I guess this isn't so surprising considering the holism with which the brain conducts itself. I.e. no specific functions are entirely localized to specific areas (although some areas do tend towards specialization). All or many parts of the brain are taking part in language, executive function, emotions. I always imagine it as a massive chunk of feedback loops all plastically wired together where there is the possibility for ostensibly pure 'cognitive' functionality (biased towards neocortex) to be processed in an 'emotional' (limbic) way. Hence why there's some interesting emotional/stress-related comorbidities in both ADHD and dyslexia (and in various other neurodevelopmental disorders). Obviously am not a neurobiologist but everything I've read about the topic suggests that our model of neurological ailments (i.e. DSM's strictly discrete categories) is not representative of how such things manifest neuroanatomically (more continuous & intertwined).