We all have a dual process memory, and in many cases it’s fantastic. It allows us to gather interesting information when we are not even aware of it. One part of our memory can critically focus on important tasks, while another part seems to just randomly chime in with nonsense information. We’ve all had those nagging interrupting thoughts before, but the important question a psychologist asks is what evolutionary purpose does this serve, or how exactly does this function?
Well let’s attempt to answer this question as I want to bring up new topics about it in the future. For Valentine’s Day, I will be writing a special post entitled “What is love – you fill that basal ganglia shaped hole in my heart!
Our first memory process is called the explicit memory (aka episodic memory). This memory type is facilitated by your hippocampus for the most part. When events occur and enter the short term memory, they can move further into longer term memory if the hippocampus hasn’t been beaten to death with too much alcohol. Yeah that’s right kiddos. When you drink to much you actually shut down your hippocampus and you end up with a memory black out. You can’t have a very good memory without your hippocampus can you?
This episodic memory allows you to recall the events as if you were bringing them up on a T.V. station. Random little clips here and there. The sight, the smell of things, but they never seem quite perfect. We typically remember the “configuration” of things. For example, I can recount the mourning of september 11th. I doubt my recount is accurate, but I remember how things felt. Such as I walked into the class room and people were just standing around the T.V. No one said a word, we all just watched. It felt like we were all staring at the screen with glazed looks on our faces unable to believe what was happening. I can only tell you that is how the memory feels to me, but I cannot say, for example, how many people where there, what exactly was being talked about by the news anchor and which classmates were standing next to me. The content of the experience is more important than the detail, at least to our survival. Wait what does that mean? Well if you go to a location and you get attack by an animal, you only need to recall the negative feelings associated with the location due to threat and pain, but not recall many teeth the lion had.
Implicit memory! Implicit memory (or procedural memory) functions on an entirely different level. If Frued were around, he’d want to call it “The Id” and also take a lot of undo credit for it. But that mad man is dead, so let’s move on! Our implicit memories are facilitated by the Basal Ganglia! It sounds scary, but don’t worry. It’s really neat!
The basal ganglia stores information at a much faster rate than the hippocampus because the hippocampus requires information to be within your attention for you to learn of something. This means that explicit memory needs to function in concert with your senses, then your prefrontal cortex (the home of working memory and attention) and then finally move back to the mid-brain where it can go to the hippocampus. The Basal Ganglia doesn’t need to send anything to the prefrontal cortex at all! It’s pretty insane.
So your basal ganglia stores information at a rate faster than 30ms. This is evident because priming studies use images that appear at this 30ms rate, and people are affected by them, however they have no conscious recollection of seeing the images. This means their basal ganglia detects it, but their prefrontal cortex does not. It takes too long for things to be processed through the prefrontal cortex! There is a big problem, though. We lack the ability to think about information in our implicit memory. Implicit memories get stored abd affect our behavior (see topics like subliminal priming) but we do not realize they are affecting us at all. For the computer programmers out there, this would be called “write only memory.” Memory that gets added to a system, but the user may not view this information. Explicit memory can be brought back into the working memory and changed if you learn something new about an event later on. Explicitt memories are infinitely changable, while implicit memories are not!!!
So what does this mean? We live in two different worlds at the same time. Most of the time they are quite similar. One world is pretty slow paced; the other one is constantly being encoded at a much faster rate. Also, we have no way to filter what our basal ganglia encodes!! It will just record everything we experience. That’s why I can’t have my T.V. on in the background any more. All those food commercials just make it harder to stick to a healthy diet. A constant barrage of meat covered in cheese all day long makes it really tough to stay on track.
So in summation, our hippocampus allows us to have memories of events in vivid detail (at times) while our basal ganglia lets us learn associates between items through repeated exposure. The basal ganglia also records most everything it senses, not just what we want it to. So treat your brain like an environment and your home is its habitat. What subliminal messages will you allow yourself to be exposed to? Ones from the media? Ones from the web? Or perhaps surround yourself with stimuli that will allow you to continue on the path you have already chosen for yourself!