Would you be kind enough to give me your considered opinion concerning the interpretation of the verb in bold in the following sentences?
I turned my eyes to her, feeling them narrow as my mind dredged up the appropriate image of the ugly flying rodent she referred to.
Please don't dredge up the sad facts of his past.
dradge up = bring to light something from one’s memory; think of It can refer to facts or information about someone else which have been gleaned from sources other than one's memory; whatever has been dredged up is frequently negative or unpleasant.
To dredge is to scrape the bottom of a lake or other body of water. The things found by doing this are not usually pleasant. The use of this phrase in the literal sense is usually in connection with searching for a missing body.
If you kill someone, you may try to hide the body in a lake. The police may dredge a lake to try to find it.
By analogy, things that are dredged up are usually something hidden and unpleasant.