As a famous forgetful fish once said, “Just keep swimming.” Dory says this. She says this a lot. The thing is, she probably can’t remember that she has even said it. This is a case of, what I would assume is, anterograde amnesia. She cannot form new memories. By talking through this form of amnesia, I hope to be able to explain a few different functions of our memory.
Memory is more than just simply…remembering. There are actually quite a few pieces to this process of forming memories.
Most everyone, including Dory, likely has an intact and working sensory memory. Sensory memory is literally just the ability to process everything that is happening around us. This includes all of the sights, noises, and physical sensations around us (these are known as iconic, echoic, and haptic sensory memory, respectively).
This is the first step in the memory process. If you never take in information, you certainly cannot store that information. However, think about all of the things we see, for example, in a day. As I sit here typing this, I can see 3 different types of chairs, 2 dog leashes, 1 dog, cement, bricks, lights, many different types of flowers, trees, clouds, the sky, etc. This is all within less than a second. Think about every time we move our heads, walk, go to another location, we are seeing many many many more things. If we actually remembered all of that, we would go insane.
Instead, our brain decides to let go of much of this information unless it is relevant for some reason. Relevance is very subjective, and sometimes even not consciously known. Yet, the brain makes decisions on what to and what not to keep.
In part, this is due to our short-term memory and it is here that Dory likely would start having problems. Short-term memory also has multiple parts to it. Within short-term memory, there is working memory/central executive functions, the visuospatial sketchpad, and the phonological buffer.
You can think of each of these as a place to store information. In working memory/central executive, we are storing everything we are wanting to pay attention to, focusing on, and controlling to and from our long-term memory storage (which is the last bit I will talk about after I finish up short-term memory); in the visuospatial sketchpad (fun name, eh), we store visual imagery and physical space memories; in the phonological buffer, we store information about language, words, and other abstract concepts like social information.
However, this isn’t really what we think of when we think of memory still. This is just what we can store for a short period of time (10-20 seconds). In this time, we can synthesize ideas, figure out what our priorities are, remember what we need to do, and allow all the different pieces of information (images, sounds, sensations) to come together.
Every time we think, we are using memory. We usually just think of it as, well, thinking, but it really is largely a memory process.
It is very possible that Dory still has enough of her short-term memory to make sense of where she is at any moment. But, the problem then lies in how to keep the processes occurring in short-term memory and transferring them to long-term memory. Once those 10-20 seconds are up, so is the memory.
However, for most people, that isn’t the case. Parts of what happens in short-term memory will make it to long-term storage. There are 2 main ways we store long-term memories: there is declarative memory and non-declarative memory.
Declarative memory is stuff we can talk about consciously. We are aware of this type of memory.
Non-declarative memory is stuff we CANNOT talk about consciously, at least not fully. These are automatic and tend to live below the line of our awareness.
Further, there are two types of declarative memory: episodic (personal experiences) and semantic (language and abstract concepts).
Dory definitely has a problem with episodic memory. She cannot form new personal experiences even if she is constantly actually engaging in new experiences, as she does. She can remember previous episodic memories, but just cannot form new ones.
Dory likely has some issues with semantic memory too. It is hard to say if she cannot learn new concepts or new words, but it likely would be very hard to do so if she could.
Lastly, there are 4 types of non-declarative memories: procedural, associative, non-associative, and priming.
More likely than not, Dory would be able to have the ability to learn some of these types of memories.
For procedural, these are our habits and skills. She definitely has retained old habits and skills such as swimming or automatic responses to others’ behaviors. However, this would be difficult with anterograde amnesia because in order to learn a habit or skill, there has to be some level of knowledge and attention about the behavior. Earlier we said that she may not actually be able to do this (and if she can, it would be very difficult).
For associative, these are classical and operant conditioning. It is likely that Dory would still be able to learn this way. Automatic associations and reinforcing someone to act or think in a certain way happens without awareness, which may bypass the areas of memory associated with this type of memory deficit.
The next 2 types of memory are not super relevant to Dory’s condition, but I will just talk through them briefly, so you can have information on them.
For non-associative memory, there is something called habituation and another thing called sensitization. Habituation is the idea that, the more we experience something, the less we will have a reaction to it. We habituate to sounds all of the time. When there is background noise, it may be annoying at first, but it eventually fades away, truly, into the background.
For sensitization, it is the exact opposite. The more we experience something, the stronger our response is. So, if we keep hearing something that scares us, every time we listen again, our body will have a stronger reaction, your heart will race more, you’ll become more anxious, etc.
The last thing when it comes to memory (for now; there are actually many other things) is priming. Priming is the idea that we can unconsciously attend to something and that will guide the immediate thoughts and behaviors following it. So, if I talk about Dory, you may be more likely to think about the ocean, the beach, being forgetful, being happy, etc.
And really, maybe that is the only reason I chose to talk about Dory…so that you can be primed to feel happy.
If not, then I hope you were able to learn something about memory. I think with this knowledge, you can really start to think about why you do or don’t remember certain things and then also work toward changing that!
Until next time.
Citation: Camina, E., & Güell, F. (2017). The neuroanatomical, neurophysiological and psychological basis of memory: Current models and their origins. Frontiers in pharmacology, 8, 438.https://doi.org/10.3389/fphar.2017.00438