There are tremendous differences in how well people can navigate: some people just always get lost. This is also a serious problem in brain-damaged patients. Yet there are no tools to diagnose or treat navigation problems. Virtual reality is the solution!
Imagine you’re driving on a highway at 120 km/hr with three small children in the back. You’re going to see your friends, who you visit often. All of a sudden you have no idea where you’re going and what exit to take. The only option is to anxiously keep driving and wait until you have a hunch about how to continue.
This is what patient AC, a 36-year-old woman, experienced on a regular basis. Not surprisingly, she was first diagnosed with an anxiety disorder. Only after a thorough follow-up examination did a neurologist discover a small lesion to the right parietal cortex. This area is particularly important in processing spatial information, and damage to this area was the cause of her navigation impairment.
The impact of navigation impairment on daily life.
Patient AC was the first to spark my fascination with navigation skills. Her condition showed that even very slight brain damage can have very severe, yet also very selective cognitive consequences. Moreover, when I examined the patient, I realized there were no standardized tests that could capture her subjective reports about getting lost. It was only when I resorted to an experimental virtual reality test battery that I could pinpoint her problems to a specific aspect of navigation ability. Later studies we did showed that around 30% of mild stroke patients report having specific problems finding their way around. Moreover, there was a clear correlation with their perceived quality of life. To me, this is a powerful motivation to work on ways to reduce these problems.
Navigation ability is a complex combination of cognitive skills.
To understand and treat navigation impairment, the first step is to understand navigation ability itself. This is a difficult task, as navigation is not a unitary function. When we find our way around, many different processes take place: we perceive our surroundings, we take note of striking landmarks, we create a mental map of our environment, we memorize the route we take, and so on. It is very important to be aware of these largely separate processes, as more often than not navigation impairment is the result of impairment in just one or two of these processes. In the case of patient AC, she suffered from impairment in order memory: she was unable to reproduce the order in which she encountered landmarks on her route. This defect was so specific that she had no problem identifying those landmarks and indicating what turns she had taken at those landmarks. Still, this highly specific impairment had a major impact on her daily life.
Virtual environments are an ideal research tool.
So what can we do when standardized methods to diagnose these problems fail? Virtual reality tools are highly suitable for this type of research. On a simple computer screen, complex and realistic environments can be depicted and you can travel through these environments using just the arrow keys. Some advantages:
- It can be used in any weather conditions: hot or cold, wet or dry, the only thing you need is a computer;
- Performance is not hindered by physical limitations; patients can walk for miles on end, without getting tired;
- As a researcher, you have full control over what is presented to a patient; busy traffic or distracting sounds can easily be avoided.
One thing to bear in mind is that virtual environments are still virtual, not real. Yet our latest data show that – for both patients and healthy controls – there is substantial correlation between performance on navigation tasks in real and virtual environments. So, although virtual performance is not exactly the same as real performance, it is of substantial value.
Serious gaming as a therapeutic intervention
Once a navigation problem has been objectively identified, we want to be able to offer suitable treatment. Serious gaming – digital exercises with game-like motivational features – proves a highly suitable tool. There are a number of reasons for this:
- Virtual environments can easily be used in a gaming setting
- Relatively low costs; once a game has been developed it can be used over and over again
- Training can be very intensive, with very little time being needed from a therapist. At the same time, digital registration of training effort and performance means that therapists can closely monitor a patient’s progress.
Applying virtual reality and serious gaming in clinical practice
I am convinced that not only navigation, but also many other cognitive domains will benefit from the use of virtual reality and serious gaming. Fortunately, more researchers are starting to look into this. So it is high time to start implementing these tools as regular instruments in clinical neuropsychology.