The unbearable lightness of being a dead salmon

Oh my god, how many salmon died by my hands during my Odell Lake sessions?

The neuroscientist Gregory Burns describes how he used functional MRI scans to show that dogs have similar basic emotional reactions to humans roughly equivalent to a level of sentience of a human child:

In dogs, we found that activity in the caudate increased in response to hand signals indicating food. The caudate also activated to the smells of familiar humans. And in preliminary tests, it activated to the return of an owner who had momentarily stepped out of view. Do these findings prove that dogs love us? Not quite. But many of the same things that activate the human caudate, which are associated with positive emotions, also activate the dog caudate. Neuroscientists call this a functional homology, and it may be an indication of canine emotions.

The ability to experience positive emotions, like love and attachment, would mean that dogs have a level of sentience comparable to that of a human child. And this ability suggests a rethinking of how we treat dogs.

Interesting. I'm not so sure that sentience is a necessary prerequisite for the humane treatment of animals, but it certainly would add weight to them oral argument.

Except I'm not so sure I believe the result. So I had a quick look at the study and it appears this entire result is based off of just two dogs, and the statistically significant increase in caudate activity appears to be restricted to a specific point in time after the test (so while the caudate activity seems to be significant X seconds after, it doesn't appear to be significant X-1 or X+1 seconds after, which does raise some suspicions that the researchers cherry-picked the results ). The presence of similar activity in two dogs does bolster the result somewhat.... but come on, two dogs?

This might be a good time to bring up the famous dead salmon study again. fMRI studies are known for being particularly dodgy on the statistical inference front. A few years ago a group of Dartmouth scientists highlighted this point when they put a dead Atlantic salmon in a fMRI, showed it pictures of humans, and managed to get a statistically significant emotional response.

You see, fMRI is apparently a particular noisy way of measuring brain activity, so it's fairly easy to throw up false positives, especially given the unit of analysis is essentially a voxel. The Dartmouth study revealed what happens when you don't make simple corrections to account for this. Now, Burn's study did make these corrections, so we can't quite claim that dead salmon have a similar level of sentience to dogs. Still, we should be somewhat sceptical of an fMRI result until it is replicated again.