Welcome to the 10th in our 17-part series on dementia. About 50 million people suffer from dementia worldwide. It is a debilitating disease, but it may be preventable. So I’ve set out to learn as much as I can and bring you along with me.
Thus far in the series we have talked about dementia itself, the different types, symptoms, and a little about prevention. Now I want to get into some more fundamental concepts about the brain itself. So for the next two episodes we’ll talk about this amazing organ, and today we’ll focus specifically on memory, which is affected deeply by dementia.
If you’re listening to this, you probably have at least a basic understanding of personal computers. In the simplest personal computer, most of the data or information is stored on a hard drive. Sometimes we think of the brain’s memory in the same way. There’s an area for memory and we pull it up when we need it just like opening a file on a computer. I sometimes joke, when I’m trying to remember something from long ago, that it was stored on backup tapes that had to be reloaded. But scientists now think that human memory is much more complex, and involves many areas of the brain. And, if I’m honest with you, even the earliest PC’s, even before they had hard drives, stored memory in at least three places — a floppy disk, random-access memory, and a very small chip called CMOS. But this isn’t about PC’s. It’s about the human brain…
With such a wide distribution of memory, it starts to become clear that damage to the synapses that make up the communications network in the brain, can seriously affect memory.
The process of memory involves encoding, storage and retrieval.
Encoding
Every memory contains not just an image or a bunch of words. It contains all of the information we are able to percieve, through the senses, plus emotional perceptsions as well. For example, what about the memory of a roller coaster ride you took. There is a lot of different pieces of information there:
-what the weather was like, the feeling of being cold, hot, wet
-the feel of the wind on your skin
-the sensation of changes in gravity caused by the momentum of the train
-the smell of popcorn or the grease on the wheels
-the sounds of screams of terror (or joy) of other riders as you waited in line
-nervousness or fear
-any people you may have been with, the anxiety or joy of being with them
-the colors and shapes an textures of the roller coaster, the people, the clothes you wore and they wore
-the taste of the sno-cone you wish you hadn’t eaten before getting on the ride
And more. Our brains put all these data together to form the memory. And there is a part of the brain that does this work of encoding, called the hippocampus. All of this information may not be useful, so the hippocampus along with the frontal cortex decide which information is useless and discard it. Some information may be filtered out in the sensory parts of the brain before they even get to the hippocampus. Kind of like a spam filter for email. And we can affect what we remember by how we focus or pay attention.
The information is stored all over the brain. The connections between these cells are changing all the time. The more they are used the stronger they get, which is why something you do regularly is easier to remember. When you use your brain in new ways, for example, learning to dance, new connections are formed. So … new experiences make you smarter, and improve your memory. This is why if you can add a second aspect to something, you can better remember it. Like thinking of the image of a blacksmith when you meet Mr. Smith.
Storage
Memories are stored by the senses themselves, then as short-term and long-term items. Sensory memory is only a fraction of a second. Short-term is a few times longer than that. Here’s something I experienced when I took an intelligence test a few years ago. Most people can remember no more than 7 numbers at a time. But if you can think of several numbers as a chunk, this becomes a single item. This is why telephone and social security numbers are divided into three parts.
Long term memory, scientist believe, is where information is stored after passing through short term memory. If you repeat something, or study something, that repetition secures this information into long-term memory. Information that relates to something you already know is more likely to be considered important enough for long-term memory. So if you’re an auto mechanic, information about a new model of car will be more easily remembered than if you didn’t already have experience with auto maintenance in general.
Retrieval
When you want to remember something, your brain brings it into your consciousness. This process is made easier when multiple aspects are known. I think this is like having different routes to a place you want to drive to. So if you want to remember where your car keys are. You need to have been aware of putting them on a hook or setting them on the kitchen table. Registering that in your brain will allow you to retrieve it better because you stored the act of placing them somewhere, with all the attendant properties of that, sight, sound, smell, touch, etc.
If you think you have a bad memory, it is more likely that you remember some things well, and other poorly. And the problem is most likely in the storage or retrieval processes.
What I can learn from what we talked about today, is, first of all, overall brain health is important to memory, because memory is all over the brain. Also, the more I pay attention to something, the better I will remember it, so intentionality is important. I need to decide which things are important to remember and add aspects to those things to ensure long-term storage and to aid in retrieval. Also, because remembering things about things I already know is easier, the more things I know about, the better my memory will be.
Real interesting stuff today, I think. So I hope you will REMEMBER it when you listen to our next episode, which will be about the relationship between aging and memory.
References:
Outsmart Dementia. (2020). The latest tools for controlling cognitive health — preventing dementia and Alzheimer’s disease. Morton Grove, IL: Publications International, Ltd.