In our previous video — “What is Neurocognitive Testing?” — we talked about the power of neurocognitive testing. Now let’s drill down into a little more detail. How can mobile video games tell us what’s happening “under the hood”? How do they measure things like visual attention, executive function, cognitive processing, speed, memory and spatial awareness? Here are some examples of the kinds of tests that we use.
With the Flanker Test, you see an arrow that is surrounded by congruent (> > > > >) or incongruent (<< > <<) flanking arrows. All you have to do is answer which direction the center arrow is pointing — but you have to do so as quickly and accurately as possible.
Problems with brain health cause significantly longer reaction times, when compared to healthy control users, and more incorrect answers. Among other things, the Flanker Task measures your executive function — meaning your ability to squelch distractors and not just go with your impulse — which in the case that most of the arrows are pointing the other way, makes part of your brain want to give the wrong answer. And we can ferret out even more: by sometimes giving a spatial pre-cue that says where the arrow is going to be (at the top or bottom of the screen), we can further measure a very subtle issue of how quickly you can reorient your attention. The speed of that is slowed down with brain injury.
Here’s another example: Trails AB tests visual attention and task switching. The instructions are simple: you simply tap on 25 dots in their correct order, as quickly as you can. This test gives us information about your visual search speed, scanning, speed of processing, mental flexibility, and executive functioning.
And then there’s a harder version. In the next one, you have to tap on alternating letters and numbers (1 – A – 2 – B – 3 – C – …), and this, additionally, tells us how your brain is doing with task switching. Both versions of this test have strong predictive measure for mild traumatic brain injury.
Stroop Effect measures how long it takes you to overcome cognitive interference. When the name of a color (“blue,” “green,” “red”) is displayed in an incongruent color (for example, the word “red” is printed in blue), it takes you longer to select the correct word.
We measure the difference in reaction times for congruent and non-congruent color words; that is, how much longer it takes you to touch the word when it’s displayed in a different color. Again, this test takes people a significantly long time to do when they have a brain injury.
We can also measure more physical issues, like coordination, which can be impaired in the early stages of concussion. In this test, you hold the tablet in front of you and keep the ball in the circle — like a water bubble in a level. Some people are better than others at this, but the important point is that if you get something like a concussion, you can be much worse.
These are just a few of the tests we use to get a quick snapshot of brain health. We then design algorithms to combine all these scores to give us a pattern of the overall state of the brain. The signature of scores can reveal a great deal about the state of brain health that can otherwise remain quite subtle and seemingly difficult to quantify.
In our next videos, we’ll tell you about how the scoring works and how brain health can be tracked through time.