Page 55 - Use Your Memory

USE YOUR MEMORY
is that we do not so much remember as gradually forget. Encom-
passing this idea is the duplex theory of remembering and forget-
ting, which states that there are two different kinds of information
retention: long-term and short-term. For example, you have
probably experienced a different 'feeling' in the way that you recall
a telephone number that has just been given to you and the way
that you recall your own telephone number. The short-term
situation is one in which the idea is 'in' the brain but has not yet
been properly coded and is therefore more readily forgotten. In
the long-term situation the idea has been completely coded, filed
and stored, and it will probably remain there for years, if not for
life.
Research into direct brain stimulation was initiated by Dr
Wilder Penfield. In more detail: when performing craniotomies
(removal of a small section of the brain) in order to reduce
epileptic attacks, Penfield had first to remove a portion of the skull
lying over the side of the brain. Before operating, Penfield con-
ducted a systematic electrical stimulation of the open brain, and
the patient, who remained conscious, reported his experience
after each stimulation. In an early case Penfield stimulated the
temporal lobe of the brain, and the patient reported a re-created
memory of a childhood experience.
Penfield found that stimulating various areas of the cortex
produces a range of responses but that only stimulation of the
temporal lobes leads to reports of meaningful and integrated
experiences. These experiences are often complete in that when
re-created they include the colour, sound, movement and
emotional content of the original experiences.
Of particular interest in these studies is the fact that some of the
memories stimulated electrically by Penfield had been unavailable
in normal recall. In addition, the stimulated experiences seemed
to be far more specific and accurate than normal conscious recall,
which tends to be a generalisation. It was Penfield's belief that the
brain records every item to which it pays conscious attention and
that this record is basically permanent, although it may be 'forgot-
ten' in day-to-day living.
More recently, theorists have returned to a position similar to
that of Flourens, in which they are suggesting that every part of the
brain may include all memories. This model is based on hologra-
phic photography. In simple terms, a holographic photographic
plate is simply a piece of glass, which, when two laser beams are
passed through it at the right angle, reproduces a ghostly, three-
dimensional photograph. One of the amazing things about this
36