Dementia, brain cell death and hallucinations without using hallucinogens...

[MaartenV]

I think that hallucinations in the last stages of dementia are like entering a psychedelic state of hallucinations due to decreased brain activity. (Kastrup about psychedelics and the brain) DMT f.e. has different stages and hallucinating is one of them, as we all know. And 'the breakthrough' or ego dissolution is another state on higher doses of DMT. People experience it as dying and as Bernardo Kastrup showed us: only decreases in brain activity were seen in the brain scanner. So, the hallucinations during dementia happen without using hallucinogens because dementia is actually the death of brain cells.

[Jim Cross]

It would be nice if it were so simple.

Brain activity decreases during deep sleep and under anesthetics but these are hardly breakthrough experiences.

Seizures caused by excessive brain activity and strong rhythmic activity during meditation can sometimes produce breakthrough experiences.

It's complicated. But I don't think dementia is in any way positive.

[MaartenV]

Here is a video where dr. Emery N. Brown, M.D., Ph.D., Harvard Medical School, and MIT Cognitive Neuroscience shows us that the thalamus is much more active under general anesthesia than during the waking state. Actually, you see no brain activity in the thalamus on the slides during the waking state. See video.Thalamus is much more active under general anesthesia than when we are awake

That seems to be the main difference between conscious and unconscious during general anesthesia. A very active thalamus under anesthesia and no brain activity in the thalamus during the waking state. See video.

[Jim Cross]

Here is a video where dr. Emery N. Brown, M.D., Ph.D., Harvard Medical School, and MIT Cognitive Neuroscience shows us that the thalamus is much more active under general anesthesia than during the waking state. Actually, you see no brain activity in the thalamus on the slides during the waking state. See video.Thalamus is much more active under general anesthesia than when we are awake

That seems to be the main difference between conscious and unconscious during general anesthesia. A very active thalamus under anesthesia and no brain activity in the thalamus during the waking state. See video.

I don't think that is quite correct.

ALL sensory input routes through the thalamus except smell. That's true during wakefulness and sleep. It may be that the thalamus is still active during anesthesia but that doesn't mean there is no activity during the waking state. The thalamus is closely associated with the brainstem which maintains basic survival functions so without activity in the brainstem and thalamus the person would be dead.

This is more accurate.

The experiments show that brain regions are activated in a different order depending on whether the individuals are awake or asleep. Specifically, in conscious individuals information from the senses is first processed by a structure deep within the brain called the thalamus before it is passed to the brain’s outer layer, known as the cortex. During deep sleep, this flow of information is reversed and signals are instead sent from the cortex to the thalamus. This may contribute to our loss of sensory awareness during sleep, and even to the occurrence of dreaming.

https://elifesciences.org/articles/10781

This also overlooks the type of activity. Wakefulness is associated with faster brain waves ( > 7-8 hertz) originating from the brainstem/thalamus and extending over the entire brain. Sleep is associated with a predominance of slower brain waves.

[MaartenV]

This study of women's brains while they are having an orgasm, proves that phenomenal consciousness exists during orgasm, even if almost all parts of the brain are deactivated or shut down and only a motor part is active (the cerebellum). (Phenomenal) Consciousness as an emergent property of the brain is off the table, in this study. Phenomenal consciousness has nothing to do with brain activity then. The whole brain is shut down

[Jim Cross]

This study of women's brains while they are having an orgasm, proves that consciousness exists during orgasm, even if almost all parts of the brain are deactivated or shut down and only a motor part is active (the cerebellum). (Phenomenal) Consciousness as an emergent property of the brain is off the table, in this study. Phenomenal consciousness has nothing to do with brain activity then.

There is a lot of brain activity in a brain still left when "almost all parts of the brain" are shutdown.