how to find mistakes in the multiple regression study

Hello everyone,

I'm working on eye-tracking papers related to reading. I'm currently studying this paper and trying to find mistakes they made in it.

What I'm specifically looking for is: could this study have been done in a different way & is the regression procedure correctly measured? Were the assumptions met? etc For example, I found that the number of participants may be too low for this type of study, so more could have been recruited for better outcome.

I have uploaded the full paper for you to have a look at. I'm completely in the dark when it comes to statistical data and find it incredibly hard to understand the logic of it. I would really appreciate any help or suggestion towards the solution. Only suggestions in short please, I do need to figure the rest myself but I need some ideas as find it tough to even start. :(