My brain doesn't work right anymore.
I have a traumatic brain injury and one of the many areas I have trouble with is math - an area that was once naturally easy and intuitive for me. I remember standard deviations, generally, and have read up on what they indicate broadly and how they are reached. When I was tested for my brain injury, there were some tests in which my abilities were worse than 3 SDs below the mean! [I am a professional with a master's degree, and was one of those students who aced everything with ease. This information on my current condition, however, matches pretty well, I think, my current state, post injury. I struggle greatly with many varied kinds of things.]
So far as I can recall, 1 SD is a significant enough deviation that I don't recall anyone ever talking about anything greater than 2 SDs above or below the mean. So my question is how "bad," may I ask, are scores such as: 0.7 SD below the mean, 1.7 SD below the mean, and a score of 3.2 SDs below the mean. I am asking for general but concrete advice on how to interpret these numbers generally, of course, and hold no one there responsible. I just want to better understand the significance of my scores, mathematically. The brain injury staff mince and avoid answering my questions about this, so maybe someone here will help me understand this information.