To upload information stored in the mind is to upload information stored in the brain because the brain is the physical part of the mind. To do this is not an easy task because the brain has neither output port nor functional modules for this purpose (to upload its information), and the information in the brain is not stored in one definite place like a hard drive or a series of memory banks in a computer but is stored scatteredly in neural circuits all over many areas of the brain, with 100 billion neurons and about 100 to 1,000 trillion synapses making up those neural circuits [1,2]. So, it certainly won’t be easy like uploading information from our computers to elsewhere.
Another problem is that current technologies that can gather information from the brain, such as EEG, MEG, and electrocorticography, are very crude (they cannot single out a specific neural circuit that contains the specific information) and cannot access information in all parts of the brain, especially that in the deep structures. Single-unit neural recordings are much finer and can record deeper, but we have to do such recordings possibly millions of time to get all the information from all information-containing neural circuits in the brain, which will certainly do some damage to the brain (and its mind). So, this seems to be quite a harmful way to upload information from the brain.
Another significant problem is that the information in the brain are in various forms: declarative memory (which also has many types: immediate memory, working memory, and long-term memory) and non-declarative memory (skills, habits, predilections,etc.) [3]. They are are stored in different types of neural substrates: neural signaling patterns, facilitation/inhibition of corresponding neural synapses' strength, modifications of neural circuits' formation, etc. The information that is stored in the form of neural synapse or neural circuit modification is not free to read directly but has to be converted into neural signals before it can be read by other neural circuits and by our instruments. So, the problem is we have to activate all those neural circuits/synapses before we can read their information. But how do we know which ones of those multitude neural circuits/synapses in the brain store information, and how we do that to all several millions of them?
What’s more, current technologies still cannot decipher accurately what exactly the signals that are gathered from the brain mean, e.g, what do those EEG/MEG signals mean – a vision of the red color?, a house?, or a man? So, without knowing what the information we’ve got represents, it is difficult to store and archive it correctly and retrieve it later effectively.
Edited part:
Because all the above problems are technical problems, I think it is theoretically possible to overcome them although it certainly requires much more advanced technology than we currently have. And it seems very likely that we will not have that technology in the near future, certainly not within a few decades from now.
The biology problem and the hard problem of consciousness and qualia.
It is important to note that the above discussion is about the possibility of uploading information of the mind to a computer, which is arguably theoretically possible. But to upload or relocate the mind itself to function or live in a computer is another matter because it will face additional 2 formidable problems: the biology problem and the hard problem of consciousness.
The biology problem:
The mind and its physical brain are alive; they change their structures to some degree overtime by neural circuit and synapse modifications to store new information or modify its skills, habits, predilections, etc. On the contrary, the computer is not biologically alive and cannot change or modify its structure (hardware) by itself. So, even if we can upload all the mind’s information to the computer successfully and try to set it function there, the mind can never really live in the computer the way it lives in the brain, where it can modify its self bit by bit overtime.
The hard problem of consciousness and qualia:
This is the problem of having phenomenal perceptions (the red color, the sound of music, the smell of the rose, etc. that appear phenomenally red, phenomenally music, phenomenally rose, phenomenal etc. in our mind) and phenomenal consciousness (the awareness of what it is like to see the red color, to hear the sound of music, to smell the rose, etc., and what it is like to be ourselves)[4] Although we have learnt a lot about neural correlates of consciousness [5], we still do not know how these non-material phenomenal manifestations occur from the material neural circuits. Some new theory explains that they are special kinds of information, which is non-material, that occur inherently in the material neural circuits [6], but this has to be verified by experiments.
Because both the biology problem and the hard problem are fundamental problems, if we cannot solve these problems first, we will never be able to upload or relocate the mind itself to function and live in a computer like the way it lives naturally in our brains.
References.
Byrne JH. Introduction to neurons and neuronal networks. Neuroscience Online. The University of Texas Health Science Center at Houston (UTHealth).
Sporns O, Tononi G, Kötter R. The human connectome: A structural description of the human brain. PLoS Comput Biol. 2005 Sep;1(4):e42.
Purves D. Chapter 30. Memory. In: Purves D, Augustine GJ, David Fitzpatrick D, Hall WC, Lamantia AS, McNamara JO, Williams SM, editors. Neuroscience. 3rd ed. Sunderland, Massachusetts: Sinauer Associates Inc; 2004. ISBN-13: 9780878937257 ISBN-10: 0878937250.
Chalmers DJ. Facing up to the problem of consciousness. J Conscious Stud. 1995;2(3):200-219.
Koch C, Massimini M, Boly M, Tononi G. Neural correlates of consciousness: progress and problems. Nature Reviews Neuroscience. 2016;17: 307-321. The full pdf file can be downloaded from here.
Ukachoke C. The Basic Theory of the Mind1st ed, 2018. p 8-18. Charansanitwong Printing Co. Bangkok, Thailand.