These tests get used for all kinds of stuff, and they get used by a lot of people who don't actually know what they're doing, how to interpret the data, or whether there's any real link between what they're measuring and what they're claiming. It's why you see shit going around like "men think of women as objects because when they look at a woman, the same part of their brain is active as when they look at a tool!" and "if you play Mozart for your baby for twenty minutes then their imagination improves, we imaged the brain to prove it!" and "we found where God is in the brain! Christians have more brain activity in this region than atheists!"

There are numerous problems with this kind of science, but the most pressing issue is the validity of the scans themselves. As I said, there's a fair bit of stats to turn an MRI image into 'brain activity', and then you do even more stats on that to get your results. Bennett et. al.'s work ran one of these sorts of experiments, with one difference -- they used a dead salmon instead of living human subjects. And they got positive results. The same sort of experiment, the same methodology, the same results that people were bandying about as positive results. According to the methodology in common use, dead salmon can distinguish human facial expressions. Meaning one of two things:

Dead salmon can recognise human facial expressions. OR

Everyone else's results are garbage also, none of you have data for any of this junk.