Canadian research on brain rehabilitation

Researchers in Toronto and Calgary, led by University of Toronto neuroscience professor Sean Rourke, PhD,  have been studying how HIV affects the brain and ways to improve the health of this vital organ. Their interim findings suggest that brain fitness exercises can help the brains of some HIV-positive people.

Study details

Researchers recruited 50 HIV-positive volunteers from major hospitals and clinics in Toronto. Volunteers did not have histories of significant substance use, impaired hearing or psychosis. Volunteers with a history of depression were allowed into the study.

Once in the study, participants had their neurocognitive functions assessed, then underwent a 10-week brain fitness program (more about that below) and on completion of the program had their neurocognitive functions assessed again.

The computer-based brain fitness program, developed by Posit Science, includes six exercises, each 15 minutes in length. These exercises help to challenge the brain, specifically aiming to increase the speed and accuracy at which this organ processes information. According to Professor Rourke, these exercises “build on each other so you get more challenging ones as you become more successful.”

Prior to starting the brain training exercises, all participants received a one-hour tutorial about how to do the exercises.

As part of the study, participants were asked to do the following:

  • about 30 to 45 minutes of brain fitness exercises each day, for five days each week, for eight consecutive weeks

So far 17 participants have completed the study and we focus on their results below.

The average profile of these 17 participants was as follows:

  • age – 55 years
  • gender – all males
  • years of education – 16
  • proportion that was unemployed or retired – 77%
  • years since HIV diagnosis – 19
  • taking ART – 16 participants
  • proportion of ART users with a viral load less than 50 copies/ml – 100%
  • adherent to ART within the past four days – 13 participants
  • proportion with a history of having a CD4+ count less than 200 cells – 87%


Researchers reviewed the neurocognitive assessments of the 17 participants who completed the study and placed 15 of them into the following three categories of HIV-associated neurocognitive disorders (HAND):

  • neurocognitively normal – five people
  • mild neurocognitive disorder – six people
  • HIV-associated dementia – four people

Two of the 17 participants who were symptom-free were excluded from this initial analysis

Results—After brain fitness exercises

After regular engagement of brain fitness exercises over eight weeks, researchers found that improvements in symptoms of cognitive problems occurred in all groups, though the most significant changes appeared in participants who entered the study with a mild degree of neurocognitive impairment.

Here are the overall trends in each group:

  • Among participants who were neurocognitively normal, there was a small and non-significant increase in neurocognitive functioning.
  • Among participants with mild neurocognitive disorder, overall neurocognitive scores rose sharply, approaching scores seen in people who were neurocognitively normal. These changes were statistically significant, that is, not likely due to chance alone.
  • Among participants with dementia, neurocognitive scores increased sharply but did not reach those seen in neurocognitively normal people.

In perspective

This Canadian study achieved several important results, as follows:

  • It is the first Canadian study to “evaluate and demonstrate the potential benefits of brain fitness exercises for neurocognitive impairment in HIV, over and above the contribution of ART,” states lead investigator Sean Rourke, PhD, and colleagues.
  • Although the present study is relatively small, several areas of improvement were documented, including different aspects of memory (working memory, verbal learning memory and visual memory). Furthermore, it provides the rationale for a larger study.
  • According to Professor Rourke, an important finding was that the burden of cognitive symptoms experienced by participants fell between 30% and 50%.  This was significant because it gave people renewed hope and self-confidence about viewing and coping with their condition. This is important because it means that people feel that they can re-engage with and participate in society. In turn, this re-engagement with the outside world will likely improve participants’ outlook on life and their sense of mental and emotional well-being.
  • The researchers note that their results so far suggest that HIV-positive people who have been diagnosed with mild neurocognitive disorders “may benefit more from brain fitness [exercises] than those with HIV-associated dementia.”

Bear in mind

The results of the Canadian study should be treated as interim but extremely promising. Only results from some participants are currently available, but there will be more data in the future. The Canadian study paves the way for more complex, larger and longer studies that seek to understand ways of improving brain health for HIV-positive people.

Moving forward

Professor Rourke is planning to conduct a larger study comparing the impact of the following interventions with HIV-positive people:

  • brain fitness exercises
  • mindfulness-based cognitive therapy
  • psycho-educational tools – sudoku, crossword puzzles, etc

Rourke would also like to explore the role of exercise on neurocognitive functioning. As mentioned earlier in this issue of TreatmentUpdate, exercise can have many health benefits, particularly on the brain. One of Rourke’s ideas is about the timing of exercise. His theory is that engaging in physical exercise for several weeks improves the flow of blood throughout the brain (and body) and also stimulates the brain to produce the brain-derived neurotropic factor (BDNF). This protein is associated with improvements in memory in some studies. After this period of physical exercise, participants can then begin brain fitness exercises. Rourke theorizes that this combination of exercise and brain fitness training could have a greater, more beneficial impact on neurocognitive functioning than either intervention alone.

Rourke would also like to conduct a study of magnetic resonance imaging (MRI) of the brain to assess the impact exercise might have on changes to blood vessels within this organ. This would better help researchers understand the impact of both physical and brain fitness exercises on the brain.

Rourke states that it is likely that a combination of interventions—such as physical exercise and brain fitness training—will be needed to help maintain and improve brain health in HIV-positive people. He also notes that understanding the lived experiences of HIV-positive people as they find strategies to successfully deal with neurocognitive impairment can help guide scientists in devising ways to help heal the brain.


We thank Professor Sean Rourke for his helpful discussion, research assistance and expert review.

—Sean R. Hosein


  1. Rourke SB, Rachlis A, Gill MJ, et al. The benefits of Posit Science brain fitness exercises for neurocognitive impairment in men with HIV: Pilot results from a ten-week cognitive rehabilitation intervention study. In: 23rd Annual Canadian Conference on HIV/AIDS Research, St. John’s Newfoundland. 2 May 2014. Abstract O039.
  2. Mapstone M, Hilton TN, Yang H, et al.  Poor aerobic fitness may contribute to cognitive decline in HIV-infected older adults. Aging and Disease. 2013 Aug 27;4(6):311-9.
  3. Fazeli PL, Woods SP, Heaton RK, et al. An active lifestyle is associated with better neurocognitive functioning in adults living with HIV infection. Journal of Neurovirology. 2014 Jun;20(3):233-42.