Hello, I need to write a dissertation on Maupassant's gothic short stories and reader reception & more specifically how the perusers/readers are involved in the stories or interpret them, what effects the writer wanted to produce on them (and how he does that). I need a detailled outline but I cannot find what are the main headlines, I mean what elements would all these stories have in common to create a reaction from the reader or to involve him further in the story. All I can think of is themes and the question of reality but it isn't enough. Could you please help me solve this problem?

If it can help, here is the corpus of short stories to study (the French title is between parenthesis) :

-The Horla (Le Horla)
-The Specter (Apparition)
-Am I insane? (Fou ?)
-The Diary of a Madman (Un Fou)
-He? (Lui ?)
-Solitude (Solitude)
-Letter of a Madman (Lettre d'un Fou)
-The Traveler's Story (La Peur)
-On Cats (Sur les chats)
-The Spasm (Le tic)
-The Englishman (La Main)
- One Phase of Love (La Chevelure)