When we talk about memory, we mean not only all that we remember but also our capacity for remembering.
So writes Aaron Nelson at the beginning of chapter 1 in his book The Harvard Medical School Guide to Achieving Optimal Memory.
Think about what it is you tend to remember. Most likely, if your memory is fairly typical, you tend to remember items and events that are important to you. The information is important because you need the facts or because there is some emotional pull or because you make use of certain processes to accomplish certain tasks. Did you know that each time you reference a memory, it can get altered, because your memories are not static.
Our memory apparatus consists of two components – short-term and long-term. Their names simply designate the duration of the memory.
Short-term memory can hold a string of 5 to 7 items, is what you make use of when you only need to briefly reference something, and dissipates quickly, especially if you are interrupted in the process of using it.
You’ve probably heard of working memory, either as being the same as, or a form of, short-term memory. Nelson explains working memory as a more sophisticated part of short-term memory, in that it is used to hold onto information necessary for a “specific purpose” and, once used, as with the rest of short-term memory, it can be discarded.
Long-term memory, as its name suggests, is of a much longer duration. In fact, it stretches way back to your childhood, and is like a bottomless well in what it can hold, though not everything in long-term memory remains there forever. The kinds of memories you hold onto for the long-term include Declarative (also called Explicit) and Procedural.
DECLARATIVE (EXPLICIT) –> EPISODIC & SEMANTIC
Declarative memory is more susceptible to aging and illness because memories of this type are stored in the hippocampus, which gets a bum deal as it ages, and is particularly hard hit by diseases such as Alzheimer’s.
Your episodic memories “are linked to events that occurred at specific times and in specific places” (like episodes in a television series that air on certain dates), whereas your semantic memories (like words and their meanings) are those items that you just “know”, but would be hard pressed to detail when or where you learned them. These memories consist of facts and meanings.
This last type of memory consists of “the skills and routines that you draw on automatically to perform actions” as part of functioning as a person. Nelson writes that “Even people with Alzheimer’s disease can perform many routine tasks until the advanced stage of the illness. Scientists believe that procedural memory is robust because it is stored widely throughout the brain [including the frontal lobes, cerebellum, and basal ganglia] and because it is not dependent upon the hippocampus, one of the memory structures within the brain that is particularly vulnerable to the effects of normal aging.”
Did you know that what is good for your body is good for your brain? Taking care of your body is taking care of your brain. (Yes, it bears repeating!) In my next post, some practical advice from Dr Nelson.
Further resources about Memory:
- KidsHealth – Memory matters
- Neuroscience For Kids – Memory Experiments
- Neuroscience For Kids – Alzheimer’s Disease
- Exploratorium Memory exhibition