Supposing that scientists could find a way to keep a human brain alive and fully functioning independent of a body somehow, would the brain be in a perpetual dream state without any outside stimuli? This is assuming that the brain had come from a living person.
Take your choice of one or the other, you can’t have a brain that is “fully functioning independent of a body” and “in a perpetual dream state” simultaneously!
Perhaps you would like to rephrase your question.
A dream state is not a state of sensory deprivation, which is what you’re describing.
One imagines that the non-existent tech required to support this brain-in-a-jar would also allow interfacing and sensory input.
The difficulty in doing this is that there is a complex dance among the CNS, the PNS and the hormonal systems. Not to mention the vascular issues.
I think “Fully functional independent of a body” simply meant the brain was being maintained without need for the support of the rest of the body or input from the nervous system.
The only way I can think to answer this very speculative question is to wonder to myself what it would be like to have no sensory stimulation at all.
I don’t see any reason to think I’d be in a “dream state” in such a situation. It would just be like being in a completely black room–only more so.
-FrL-
Or possibly the opposite, a very white room. I’m not sure how it works for blind people, but I have heard that amputees suffer phantom pains from lost limbs because nerves, in the absense of sensory input, become increasingly more sensitive “looking” for that input that eventually it’s just a constant buzz of feedback or something. In any case, I’d hate to be the brain stuck in that black box unless someone found a way to hook it up to outside input and output.
Has anyone been able to measure brain function of a developint fetus? Not fully isolated from sensory stimulation, but wouldn’t it be close?
There have been a few other threads on this topic.
Here are three.
What are the practical barriers to a successful brain transplant?
Kinda. What happens is that the neurons associated with the lost limb grow into adjacent areas of the sensory map in the brain (see Ramachandran, et. al.) Note, though, that the adjacent sensory area next to the sensory area that now has no connection in the case of an amputation has NO relation to the adjacent area on the body. In other words, if an arm is amputated near the shoulder, the adjacent area in the body’s sensory map is NOT the shoulder; it could be the nose, for example.
The best answer comes from knowing what happens during sensory deprivation experiments, where subjects are placed into light, sound, and smell proof tanks filled with warm salt water. Before long, the sensory deprivation produces hallucinations, reportedly due to the brain’s need for input.
I assume the brain would experience a more extreme version of what one experiences during regular sensory deprivation which according to wikipedia, “though short periods of sensory deprivation can be relaxing, extended deprivation can result in extreme anxiety, hallucinations, bizarre thoughts, depression, and antisocial behavior.” and it can be used both for torture and therapy
Wow, I didn’t know sensory deprivation could cause all that.
Oddly, it kind of makes me want to try it.
-FrL-