How to turn off import image dialogue box

Hi all! I'm not sure when this started, but it's relatively new (meaning it didn't used to do this). I'm importing a bunch of tiff files into a document. And every time I import one, a dialogue box shows up. Is there a way to turn this off? I can't find it in the preferences. I'm attaching a screenshot of the dialogue box. Thank you! 

PS I did search for the answer online, but didn't find it.