"When and while I think in the first person, present tense mode, I must necessarily exist."

Question: Can this famous Cartesian epistemological hypothesis be empirically verified?

The answer, I submit, is yes. However, with the peculiar proviso that the empirical verification (thought experiment/thought act) that occurs must always remain subjective and personal, rather than objective and public. — charles ferraro

Rubbish.

Thought experiments are not dependable methods of verification/falsification.

And...

This directly conflicts with the bit you wrote about all philosophical theories. Incoherency and/or equivocation is inevitable. Both are unacceptable, regardless of which is the case.

Arthur Schopenhauer claimed that the human brain (the understanding) spontaneously constructed perceptual objects by applying (a) the pure “a priori” intuitions of space and time and (b) the transcendental principle of cause and effect to the body’s subjective “under the skin” sensations. — charles ferraro

Close, but no cigar.

The brain does not construct perceptual objects. The brain's all by itself inside the skull with neither tools nor materials. Sense perception is direct. The brain does not 'construct' a tree. Rather, it helps facilitate the creature's ability to see the tree. The brain is necessary but insufficient for seeing, smelling, hearing, tasting, grasping, rubbing the tree, as well as thinking and/or talking about the tree.

Brains in vats are dead.

Creative Soul: What the hell are you talking about?

What are the basic hypotheses that comprise your so called OWN theory of mind that are subject to empirical test? What specific "If, then" statements does your own theory of mind generate, the validity of which, as you claim, can be put to objective empirical experimental test?

By the way, Einstein was noted for the many thought experiments he did conduct such as, for example, trying to imagine what it would be like (what his subjective experience would be like) to ride on a beam of light? However, this didn't mean that the validity of what he imagined to be the case subjectively didn't need to be put to objective empirical verification.

Also, Schopenhauer didn't smoke cigars so he really wasn't trying to land one; and only dogmatic brains are dead, not just those in vats.

The fact of the matter is that no one (neither you, nor I) will ever have airtight empirical verification about whether, or not, Schopenhauer's or Sartre's epistemological theory is empirically valid. Why? Because, unfortunately, neither theory, no matter how beautiful and complex its insights, generates empirically testable hypotheses.

For example, try to provide an empirical, experimental test for the following hypotheses:

Schopenhauer: If the human will is absolutely free, then guilt attaches to the "esse" rather than to the "operari."

Sartre: If human Being-for-Itself is defined primarily by a Pre-Reflective Consciousness, then such a consciousness will always be devoid of an Ego.

With respect to your "rubbish" comment.

Descartes' "When and while I think, I must exist" is a thought-act, an intellectual performance, that is existentially consistent and existentially self-verifying only when it is performed by the meditator (you and I) in the first person, present tense mode. In this sense, it is unique. One must execute it in order to "see" its truth. There is nothing incoherent about this!

Dude check out phantom limb syndrome.

Thanks for that Schopenhauer reterence.
You ask for an origin of 'bodily sensations', but from the pov that all perception is an 'interaction event' between 'organism' and 'environment' (Bohr et al), we might understand sensation as a bi-product of 'perturbation of structure of organism'. Maturana was the biologist/philosopher who developed the idea that 'cognition' was equivalent to 'the general life process' in which adaptatations to perturbations operated to maintain the integrity of the organism. Organisms were seen as emergent dynamic structures, far from equilibrium (Prigogine), which maintained themselves by 'successful' adaptation to perturbation. (BTW, the concept of DKS, ...dynamic kinetic stability.. has been used in developments in abiogenetic theory (Pross) as a counter principal to entropy increase) No doubt this 'systems view' of cognition can designate some components as subsystems which monitor adaptation. That 'monitoring' could be equivalent to what we call 'awareness'.

In your definition of this is an 'epistemological' issue, we might bear in mind Rorty's point that 'philosophy' per se has no epistemological authority outwith scientific advances.

Fast forward to present day neuroscience and find your answer. — I like sushi

The true understanding of neuroscience must be considered limited to the problems that they can really solve. Neuroscience can obviously solve some problems, but in my impression, you may seriously be overestimating its ability to solve arbitrary problems phrased in the language of neuroscience. My own impression is that they are many more questions that they cannot answer than questions that they can.

A true understanding of philosophy must be considered limited to them problems that it can address (not solve). Sciences can actually provide practical limited solutions whilst blind speculation may accidentally stumble on something novel when applied - by chance rather than intent.

The realm of ‘understanding’ is a phenomenological puzzle and a physical one (there is no ‘actual’ difference, they’re just conveniently sectioned from each other in order to feed into the working paradigm of the ‘epistemic’ and the ‘ontic’).

Thought experiments are valuable for suggesting possible subject matter for notions or abductions towards potential hypotheses, so they are a lot of steps before verification.