Death and NDEs Flashcards
Dualism
Cartesian duality of matter and mind.
Monism
Physicalism - physical matter of brain is the mind/mind is what the brain does.
Idealism - the mind takes precedence over matter
Neutral monism: there is a third substance that is more fundamental than matter and mind.
Brain death
Glucose metabolism goes down.
NDE core components
3-9% of Americans say they had
- Bright light and tunnel
- Seeing dead people
- Feeling that one is dead
- Out of body experience
- Positive emotions
Are people near death when they have NDEs?
Many people have NDEs without danger.
Movement towards light/tunneling
Retinal ischemia - blood and oxygen supply to eye is depleted. Can be caused by G-force in pilots. Fainting, tunnel-like peripheral to central visual loss develops over 5-8 seconds.
Phosphene also allows to see light without light entering eye. Low blood pressure, fainting, standing up too quickly, magnetic fields.
Glaucoma - loss of peripheral
Epilepsy - bright light
Extreme fear and hypoxia -> tunnel vision
Organization of visual cortex - excitation leads to tunnel
Out-of-body experiences
Can be artificially induced by stimulating right angular gyrus. Could result from failure to integrate multisensory information and represent oneself. Ehrsson - can use virtual reality to simulate - skin conductance response confirms.
Cotard syndrome
Patients convinced they are dead. Sometimes really graphic. Parietal and prefrontal cortex.
Seeing ghosts
Alzheimers, Parkinsons, posterior or parietal cortex atrophy can lead to seeing ghosts.
Charles-Bonnet syndrome
Macular degeneration -> vivid hallucinations like ghosts and fairies. Increased activity in perceptual areas of brain in the absence of visual stimulation. Compensatory over-activation in brain structures nearby the damaged areas?
Feeling a presence
Left angular gyrus - feels like somebody is behind you.
Positive emotions of death
Can be mimicked by ketamine. Also dopamine and opioid systems, which become active in highly traumatic or dangerous events.
