There is no scientific evidence
that the various vitamins, minerals, pills, and other supplements that are marketed
as boosting your memory actually do so. They may be good for your health, and
they are certainly good for the pharmaceutical companies that sell them, but that
is all.
Memory is a complex phenomenon that affects
many neural circuits in the brain. These circuits are strengthened by various
types of neurotransmitters that bind to receptors, like keys that open locks.
There have been many studies on substances that can slow the memory loss associated
with certain degenerative diseases. But when you introduce an external substance
into the delicate balance of your brain’s neurotransmitters, it is more
likely to harm your memory than to improve it.
For example, caffeine
acts as a stimulant by raising the level of adrenalin in your body. In the short
run, caffeine can help you to concentrate. But in the longer run, it can also
cause anxiety and insomnia, both of which interfere with your memory.
HOW EXERCISING YOUR MEMORY STRENGTHENS IT
To excuse their memory
lapses, people sometimes cite the saying, “Memory is a faculty that forgets”.
But there is really no reason to be ashamed of forgetting things. Forgetting is
a natural phenomenon. It is even essential. In fact, the reason we forget is that
our brains are organized to eliminate anything that might clutter them up needlessly.
We forget mainly those things that were not encoded
firmly enough in our networks of nerve cells. In this respect, forgetting differs
from amnesia, which is an excessive memory
loss due to a physical injury to the brain or a psychological trauma.
There
is no magic pill you can take to improve your memory (see sidebar). But you can
improve it in the following two ways.
1) Adopt a healthy lifestyle,
and in particular get enough sleep.
Contrary to what you may
sometimes hear, you cannot learn new things while you are sleeping (for example,
by listening to an audio cassette). But you can more effectively retain the things
you learned during the day if you get a full
night’s sleep afterward.
Taking sleeping pills, however, will
not help your memory, because they reduce the time that you dream, and dreaming
is a phase of sleep that is thought to be very important for memorization.
2)
Do things that exercise your memory.
For example, reading is an excellent
way of exercising your memory, because it makes you continuously apply your attention
and your visual perception, construct mental images, organize information, and
do other things that are all essential for a good memory.
There is one form of amnesia with
which all of us are familiar, because we all experience it every night: the kind
that happens when we are asleep! While we are sleeping, many things are going
on, not only in our external environment but also in our inner world (for example,
when we have dreams or nightmares, or walk or talk in our sleep). However, most
of the time, when we wake up, we have no recollection of these activities. We
are even so used to this phenomenon that if we cannot recall what happened during
some part of the day, we are often inclined to wonder whether we had simply fallen
asleep.
TYPES OF AMNESIA
Amnesia is a major memory loss,
greater than the simple forgetting that occurs normally in everyday life.
Amnesia
can affect some areas of memory while leaving others intact. For example, it often
erases memories of the recent past while leaving those of the distant past better
preserved. Memories
of habits (procedural memory) are usually better preserved than memories
of facts and events.
Another kind of amnesia that many of us have experienced
is the kind that follows surgery under general anesthesia. For such anesthesia
to be considered successful, the patient not only must have no reaction to the
operation or to any pain involved in it, but also must not even remember any pain
or other events that occurred during it.
ANTEROGRADE AND RETROGRADE AMNESIA
When someone suffers
an accident that results in amnesia, the first thing the doctors try to determine
is whether the memories lost are of information learned before the accident, or
afterward.
If patients can no longer recall
events from their lives before the injury, they are said to have retrograde
amnesia.
But
if they can no longer acquire new memories from the time of the accident onward,
then they have anterograde amnesia.
Anterograde amnesia leads to some
strange situations. People who have it forget their doctors’ names and,
every time they see them, greet them as if they were meeting them for the first
time.
These people must use all kinds of strategems
to lead an apparently normal life. For example, they may carry around a little
notebook in which they write down what they do every day, so that if anyone asks
them about it, they can give some kind of an answer. But if, for example, they
go to a play and write down its title, when they read it back, they will not have
the slightest recollection of whether it was any good.
Various forms of amnesia can selectively affect
various types of memory, which can be classified according to their duration
or the
type of information to be recalled.
Another way of classifying
memory is according to whether it concerns things that happened in the past (retrospective
memory) or things that you need to remember that are going to happen in the future
(prospective memory).
Retrospective memories can be either semantic
or episodic. Prospective memories also can be divided into two types:
the kind that are triggered by a time cue (for instance: “Remember to go
to the doctor’s at 8:00 AM”) and the kind that are triggered by an
event cue (for instance, remembering to mail a letter when you are walking past
a mailbox). Event cues need not have any direct connection with the thing that
you want to remember, as witness the classic example: tying a piece of string
around your finger, then associating it with something that you have to do later
on.