No it's not. 6-4 is possible if you mapped out when it turns Green. If you know the pattern of it, you can condition yourself to react earlier. If a person is truly average at reacting to it, but they know when it will turn green, they can burn their reaction "lag" before or right as it is turning green and get a higher score.
The only reason I bring it up is because the timing is not random; if you had a truly random timing that would be null and it would more accurately measure how well you can react. This test however is not random (or the range it has is quite small), making it easier for someone to do that.
In that case, it wouldn't be an accurate representation of how fast you can truly react, I just simply mentioned that you can get your score lower if you know how to play the system. Same as how you can study for IQ tests and possibly get inflated results because you know what they will ask you.
The only reason I bring it up is because the timing is not random; if you had a truly random timing that would be null and it would more accurately measure how well you can react. This test however is not random (or the range it has is quite small), making it easier for someone to do that.
In that case, it wouldn't be an accurate representation of how fast you can truly react, I just simply mentioned that you can get your score lower if you know how to play the system. Same as how you can study for IQ tests and possibly get inflated results because you know what they will ask you.