Years ago I've read about a young man you had lost a large section of his brain (frontal lobe) in an accident but surprisingly he survived it and continued his normal life. You may have read about that.

Now let's break down the question into 3 steps. Which parts of the brain can we remove without:

  1. Affecting the normal life. This means, still being able to see, talk, understand, and more. Just like a normal person.
  2. Losing conscious. This includes just being able to maintain conscious, being able to think and understand.
  3. Dying. Which means only having the crucial organs such as heart and lungs running.


I'm neither looking for a list of every part of brain's million sections, nor it's possible to cover them all in a single answer. I'm merely looking for a list of widely-known largely-scaled sectioned, such as the below image.

Brain sections

Image credits goes to Mid Brain Power.

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    $\begingroup$ this reminds me of en.wikipedia.org/wiki/Phineas_Gage $\endgroup$
    – JM97
    Jul 25 '17 at 6:21
  • $\begingroup$ Thank you for the link. This is a similar accident, didn't know about it :) $\endgroup$ Jul 25 '17 at 6:25
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    $\begingroup$ This question is too broad. For example, what do you consider to be a part of the brain? Glial cells can be removed without any consequences. Neurons are constantly dying in your brain too, apparently without consequences. Perhaps you are aiming at which anatomical structures can be removed in totality? Perhaps you can define in the question at what scale you are thinking, and if you are talking bilateral transection, or unilateral only etc. $\endgroup$
    – AliceD
    Jul 25 '17 at 8:50
  • $\begingroup$ If you have examples of where my comments are not useful let me know. In general I am just trying to improve questions. The best posts are specific, clear questions and those typically receive the best answers as well. $\endgroup$
    – AliceD
    Jul 25 '17 at 9:42
  • $\begingroup$ I think you just don't recognize how broad this field is. I am in the field of studying consciousness, and it is clearly not understood within the field what structures are necessary for consciousness or even if it makes any sense to think about it in terms of particular structures at all. This thread is just going to produce speculation, and so far the only answer is horribly misleading. I agree with @AliceD that this is far too broad. $\endgroup$
    – Bryan Krause
    Jul 25 '17 at 16:17

Many areas of the cerebral cortex aren't essential to life/consciousness, damaging/removing them will only destroy the function associated with that area, e.g. visual cortex in the occipital lobe, auditory cortex in the temporal lobe etc. The Corpus Callosum can sometimes be bissected without any major detrimental effects to the "patient/victim".

Edit: The point here is that what appears to be a major link between the hemispheres of the cerebral cortex can be destroyed without necessarily killing the patient. Whether it falls under the same surgical category as a frontal lobotomy or not, I don't know.

Generally the "lower" portions of the brain, midbrain and brainstem are more important as regulatory centres. However these are each made up of multiple smaller regions, each involved in multiple functions, e.g. the Pons, medulla, thalamus. Removing any of these could have wide-ranging consequences, e.g. the thalamus is important for integrating multisensory information.

So, broadly speaking, cortex damage is OK, midbrain/brainstem, probably not unless you only removed very small regions (e.g. removing the cochlear nuclei from the Pons would probably only affect hearing).

If you use the added image, you can predict what removing each brain area would affect, removing the brainstem would remove respiratory centres, certain death. Removing visual areas would lead to blindness, but probably not death.

Fully answering your question would probably require an entire book to list all of the known brain regions and the implications of removing them.

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    $\begingroup$ No no no - the corpus callosum cannot be bisected without major and detrimental effects. It can be bisected without causing death but that is fully different. It can be bisected and result in a higher quality of life for someone having debilitating seizures otherwise but that is fully different. The thalamus isn't important just for "integrating multisensory information" - removing the thalamus would completely destroy someone's ability to experience external stimuli. $\endgroup$
    – Bryan Krause
    Jul 25 '17 at 16:15

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