What do we have when we introspect? – we have consciousness of a memory of a short part of the recent stream of consciousness. We are not looking directly at an instant of consciousness. We are looking at recently past consciousness and we are not looking at an instant but at whatever is grouped in one unit of memory. The consciousness that we experience is not permanent – it was gone almost immediately leaving only a little memory. As soon as we try to examine its details, we are looking at a memory. Unless we have a photographic memory, a lot of detail is lost in forming a memory and there is a ‘smudging’ of the experience over a somewhat longer period of time in the memory process. There is no reason to believe that a recalled memory is identical to the original conscious experience. We experience consciousness but we cannot actually examine it directly, only the memory of it.
Well, the memory of recent conscious experience might by useful. Suppose it is very close to the conscious experience – what does that give us? Conscious experience is not what it seems. It seems like consciousness is looking directly at the input of sensory information. But this is not so. Its formation is entirely opaque; we cannot experience the making of conscious experience. The creation of consciousness is a purely unconscious process and it is complex. The conscious experience is constructed from the sensory input and the prediction of what the sensory input was assumed to be, and our knowledge of the world. It is many layers of processing from the raw sensory input. Our consciousness of movement is the movement we planned and not necessarily the resulting movement. Everything is constructed including the ‘self’ that experiences the conscious stream. Our conscious models of thoughts, decisions, values, and emotions are constructed with even less contact with the real operations of the brain than sensory/motor information. Examining this stream of consciousness with a conscious examination of it is playing in a hall of mirrors.
Consciousness does not exist to allow us to understand our brain. Why should it? Why would there be any evolutionary pressure for our brains to understand our brains? What the brain constructs is experiences and it does it in a way that makes them a useful memory library we can use and learn from. If we want to learn about our own brains there is a problem with the usefulness of introspection. It can only answer some ‘what’ questions of limited value. To understand how the brain works we really want the ‘how’ and ‘why’ questions addressed and they are precisely what memory of consciousness or even consciousness experience itself cannot give us.
We must forget about studying our brains from subjective, inside observation. We must treat our brains objectively to gain understanding of how they work. There are many people who do not accept this and insist that we can study the mind in a subjective way. Indeed, to some people the subjective mind is the only interesting part of thought or brain which is worth studying. This subjective approach seems to me to be a waste of time and effort. It is rather boring (scientifically) at best and misleading at worst. All that this studying would give us is what we already have. It will give us a subjective experience of a copy of a subjective experience. It will not give us what consciousness physically is or how or why it is as it is.