Dogs are (like) people. Blobs are not feelings.

I saw this article in the New York Times, by Emory researcher Gregory Berns, come up on my newsfeeds in the last several days, and I've gotten emails about it from friends and family. After thinking it over, I couldn't let it pass without comment.

As anyone I know could tell you, I am a dog person. To an unhealthy extent.

Don't look, Vincent...
via Lostpedia

• The only time I cared about anyone in Lost was when the dog Vincent tried desperately -- and ultimately in vain -- to follow his human friend Dawson, who was leaving the island on a raft, into the ocean.
• If there is a dog at a party, I will begrudgingly leave it for a few minutes at a stretch to interact with my human friends. I would rather just lie on the floor with it, in whatever clothes I'm wearing, and pick up its vibe.
• I will also play with it until parts of my body stop working, and usually only when somebody points out that fact out of concern for my continued health.

So when I initially saw Berns' article, and the subject it broached, I was pleased! Yes, I say, let's consider the question of whether dogs are people. Personally, I think that's too simple a proposition to capture the truth, but we'll get to that.

The bottom line of my reaction is this: I appreciate what the article was trying to do -- and unlike a lot of scientists I know I don't say this next bit a lot, because popularizing science isn't always bad -- but I found it really inappropriate in tone, scope and scientific content.

The elements of neural activation Berns was citing basically correspond to evidence of pleasure, reward and motivation. (My friend Ryan, who works on animal behavior in rats, points out that regardless of what they actually can do, the dogs in question weren't demonstrating "love and attachment," they were demonstrating "preference.") The caudate, which is part of a structural assembly called the striatum, interfaces with some of the evolutionarily oldest structures in the mammalian brain. As per the experiments on drugs and rats in a recent post, these areas -- while varied in their exact purposes and connectivity profiles -- largely support the dopamine-powered "reward" circuit, technically called the mesocorticolimbic pathway. I'm not an expert on it, and I'm fuzzy on the caudate's specific role within the circuit, but Ryan agrees Berns' attribution to it of such nuanced emotions (much less personhood) is an overreach.

Yes, it's swirly. Brains are weird. via Brainposts

In a very crude sense this circuit is the reason we do anything -- without integrating a sense of motivation and anticipation of reward into our value judgments, we'd be so apathetic we wouldn't bother to eat, and we'd just die. It's also the circuit implicated in drug addiction, or for that matter, *anything* addiction. In many cases, the kinds of things that circuitry is responsible for are the impulses we actually need to fight to be considered persons, at least in the conventional moral sense. If you've heard the phrase "he was behaving like an animal," there's reason to believe the culprit was, colloquially speaking, letting his striatum drive the car unsupervised.

If anything, what we need to show dogs are people is indication of "higher" functions, or whatever you want to call them.

Side note: personally, I think the moral significance of living beings occurs on a sliding scale, where a goldfish registers and its well-being is worth something, but isn't equal to a person; and a dog is closer to people but generally comes up slightly short (though sometimes very slightly... and maybe there's some overlap, with dogs I'd choose to keep alive at somebody else's expense). Some other blog post I'll explain how I see this as consistent with Giulio Tononi's work on consciousness. Other scientists, including my one-time boss Julian Paul Keenan and his mentor Gordon Gallup, have considered the value of using self-consciousness (as determined by the ability to understand the significance of one's own reflection in a mirror) for one of the criteria of "personhood." The point is there are a lot of ways of approaching this problem, and few of them are simple, which stems from the simple fact that people are complex. (*snap*)

Complexity. Deal with it.
via WiffleGif

Anyway... if we hypothetically bought Berns' reasoning, i.e. that evidence of comparable activation patterns in comparable cognitive paradigms is evidence of comparable function, and thus personhood (which can get a bit fishy), I argue we'd need a lot more and better benchmarks. We'd need dorsolateral prefrontal cortical activity, indicating self-control and abstract thinking. We'd need ventromedial prefrontal activity, and insula, maybe anterior cingulate -- or their homologues, anyway -- corresponding with complex emotional responses, especially social ones like guilt and empathy, being part of dogs' decision-making processes. After all, these are among the things people say separate us from animals.

All four areas -- ventral striatum (VS), ventromedial prefrontal cortex (vmPFC), insula (INS), and anterior cingulate cortex (ACC) in one handy, murderous image.
Front of head is to the right. via PLoS ONE, h/t Al Fin.

But we probably shouldn't buy Berns' reasoning. That's because:

1. If you're going to try to build homologues, most of the time mammalian brains -- which are, after all, like a series of iPod models with incremental improvements -- will roughly line up, so you'll have something to compare. It's really a question of how developed and interconnected those areas are. Or at least, we know it'll probably be a combination of tricky things.
2. Dogs are generally going to be able to do, and show activation in, a lot of the simple tasks we use in humans, simply because making really sophisticated experimental designs to probe thinking and feeling is complicated. Neuroscientists and psychologists have to constantly refine and revise experiments to ask more and more specific questions.
3. Dogs don't have parts of their brains that don't work. NOTHING does. Brains don't have areas that can't be made to "light up" under the right circumstances. If we did, those traits would be selected against in evolution, because we'd be burning calories with useless brain matter that we could've used for something else. (Next time somebody says we only use 10% of our brains, hit 'em with that.)

Judges? Bzzzzzzzzzzzt.

via rebloggy

So ultimately, this is like... well, it fails to expand on anything we don't already know about dogs from just hanging out with them, for the most part. Except that there are some commonalities in what areas do what things, which we always would have expected to see. And on top of that, Berns used one of the relatively few structures, outside of sensory areas, that we couldn't use to persuasively argue that dogs share some of the most important aspects of personhood.

And just to wax advocate for a moment here, the sentence "by looking directly at their brains and bypassing the constraints of behaviorism..." makes Ryan, generally a very peaceful person, very inclined to violence. Without behavioral research, we wouldn't know (or continue to learn) about what makes animals AND people behave the way we do, and how our brains work that magic. Nobody is saying we should all think of people like Skinner thought of rats. The only thing imaging provides in this context is a more global perspective on neural activation patterns during that behavior. And I'm an imaging person saying that!

Look, lots of people criticize neuroimaging researchers for vastly overreaching in their claims based on relatively fuzzy, and difficult to interpret, imaging data, and this is a perfect example of that. So while I in large part agree with the premise of the article, I completely disagree with how Berns arrived at it, and how he depicted the science that brought him to that conclusion. I'm pretty disappointed with the article as a high-profile outreach on behalf of the science community.

Next time, maybe I won't have to be so ruff on him.

Yes, I'm here all week.

Rat Park: Science Caper or Curio?

caruba via flickr, h/t to Joe Kloc

Funny that this was the thing that got me back to my blog after an extended hiatus (though I've got like 4 drafts 80% done in the pipeline, waiting for polish). Procrastination can work wonders.

My friend Ryan, a fellow neuroscience grad student working on reward, motivation, and addiction using a rat model, pointed me to this blog post. The writer is Tom Stafford, one of the two authors of the popular science book Mind Hacks, and a researcher at the University of Sheffield. The post recapped a series of studies conducted in the '70's by Bruce Alexander and colleagues at Simon Fraser University, in which they built their test rats a large, well-furnished playpen, then tried to replicate classic drug addiction studies.

What they found, as Stafford describes, surprised them -- the rats living socially in the open, enriching pen actually avoided drinking water laced with morphine, instead of consuming the drug to the exclusion of nearly all other behavior. Stafford also points readers to this comic by Stuart McMillen that illustrates the story. Stafford then concludes the post by musing, among other things, that "even addictions can be thought of using the same theories we use to think about other choices, there isn’t a special exception for drug-related choices."

Okay, so. We've got a lot of crazy ideas kicking around here, so let's take this slow.

First off -- while I haven't read Mind Hacks, Stafford appears to be a pretty accomplished researcher, and my default position is to be glad that people are writing fun science books unless and until I have reason to suspect they're doing more harm than good. After all, I wouldn't have heard about this if not for his post. McMillen's comics likewise seem fun and clever, and remind me of a more serious counterpart to nerdy staples like The Oatmeal or Saturday Morning Breakfast Cereal. (If you haven't seen these -- not to even speak of XKCD -- run, don't walk, to way funner and smarter nerd porn than anything I've done yet. Go ahead, close this tab.)

With that out of the way, I'm... not placated by the story here. There are a number of reasons for this. In order of increasing discomfort, here they are:

(Note: apologies for linking to academic papers. I know many would-be readers don't have access to them. If you're affiliated with a University, try searching for them using your library's website; if not, try to reach out to somebody you know who is.)

1. While the role of context and social structure in drug abuse is still not a big enough issue, it isn't anything new either. Drug addicts who enter rehab clinics, get clean, then go right back to their old stomping grounds are surrounded by people and paraphernalia that remind them of their temptation, which can undo all their progress. Going beyond addiction, behavior of all kinds can be triggered almost automagically just by finding yourself in familiar settings -- as anybody who's moved and then started to drive home to the wrong house can attest. And I can't even begin to broach the social science literature on the influences of socioeconomic status, education, access to healthcare, etc. on propensity for drug use (here's just one example out of hundreds). So implying the ideas derived from this study should rewrite the rules on addiction is a sizable overstatement.
2. The biggest question-mark in this article, and the statement that I think needs the most gratuitous linkage, reads "There have been criticisms of the study’s design and the few attempts that have been made to replicate the results have been mixed" [emphasis added]. The fact that literally the subsequent sentence hand-waves that away -- "Nonetheless the research does demonstrate that the standard “exposure model” of addiction is woefully incomplete," -- using such strong language to criticize a whole field seems, to me at least, way off-base. You don't say a model (even a simple one constituting only part of prevailing theories on drug use) is "woefully incomplete" because of a 40-year-old paper with replicability issues, and you certainly don't say that without at least pointing readers to those attempts to replicate.*
3. To say that rats could be put in any environment where they'd stop taking drugs entirely, given a choice and even encouragement, is a seriously bold claim; or at least it is today. In the decades since those studies were conducted, rats have been -- beg pardon, for folks who have concerns about the ethics of animal research -- tested on every drug under the sun and given practically any task imaginable, and a huge portion of those results have translated pretty well into human findings. An entire literature has emerged on the science of reward and addiction, a field in which Ryan and his mentors, Brian Baldo and previously Kent Berridge, are participants. And we've got pretty solid ideas about the systems in the brain where these behaviors are generated. So it would require more than a little replication to validate those claims.
4. Most unsettlingly, there seem to be some oddities about the experiments and the way they're being presented. Correct me here, dear readers, if I missed something.

• In McMillen's comic, he writes that Alexander et al. "covered the floor with fragrant cedar shavings for the rats to nest in". When Ryan and I read that, we Macaulay Culkin'd so hard: cedar is toxic.



quicheisinsane via flickr

• Here's an example of one such finding. A 1997 review of bedding materials in labs around the world found that pine shavings were extremely cytotoxic compared to corncob, straws and other materials. In fact, a paper published as early as 1968 -- that's almost a decade before the Rat Park experiments -- found cedarwood to be a bad environment. If it's true, then, that the bedding was cedar, then Houston, we have a problem.
• Even more confusing, the paper linked to in Stafford's post said the floor of the pen was sawdust -- different, but still linked with a few major respiratory problems. So was McMillen reading a different paper? Did the research team use different bedding systems in their different studies? It looks like the latter, based on this 1981 study that mentions cedar shavings. (Once again, though, since I'm not an expert I don't know how these problematic conditions would affect the results; they just add a lot of uncertainty, and speak to the possibility that there were unaddressed or as-yet-unknown problems in their methods.)
• *For the interested, here's a thesis published in 1985 that suggests that "during a colony conversion the supplier inadvertently introduced strain differences making the present rats more resistant to xenobiotic consumption." It's only one non-replication, but even so I didn't have an easy time finding it.

So in general, the post made me a little uncomfortable at times, and the study did too. When it comes to a topic as stigmatized as drugs, there are always people with pet opinions looking for validation; so while nobody should be hushed, everybody should try to speak carefully. Implying that we can think of drug use as a totally non-compulsive act, and therefore subject to the same moral culpability as all other actions, is a proposition the neuro and psych communities have spent years and years trying to overcome. Drug courts, which have experienced so much success as alternatives to prison, were only made possible by thinking about addiction as a problem to fix, not a sin to punish.

To say otherwise -- to put all that progress at risk -- should not be done lightly.