Is this considered neuro ociation? ?

I had to read the book The Great Gatsby for school, and I pictured the cover as the other book that was sitting on the bookshelf, The Gl Menagerie. So pretty much when I thought of The Great Gatsby, I didn't remember the actual cover, just the cover of another book. Someone told me that this was some kind of neuro ociation? What does that mean?? If that's not it, do you think there's a reason I mixed up the covers?