How are “memories” stored in the brain?

I am watching Through the Wormhole with Morgan Freeman. It’s an interesting show. One of the things scientists are wondering in this episode is how the brain is built, how it stores information, and how we remember the things we see, taste, hear, smell, and feel. Well, I hate to act like a know it all, but… well…

It’s seems very simple to me. We all remember certain events very vividly. Why? Because that event meant something to us. Let’s say a person you love surprises you with cookies after school. You might remember their face at that point in time, the smell of the cookies, the facts like the weather, the season, the month, maybe even the day or hour. You remember the feeling, the sights, the smells, the sound of this special person’s voice. It is a very vivid memory because it meant something to you. It was very personal. It stirred up personal feelings towards someone. So, you remember this event very well.

What about the other day when you walked down the hallway and picked up your shoe… Then walked back to your bedroom, grabbed the other shoe, and put them on… Then had a bowl of cereal before getting into the car and making that 1 hour drive to work… again…? Do you remember everything in a morning like that? I think you think you do, but I don’t think you really do.

How does your brain store information? The same way still frames are stored in an MPEG video file. The information in the frames which stands out is stored as special information. Everything else, such as a blue sky in a 5 minute scene, is stored as the same information and simply used over and over again in each frame of the video. Only the areas of the video which change are stored as separate, special information.

I think this is how the brain stores information. The structure of my house is stored in my brain. It never changes. Many things in my house don’t move. Other things in my house move around, and still others are shuffled about from here to there. The things like my walls are stored in my memory almost permanently. They don’t change, so my brain doesn’t bother “remembering” their position for every point in my day compared to what it was I was doing. My brain has simply memorized where my walls are, and this data is compared to what I may have been doing in a virtual reality sort-of-way.

This is why people who move repeatedly make turns towards their old house. They’re brain has not re-written the information for their house. The location of the old house is almost hard-wired into the brain. This is also how you manage to drive home late at night only to realize you don’t remember driving the whole way…

Anyway, the special things that happen in your life are the things which are stored in memory separately. The normal, everyday things are not really stored in each and every memory, but rather stored away to be pulled out when the brain marks an event as happening in a stored location. And those everyday, un-memorable occurances? YouTube.

Sorry, technically, YouTube videos, which are converted into Flash Video formats, follow the same rules as MPEG videos. The stuff that changes is stored as significant and the stuff that doesn’t change from frame to frame is only stored once. However, the YouTube site, or rather visiting the YouTube site, is similar to short term memory. You watch a YouTube video, it makes you laugh, you might pass it on or show it to other people, but then it fades into oblivion. Same thing with your brain. We have what is called short-term memory and long-term memory. Those short-term memories stick around in your brain like every other memory – until your brain decides it’s not important and breaks it up into little pieces. These pieces are compared to other information already stored in the brain and the pieces which match well enough are considered the same, and thus only stored once.

This compression is combined with a huge database that keeps track of the comression process. For instance, your brain might remember bits and pieces from your 10th birthday. It would correlate these bits and pieces, through the database, with the spacial memory of your house. The brain would do all of this for the sights you see, the smells you smell, the sounds you hear, the surfaces, temperatures, pains, and pleasures you feel, and the foods and drinks you taste.

And its not continuous memories. It’s all stored with compression.

“So does this mean our brain can’t hold as much as we thought it could?”

How should I know. I’m not a scientist.