On stuttering.

On stuttering.

CaptureDuring his first year of graduate school at Harvard, a friend of mine was trying to pick a research advisor.  This is a pretty big deal — barring disaster, whoever you choose will have a great deal of control over your life for the next five to eight years.

My friend found someone who seemed reasonable.  The dude was conducting research in an exciting field.  He seemed personable.  Or, well, he seemed human, which can be what passes for personable among research professors at top-tier universities.  But while my friend and the putative advisor-to-be were talking, they got onto the topic of molecular dynamics simulations.

My friend mentioned that his schoolmate’s father studies simulations of cellular membranes.  And that guy, the father, is incredibly intelligent and very friendly — when I showed up at a wedding too broke for a hotel, he let me sleep on the floor of the room he’d booked for himself and his wife.

But the putative advisor corrected my friend when he mentioned the guy’s name.  “Oh, you mean duh, duh, duh, duh, Doctor ________.”  And smiled, as though my friend was going to chuckle too.

stutter_by_visualtextproject-d49ak0vThat’s when my friend realized, okay, I don’t wanna talk to you no more.  He found a different advisor.  He never regretted his choice.

Well, no, that’s not true.  All graduate students regret their choice of advisor sometimes.  But my friend never wished he’d worked for the jerk.

Yes, some people, with a huge amount of effort and probably an equal measure of luck, are able to get over stuttering.  But most can’t.  So it’s crummy that even well-educated, ostensibly sophisticated people would feel entitled to mock somebody for a stutter.  Presumably even that jerk would’ve refrained from an equivalent comment if my friend’s schoolmate’s father was blind or confined to a wheelchair.

But stuttering, along with a few other conditions like depression and obsessive compulsive disorder, still gets treated like a moral failing.  Like a sufferer should be able to try harder and just get over it.

That attitude is especially bad as regards stuttering, because mockery and castigation seems to make the condition worse.  There are genetic factors that confer a predilection toward stuttering, but (unpublished, evil) work from Dr. Wendell Johnson showed that sufficiently vituperative abuse can cause children of any genetic background to become stutterers.

CaptureYou’ve read about the “monster” study, right?  Dr. Johnson stuttered, and he had a theory that his stuttering had been exacerbated by people’s well-meaning attempts to cure him.  His parents would correct his speech, draw attention to his mistakes, exhort him to be more mindful when talking.  Dr. Johnson thought that the undue attention placed on his speech patterns made him more likely to freeze up and stutter.  And, once that cycle had begun, his brain dug itself into a rut.  He began to castigate himself for his mistakes, perpetuating the condition.

Of course, that was just a theory.  To test it, you’d want to show two things.  First, that by not paying attention to the mistakes of an incipient stutterer, you can help that person evade or cure the condition.  And, second, that you could cause well-spoken people to develop stutters by convincing them and their interlocutors that they already were stuttering, and castigating them for it.

It’s totally ethical to conduct the first experiment.  The process itself would cause no harm, and the intention is to improve someone’s life.  If you can help someone get over a stutter, you’ll smooth future social interactions.  Stave off some mockery from colleagues at Harvard.  That sort of thing.

But the second experiment?  The process is miserable for the study subjects — you’re cutting them off all the time, criticizing them, forcing them to say things over and over until their thoughts are expressed perfectly.  And, worse, if you succeed, you’ve saddled them with burdens they’ll have to deal with for the rest of their lives.  Let the mockery commence!

CaptureDr. Johnson made one of his students conduct that second experiment on six orphaned children.  In the end, none of the children developed the syllabic repetition typical of most stutterers, but they became extremely self-conscious and reluctant to speak — symptoms that stayed with them for the rest of their lives.

Indeed, the symptoms triggered in those children are equivalent to the symptoms monitored for a stuttering model in mice.  One of the genetic factors associated with stuttering was recreated in mice, and those mice exhibited a condition somewhat analogous to human stuttering.

Dr. Dolittle did not participate in this new study, which made matters much more difficult for Barnes & colleagues.  If you don’t know what a mouse is saying, how do you know whether it’s studying?  They did measure variance from one vocalization to the next — in humans, repeating the initial syllable of a word lowers total syllabic variance — and saw that their mice with the stuttering gene repeated sounds more often.

Their best measurements, though, were the rate of squeaking, and the length of pauses between squeaks.  Like an oft-badgered child, the mice with the stuttering gene talked less and spent more time waiting, maybe thinking, between statements.

And it pleases me, given my pre-existing biases, to see more data showing that, if somebody stutters, it’s not that person’s fault.  Genetic predilection certainly isn’t the same thing as destiny, but it’s a nice corrective to the mocking jerks.  Sure, you can speak fine, Mister Mockingpants, but are you fighting against the current of a lysosomal targeting mutation?

(Oh, right, sorry, my mistake. Doctor Mockingpants. You jerk.)

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Capturep.s. As it happens, the mutation Barnes et al. introduced into mice is involved in the pathway I studied for my thesis work.  They introduced a mutation in the Gnptab gene (trust me, you don’t want me to write out the full name that Gnptab stands for), which is supposed to produce a protein that links a targeting signal onto lysosomal enzymes.  In less formal terms, Gnptab is supposed to slap shipping labels onto machinery destined for the cell’s recycling plants.  Without Gnptab function, bottles & cans & old televisions pile up in the recycling plant. The machinery to process them never arrives.

Which does seem a little strange to me… stuttering is a very specific phenotype, and that is such a general cellular function.  Lysosomal targeting is needed for all cells, not just neurons in speech areas of the brain.  It’s a sufficiently common function that biologists often refer to Gnptab as a “housekeeping” gene.  And proper lysosome function is sufficiently important that problems typically cause major neurodegeneration, seizures, blindness, and death, typically at a very young age.  Compared to that litany of disasters, stuttering doesn’t sound so bad.