The assumption is that all memory is stored in the brain and body, for where else could it be stored?
The materialists do not believe in a ghost in the machine. /anecdata
It means if you take us apart and put us back together again the ghost will have left. It will be a huge disappointment for cryogenics.
If people want longer lives the body will have to be kept alive in an induced coma state and heart rate slowed. Or use some novel regenerative therapy.
Otherwise that machine (body) is never coming back to life once its ghost has left.
It means an entirely different type of neuroscience that most scientists are uncomfortable with. Having to do with Consciousness