i haven't had any split brain operation done or anything but my personal experience as someone with dissociative identity disorder is that i can usually tell which parts are more left or right brained based on how they react to everyday events

for our particular brain , the logical ones usually have immediate reactions that suck (like borderline personality disorder) and the emotional ones tend to have mish mash wordses feelings

(idk how to write that it's like words-es, the s at the end is very gender for emotional feelings words so all of them tend to have it)