Actually, thinking about it, I can do a before and after comparison. I've taught maths for 40 years, and it has always been my "thing". Before ME, I would read a long A-level question, take it all in, form a strategy (which sometimes meant answering subquestions in a different order), then answer it, checking back on the question for details. Now I have to read a question several times to make sure that I haven't misread it, and work through it step by step, answering one part at a time and checking back regularly to keep that part in my mind. It hasn't damaged my ability to solve the problems, but it has damaged my working memory.
It has also damaged my total thinking stamina. After the A-levels in June, I would sit down one weekend with perhaps 12 hours of paper in front of me and turn out specimen solutions (we used to meet up, get and give feedback from the boards), often more or less in one sitting with breaks for food. Probably about 8 hours' careful work. Now I can only work at them for an hour at a time at most, possibly two in a day.
Of course it will be put down to age. That's why so many people must dread reaching 50, as I went down with ME when I was 49, and by the summer when I was 50 I was transformed. It couldn't be the ME, could it? Or perhaps it is psychological: I have a dread of maths questions, so much so that I still do some private tuition. (What is the emoticon for - warning, cynic here?)
Perhaps that is why I find it so hard to read these scientific reports.