increased degrees of private processes, such as dissociation, absorption, reduced spontaneous thoughts and an altered perception of time25,29–31.
Interestingly, hypnotic experience appears to create a ‘more real’ subjective experience and brain states closer to an actual experience, as well as facilitates focus on the recall of any kind of memory25–27.
In addition to its use in clinical contexts, hypnosis can be used in neuroscience research to study the neurobiological basis of hypnosis itself, but also as a tool to understand other phenomena32.
The latter approach uses hypnosis in an instrumental manner to produce specific effects of interest and sometimes even models particular conditions25,33,34. Two previous studies suggested that NDE experiencers had safely re-experienced their NDE with a high level of multisensory awareness and in a very detailed way using hypnosis35,36.
Using a 32-channel EEG, Palmieri and colleagues26further suggested that associated electroencephalographic measures are suggestive of episodic memories of real events (notably because of the presence of theta activity associated with the recall of NDE memories) –although not necessarily corresponding to events in the external (real) physical world.
Very recently, Facco and colleagues37have succeeded in inducing OBEs under hypnosis in high hypnotizable people who neither experienced a NDE nor an OBE. EEG data captured by a 32-channel system showed a decrease in beta and gamma band activity in the right parieto-temporal area associated with a subjective OBE37.
Overall, “recreating” NDE features in a controlled laboratory setting may allow to overcome the limitations inherent to the study of NDE (e.g., no monitoring of brain activity during the genuine NDE).
Nevertheless, to date, no study has examined induced NDE phenomenology by hypnotic induction using high-density EEG in people who have already lived a ‘genuine’ NDE (i.e., NDE experiencers).
Given the unfeasibility to design a scientific study where subjects would experience a NDE in real-life situations and their unpredictability, we employed hypnosis to explore the NDE phenomenon through a within-subject comparison.
To this end, we invited a group of individuals who had already experienced a genuine NDE to recall this event along with another emotionally positive autobiographical event dating to the same time period, in two conditions: during normal consciousness and during hypnosis. In addition, the present study has been designed specifically to prospectively and jointly explore the phenomenological experience using questionnaires and the associated neural correlates using high-density EEG.
This method allowed to closely assess the experiencers’ subjective first-person phenomenological experience in parallel with state-of-the-art brain monitoring, combining the subjective experience and their neural correlates in a single setting.
Given the very rich content information that characterizes NDEs38–40, we here focused on the two most frequently reported and characteristic features of the NDE experience during the recall: the intense feeling of peacefulness and OBEs10,11,17,41.
Here, we show how to exploit hypnosis to provide first-person experience of a NDE phenomenology that simulates what experiencers had lived during their previous authentic experience.
More information: Vanessa Charland-Verville et al. Characterization of near death experiences using text mining analyses: A preliminary study, PLOS ONE (2020). DOI: 10.1371/journal.pone.0227402
