This free Information Age Education Newsletter is written by David
Moursund and Bob Sylwester, and produced by Ken Loge. The newsletter is
one component of the Information Age Education project. See http://iae-pedia.org/
and the end of this newsletter.
Bottleneck in Your Brain
“The important thing in science is not so much to
obtain new facts as to discover new ways of thinking about them.” (Sir
William Henry Bragg; British physicist and chemist who uniquely shared
the Nobel Prize in Physics with his son, William Lawrence Bragg, in
This issue of the IAE Newsletter focuses on a human brain’s working
memory. Working memory is used to retain and manipulate information
during a short period of time. This ability underlies complex reasoning
as well as other complex activities such as reading and understanding a
sentence or a paragraph. Working memory performs executive functions,
directing other parts of the brain to carry out various activities.
Torkel Klingberg (Ph.D. and M.D.) is a prolific researcher and writer
on working memory and attention. He is a professor in cognitive
neuroscience at the Karolinsky Institute in Stockholm, Sweden. Much of
the content of this newsletter is drawn from his recent book
A Very Simplified Brain Model
Here is a simplified model of a human brain. Senses such as sight and
hearing bring in an immense amount of information. Some of this is
ignored, some goes into your subconscious where it is processed at a
subconscious level, and some goes into your working memory. What goes
into your working memory depends considerably on your focus of
attention. Working memory and attention are closely related.
Your working memory directs various other parts of your brain to
process the incoming information that you are paying attention to. Much
of this processing is done in a highly automated manner, using the
procedural and episodic parts of your long-term memory. For example,
with little conscious effort, you can interpret meaning from a simple
sentence you are reading or a simple utterance you are hearing.
However, if the sentence or utterance is long and complex, your working
memory must remember pieces of it in order to give direction to the
rest of your brain in extracting meaning from the various interrelated
Your brain contains a very large amount of long-term memory, but it has
a very small amount of working memory. More than 50 years ago George
Miller (1956) published his seminal paper, The magical number seven,
plus or minus two: Some limits on our capacity for processing
. Since then there has been considerable research on
quite limited—seven plus or minus two or perhaps a little less—capacity
of working memory.
In this simplified brain model, working memory is a bottleneck. If it
were larger, our overall brain would be more capable. We would be able
to focus attention on more different things at one time, and we would
be able to direct active thinking on more different things at one time.
Multitasking has received a lot of attention in recent years.
Multitasking is a situation in which attention and use of working
memory are simultaneously focusing on two or more different tasks. A
computer with two or more central processing units provides an analogy.
Each CPU is able to function with considerable independence. Multiple
CPUs make possible a certain type of multitasking and thus can increase
the total productivity of a computer system. However, the hardware and
software must resolve conflicts as different CPUs draw from and/or
change the same pieces of information in the computer’s memory.
Part of the research on human working memory has focused on dual
tasking—that is, working on two tasks at the same time. A variety of
research tools have been developed to measure the effectiveness of
working memory in directing overall brain processing on two
simultaneous tasks. As an example, research has been done on the dual
task of driving a car and using a cell phone. The driving task requires
paying attention to visual inputs as well as sounds such as horns and
sirens. The cell phone task requires paying attention to voice input
and constructing responses to this input. If the cell phone is not a
hands-free, voice activated system, using it can place still more
demands on the phone side of the dual tasking.
Research—as well as lots of empirical data from traffic accidents—has
provided good insight into how this set of dual tasks overloads working
memory, leading to degradation in accomplishing each of the tasks.
Degradation in the driving task leads to an increased chance of traffic
accidents. Degradation in cell phone communicating may lead to poor
Torkel Klingberg’s book explains how one’s total productivity can be
increased by dual tasking. As a simple example, consider listening to
music while reading a book. The music proceeds as a set pace, while you
can increase or decrease your reading speed and glance back to a part
previously read if you feel you have missed an important detail.
If both the music listening and the reading are being done mostly
for pleasure and entertainment, then this dual processing essentially
achieves two in the time of one, so may increase your total pleasure.
However, suppose that you are listening to the music in order to do a
careful analysis of the style, quality of the music, quality of
performance, and so on, while you are reading a textbook in order to
understand and learn its content. Now you will experience degradation
in accomplishing each task.
Torkel Klingberg’s book includes a brief discussion of multitasking
capabilities of women versus men. He notes that the research literature
suggests “no significant difference.”
The Flynn Effect
Quoting from Graham and Plucker (2002):
In his study of IQ tests scores for different
populations over the past sixty years, James R. Flynn discovered that
IQ scores increased from one generation to the next for all of the
countries for which data existed. This interesting phenomena has
been called "the Flynn Effect." Many of the questions about why this
effect occurs have not yet been answered by researchers.
Torkel Klingberg’s book suggests that the increasing IQ is due to
improvements in working memory. He argues that day-to-day life in our
world has forced people to deal with more complex problems and with a
greater volume of information. He also notes that some of our forms of
entertainment have added to this increased demand on our working
memory. For example, many movies and TV programs now include several
different, interwoven strands in their stories. Many novels now include
several different but interwoven strands. The stories and possible
actions in computer games have become more complex. These and other
changes over the past 70 years place increased demands on working
memory. The plasticity of working memory leads to improved performance
of working memory and long-term memory. This, in turn, leads to
increased scores on IQ tests.
Of course, this past 70 years is not enough time for significant change
to have occurred in the genetic makeup of the brain. So, in terms of
nature versus nurture, the change is due to nurture. Note, however, the
combination of epigenetics and cognitive development is a rapidly
growing area of study and research. See
epigenetics has shown us that environment can turn certain genes on or
off, and such a switch in a gene’s activity can be passed on from one
generation to the next.
Increasing Working Memory
It has long been known that a brain has considerable plasticity.
Learning changes one’s brain. Active use of what one has learned
preserves and strengthens the neural connections that constitute the
Klingberg and other researchers have asked the question, “Does working
memory have a type of plasticity so that it can be improved through
appropriate interventions?” The book discusses two types of research
Computers and Chunking
- A variety of working memory exercises have been developed that
can be used to produce long-term improvements in working memory. This
is true both in discipline-specific areas (for example, mental math
problem-solving exercises leading to improvements in the math-oriented
capabilities of working memory) and discipline-independent exercises
leading to improvements that cut across disciplines. For example, see
Posit Science at http://www.positscience.com/science.
- Drugs exist that improve executive and attentional functions of
working memory processes. Examples include caffeine and Ritalin, as
well as a number of drugs being developed to help deal with Alzheimer’s
and other brain diseases. Ritalin is widely used with ADHD students,
but it has an equal effect on the working memory of non-ADHD people.
Working memory can only deal with about a half-dozen chunks of
information at one time. However, a chunk can be quite a few individual
pieces of information. For example, suppose you are math oriented and
have memorized the value of pi to 10 decimal places. A friend
tells you his phone number is 314-159-2653. Aha! The first ten digits
of pi. You just remember the chunk that your friend’s phone number is
Suppose that you have a phone that stores phone numbers based on
two-letter combinations. The single chunk PJ (nick name or
initials) is all you need to remember to access the person Paula Jones.
Now, carry that idea over to the very large number of problems that
a computer can solve. What you need to recall from memory is a chunk
that identifies a particular program. Suppose, for example, that you
are analyzing a set of data that is in a spreadsheet on a computer. You
need to figure out what these data mean. A relevant computer chunk
might be “I know how to use the Excel spreadsheet program to graph a
set of data.” You multitask as you continue to hold the overall problem
in mind and at the same time tell the spreadsheet program to graph a
specific part of your data.
In some sense, this graphing activity is like using the procedural
part of your brain, except you are using the procedural part of a
computer brain. You tell it to carry out a procedure that you “know” it
knows how to do, and it does it. Contrast this with doing such a
graphing task by hand. The by-hand approach can easily require all of
the capabilities of your working memory and may well lead you to
forgetting the original problem or why you are graphing the data.
Research on brain plasticity and training the brain, research on
various drugs, and steady increases in computer capabilities are giving
us tools to help deal with the limitations of working memory. All three
of these approaches are appropriate topics for teachers and their
students to know about and for curriculum developers to take into
Graham, Charles and Plucker, Jonathan (2002).
The Flynn effect. Human Intelligence.
Retrieved 5/5/2010 from
Klingberg, Torkel (2009). The overflowing brain:
and the limits of working memory. Oxford University Press. A number of
Klingberg’s papers are available online at
Miller, George A. (1956). The magical number
seven, plus or minus two:
Some limits on our capacity for processing information. The
Psychological Review, 1956, vol. 63, pp. 81-97. Retrieved
About Information Age
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