Computers will remain idol if not told what to do. Will the brain lie dormant if not stimulated by the senses?

As a thought experiment, what if one could become devoid of any sensation, no sight, no sense of smell, no nothing.
would the person be capable of thought?

And if so, or perhaps not so. The obvious question then arises, what about memory?, the recollection of past experiences
stored within the brain as paradigms of fired neurons that react the same way every time we experience something of a similar nature.
How does this act occur if their is no initial stimulus?

Is it just a random event within the brain, where nuerons fire randomly even without stimulus, to slow potential atrophy of regions not often used.

or is it an act beyond or current understanding, the soul, mind, or some act of divinity perhaps?