We're biologically incapable of ignoring our senses. I want to clarify what I mean by this, because as posters have suggested we actually can do so, for example by blinding or gouging our eyes. I'm talking about ignoring our senses by a pure act of will. One of course could argue that an act of will is involved in blinding oneself, and this is true. By a pure act of will I mean one in which no external physical act is involved. For example:
Looking at human being and seeing it as an Orangutan, with no discernable difference to seeing an actual orangutan.
Holding an ice-cube and willing it to feel hot
I imagine a computer would have complete control of its sensory input and how it can be viewed. Whereas I can imagine a human being as an orangutan, but not physically see one as such, a computer should be able to see it exactly as that, if it so chose.
Given this, would a concious computer naturally decide that the world was a figment of its imagination?
I am aware that humans are capable to sensory adaptation to a certain degree. Although humans can hallucinate or dream, these are generally not something that we can conciously will. A human takes drugs to hallucinate, but even then cannot will the form of his hallucination; a human can dream when he s asleep, but the same goes (yes, there may be a slight degree of control, but generally not).
I would also suggest that evolution would have made it very difficult to ignore our senses, as it would simply be dangerous.
I am suggesting a computer would have complete control of how its sensory input would be represented to itself. We're not concious of the nerve impulse when a photon strikes a rod/cone in the eye, what we sense is the whole picture. I'm suggesting that this whole picture, for the computer would be entirely under its control. A simple example would be inverting all the colours. A more sophisticated way would be to change the form of objects in a faithful way.
The equipment that takes in the sensory input cannot ignore the sensory data, but the the interpretation is modifiable. Using Kants language, the forms of perception is not under concious control for a human, but I'm holding that it is so for a computer.