So there's a few Vulcan medics kicking around some planet and Dr.Phlox is talking with them about a Vulcan/Denublian disorder. He has a colleague with whom he's been working with in the past, but it'd take five days to contact said colleague. One of the Vulcans says, "I'm afraid we'll have left here by then." Later in the same episode, some Vulcan says he "regrets to inform" someone of something. And did not Spock frequently comment on things as being "Fascinating?
Afraid? Regret? Fascination? Aren't these all emotions?
Yes, the first one is a turn of phrase and not a literal fear, but still.. it's effectively a 'regret', and regretting something is emotional. The logical way to comment upon that would be, "You can not tell us about it in five days, for we will have left by then." End of story. The logical way to 'regret' is, "I have made that mistake in the past. I shall attempt to not make it in the future. Things would have gone more efficiently if I had known I was going to make that mistake, or if I had prevented it." Now, 'fascinating' might just be a more succinct way of a Vulcan saying, "worthy of further research", but still...they don't seem to put all that much effort into making them use non-emotional turns of phrases save for that one curmudgeon they ran into pretty early on in Enterprise (Cpt.Archer: "Would you like to board our ship and meet my crew?" Vulcan: "Humans have never interested me.")
Just remembered another one.. they run into a small ship full of Vulcans who are "Vulcans without Logic" (not -really-, they're just running the same social experiment that led to the Romulan branch-off). One of them has a dad in the Vulcan High Council. When the Councilman (who is dying) finds that Enterprise is in contact with his son, he asks Archer to have his son call him back. The son says he won't because last time he talked with his highly traditional and orthodox-vulcan father, his father said, "You have brought shame to fifteen generations of this family."