A Theoretical Basis for Surges of Electroencephalogram Activity and Vivid Mental Sensation during Near Death Experience

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Kanad Ray et. al. / International Journal of Engineering Science and Technology Vol. 2(10), 2010, 5484-5487

A Theoretical Basis for Surges of

Electroencephalogram Activity and Vivid

Mental Sensation during Near Death

Experience

Kanad Ray

Faculty of Science and Technology Icfai University

Central Hopetown, Selaqui, Dehradun, India M.K.Roy

Department of Physics (Ex)University of Calcutta, 92 APC Road, WestBengal, India

Abstract

According to Chawla et. al.[1]near-death experiences could be caused by a surge of electrical energy released. We account for this spike using an electromagnetic-physiological theory based on transmission line model plus cortical network activity and using known properties of forward and backward propagating waves proposed earlier[2-5]

Key-words:nde, brain waves ,Bloch waves, transmission line

1.INTRODUCTION

Near Death Experiences (NDE) are the experiences that one feels or observes when one is near to death. Level of consciousness at the end of life in critically ill patients is poorly characterized. Research is going on to find out the biological basis of NDE. One of a major is brain waves during NDE. Chawla et al[1] who studied brainwaves of dying patients, found there was a surge of electrical activity in their brains just moments before their lives ended. They observed a spike of short duration in electroencephalogram(EEG) activity which declined to a level of activity associated with burst suppression. According to them NDE could be caused by a surge of electrical energy released as the brain cells fire one last electrical impulse which starts in one part of the brain, spreads in a cascade and this may give people vivid mental sensations. We account for this burst of brainwave activity using a neurophysiological- electromagnetic theory of “brain waves” based on known (but highly idealized) properties of synaptic action and has been formulated with implications for a large scale integration required for cognitive processes[2-5].

2.METHOD

A salient feature of nervous systems and their components are their noisy, random character. The action potentials are the lingua franca of almost all nervous systems. The ionic currents flowing through such channels are microscopic, discrete and stochastic. It is only if thousands of channels are closely packed together that the transition from microscopic, binary and stochastic current to macroscopic, continuous and deterministic current as seen classically in the Hodgkin-Huxley squid axon appears. Nerve Cells can be divided into two major categories:

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Myelinated and Non-myelinated. Myelinated Neuron is covered by sheaths of lipid material (Called Myelin) with periodic gaps called nodes of Ranvier.

The theoretical possibility of dynamic changes in axon propagation is intriguing as it provides an additional layer of computing power to the neuron. A myelinated axon can be modelled as a lossy transmission line of infinite periodic structure and regarded as a cascade of identical cells(Fig.1).

Figure. 1

Each cell is a two-port composed of a parallel admittance Y and two transmission line segments of length d/2 at each side of the admittance. The admittance of each cell plays the role of Ranvier node and a model will be adopted [2-6] where Y =G+jωC

Gconductance C  capacitance

Ranvier nodes cause the neural transmission delay [7] which is crucially important for a realistic model. Periodic structures are described by the so called Bloch impedance. The characteristic impedance Z0 of transmission lines do

not depend on the point where it is measured, the Bloch impedance is different if the terminal planes of the unitary cell are shifted a distance l in the z direction [8].

Periodic structures may be analyzed in terms of the forward and backward propagating waves that can exist in each unit cell(Fig.2).

Figure. 2

A periodic structure determined in a load impedance at the Nth terminal plane is shown in Fig.3.

Figure. 3

) tan(

0 0

0 0 0

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l k jZ Z Z Z

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The total voltage and current at the nth terminal plane will be a superposition of an incident and reflected Bloch wave.

The input impedance at the nth terminal plane is

We conjectured that brain waves can be treated as “Bloch waves” which may provide an important mechanism for a large scale integration required between the constantly interacting areas of the brain.

The potentials that produce EEG are generally thought to be caused by the extracellular ionic currents caused by dendritic electrical activity where as the fields producing MEG signals are associated with intracellular ionic currents. The electrical potential generated by single neurons are far too small to be picked by EEG or MEG. These activities therefore always reflect the summation of the synchronous activities of billions of neurons. The transverse electric and magnetic fields of the Bloch waves could therefore be directly attributed to the extra and intra cellular currents mentioned above.

3.DISCUSSION

So far we have only discussed about steady state but the lines can be subjected to sudden changes as in the case of NDE. When a transmission line is connected to or disconnected from a source transients are a natural outcome. This explains the surge of electrical activity during NDE as there are sudden changes in input voltage and/or current giving rise to impulse. Vivid mental sensation, like out of body experiences during this time can be linked to multisensory and cognitive processing in the brain[9]. Some have observed it in connection with neurological conditions such as epilectic seizers and migraine[10-11]. Moreover vestibular illusions(of elevation,rotation) and multisensory illusions(of visual limb shortening and movement) could be evoked by electrical stimulation of the same cortical area where higher stimulation currents induced out of body experiences[12]. Clinical observations also suggest that random eye movements(REM) state intrusion contributes to NDE[13]. Findings anticipate that under circumstances of peril, an NDE is more likely in those with previous REM intrusion. Suppression of an activated locus ceruleus could be central to an arousal system predisposed to REM intrusion and NDE[13].So the sensation during NDE can be attributed to a disintegration within personal space(multisensory dysfunction) and a disintegration between personal space(vestibular) and extrapersonal space(visual) due to interference with the temporo-parietal junction[12].

4.CONCLUSION

Brain waves treated as “Bloch waves” could be of great importance as they contain detail mechanism of formation subject to different constraints and conditions. It may lead to confirmation of findings and refine the technology which in turn could provide profound insights into human consciousness.

References

[1] L.S. Chawla, S. Akst, C. Junker,B. Jacobs,M.G. Seneff, “Surges of electroencephalogram activity at the time of death:a case series”,Journal

of Palliative Medicine 12,issue.12,pp.1095-1100,2009

[2] Kanad Ray, “Modelling of the action potential propagation in nerve fibre”,presented in “MP2009” in Amsterdam,1st-4th

August,2009,MathPsych, 43,Society for mathematical Psychology and European Mathematical Psychology Group

[3] Kanad Ray, “Could brain waves be treated as Bloch waves”, accepted for presentation in “CNS 2010” in Montreal,Canada, 17-20th

April,2010.

[4] Kanad Ray, “A transmission line model of brain waves”, accepted for presentation in “WMVC10”atKakatiyaUniversity,Warangal,13-15th

March,2010.

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[5] Kanad Ray and M.K.Roy, “A theoretical basis for brain waves with implications for a large scale integration required for cognitive

processes”- Proceedings of the 9th_{IEEE International Conference on Cognitive Informatics,Beijing,China,7-9}th_{July, ICCI’10, pp.436-440,}

2010, IEEE computer Society

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[7] Huxley and Stampfi, J.Physiol. No. 108 pp 315-339, 1949.

[8] R.E. Collin, Foundations for microwave Engg.(Mcgraw-Hill, 1972)

[9] O. Blanke , “Out of body experiences and their neural basis”,BMJ, 329(7480),pp.1414-1415, 2004

[10] O. Devinsky, E. Feldmann, K. Burrowes, E. Bromfield, “Autoscopic phenomena with seizures”, Arch Neurol,46, pp.1080-1088,1989

[11] P. Brugger, M. Regard, T. Landis,”Illusory reduplication of one’s own body-:phenomenology and classification of autoscopic phenomena”,

Cogn Neuropsychiatr, 2, pp.19-38,1997

[12] O. Blanke, S. Ortigue, T. Landis,M. Seeck, “Stimulating illusory own-body perceptions”, Nature 419, pp.269-270, 2002

[13] K.R.Nelson, M.Mattingly, S.A.Lee, F.A.Schmitt, “Does the arousal system contribute to near death experience?”,Neurology, 66,

pp.1003-1009, 2006