Response to commentaries on ?A neurobiological model for near-death experiences?

Abstract

We are pleased and grateful for the interest that our work has elicited in the preceding commentaries, and in the following pages we present pertinent responses.Our neurobiological "model" for near-death experiences (NDEs) was intended to be a preliminary work to be completed or modified by others, and may be considered a scientific hypothesis rather than a model. It fulfills the following criteria for scientific hypotheses: it is formally structured and not semantically empty, it is rooted in pre vious scientific knowledge, and it can be empirically tested by scien tific procedures (Bunge, 1979). This last condition deserves commentary. From the strict scientific point of view, NDEs could be provoked in some individuals in order to measure the different biochemical and electrical brain changes corre lated with them. However, accepted and sound ethical principles do not permit that. With the current use of noninvasive brain imaging sys tems, that impediment could be surmounted by the constant monitor This work has received financial support from FONDECYT (Project 1111-88).

Evolution and the relationship between brain and mind states.

“…We must stress that we are not describing two different phenomena but are employing two different levels of abstraction. This approach was used in our neurobiological model of NDEs (G6mez-Jeria and Saavedra Aguilar, 1994; Saavedra-Aguilar and G6mez-Jeria, 1989aG6mez-Jeria, , 1989b.…”

Near-death studies and modern physics.

“…consciousness (Blacher, 1979;McHarg, 1978;Schnaper, 1980), temporal lobe dysfunction, hypoxia/ischemia, stress, and neuropeptide/neurotra nsmitter imbalance (Saavedra-Aguilar and G6mez-Jeria, 1989a) sigma receptors and excitatory amino acid receptors (Saavedra-Aguilar and G6mez-Jeria, 1989b), NMDA-PCP receptor, the sigma receptor, and the endopsychosins (Jansen, 1989(Jansen, , 1990, serotonergic mechanisms (Morse, Venecia, and Milstein, 1989), brain-stem function (Cook, 1989), endor phin release (Blackmore, 1993;Thomas, 1976), stress-induced limbic lobe dysfunction (Carr, 1982), autoscopic hallucinations (Lukianowicz, 1958), the replay of the birth experience (Sagan, 1979), the deper sonalization syndrome occurring in the face of life-threatening danger (Noyes and Kletti, 1976), altered state triggered by the threat of im minent physical death (Quimby, 1989), protective functions to conserve energy and provide necessary brain stimuli (Krishnan, 1981), hallu cinations (Gibbs, 1987;Menz, 1984;Siegel, 1980); the denial of death (Ehrenwald, 1978), regression in the face of death (Lowental, 1981), stress induced psychological phenomena (Appleby, 1989), fulfillment of prior personal expectations of death (Schnaper, 1980), multiple person ality disorder (Serdahely, 1992), psychological transition (Tien, 1988), hypnagogic sleep (Counts, 1983), and religious expectations (Palmer, 1978).…”