In my previous life before I became a full time writer, I was a cognitive neuroscientist. I did my PhD dissertation at MIT in a lab that did a lot of research on learning and memory. While the potions used in Rosemarked are fantasy, I did try to incorporate neuroscience principles into the story.
Memory is often modeled as being comprised of several different types. There is semantic memory, which is knowledge general knowledge about the world, episodic memory, which are your personal memories of events, and then there’s procedural memory, which has to do with skill learning and how to do things.
For example, let’s take riding a bike. Semantic memory would be knowing what a bicycle is. Episodic memory would be remembering how you got a big red bike on your seventh birthday. And procedural memory would be the actual skill of riding a bike.
It’s very common memory loss to apply to one memory system and not others. The famous neuroscience patient H.M., for example, lost all ability to gain new knowledge about the world, but was still able to acquire skills with repetition. Likewise, in Rosemarked, Zivah’s potion took away Dineas’s knowledge and personal experience while retaining his warrior’s instinct and skill with weapons.
Zivah’s potion also had the unintended effect of giving Dineas some respite from his traumatic memories. Does that have any bearing in real life? There’s some very interesting branch of PTSD research going on right now that has to do with blocking traumatic memories. This could be through introducing drugs right after a traumatic incident to keep someone from developing a very vivid memory of it.
There’s also research going into attenuating a memory after it’s been formed. When you recall a memory, there’s a window of time in which it’s vulnerable to tampering. So this type of treatment would involve having patients purposefully recall the traumatic event, and then giving them the drug to disrupt the memory. The point of these treatments is not to make the patient forget about the event completely, but to make them weaker so they no longer have the same power.
Rosemarked differs from these real life examples in several ways. First of all, Zivah completely erases all of Dineas’s memories without the need to have him recall them. And second, Zivah has the ability to restore Dineas’s memory on demand.