Memory
This was a post I started to write the minute I finished the Alzheimer's post, and I wasn't too pleased with it. I just got round to posting it. Try and enjoy!
Many people believe that memory is a rapid storing of information like you hitting CTRL + S to save an image to your computer, and recalling is like opening it from your file explorer. (Sorry, I hate Macs)
The truth is, it’s complex. It’s like when you try to move your mouth. It seems like one fluid motion, but in reality is 43 muscles working in conjunction. This is how your brain does it, through a process often called distributed processing.
Currently, the leading neuroscientists believe that memory is a series of complicated actions done by your brain. Basically, each memory is divvied up into several parts, such as speech, sights, sounds, sensory emotions, and such. Each part of your brain responsible for that action then encodes the parts they receive and store it for later reference.
So, imagine you are trying to remember sitting on a beach chair. Everything you see, namely the sea, (or ocean you specific people), part of your legs, hopefully some sand, some other people unless it’s winter, and the sky will be saved in your visual cortex, the people talking around you will be stored in your language areas, and such for temperature and feelings.
While recalling this information, you access that encoded data and decode it to reform that memory. That is the basic principle behind memory: instead of a file cabinet, it’s a torrent system.
Why? Well, say you want to remember stuff, but half of your brain is sliced off. Would you like to remember half of your memories or all of them just with less detail? Ignore the fact that you would die if half of your brain was cleaved off.
But wait! There’s more! There is more than a single kind of memory! There are explicit, implicit, episodic, semantic, retrospective, prospective, and short term memory.
Explicit (declarative) memory is where you consciously recall the information. It isn’t subconscious like implicit (procedural). Explicit is generally for facts, or things that can be stored and retrieved at will. An example would be knowing where the struts are on a guitar. You consciously recall that information.
Implicit memory would be like just knowing how to play the guitar itself because you’ve done it before. It’s also known as procedural due to it strengthening through repetition, known in general as LTP (long term potentiation).
Explicit memory can be divided into two types: episodic and semantic. Episodic memories are specific events from your own past, such as places you’ve been to.
Semantic is a memory that you acquire throughout your life. It may have had a personal context earlier, but now is just a placeholder for knowledge.
Semantic memory derives from episodic memory, while episodic supports semantic. The main difference is that semantic mainly occurs in the frontal and temporal cortexes, whilst episodic is mostly centered in the hippocampus, and stored in the neocortex.
Memories are scattered through the brain as stated, and are all retrieved to form an episode in the hippocampus.
An interesting subset of memory is something known as “flashbulb memory”, a memory of a particular event and its details, of an event that is particularly surprising or upsetting. These are speculated to be highly resistant to being forgotten, possibly due to the strong emotions associated with them.
Memory is important in our complex, crazy life. Without it, we wouldn't have anything we take for granted (except the earth).
science.howstuffworks.com
