Differential recall as an objective test for abuse?

Peter Watts is one of my favorite fiction authors, a fact that should probably worry me.  Normally I don’t like hard sci-fi, but Watt’s biology is interesting, plot-integrated, and plausible.*   For example, see this presentation from Blindsight, “literary first-contact novel exploring the nature and evolutionary significance of consciousness, with space vampires”, explaining how vampires came to be.

Those of you who can’t be arsed with videos in blog posts, I understand, and please take my word for it that he presents a very scientific explanation for how a subspecies of humans with vampire-like traits could evolve, interbreed with the normal humans, die out, and then be revived via collection and activation of dormant vampire genes.  And it is absolutely plausible.

His other big work is The Rifters Trilogy, which is based in part on the idea that people with untreated traumatic backgrounds (the protagonist was molested as a child) are more suited than their emotionally healthy peers for dangerous, stressful work (e.g. maintaining a power facility miles under the ocean seeing no one but each other for months).  I don’t remember how much he justified this at the time, because what he said was plausible enough to make for a good story and that was enough for me.

My current non fiction book is Blind to Betrayal.  The awful cover implies it’s solely about infidelity, but it is actually about how people willfully blind themselves to all sorts of betrayal from people they are dependent on- everything from children pretending their parents don’t molest them to people discriminating based on race while claiming to be race blind.  In chapter 8, they discuss divided-attention versus selective attention.  Divided attention is what lets us multitask, selective attention is what let’s us filter out extraneous information.  People (both adults and children) who score highly on the Dissociative Experience Scale (which the authors contend is associated with trauma and selective blindness to evidence of betrayal) tend to score better than low-DESers on divided attention tasks and worse than low-DESers on selective attention tasks.  People with traumatic pasts also have worse memories for trauma-associated words (e.g. rape, kick) and pictures, but no deficit for neutral words and pictures.

I take these results with a grain of salt, because they are very close to implicit association tests and that methodology has come under question.  But if we accept them as correct for now, I see three very obvious conclusions:

  1. Peter Watts was dead on
  2. Human beings are amazingly adaptive, and this is another reminder that what often looks like sheer dysfunction is at least an attempt to adapt, although it doesn’t always work.
  3. If individual variation is low enough, we have a test for abuse.

One of the tragedies of investigating abuse of children is that it’s very very hard.  Children lie, in both directions.  They lie spontaneously, and they lie after being deliberately coached.  A well meaning investigator can accidentally induce a child to invent a story of abuse.  And the investigation can itself be traumatizing to a child if they weren’t actually abused.  But if the variation in recall of trauma to non-trauma words is low enough, you could just give every kid a memory test every year.  Any wild variation from the norm or the kid’s historical record could be flagged for further investigation.

You could also use it when you have worrisome but highly ambiguous indicators, like for example the time I told my girl scout leader “something bad is happening at home” and refused to elaborate. I have no recollection of this, but according to my parents it happened right after my brother had some intensive medical testing, and they had had a talk with me about not blabbing about it around our school.  My girl scout troop leader quite rightly couldn’t let that go, but she also knew my mom worked with kids and even a whiff of investigation could ruin her life forever.  This story turns out okay.  My parents dropped me off for interrogation by my troop leader with instructions to answer everything she asked honestly, she correctly deduced I was not being abused, and she did not report my parents to CPS. But an objective test would have saved everyone a lot of anxiety.  It would also be useful in situations with a high false report rate, such as custody battles.

I don’t know if this research is at the stage where they could use it diagnostically, but I hope someone is working on it.

*Although noticeably less so in his recent release Echopraxia, where I had trouble following both the plot and the science.  I thought it might be surgery-brain, but a friend had the same reaction.

The origins of traumatic bonding

There’s a phenomenon known as traumatic bonding, in which an abused child or spouse bonds to their abuser even more strongly than they would in a health relationship. It’s usually attributed to intermittent reinforcement.

I have an alternative explanation. My cat currently has a retinal tear, which means his life consists of pain, a mysterious cone around his neck that blocks his vision and hinders his movement, and waking up several times a day to the being he loves most in the world, his sole source of food and protection pinning him down and stabbing his eyeball (antibacterial eye drops). Three times in one week this being has put him in a tiny cage and takes him to a place where they torture him even more (fluorescent staining at the vet). He used to love head rubs, now he flinches every time I touch the top of his head, because he associates it with eye drops. He is displaying every symptom of human depression an animal is capable of.

The thing is, I’m inflicting all this on him because I love him.  I am trying to save his eye, and I have absolutely no way to explain that to him.  And it got me thinking: lots of parenting is like this.  Even once the kids are technically old enough to understand English (a feat Nemo looks increasingly unlikely to to master), there’s lots of things you have to do for their long term good that they really hate in the short term.  Some of these things they will eventually understand and be grateful for, some they will always hate.   Either way, no human would ever survive to adulthood if they rejected their parents every time they did something that, from the child’s perspective, looks like torture.

So maybe we’ve evolved to have the capacity to love someone even if they hurt us, because we can’t tell good hurt from bad.  Traumatic bonding could arise either straight from that, or from a perversion of that system, the same way chronic clinical depression arises out of useful emotions.

Depression, symptoms and definition

Slate Star Codex consistently makes me feel bad about the quality of my most sciencey entries by blowing them away.  Here he does it with SSRIs.  One of the many, many data points he offers is that there is a very well known and consistent effect that doctors (and other observers) notice their patients acting less depressed (as measured by sleep patterns, appetite, ability to leave the house, hygiene standards, etc) well before patients report themselves feeling less depressed.

There are a lot of possible explanations for this.  One possible one is that we’ve reversed cause and effect: rather poor sleep, appetite, and executive function being side effects of depression, depression is a consequence of poor sleep, appetite, and executive function.  Moreover, it’s a delayed consequence.  One night of good sleep doesn’t even make up for a week of bad sleep, much less months.  So even if antidepressants instantly removed all the road blocks in someone’s life, it will take a while for those lack of road blocks to translate to feeling better.  Under this model, wondering why you’re still sad a week after starting anti-depressants makes as much sense as wondering why you’re still weak after two sessions of physical therapy. *   If the depression led to some choices with lasting consequences- quitting school, ending a relationship-it might well be impossible to give them back the life they would have had without depression.  That doesn’t mean the drugs aren’t working or aren’t useful, it just means they aren’t magic.

I didn’t intend this, but I think I just re-arrived at my model of depression as a symptom.

*This analogy was originally “starting a diet and being shocked you don’t immediately lose 30 pounds”, but that would reinforce the screamingly incorrect idea that diet has a simple causal effect on weight.

Patterns of pain

When I first regained feeling in my lower right jaw, I could feel everything.  I could feel the vibrations when I talked or drove.  I could feel the change in air pressure when I breathed (even through my nose) or had a fan on me.  I could feel the change in blood pressure driven by my heart beat in the lower right of my jaw.

And by “feel” I mean “felt pain in response to” (the vibration was a separate sensation that accompanied the pain).

The pain ebbs and flows, but I stopped feeling my heartbeat and breath a few days ago .  The fan is still uncomfortable (which is awesome in the middle of a heat wave), there’s a constant ache that is much less susceptible to pain medication, chewing (even on the other side) hurts some, and if I tap my two front right teeth together I want to die.  I nonetheless keep doing it completely on purpose, because I just cannot believe that something so light hurts so much.  If I put something- even hard metal- between them, I can apply much more pressure before it hurts.  I used to have a milder version of the same thing with my right molars and pre-molars, but that has subsided for now.

When I’m not actively experiencing this, it’s kind of fascinating.  I can occasionally feel my heartbeat in my fingers while meditating, but nothing like this.  And how on Earth could teeth detect anything to do with air?  The implication is that my and everyone else’s nerves are always capable of this sensitivity, but choose to ignore it.

I am limited in how much I can research this right now, because nothing breeds neuropathic pain like reading about it.  But my OT found me this continuing dental education article on the teeth as sensory organs.  The gist seems to be that teeth have nerves, and they use this to avoid breaking themselves by biting too hard.  The article doesn’t discuss it, but teeth are temperature sensitive as well, so I assume cold is bad for the teeth as well.  Teeth that have their nerves removed via root canal are more prone to breaking, and the author’s conclusion is that this is because they’re incapable of noticing when they apply too much pressure, the same way lepers injure themselves.

From this, I conclude that my teeth were detecting very minor sensations as dire threats.  This is one reason I think it’s important to keep doing things that hurt (when you know they won’t cause actual injury): the nerve needs to experience a range of experiences so it can learn what genuine danger feels like, so it stops overreacting to minor sensation changes.  This is also why good pain meds are so key to recovery: without them, I couldn’t risk heavier sensations.  I also think they might “train” my nerve to not freak out so much, which would be why at first a tiny dab of topical pain killer brought me hours of relief.

It’s also clear that the nerves on the top and bottom of my jaw are “talking” to each other, or that something in the jaw muscle recognizes “closed” as a state.  That’s the only way it makes sense for two teeth touch to hurt when the same teeth holding a piece of paper or a metal spoon don’t.  Even though the pain feels like it’s only in the lower right front tooth, it’s actually a product of synthesis of several different nerves (or rather, several different branches of the trigeminal nerve).  You have to admit this is pretty cool, even when it’s excruciatingly painful.

Monday morning quarterbacking

The infection in my jaw has been growing for either 1.5 or 6 years, depending on how you count the first surgery to remove it.  I was already practiced at ignoring dental pain because I’d had trigeminal neuralgia on the other side for even longer.  In retrospect it’s obvious the pain had been life altering for at least several months, but I either didn’t consciously notice the effects or didn’t link them to the cause.  Now I’m looking over the last six months or so and analyzing what else might have been a side effect of the pain.  I’ve already talked about my concentration and focus, but today it occurred to me my relationship with alcohol had changed too.

I’ve always been a very, very light drinker, a drink or two every few months, because that was the frequency with which it was fun.  It wasn’t a conscious decision, and the frequency was highly variable- I might drink twice in one month if two drinking occasions came up, and then go six months without when none did.  It’s a matter of social environment, and I don’t have a good definition of what the “right” time is, I just know it when I see it.

So it wasn’t really weird that the last drink I remember having was at New Years.  Except it was. My reason for not drinking at a given event was no longer “eh, this is not the day” but “no, that will take something I can’t spare.”  I couldn’t have told you what it was, but I knew I didn’t have enough.  And this isn’t just me applying 20/20 hindsight, I told someone this exact thing before the new infection was diagnosed.

Looking back now, it seems entirely plausible that alcohol would be competing for the cope that was being used to cushion the pain, or would have weakened one of the systems that was fighting the infection (immune,  liver).  I would expect chronic infection to be a drain on the immune system and alcohol to be a tax on the liver, which means one of them has to be crossing over in order to see this effect.  Eyeballing it, I find the liver the more likely crossover point.  I definitely wasn’t drinking enough to have even a marginal effect on the liver of a healthy person, and while I was not healthy, I also wasn’t drinking hardly anything.  If the liver was the shared resource, that implies the infection (and/or the parasite I may have) was kicking out enough toxins to tax my liver.  That’s pretty concerning, given that the liver is enormous and however impressed the dentist was, the absolute volume of the infected tissue was just not that big.

“But look how much bigger it is” is not an actual medical argument, even if you could fit all of my gum tissue in the liver many times over.  A quick googling reveals that bacterial periodontitis leads the liver to produce more C-reactive protein.  I had “cardiac” CRP, which I believe is the same thing, tested a month after my last surgery (timing is a coincidence) and it was low normal.  I don’t have any numbers for the intervening period.  There are several studies showing an association between liver damage and periodontitis.  Most are mostly small, retrospective, and unable to distinguish cause and effect, but this one used both animal models and treatment to demonstrate that bacterial gingivitis taxed the liver.

There’s no way to prove the liver is what I was keying in on, but it certainly looks plausible.  And in a situation where I’ve had almost no information or control, I’m kind of proud of myself for listening and protecting myself, even when I didn’t know from what.

What I want to be when I grow up

Long ago, “fever” was considered an illness in and of itself, not a symptom.  Imagine yourself as an 18th century doctor with that mindset, but 21st century technology.  Sometimes people feel better after two days of rest and fluids, sometimes they die, sometimes they live but are permanently weakened.  Mostly it seems like the weaker people die, but not always.  Sometimes antibiotics help.  Sometimes they don’t.  Sometimes one antibiotic helps but another doesn’t.  Tylenol always seems to make people feel better initially, but sometimes the fever rebounds.  Sometimes interferon helps, sometimes it does nothing.  Some people who get a lot of fevers seem to benefit from anti-retrovirals (what we know now as the HIV cocktail), but lots of others don’t and they have pretty nasty side effects.  Vaccines don’t seem to affect lifetime fever numbers very much, but do reduce the occurrence of the fever with specific symptoms.  We can’t tell if working with animals makes you more or less likely to catch a fever.  You can make some guesses based on whether or not the person experienced recent trauma, associated symptoms, and the symptoms of people around them, but it’s essentially guess and check.

I think that’s where we are with depression and anxiety.  They’re real, just like fevers are real, but they are symptoms with many possible underlying pathologies.  We already know some of these: thyroid disorder, anemia, chronic abuse, vitamin D deficiency.  But we’re not even very good at screening for those, much less the fringier ones like sensory processing disorders or digestive disorders.*  And who knows what kind of neurological or developmental issues could produce.

It’s even trickier because depression/anxiety can cause a lot of physical problems.  It’s hard to eat well or exercise with a lead blanket on you.  The physical effects of stress are real and costly.  Whether the mental or the physical came first, they can rapidly form a self-reinforcing cycle.

As I’ve mentioned before, my hypochlorhydria was diagnosed when I went to a psychiatrist for anxiety.  It turns out a well founded subliminal fear of starving to death makes you antsy. I have a friend who had been diagnosed with dysthemia (mild depression) for years before she developed an eye thing and finally got diagnosed with adult onset, type 1 diabetes.  One possibility is that all the symptoms of depression were caused by insufficient insulin.  Another is that the anti-depressants damaged her pancreas and caused the diabetes.  This is why I want to be a psychiatric NP.  Therapists don’t get to do the physical side, medical generalists and other specialists don’t get to deal with the mind enough, and MD specialties are too isolated.  The idea of taking apart those vicious cycles and helping people rearrange the parts into what works for them is incredibly powerful to me.