Question: I'm looking to find some resources to read about the following:  

When we talk about a general concept (the word pencil in "a pencil is made of wood"), we actually have a mental image of a **particular** object in our mind (a particular pencil with a particular color in the example).

I'm looking to read about this and similar issues. I don't even know what topic to look into. I've looked a bit on Frege's work but I didn't find what I was looking for. I'd appreciate suggestions.

Answer: 
Ernst Mach and Julian Barbour suggest that *time is our perception of change*, and perhaps that's one of the best definitions of time I've found. The only physical fact lying under such definition is *change*, which we can perceive subjectively.

Before answering your question, a mental experiment. Imagine you are a prisoner in a jail cell where you cannot perceive change, at all. No prisoners near, no windows, no signals, noises, visits, nothing. Evidently, in such circumstance you will quickly start losing the sense of time. We need change perception to be aware of time.

In such experiment, you have anyhow some change perception. You can feel your heart beating, your respiration has a rhythm, your body functions follow a period. Using such information, you have a minimal perception of change that allows you to get a minimal notion of time. In ultimate instance, you can count lambs. 

But in your experiment, there are only two events (or one). That is equivalent to say that there's no perception of body functions, of respiration, of nothing. Not even labs counting. Cerebral death. The two events can be considered to waking up twice, for small instants, in the middle of the night, not knowing which is which.

Under such light, your question have two possible answers: 

* "nothing happens", and "time still pass". That is equivalent to say that even if nobody hears it, there was a noise.
* "nothing happens", and time does not pass. That is equivalent to say that if nobody hears it, there was **no** noise.

So, from this perspective, your question would be highly biased by preconceived ideas about perception. If the existence of the time entity is subjectively dependent, the idea of modifying the perceptive conditions would only have a rhetoric impact, since we cannot modify our perception to such extreme.
It depends.

If nothing is changing because in fact there is nothing there then it's right to say that no time is passing because there is nothing there including time. 

If nothing is changing because everything is actually in stasis but could potentially change then time is passing.

If nothing is changing because everything is actually in stasis and cannot even in principle change then time is not passing because time is the potential for change.

If nothing significant is changing then time is still passing.