Impairments in Working Memory after a TBI
People who suffer from a
traumatic brain injury (TBI) often notice that their memory is not as good after the accident
as it was before the accident. One post-TBI memory problem is amnesia.
There are two types of amnesia: retrograde amnesia, which involves losing
memories of events that occurred before the accident, and anterograde
amnesia, involving the loss of memories of events that occurred after
the accident. It is common when the brain experiences trauma to lose memories
around the time of the accident. As you recover from your TBI, you will
most likely find that memories from before the accident will come back.
However, in the longer term, you may find it difficult to form new memories.
Contrary to what we see in the movies, anterograde amnesia after a TBI
is much more common than retrograde amnesia. In this article, we will
focus on specific problems that cause anterograde amnesia—difficulties
in storing new information after the TBI.
Working memory involves the immediate storage and manipulation of new
information for a variety of cognitive skills, such as learning, problem
solving, planning/organizing, and active listening. Working memory is
like a chalkboard in the brain—memories are stored in the very short-term
and can be quickly erased or overwritten if needed. If the information
coming into working memory is important – for instance, if you know
that you will need to remember a name or directions – you may rehearse
that information, moving it from your working memory process and into
short-term or long-term memory.
Working memory is vulnerable after a TBI, and can cause many problems
when trying to recall even the important information you want to remember.
For instance, while talking to a friend who says she is going to college
in Maine, you may ask her a few minutes later where she is going to college,
forgetting that she already told you moments ago. You may find it difficult
to keep track of what everyone is saying in a conversation or to follow
the plot of a TV show. This can be understandably embarrassing, and often
a person who has working memory problems after a TBI will learn to cover
up those problems by using other people’s facial expressions to
guess the right answer, or simply nodding in agreement.
Since working memory is integral to everyday life and essential for returning
to work or school, it is a good idea to see a neuropsychologist, who can
test you to find out what types of memory you have issues with and make
recommendations on how to help. Some speech pathologists also specialize
in memory and will figure out what memory strategies are the best for
you, and help you practice using them.
There are two main types of memory strategies: internal (which happen
in your own head) or external. Examples of internal strategies are using
visual imagery, associations, or chunking (breaking things down into small
units) to better hold onto information coming into working memory. Examples
of external strategies including using a planner to keep track of your
schedule and stay organized, reminder applications on your phone, and
computer-assisted training tools. Many find that a combination of both
internal and external strategies helps compensate/overcome memory difficulties.
Ask your doctor about getting a referral to neuropsychological or neurological
testing and see if a memory specialist can help develop a treatment plan
that is best for you.
In contrast to working memory, long-term memories, like recalling your
10th birthday party, are not commonly impaired in TBI. However, you may
experience memory retrieval problems of verbal long-term memory, called
anomic aphasia. This means you have trouble coming up with the word for
what you are trying to say. You “know” it, but not aren’t
able to think of the word, or it’s on the tip of your tongue. Luckily,
speech pathologists are trained in helping you overcome anomic aphasia
with specific strategies and therapies, such as Circumlocution Induced
Naming Therapy and visual aids. Again, a referral to a specialist can
be tremendously helpful in your recovery.
There are other things you can do to make sure your memory is the best
it can be. Sleep and fatigue have a huge impact on memory. Post-TBI sleep
disorders are very common, so it is important to talk to your doctor about
what to do to have a normal sleeping pattern. Learning is usually best
in the morning, when you are more alert, than later in the day, when you
may be fatigued. Certain drugs, like caffeine and nicotine, can affect
your sleep and are discouraged after a TBI. Some medications, like prescription
painkillers, can also affect sleep and ability to concentrate. You might
notice that it is difficult to do multiple things at once because it is
hard to remember everything you are doing. All of these issues are important
to consider when addressing memory problems.
While memory problems post-TBI can be very frustrating, there are a number
of treatments and therapies designed to help, as well as things you can
practice at home to make your memory more functional. Memory problems
vary from person to person, so make sure you get a personalized treatment
plan from your doctor to help with your specific memory difficulties.