Wednesday, January 14, 2009

The Smell of Fear

Looking back on it, the kid was rattled — I think that, even through the distortion of hindsight, that’s a valid memory.

I was taking a break from dog tasks in the search for a missing adolescent girl. When I showed up at the command post, exhausted but willing to fly a desk for a while, they put me in the Operations Section, and set me to debriefing teams as they came in from the field.

A bit about debriefing: it is perhaps the second-most important part of any search, behind the “planning” function of deciding where to assign teams to search. Most searches that I’ve seen fail did so not because a searcher missed the subject, but because no searcher ever got within a reasonable detection distance of the subject. The second-most common mode of failure, though, is when important information fails to make its way from the field to the Planning Section.

The very young field-team leader before me had been assigned to search a neighbor’s farm. He and his grid team of human searchers had found nothing in the parts of the task he’d been able to accomplish; but what really stood out was how emphatically he pushed the need to send other searcher back to check the parts he couldn’t access because of locked gates.

“You need to check those fields,” he’d said. Yes, even then I was surprised that such a common on-task occurrence had fazed him so badly. Patronizingly, I admit, I put it down to his youth and inexperience.

Still, I dutifully entered, in the debrief section on the flip side of his TAF, or task-assignment form, something like: FTL reports parts of areas inaccessible: advises follow up.

That was enough, I know, to get the area searched again, and it was, more than once. What I hadn’t known at the time was that Heather — we’d arrived at the search separately, and were on different sleep cycles so I hadn’t seen much of her — had taken a dog out to that same farm the previous night, and had also come back rattled, reporting an inability to get to the whole farm but begging Ops to get another team in there.

Heather don’t rattle so easily.

They were both, in retrospect, absolutely correct to be agitated: as the parallel police investigation began to center on the caretaker for that farm, the incident gradually became a criminal search. Eventually, searchers found our subject’s quad rider, buried in manure, which along with a confession helped lead the police to a not-so-shallow grave that the perp had dug with a back hoe.

Now I don’t know whether odor had anything to do with the instinctive fear both team leaders apparently experienced at a murder scene with a body nearby. Certainly, there’s a literature linking odors to fear responses. And it beats the hell out of ESP as an explanation. But the story did come to mind when I encountered a surprising paper linking mad cow disease with fear responses.

Bruno Lobão-Soares and colleagues at the University of Sao Paulo were looking at the curious effect of a gene called Prp-C. This gene makes a protein that becomes, all by its lonesome, an infectious agent merely by becoming misfolded. In ways we don’t completely understand yet, the misfolded, Prp-Sc, protein gains the ability to convert its brethren to its derangement. This chain reaction causes a slow buildup of junk protein in the brain that leads to massive destruction of tissues and a variety of brain-wasting diseases: mad-cow, or bovine spongiform encephalopathy, in cattle; scrapie in sheep; chronic wasting disease in deer and moose; and Creutzfeldt–Jakob disease in humans.

This is a particularly frightening family of disorders, because unlike viral or bacterial infections, there is no living (if I can push the definition, for a virus) pathogen you can kill to prevent spread. Because the disease comes from an infectious protein, called a prion, it’s extremely difficult if not impossible to make contaminated tissues safe to eat: heat, radiation, chemical agents all tend to leave the Prp-Sc protein unscathed, and able to devastate a mind, if consumed. That’s why reports of scrapie, or mad cow, result in thousands of animals being killed, burned, and buried rather than eaten; it’s why hunters across the country are examining their kills carefully before they have them butchered.

But here’s the interesting thing the Brazilian Beat saw when they exposed PrpC-genetically engineered mice to a snake:

  • Both mice engineered to lack the protein and those engineered to have unnaturally high levels of it were singularly incautious in the presence of snakes (one of the signs being decreased sniffing behavior). But there was an important difference:
  • The over-endowed mice were hyperactive, fearless, and bizarrely motivated to seek sensual stimulation — by sight, touch, and smell.
  • The mice without the protein simply had no ability to concentrate on anything, fearful or otherwise — as the authors wrote, “... the Prp-C deficiency might lead to attention deficits.”

Now, linking prions to fear responses — which we know can be initiated by smells — would have been enough to warrant notice in these august pages. But what really floated this bloggist’s boat was the tricky similarity of symptoms brought about by completely opposite problems.

I’d be remiss if I didn’t note that I’m winging it here — I might be all wrong — but I’m fascinated by the possibility that two people we might call, at first glance, “impulse-control impaired” or even “hyperactive” could be acting that way because of profoundly different causes. One has diminished ability to attend to details; the other has an over-active urge to focus on them.

Isn’t science fun?

But I’ll tell you one thing: the next time I sense that level of anxiety in an incoming team leader, I will add to the TAF: FTL wigged out as all shit — this may be something real.

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