by Ruth Beran
After a stroke, survivors often have visible impairments like lack of movement or slurred speech, but often more subtle functions like their memory are also affected.
“In the good old days when you had a stroke or some sort of brain injury we looked at purely your motor skills rehabilitation, so that you could walk. And we used to think that cognitive rehabilitation was not possible,” says Moffat Mathews from the University of Canterbury. “Now we’re finding out through different studies round the world that the brain does in fact repair itself. Even if one part is not repaired as we expect it to, we are able to find different ways of using the brain so that we can remember things.”
Moffat is part of the Intelligent Computer Tutoring Group which is finding similar results from a study using a virtual reality environment they have developed for training stroke survivors to improve their prospective memory.
Prospective memory is remembering to do things in the future, like take a pot of the stove once it’s boiled. “In order to be able to remember something to do in the future you have to be able to remember in the first place,” says Prof Tanja Mitrovic. “So you have to have relatively good working memory and also retrospective memory in order to remember things in the future.”
From left to right: Tanja Mitrovic and Moffat Mathews; the virtual reality environment on a computer with Kris Wilson behind the joystick and Jay Holland assisting her Photo: RNZ / Ruth Beran
Tanja explains that the memory training consists of 10 sessions. “So in the first session they have to undergo a lot of tests, so we have a psychologist who administers the tests, looking at working memory and prospective memory and other aspects of cognition.”
Then participants are tested again after two weeks to ensure their prospective memory is relatively stable. Then they begin training to assist in memorising things better.
“We show them pictures and teach them how to combine pictures and make them memorable and make them unique and funny or challenging for themselves so that they can memorise them better,” she says. “Then after that we give them videos to train on and then finally the virtual reality environment.”
The virtual reality environment is a 3D house which contains several objects that participants can interact with, like an iron, kettle, piano, radio or cell phone.
“So we start off by giving the participant the list of tasks,” says Jay Holland. “Such as: at 5.36pm draw the curtains, once you’ve heard the racing results feed the fish, when your cell phone battery becomes low charge your cell phone, things like that.”
The participant gets five minutes to memorise the tasks, with as many as nine tasks to remember in later problems.
Kris Wilson is a participant who suffered a stroke 3.5 years ago in the occipital lobe, or back of the brain which means she doesn’t look like she’s had a stroke but her memory has been severely affected. She recently completed the programme and feels that despite being challenged, the training has helped her memory.
“When you have a brain injury and you have serious issues with short term memory, you could remember one minute and not remember it the next. Some days are good, some days not so good. It all depends on your stroke,” she says. “I cannot work because of the stroke. And I can’t work because I can’t trust what I remember and what I can do, so if I could improve my memory so that I would be able to become employed that would be really good.”
Kris has found that the whole training process has helped her look at things differently, and provided her with strategies to better remember things.
“I feel that I’ve learned strategies that I’ve taken on board that I try to remember to use,” she says.
The team have conducted studies with young people with no brain injury, people over 50 years old with no brain injury, and stroke survivors. For the young people, there was no difference.
“That’s kind of what we expected as well, their prospective memory is good, they’re able to use it, they don’t need any rehabilitation,” says Moffat.
For the elderly with no stroke, there was some difference in the prospective memory after the study.
“With stroke patients currently we’re finding a significant improvement in their prospective memory over the time of the study, and the study runs for about ten weeks,” says Moffat.
Since this story was recorded, the team has analysed more results and found the same significant improvement.
For Moffat though, this isn’t just about the research.
“This actually affects people’s lives,” he says. “It affects their feelings of self-worth. It affects whether or not they feel like they’re wanted or needed in their family or their community. It affects whether they feel like they’re a burden to other people.”
Eventually, the training programme may be made available in people’s homes but there is still a lot more research to do before that happens.
