The memory episode encoding is fully semantic or not? Are there any visual, acoustic imagery, etc.? It is 100 years old question. But did you know any new statistical studies of big number of people?
Did you sure what you are talking about? The visual memory? Is it the same you see in the real world? If so you see hallucinations:). Is it measured by any scientific device? Why do psychologists say about the notion of imagery!!:) It seems to me is not scientific!! Of course, we have in our brain some "instruments" to work with memory, thoughts, etc. But everybody`s mind is inaccessible to anyone.
I think the consciousness can not be explored in principle, particularly because it is strictly individually. We can not make any statistics, any study of large number of people :). The one will say "yes, it is my visual imagery in MR image", the other may says differently, the third person can simply lie, etc. There is a Russian proverb "there are as many different opinions as number of people".
"il y a autant d'opinions différentes comme il y a des gens" da eta pravda. nevertheless, check if these papers help you in your queries. Rabin et al. concludes:
"detailed episodic representations supported by the hippocampus may be pivotal for imagining the experiences of personally familiar, but not unfamiliar, others"
Article Genetic overlap between episodic memory deficits and schizop...
Article Episodic memory for object location versus episodic memory f...
Article Imagining Other People’s Experiences in a Person with Impair...
Article Cortical reinstatement and the confidence and accuracy of so...
I do not believe in your vivid visual pictures of your episodic memory. Why? What is for example an internal speech, music? (How did Beethoven write his last fantastic quartets?:), the main theme of the 9 symphony was invented much earlier :))
I understand this in the only one way. It is only our FAITH that we "hear" something ;) inside our heads. I think we can not able even to DESCRIBE how we remember, think, etc..It is possibly the main reason why the consciousness can not be scientifically studied.:)
Beethoven was deaf from 1798 to 1827. "The cause of Beethoven's deafness has variously been attributed to typhus, auto-immune disorders (such as systemic lupus erythematosus), and even his habit of immersing his head in cold water to stay awake.The explanation from Beethoven's autopsy was that he had a "distended inner ear," which developed lesions over time" according to wikipedia so something he did hear in his head.