Tag: sensory integration

Binaural Beats

[I hesitated to write this because I don’t want to jinx it.  I’ve only been using it for four days and things have a tendency to stop working for me, but I’m really excited and wanted to share.]

I first heard about binaural beats when a massage place I occasionally go to invited me to Hemi-Sync® weekend workshop, which is the brand name for a particularly well marketed form of binaural beats.  Hemi Sync (short for hemisphere synchronization) sounds extraordinarily made up.  In their own words:

The audio-guidance process works through the generation of complex, multilayered audio signals, which act together to create a resonance that is reflected in unique brain wave forms characteristic of specific states of consciousness. The result is a focused, whole-brain state known as hemispheric synchronization, or Hemi-Sync®, where the left and right hemispheres are working together in a state of coherence. Different Hemi-Sync® signals are used to facilitate deep relaxation, focused attention or other desired states. As an analogy, lasers produce focused, coherent light. Hemi-Sync® produces a focused, coherent mind, which is an optimal condition for improving human performance

The website offers hundreds of (extremely expensive) CDs sorted into categories like “behavior modification”, “cancer support”, “weight control”, “learning and information” and “shamanic”.  The “research article” section has one peer reviewed study, which I found equivocal, and a bunch of self hosted articles.

It seemed so unlikely as to be unworthy of consideration that just listening to sound could force an arbitrary brain to do arbitrary things.  On the other hand, if it was going to work for anyone, it would be me.  I have misophonia, which basically means arbitrary sounds are physically painful.  I don’t know if this is part of the technical definition, but for me sound is also often very attention grabbing when it shouldn’t be.  You know how you involuntarily shift attention when you hear your name across the room?  Imagine if you reacted like that every time anyone spoke.  And you worked in an open office.

Misophonia + sound = chronically activated sympathetic nervous system (the fight/flight/freeze response).  That is an excellent mode to be in if you have encountered a tiger, but a lousy way to spend 80% of your life.  It’s not just that you’re tense and anxious, although those are unpleasant: sympathetic activation directs energy towards tiger-avoidance systems (voluntary muscles, heart, lungs, vigilance) at the expense of long term investments like the immune system, tissue repair, and even digestion.  And it’s self reinforcing, because you become more sensitive to sound as the SNS ramps up.

We know sound can provoke immediate, strong emotional reactions.  Apparently the properties of human screams are wired directly to fear in your brain.   Sound affects how food tastes.  So it doesn’t seem crazy that certain sounds activate or at least facilitate the parasympathetic system.  That would give you an immediate feeling of relaxation, which helps you concentrate and reduces pain, and long term could lead to a greater marginal investment body maintenance, which is good for your health.  It is not as simple as “listen to tape, develop super powers”, but it seemed at least worth trying for me.

This shit is great.

Too soon to say anything about the long term effects, but this is a better muscle relaxant than anything I’ve tried.*  Moreover, it has the largest effect on the muscles that are most tense.  My shoulders and especially my lower back resist massage because pushing on a tense muscle hurts, and whatever gains I do get to be lost very quickly.  My jaw is in a pain<->tension cycle from the nerve damage.  They’re all dramatically better after some time listening to binaural beats, even under adverse conditions like the open office.  I am still kind of dumbfounded that I am getting up from working  in an open office more relaxed than when I sat down.  Actually I’m dumbfounded I’m working in an open office at all, I’ve spent most of my time as a conference room refugee.

So obviously I did get a concentration effect.  The open office is still not my ideal environment, but I can now see why other people called it “not ideal” rather than “Satan’s waiting room”.  It may have tempered my immediate response to noise, but the real gains have been that I recover from disruption much faster, which is exactly what you’d expect from something encouraging the parasympathetic without disabling the sympathetic.

The one thing it doesn’t help me with is sleep.  It’s great for power naps or falling asleep, but I wake up ~40 minutes later.  I have the same problem with meditation, which makes me think listening to these tracks does share qualities with meditaiton.  Speaking of which: I have found binaural sound to be really helpful for meditation- either focusing on the sound itself, or using it as a backdrop for a guided meditation.  Without it, when I meditate I feel simultaneously stuck and unmoored.  With it, I have a sense of flow, and a thing to concentrate on that has no chance of connecting to pain.

You can find a lot of these by searching for binaural or hemi-sync, but so far my favorites are:

I like this one because it has patterns repeating on intervals of different lengths.

Binaural Beat Machine: lets you configure the beat to your exact specification.

There’s also tracks on Google Music and I assume Spotify, although I have no loyalty to any of them.

*Short list: cyclobenzaprine, xanax, massage, acupuncture, various forms of bodywork that get very upset if you call them massage, theanine, magnesium/calcium, warm baths, heating pads.

Motion Sickness

The typical explanation for motion sickness is that your inner ear and your eyes disagree about whether or not you are moving, your body interprets it as food poisoning, and prepares to throw up.  This does not quite make sense to me, because it fails to explain any of the following:

  1. Why being a passenger is so much worse than being the driver.
  2. Why playing video games (eyes say movement, ears say stationary), reading in a bus (eyes say stationary, ears say moving) and riding a roller coaster (eyes and ears both say moving very fast)  produce the same feeling.
  3. Why smooth rides (subways, no-turbulence airplanes) are so much easier than busses, or why highways are easier than stop and go traffic.
  4. Apparently other people consider nausea a stomach issue, but for me it’s very much a head issue.  Motion sickness also gives me headaches.  What’s up with that?  Why is it so tightly correlated with sinus pressure?
  5. Why does low blood sugar feel so much like motion sickness?
  6. I’ve never experienced this, but television assures me heavy drinking produces the same effect.  Why?
  7.  Why does motion sickness give me temperature fluctuations.

I’ve heard a partial explanation for #3, which is that your inner ear actually senses acceleration, not movement, so a steady velocity doesn’t feel like movement.  And we have a very compelling proximal explanation for #6: the difference in density between water and alcohol stimulates your inner ear both as you get drunk and as you sober up.  So obviously the inner ear is very involved in this, but how?

Alternate hypothesis: motion sickness is designed to keep you from eating, because your body is not in a good state to digest. One way that can happen is if your sympathetic nervous system (responsible for fight-or-flight-or-stand-there-being-really-anxious) has kicked in, because it redirects blood flow and energy to things that are immediately useful in escaping from tigers (muscles, senses) and away from things that solve future you problems like digestion and the immune system (which are regulated by the parasympathetic nervous system).

Both the sympathetic and parasympathetic systems are regulated by the hypothalamus.  For fun I googled “hypothalamus motion sickness” and the first result was this rat based study,* which put rats in a “animal centrifuge” to induce motion sickness. I couldn’t find video of a rat centrifuge, but NASA helpfully provided video of a dog centrifuge.  It looks not quite as bad as a tilt a whirl, although the rats were exposed to double gravity so I should probably cut them some slack.

During their amusement park adventures, the rats experienced a spike in histamine production in the hypothalamus (how cool is it that we can continuously measure that?), and caused the rats to display characteristic motion sick rat behavior.  Inhibiting histamine production or removing the inner ear (the part that detects motion) caused both of these to disappear.  Histamines also help regulate body temperature, so that’s #7.  This suggests that anti-histamines would be useful at fighting motion sickness.  The good news is that this is correct, the bad news is that they make you sleepy and possibly give you Alzheimer’s.   That’s fine for any one time but I don’t want to make a lifestyle out of taking them.

A website my laptop unfortunately ate the link to has a subtly different explanation:  your brain tracks motor movement via an efference copy, creates a prediction of what sensory changes that should create, and they compares that to the actual sensory input.  Motion sickness might be your brain saying “these are too different, abort, abort”, or buckling from the intensity of calculation needed to reconcile the input.

I have always wondered why I/people hold my (our) breath during times of stress.  Unless you’re being hunted by a xenomorph right that second, oxygen deprivation is not helpful.

An artist's rendering of when holding your breath is useful
An artist’s rendering of when holding your breath might be useful

The most convincing hypothesis I’ve found is that your brain can only do so many calculations per second, compensating for breathing takes calculation, so you stop breathing.  That this rapidly starves your brain of oxygen, lowering the number of calculations you can do, is exactly the kind of long term thinking I expect from the human body which, lest we forget, takes in air and food through the same hole.  If both breath-holding and nausea can be caused calculation overload, we would expect the same things to cause them both. I can think of two things that do exactly this off the top of my head- sparring (but not drills) in martial arts, and playing Katamari, both of which involve complex spatial reasoning.  These are not great examples because there’s a lot of confounding variables, like extreme physical exertion while being hit in the stomach.

To summarize my speculation:  sensory input requiring too high a rate of calculation points you towards your sympathetic nervous system, which makes you nauseous so you won’t eat while you’re not capable of digesting.

This suggests that anything that kicks you towards the parasympathetic system should reduce motion sickness.  Unfortunately the parasympathetic and sympathetic systems run on the same neurotransmitters, so looking at the relevant drugs does not provide useful information.

This also suggests that anything that lowers the number of calculations you need to do will be helpful.  BCMC tested a heads up display that showed users their head position relative to the horizon.

Studies found it overwhelmingly helpful, although I haven’t dug into that paper in detail yet.  Unfortunately there’s no way to purchase the technology, so I’m left hoping someone picks up the patent.

In conclusion: we don’t really know what causes motion sickness and that there’s no known really good treatmen.  I am going to experiment with consciously tracking my head position relative to horizon and with rhythm games (which help integrate sensory data).

*The second result appears to be the exact same experiment, done 10 years earlier, with the exact same result.  It’s nice to see something reproducible.

Autism as Developmental Injury

Left untreated, people with phenylketonuria (PKU) can develop intellectual disabilities, seizures, and “other medical problems”.  But PKU does not cause any of those.  Phenylketonuria + a normal diet causes a build of of phenylalinine in the body, which causes those problems.  If PKU is caught at birth and the sufferer is kept on a phenylanlinine-light diet, they will never develop these problems.

Henry Markram suggests that something analogous is going on with autism.  He and his collaborators think that the actual problem is that autistic babies have extraordinary sensory sensitivity, and this sensitivity causes defenses that cause them to miss certain critical information during developmental periods.  What is challenging but achievable (the zone necessary for learning) for other people is overwhelming for them, so they don’t learn.  The developmental window closes and they’ve lost their chance to truly master that skill.  But if they were given stimulus in their zone of achievable challenge, they would learn those skills and maintain them for life.  They might continue to need accommodations, the way phenylketonurics need to stay on a phenylalinine-light diet their whole life, but with those accommodations they could function “normally”.  This is known as the intense world hypothesis.

The example they give is the critical period for learning language.  You *can* learn a new language after the critical period, but it will never be as easy, most people will never attain genuine fluency, and if you never learn any language it may be truly impossible to pick one up later.  If normal human speech is overwhelming to an autistic infant they will miss that period and their language will be impaired for life.  But if they’re given regular access to speech they are comfortable with (probably quieter and slower) they could learn it just fine, the same way hearing impaired children do fine with sign language.

I was also really impressed with the writing of this lay-press article.  I’ve been avoiding doing take downs, especially of popsci articles, because there are millions of wrong things every day and criticizing them is easy.  For a while I could justify them as case studies in critical reading, but now it just feels bad.  This had led to a lot of aborted blog entries, as I read something amazing and then realize it’s too flawed to pass on uncritically.   I don’t agree with everything the article says (insisting there’s only one cause of autism strikes me less as brave and more as idiotic), but it lays out its case in an informative and responsible manner.

Adventures in amateur research: implausible mechanisms

I’ve referred to the scientifically questionable book my scientifically questionable sensory integration therapist gave me before.  It’s name is  The Fabric of Autism.  Let me walk you through its loss of credibility.

As I mentioned before, TFoA refers to the hypothesis that thiomersal causes autism as accepted fact.  That is a very big strike against it.  But all the best theories were once fringe hypotheses, and people who believe one fringe hypothesis will often believe another, so I kept reading.

Then TFoA referred to information the author received from patients using Facilitated Communication, accepted as naturally as if the patient spoke.  I vaguely remember FC from a psych 101 class I took in 2004: FC was a breakthrough that allowed autistic people to write out their thoughts, thoughts mainstream practioners had denied they even had.  People thought to be entirely nonverbal were writing novels.  It was a miracle.

Only FC was being used by people who had never learned to read or write.  You can pick up verbal language without explicit instruction, but not written.  And even if you could, autists were writing full sentences without looking at the letters- and the FC hunt-and-peck method is simply impossible to touch type with.  FC went on to fail every double blind trial thrown at it.  In the time between introduction and discrediting, several people were sent to jail for sexual abuse, where the only evidence was FC-expressed accusations.

I checked wikipedia, and my recollection was more or less correct.  They present it as more controversial and less laughably terrible than my class, and it’s always possible new research was done or the technique has changed since I took my class.  Or maybe it just happened to work for these individuals. But given how horribly misused faciliated communication was in the past, I believe the author should note that history and what makes this FC different from the bad old days.  Failure to do so is strike two.

Then the book had a good stretch.  It posited some plausible mechanisms for how sensory and inner ear problems could hurt the digestive system.  Then it tried to do the reverse.  I’m well disposed to this sort of thing.  Anything that isn’t self-reinforcing will stop.  But the mechanism proposed was that poor digestion leads to bad posture, and that causes the endolymphatic sac in the ear to underinflate (this is what we spent so much time on Wednesday).

I can’t prove that doesn’t happen.  But I am very, very certain that bad posture would have a lot of other, more noticeable effects, some of which would themselves affect the ear.  A mechanism that broad should be accompanied by a list of other expected symptoms- something the user can compare their own symptoms to and see if this offers a parsimonious explanation.  TFoA does none of that.  It offers no checkpoint for a user to say “oh, this isn’t me” and walk away.

I didn’t consciously decide that that was the last straw, but I haven’t picked up the book since.  And while I kept up with my old exercises, I didn’t work on incorporating new ones.  This is to my detriment, since the exercises really do seem to help no matter how terrible the science they’re based on is.  I have some hypotheses as to why that is, but I can’t share them without committing all the sins I just accused the book of, so they will need to wait for more research.