Visual distractions cause memory overload
Too many visual distractions
may affect our ability to
concentrate, says a report published in Science (2001;291:1803-
6). Excess visual input fills up
working memory, the process in
which information is temporarily stored in the brain. The
amount of free working memory
affects the level of concentration, so as the memory fills up it
becomes more difficult to ignore
distractions.
"Our findings suggest that,
especially in an environment in
which visual distraction is likely,
it is crucial that mental processing resources are available for
excluding potentially interfering
information," says Dr Jan de
Fockert, one of the report's
authors. "When working memory is occupied, our brains cannot
filter out distracting visual
information."
In the study volunteers
were asked to remember
a sequence of numbers,
while being distracted
by celebrity images. The
more numbers the volunteers were asked to remember, the more difficult it
became to ignore the visual
distractions. Functional magnetic resonance imaging was
used to measure brain activity while the study's participants performed the
attention and memory
tasks. Analysis revealed different areas in the frontal cortex,
which related to the amount of
strain being placed on the working memory. The areas in the
brain that are believed to be
associated with face image processing showed greater activity
under conditions of high working memory, implying that visual distraction was greater the
more the working memory was
occupied.
Dr de Fockert pointed out
that visual distractions and
straining the working memory
were integral features of everyday life. "For example,
when driving a car in busy traffic, a demanding conversation
on a mobile phone will reduce
the availability of working memory for excluding distracting
information, such as billboards
along the road. These distractions compete for attention and
reduce task performance."
Although it has not been
proved that watching Eastenders
will prevent you from doing
effective anatomy revision, Dr de
Fockert advises that you should
"try to avoid taxing mental tasks
when dealing with visual environments that include distracting objects." He went on to
instruct, "Do not engage in deep
thought or demanding conversation when driving."
Siān Knight, London
studentBMJ 2001;09:85-128 April ISSN 0966-6494
