Friday, June 21, 2013

Short- and Long-term memory

Anyone who has done much in the way of computer shopping, knows that there are two types of memory: memory (RAM) and disk space. Memory is the working memory of the system and is akin to raw brain power (though processor speed plays a big role here too); this memory will often hold the application you are running as well as much of the file you are working on. It can hold the processing algorithms of a high-end RPG, or all the pixels of the image you are editing as well as the Photoshop program you are editing in. A computer with poor RAM will be slow regardless of the speed of the processor--a processor can only process what is in the RAM.

Computers also need large disk drives; these not only are used for storage space for projects and applications that are not currently in use, but it also acts as a memory vault for active processes. For example, a program bumping up against the limits of its RAM, will temporarily write some of its thoughts to the drive, then pick them back up moments later when they are needed. Applications are constantly writing to and pulling things off the hard disk, from clip art, to subroutines, to macros, to the textile textures for a character's BUDs in Call of Duty.

The human brain also has two types of memory, which we have come to know as long-term and short-term memory.

Unlike computers, which can have gigabytes of short-term memory (RAM,) the human brain can only hold about three things in its working memory at one time. In other words, humans have pathetic RAM capabilities.

If our RAM is poor, how do we go about thinking and synthesizing? How do we process our information?

The answer is packets.

When a child is a baby, their packets are small: they may begin to understand that the sound of the word “cat” refers to that thing that is soft and warm, and moves about the house, and sometimes makes them laugh. Soon, they learn to read and associate the written word “cat” with the word they already know how to say and with their pet, “Fluffy.” They begin to associate everything about their own cat, the cats they see at other people’s houses, the zoo, on TV, or in books with the word “cat.” Tigers, lions, bobcats, panthers, etc. all become part of the cat-packet. At some point they learn that "CAT" is also a type of medical scan, or a type of edible fish, a burglar, a way of moving, a type of eye shape, etc. If they grow up to be geeks, "CAT-5" will have its own meanings and associations. (If they’re DC-style geeks, they will have Selena Kyle; if Marvel, Kitty Pryde.) Their cat-packet grows and grows.

By the time a person is 30, the word "cat" has become a massive packet of information and experiences. These memories and associations are stored in our long-term memory—to our hard disk. When they read the word or when it comes up in conversation, the word triggers access to all these associations. We don’t have to upload everything from our cat-packet on our hard drive up into our working memory, just the word alone allows us to proceed. As the conversation progresses, the association that meets the needs of the moment comes to the fore and rises to our active memory.

In this way, our brains summarize what we know. This summarization allows us to hold huge amounts of information at the ready, even when we can only think of three things at a time. However, it really only works for the things we have in long-term storage, which makes having a lot of things in long term storage important. Knowledge turns out to be key.

In this, ED Hirsch has (again) been a pioneer. As a chemistry graduate student, he wondered why some of his students seemed to grasp new information quickly, while others struggled. Looking into it, he realized that the students who learned quickly had more background knowledge—more information in long-term memory—than the students who had greater difficulty. The better students had information in ready-to-go packets, which they could pull out and use to understand the new material.

In a famous example of Hirsch’s, he would show people an excerpt from the sports pages, detailing a complicated baseball play. Words such as A-Rod, five-three-two, shortstop, etc. can’t be understood by someone who doesn’t know much about baseball. But such words bring the play to dramatic life to someone who is in the know. Not only do baseball people know exactly what the article is saying, they learn new information from it and can add it to their baseball-packet. Without a good baseball-packet to begin with, nothing new can be learned.

As another example, I used the term “RPG” above. If you didn’t know what that was, you wouldn’t have had a clue what I meant (role-playing game.) However, to someone who knows, they could envision everything from Dungeons and Dragons to Grand Theft Auto to Pokemon. While one person’s RPG-packet could be tiny, another person’s could include the experiences of years of game play.

To apply this to education, it takes knowledge to gain knowledge. Learning is easier the more you can retain in long-term storage and summarize into packets. Not only is learning easier, but the 21st-Century skills of understanding, applying, and analysis become easier too. In fact, you can’t really analyze something if you don’t know it.

From the link: (kitchen table math, the sequel: why students have to memorize things)
If our schools are going to ask students to 'think' about material they haven't learned, students are going to be thinking about 3 to 5 small, not-well-elaborated items at a time. Period. Their thinking will be superficial, and the conclusions they reach will be superficial, too.
Schools have downplayed knowledge in favor of trying to get kids to think. But you can’t think without knowledge. As a result, we have stranded our kids in no-mans-land and left them with no tools at all.

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