Increase Memory Power
Types of Memory
The following information is from the folks at Posit Science, who have brought you a number of world class computerized brain fitness programs, including this one.
The Increase Memory Power task: Choose a song with lyrics you enjoy but don’t have memorized. Listen to the song as many times as necessary to write down all the lyrics. Then learn to sing along. Once you’ve mastered one song, move on to another!
The reason: Developing better habits of careful listening will help you in your understanding, thinking and remembering. Reconstructing the song requires close attentional focus and an active memory. When you focus, you release the neurotransmitter acetylcholine, a brain chemical that enables plasticity and vivifies memory.
But what is “memory”? It actually takes many different forms. The biggest categories of memory are short-term (or “working”) memory and long-term memory. Both can weaken with age, or due to a variety of other reasons.
Even within short- and long-term memory, there are different categories.
We’ve described these types below.
Many Faces of Memory
Short-Term Memory Short-term memory—closely related to “working” memory—is the very short time that you keep something in mind before either dismissing it or transferring it to long-term memory. Short-term memory is shorter than you might think, lasting less than a minute. It’s what allows you to remember the first half of a sentence you hear or read long enough to make sense of the end of the sentence. But in order to store that sentence (or thought, fact, idea, word, impression, sight, or whatever else) for longer than a minute or so, it has to be transferred to long-term memory.
As we grow older, and with many cognitive conditions, our short-term memory span often becomes even shorter. This makes us more likely to have trouble keeping up with certain tasks, such as remembering which button to push in a bank’s phone menu. It also gives our brains less time to successfully move new information to long-term memory, which makes us more likely to forget details of recent events, such as a story our children tell us or instructions our doctors give us.
Many Faces of Memory
A long-term memory is anything you remember that happened more than a few minutes ago. Long-term memories aren’t all of equal strength. Stronger memories enable you to recall an event, procedure, or fact on demand—for example, that Paris is the capital of France. Weaker memories often come to mind only through prompting or reminding.
Long-term memory isn’t static, either. You do not imprint a memory and leave it as if untouched. Instead, you often revise the memory over time—perhaps by merging it with another memory or incorporating what others tell you about the memory. As a result, your memories are not strictly constant, and are not always reliable.
There are many different forms of long-term memory. The two major subdivisions are explicit and implicit (described below). Although understanding these differences is helpful, the divisions are fluid: different forms of memory often mix and mingle.
Explicit memory (also called “declarative memory”) requires conscious thought—such as recalling who came to dinner last night or naming animals that live in the rainforest. Explicit memory is what most people have in mind when they think of “memory,” and whether theirs is good or bad.
Explicit memory is often associative; your brain links memories together. For example, when you think of a word or occasion, such as a wedding, your memory can bring up a whole host of associated memories—from white dresses to dancing to a thousand other things.
Episodic memory is one type of explicit memory. Episodic memory provides us with a crucial record of our personal experiences. It is our episodic memory that allows us to remember the trip we took to Vegas, what we had for dinner last night, who told us that our friend Maryann was pregnant. Any past event in which we played a part, and which we remember as an “episode” (a scene of events) is episodic. This form of memory appears to be centered in the brain’s hippocampus—with considerable help from the cerebral cortex. To read more about this type of autobiographical memory, click here.
Long-Term— Explicit—Semantic Memory
Another type of explicit memory is semantic memory. It accounts for our “textbook learning” or general knowledge about the world. It’s what enables us to say, without knowing exactly when and where we learned, that a zebra is a striped animal, or that Paris is the major city in France. Scientists aren’t sure where semantic memory happens in the brain; some say in the hippocampus and related areas, while others think it’s widely spread throughout the brain.
As with episodic memory, semantic memory ranges from strong (recall) to weak (familiarity). Unlike episodic memory, semantic memory is better sustained over time. We are often able to retain a highly functioning semantic memory into our 60’s–after which it undergoes a slow decline.
Implicit memory (also called “nondeclarative” memory) is different from explicit memory in that it doesn’t require conscious thought. It allows you to do things by rote. This memory isn’t always easy to verbalize, since it flows effortlessly in our actions.
Procedural memory is the type of implicit memory that enables us to carry out commonly learned tasks without consciously thinking about them. It’s our “how to” knowledge. Riding a bike, tieing a shoe and washing dishes are all tasks that require procedural memory. Even what we think of as “natural” tasks, such as walking, require procedural memory.
Though we can do such tasks fairly easily, it’s often hard to verbalize exactly how we do them. Procedural memory likely uses a different part of the brain than episodic memory—with brain injuries, you can lose one ability without losing the other. That’s why a person who has experienced amnesia and forgets much about his or her personal life often retains procedural memory: how to use a fork or drive a car, for example.
Implicit memory can also come about from priming. You are “primed” by your experiences; if you have heard something very recently, or many more times than another thing, you are primed to recall it more quickly. For instance, if you were asked to name an American city that starts with the letters “Ch,” you would most likely answer Chicago, unless you have a close personal connection to or recent experience with another “Ch” city (Charlotte, Cheyenne, Charleston…) because you’ve heard about Chicago more often. In the brain, the neural pathways representing things we have experienced more often are more salient than those for things with which we have fewer experiences.
As with short-term memory, long-term memory can weaken with age or with cognitive conditions. For example, it can be harder to complete a procedure that was previously quite easy for you. You might forget a step to baking a cake you’ve baked a hundred times, and that you thought you had firmly committed to memory.
Now that you know how memory enables your life—from washing your hands to reminiscing about your child’s wedding—think about how important it is to keep your memory in top form. An effective brain fitness regimen can help.