I always tell my partner to stay quiet when I’m merging into a busy highway, or when it’s raining heavily.

This idea is just as bad as moving tactile controls onto a bloody touchscreen.

It’s been shown over and over again that conversing, or even simply listening to people talking, impacts other signal processing in the brain.

Here’s one

… the parietal lobe activation associated with spatial processing in the undisturbed driving task decreased by 37% when participants concurrently listened to sentences. The findings show that language comprehension performed concurrently with driving draws mental resources away from the driving and produces deterioration in driving performance…