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.