One could argue that, if memories are indeed associated with the body as a whole, amputation of an organ or general tissue loss should noticeably impair recall, which doesn’t seem to be the case. The problem is: it isn’t the case with the brain either. Memory lapses in Alzheimer’s patients only become noticeable after 40% to 50% of brain cells are already dead.
Illnesses that affect only the brain, such as Alzheimer’s, as well as localized physical trauma to the brain alone, can significantly impair recall even when the rest of the body remains intact. This doesn’t imply, however, that memories are all in the brain. It suggests only that brain illness and trauma can impair our ability to amplify otherwise obfuscated experiences, wherever these experiences may reside.
We know that the reverberation process that amplifies mental contents happens only in the brain, taking up relatively small amounts of neurons in specific areas. It’s thus no surprise that, if damage to key brain pathways prevents the flow of information into these specific areas, lucid awareness of the corresponding experiences becomes impossible. The memories will still be there in the body, but the patient will report an inability to remember — that is, to become lucidly aware of — certain things.
Brief Peeks Beyond: Critical Essays on Metaphysics, Neuroscience, Freewill, Skepticism, and Culture
Background on Bernardo Kastrup