Help me out

I've thrown together this image for a manuscript I'm trying to finish up. I'm not entirely happy with it as it stands, so looking for a few pointers.

For those memory-research naive, what does the diagram give you? Are you any more informed about Memory loss? Anything particularly unclear?

For those of you with a bit of a background in this stuff, I'm not sure about the caption coming off of the Event Theta (the little easter egg symbol). PTA extends aft AND before the insult, but I worry that it'd start to look really scruffy if I shoehorn another event in just before and recolour. Also, PTA doesn't really cut it - there are also confusional states and other stuff. Is there a pithier way to get at this?
Also - I guess for anyone - if I added more colour (they want glorious technicolor in their publication), what would be fair candidates? A colleague suggested the PTA-period getting a different colour, but the program I'm using, Paint.net, although nice (and free) doesn't appear to offer you gradients from one colour into another so it would look a bit blocky and coarse. Could colour certain events... however, in all cases, I would prefer to add colour when it actually means something, and to definitely avoid it when it actively confuses.

Any comments hugely appreciated, folks!