Updated June 17, 2015.

Common changes in thinking and mental processing associated with chemotherapy include what is called executive functioning—the wherewithal to do certain things that usually come naturally to us, provided we are healthy and we’ve had enough sleep. Executive functioning includes judgment, hindsight and foresight, processing speed or reaction time, working memory, and organizational skills. Interestingly, these are some of the same areas affected in individuals with attention deficit hyperactivity disorder, or ADHD.


Working Memory

Working memory describes the ability to keep several ideas in focus, in the forefront of the mind, all at the same time. People can memorize a nearly infinite number of facts, but none of us can handle more than a few items or chunks of information at a time. For example, we might forget to buy stamps at the grocery checkout, even though we planned to do so earlier in the day. That plan was no longer in our working memory.

Working memory might also be a factor in some reading disabilities, since it controls the ability to recall words read earlier in a sentence.

In the doctor's office, the mental status exam is used to assess your immediate and working memory. You might be asked, for instance, to do a digit span, or listen to a series of numbers, hold them in your head and repeat them back.

Can You Improve Your Working Memory?

The answer appears to be yes, depending on the type of workout you give your brain--and also depending on your capacity to train. Scientists don’t yet know for sure whether strategies for aging adults also might help those with chemobrain, but there are reasons to believe this may be true.

Physical activity and cognitive training seem to help people with many different conditions that affect memory, and these tools may also pan out for people with chemobrain.

In a study of older adults with memory loss, but not dementia, a “brain-workout” program over 10 weeks resulted in improved performance. Some improvements were still found five years later. The workout program was a combination of encouraging physical activity and providing an instruction manual of sorts, with memory tools, structured items to help with setting and reaching goals, and also quite a bit of following up by phone to keep study participants on track.

Does Working Memory Have Limits?

The late George Miller, PhD, psychology professor at Princeton University, studied working memory. He found that most people can’t recall lists of numbers when they get beyond seven digits. Interestingly, people who could do more than seven digits had not fought a battle with the brain and won; rather, they used the brain’s natural design, tending to consolidate groups of numbers or letters into fewer memory slots—a process called "chunking."

One example of this process is the string of letters, "FBICIA.” People familiar with U.S. intelligence agencies only "spend" two chunks of memory rather than six for the six letters, so they seem to recall more letters in all. In recent years, scientiests downsized our working memory limits from seven to somewhere between one and four chunks of information--the downgrade was due to new techniques that prevent people from doing the FBI-CIA trick.

Chemobrain Research

Data on chemobrain are very limited. There is still quite a bit of debate about how much exercising--and exercising your mind--can help various conditions that are associated with impaired memory and cognition, but there is reason for optimism.

Researchers have looked at adults with stroke, young adults without ADHD, children with traumatic brain injuries, and, according to one investigator, the general pattern has been that, as long as you have working-memory problems and you have the ability to train, you can improve your abilities.

Sources

Management of Chemotherapy Induced Cognitive Impairment. http://www.oncolink.org/resources/article.cfm?id=1057. Accessed December 2014.

American Psychological Association. A workout for working memory. http://www.apa.org/monitor/sep05/workout.aspx. Accessed December 2014.