One area of particular
interest, and of which our understanding is quickly growing, is that
of human memory. Our memories are astounding in their capacity --
for example, a young child learns about 10 new words each day, and
the average adult can easily develop a vocabulary including over 100,000
words. It is the evolution of our memories that has, in large part,
preserved our species. The key to our survival has been the ability
of one generation to pass along its insights, innovations, and experiences
to the next, so that they can improve upon them and progress more
quickly forward.
Human memory can
most broadly be defined as a function of the brain that gives us our
ability to store and retrieve information. Science is fairly confident
of the fact that there are many different types of memory, and many
different mechanisms for their storage and retrieval processes. There
are, potentially, as many types of memory as there are types of information
and input to remember, and so the concept of one single brain section
holding responsibility for memory has become somewhat obsolete.
In fact, there
is general agreement upon the existence of sensory memories (taste,
visual, tactile) as well as more conceptually based memories (episodic,
procedural, declarative). All of these individual memory modes can
combine to form much more complex and varied remembrances. Consider
any significant childhood memory, perhaps the first time you can remember
riding your bicycle without training wheels. During the moments in
which that memory was created, your brain was processing thousands
of pieces of information, and your memory had to decide which of those
pieces were important enough to be worth storing for later retrieval.
You might remember the emotions of fear and excitement; the tactile
sensation of wind on your arms, or of the scrape on your knee if you
fell; the sound of your mother's encouraging words; procedural information
(how to move your legs to push the pedals, the fine motor control
of steering), and episodic information like the time of day, your
age, and your general surroundings.
You probably do
not remember less-central information such as the shoes you were wearing,
or the colors of the cars parked along the curb where you rode; this
information might have entered into your short-term memory, from which
you might have been able to retrieve it for a few hours or even a
couple of days. But only that information most central to the memory
as a whole makes it into your long-term memory, where it lives for
years —possibly an entire lifetime.
The multitude
of information stored in long-term memory, and the wide variety of
types of information stored, make it difficult to believe that any
one brain structure could be solely responsible for that storage.
Indeed, most theories point towards a long-term memory system that
stores various types of remembered information in the brain areas
most closely related to it —i.e., remembered words would be stored
in the brainÕs language center, whereas a remembered sound would be
placed on a mental "shelf" somewhere near the brain's temporal
lobes, primarily responsible for hearing. Then, the billions of
interconnected neurons link these discrete pieces of a more complex
memory together, so that, when retrieved, all of the information about
that first bike ride comes to mind as a whole, rather than as a jumbled
assortment of parts.
While the brain's
hippocampus
(meaning "sea horse" because of the similarity in outwardly appearance)
seems to be more directly related than any other structure to memory,
it acts as a control center rather than a storage unit in and of itself.
It, along with the entire cortex, and possibly white-matter cells
throughout the nervous system, are generally thought to be capable
of holding memories.
How should science
quantify a memory? What is the smallest piece of a memory, and where
and how is it stored? The physical mechanisms making this intricate
process possible are still being explored, and remain little-understood.
Some theories suggest that protein particles are the building blocks
for individual pieces of memories, although science has yet to explain
how the relatively low durability of proteins can account for the
sometimes lifelong persistence of a memory. Others point to chemical
changes in individual neurons as accounting for memory as well as
other long-term, slowly-changing mental phenomenons like sense of
identity and consciousness.
How Does The Brain Work?
Start With 100 Billion Brain Cells Called
Neurons.
The brain is, by far, the most complex and mysterious organ in the
human body. Composed of over 100 billion cells called neurons, this
amazing structure is the center from which all of our skills of higher
reasoning originate -- creativity, learning, imagination, planning,
and, perhaps most notable of all, our sense of identity.
Click here to learn more about how the brain works.
Parts Of The Brain:
From Brain Stem To Cerebellum and From Cortex
To Frontal Lobe.
On a larger scale, the brain is made up of four distinct lobes
on both the left and right hemispheres. The frontal, temporal, parietal,
and occipital lobes each have primary processing functions, such
as cognition, hearing, sensory input, and vision respectively, but
they also serve act to regulate one another. Click
here to learn more about the Parts of the Brain.
Seeing Brain Function With MRI & PET Scans
A Window Into Brain Activity.
The study of brain functions has been greatly augmented in recent
years by the development of high-tech imaging techniques that allow
scientists to observe the living brain in action. Click here to learn more about MRI
and PET Scans.
What Is Consciousness?
You Are What You Remember.
Consciousness itself is clearly quite a controversial and subjective
topic. It is thought to involve both the modern neocortex found in
all higher mammals (cats, dolphins, elephants, etc) as well as certain
profoundly developed sections of the brain stem only found in humans.
Click here to learn more about
Consciousness.
CopyrightŠ 1996-2008 Compact Disc Incorporated. All rights
reserved. Memory Works, MemoryZine, Best Intentions, Nature of
Memory, Cognitive Technology, Memory Monitor, Multi Modal Model,
Memory University, Memory Workout, Memory Assessor and PMI
Practical Memory Institute are registered trademarks, and Memory
Readiness, Ask Doctor Memory, The Memory Doctor, Memory Fitness
Games, Sharper Memory, Memory Institute, Memory Health Notes,
Memory Store, Cognitive Vitality, kIosQ, New Approach to Memory
Fitness, The Source For Memory Health & Fitness and Retraining
Cognition are trademarks of Compact Disc Incorporated.
