How do we become conscious of an apple?
To be conscious of something is to know that we know of it. Let's follow through how this works in the simple case of becoming conscious of an apple that we can see.
In panel 1, below, we see the apple, our transient processing (B) detects and characterises it and asserts (3) it into persistent storage (A) as a symbolic apple. It is stored in such a form that it can control (4) subsequent transient processing (B) to assert (3) any changes to the apple – for example its position relative to us - into persistent storage (A), so that the symbolic apple remains a useful persisting record of the actual seen apple. We now know about the apple, but not yet consciously.
In panel 2, we query (6) persistent storage (A) by paying attention to our own internal representation of the apple. We therefore have available to transient processing (B) not only the visual input (1) of the apple, but can also access (6) our internal symbolic representation of it, which may include attributes of it, such as its position and colour. We can now produce an output action (2) that responds to the symbolic information. For example we could (consciously) point out the apple to someone, we could talk about it or we could make a conscious decision to eat it.
Note that in panel 2 we are now treating as inputs, two different versions of the apple: the raw visual impression of it (1)the symbolic representation of it (6), that we have detected and tracked. The potential richness of our conscious awareness of the apple will depend on how it is embedded within a context of other real world or mental objects, of potential actions, of actual and expected valence (feelings) and of a time sequence of previous and planned actions and consequences. Our ability to access that context will in turn depend on whether we can direct our attention to access this information (be mindful of it) and make use of it.
The model is fully developed and described in my ebook 'On the mechanisms of consciousness' (available on Amazon for only £3 - do take a look!).