In a recent fMRI study, a salmon was shown a series of pictures of human faces showing various emotions: can a salmon distinguish them? and what brain regions are involved. 15 pictures, ten seconds each.I won't bore you with the anatomy. Because of the small size of the brain, exact brain structures could not be distinguished, but something in the brain did light up. A statistically significant number of voxels, comprising an area of 81mm3 in the midline of the brain, were active (p<.0001).So can fish interpret human emotions from a picture? I have no idea. I do know, however, that that fish can't do it: it was dead.
It is definitely worth the time, so go read the rest of it.