17 February 2011 

Studying memory provides clues for helping the brain

Some studies have suggested that older HIV-positive adults can have mild to moderate deficits in what brain researchers call “working memory.” According to neuropsychologist and associate professor of psychiatry Steven Woods, PsyD, who teaches at the University of California at San Diego, a centre for excellence in neuroAIDS, working memory refers to “the ability to hold, store and manipulate information in the brain.” Deficits in working memory may play a major role in some of the neurocognitive dysfunction seen in some HIV-positive adults.

While conducting a cross-sectional study with HIV-positive people, Dr. Woods and colleagues unexpectedly found that some older HIV-positive adults had better assessments of working memory than younger HIV-positive adults. Specifically, it appeared that some older participants had developed strategies, either deliberately or inadvertently, to help them remember the locations of a series of visual designs. By comparison, older HIV-positive individuals who did not use strategies were far more likely than younger HIV-positive persons to make working memory errors. 

Remembering visual designs might seem trivial to non-scientists, but for neuropsychologists and other scientists who study the brain, these tests provide important insight into memory.

Dr. Woods’ team was intrigued by how effective spontaneous memory strategy use was in the older adults and suspected that some older HIV-positive people somehow gained insight into their memory problems and found ways to compensate. This suggests that it is possible to help HIV-positive people who have a mild-to-moderate degree of neurocognitive impairment to overcome these difficulties.

Ideally it would have been best to have conducted a randomized controlled clinical trial that recruited both HIV-positive and HIV-negative people for purposes of comparison. However, the findings by Dr. Woods’ colleagues are exciting because they document that the brains of older HIV-positive people may be able to develop effective strategies to compensate for some aspects of HIV-related neurocognitive impairment.

What’s next?

Rehabilitation programs for the brains of HIV-negative people who have suffered traumatic brain injury from accidents or strokes have been developed. Some of these programs have been found to be successful in randomized clinical trials.

However, most otherwise-healthy HIV-positive people who take potent anti-HIV therapy (commonly called ART or HAART) do not have such a serious degree of cognitive impairment as someone who has injured their head in a car accident or had a stroke. So existing brain rehabilitation programs need to be adapted and tested to meet the needs of HIV-positive people.

There are also so-called brain training exercises that have been developed to help older HIV-negative adults improve and restore their ability to use language and numbers. In an interview with CATIE News, Dr. Woods notes that brain training programs have not yet been formally tested with large numbers of HIV-positive people with mild cognitive impairment. He makes the following points:

“It is not clear if such exercises can correct or compensate for the specific effects of HIV infection on the brain. Data are lacking for us to know if early use of these programs in people without HIV-related cognitive impairment will delay the onset of these problems.”

Until such data do become available, Dr. Woods says that brain training exercises, crossword puzzles, jigsaw puzzles and numeracy games such as Sudoku represent “a low-risk investment, as for most HIV-positive people these exercises will not be harmful.”

As more HIV-positive people are aging, they and their doctors are concerned about the possibility of accelerated decline of the brain. Neuroscientists are studying memory and higher intellectual functioning to try to find ways to help HIV-positive people better cope with the effects of aging. Expect to hear results from these studies in the next several years.


For additional information about improving brain health in the setting of HIV, see “A Mind of Her Own” by activist Maggie Atkinson in the winter 2010 issue of CATIE’s Positive Side magazine at:

                                                                                                            —Sean R. Hosein


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