If
all the data received by our senses were stored in our memory, we would soon be
overwhelmed. The subconscious sorts through the input and retains only a
fraction for permanent memory storage. Every second, the eyes absorb ten million
bits of information, the skin takes in one million bits, and the ears receive
one-hundred thousand bits. Of these millions of bits processed, only about forty
bits reach the conscious mind. Data that are not deleted are sorted and filtered
by the subconscious, then consigned to long-term memory.
The
active brain can remember things that actually did not happen or
that are not correct. The mind makes assumptions to link events. People
remember words that are implicit or not stated, with the same probability as
explicit words. Studies with fMRI have demonstrated that the same brain areas
are activated during questions and answers about both true and false events.
This may explain why false memories can seem so compelling to the individual
reporting the events.
Types of Memory
Remembering – storing memories in a memory bank, and recalling them – is a
biological process which involves dedicated brain structures as memory banks
variously specialized for different types or categories of memory function.
Knowing that memories are formed in different categories, and that they move
between categories, can help in developing strategies for improving memory and
learning.
There are two broad categories of memory: non-conscious, and conscious. The
latter includes short-term, and long-term memory.
Non-conscious memory,
takes two forms. One of these, implicit memory, automatically stores
experience and concepts and plays a role unconsciously in affecting perception.
The other form, muscle memory, plays a role in the mechanical execution
of a series of motions, as in riding a bike or playing a musical instrument,
learned through repetition over time.
Short-term memory, is the working memory. It's a place for stuff that you
need to hang on to for only a short time. Maintaining information for only a few
seconds, it enables you to remember a current thought, and so, for instance,
take part in a conversation, keep a lecture in context as it progresses, or
maintain the thread of a story or movie.
Long-term or permanent memory: The memory of the events and facts that we
can consciously recall and verbally describe. It includes that of words,
symbols, and general knowledge about our perception of the workings of the
world. Information of a personal nature, things witnessed or experienced, is
better remembered when associated with emotion.
The
brain links information on an unconscious level. You can consciously help to
maximize this effect. As you perceive new input, match it as best possible to
material already in your memory, by using images, sounds, key words, and concept
maps. A vital ingredient for memory is reviewing, and it is effective only when
done at specific times after absorbing the information. For instance after one
hour, one day, one week, and six months.
The Emotional and Thinking Brains
This
is a good juncture to explain the difference between different types of stress.
Unhealthy stress is either too low or too high. Healthy stress is often just
called a challenge. Frequently, the distinction is conditional on how much
control we perceive that we have over the stressor. In challenging situations,
the body releases chemicals such as adrenaline and norepinephrine. These enhance
learning by increasing motivation, sharpening our perceptions, and even
strengthening our body. On the other hand, unhealthy stress raises alarms all
over the body by releasing cortisol, the survival hormone. In this book, I use
the word stress to refer to unhealthy stress.
Neuroscientist Joseph LeDoux discovered a particular relationship and
interaction between the emotional and thinking brains, and identified the neural
pathways that carry information from the senses to the brain. Information
entering through the eyes or ears goes first to the thalamus, which acts as a
sorting area to assign different information to different parts of the brain. It
compares new data with existing information and decides whether to compress,
absorb, or ignore the new input. If the incoming information is emotional, the
thalamus sends out two signals. With survival a priority concern, the first
signal goes to the emotional brain (limbic system, specifically, the amygdala),
and the second to the thinking brain (neocortex). This means that the
emotional brain has the information first and, in the event of an emergency, can
react before the thinking brain has even received the information and had an
opportunity to consider options.
In
such a case, the amygdala sends instructions to the lower reptilian brain to
flood the body with stress hormones. There are more neural connections going
from the limbic emotional center to the neocortex than vice versa.
With continued arousal of the amygdala, it is difficult to break out of the
resulting fight or flight cycle. So reason does not rule, and we are left
hanging in the middle of a crisis.
The
hippocampus helps create long-term memory by assigning data to different parts
of the brain. For example, the names of natural things such as vegetation and
wildlife are stored in one part of the brain, while man-made items such as cars
and furniture are retained elsewhere. Likewise, the event, or what happened, and
its meaning are laid down in separate parts of the brain.
Emotion drives attention which, in turn, drives memory. James McGaugh, PhD, of
the University of California at Irvine, said, "We believe that the brain takes
advantage of the chemicals released during stress and powerful emotions to
regulate the strength of storage of the memory." Journalist Jill Neimark said,
"A memory associated with emotionally charged information gets seared into the
brain."
It is the management of emotions that gives learners greater command over their
learning.
Although the brain thrives on challenge and complexity, its primary drive is
survival. It needs to survive socially, economically, emotionally, and
physically. The brain is pre-wired to learn and, if optimum conditions are not
present, employees may learn to fear change in the workplace, and
students may learn to fear subjects like math. Overwhelming stress has a
detrimental effect. Researchers have evidence that high stress experienced by a
pregnant woman can distress the fetus, resulting in learning difficulties for
the child later in life. Among infants and toddlers, high and chronic levels of
stress can make learning more difficult, perhaps even shrinking the part of the
brain associated with memory.
Tips to Remembering
Imagine that I recite a list to you of thirty items. I then ask you to write
them down after I finish. You would remember things that are:
at the beginning
of the list
UnUsUaL
repeated, repeated
at the end of the list
The
first and last items are known as primacy and recency. Every study
session has them. If you study for one hour, then take a break, you get one of
each. If you study for twenty-five minutes, take a short break, then study
another twenty-five minutes. You get double the primacy and recency events. How
great is that?
Memory is not stored in a single location in the brain. It is deconstructed
and distributed all over the cortex. The emotional content is stored in the
amygdala, visual images in the occipital lobes, memory of the source in the
frontal lobes, and venue is stored in the parietal lobes. Remembering is
actually an act of reconstruction.
Memory Decay,
or loss of remembered events, is a natural phenomenon as new experiences
displace existing memories. You can easily counteract this loss of learned
material through periodic review. Review can facilitate the preservation of at
least 80 percent of your learned material. Without a systematic review process,
the material evaporates to a 20 percent retention level.
A
greater variety of input streams from eyes, ears, tactile, and emotion allow for
more pathways to exist for dynamic reconstruction, thus creating richer memory.
Multi-modal instruction makes a lot of sense. Accelerated Learning addresses the
need.
To
get a handle on just how unlimited our ability to learn is, multiply the number
of neurons (10 billion) by the number of branch spines (10 million) by the
number of dendrite spiny protuberances possible on each spine (100 million). The
result indicates how many new connections are possible when learning. Using this
size font, the answer is a 1 followed by zeros that extend for some 6.2
million miles!
The capacity of our memory is virtually unlimited.