Welcome back to Reading the Research, where I trawl the Internet to find noteworthy research on autism and related subjects, then discuss it in brief with bits from my own life, research, and observations.
Today's article describes, in technical detail, why unpleasant sounds are unpleasant. I found this particularly notable due to my oversensitive hearing, a problem which many autistic people suffer from. These test subjects were neurotypical, but I bet if you hooked me up to the monitoring equipment and did the same trials, you'd get the same kind of response, only worse.
The gist of this study is this: they hooked people up to a brain scanner and played a bunch of sounds for them, including unpleasant ones that were artificially created (car horns, fire alarms) and natural ones (baby crying, human screams). They then asked the people whether the sounds were continuous or interrupted, and how unpleasant the sound was on a scale of 1-5. In the meantime, they monitored the peoples' brain reactions to the sounds.
They found that high frequency sounds blurred together in the brain. However, Lower frequency sounds, especially unpleasant ones, not only activated the hearing circuits of the brain, but also activated other parts of the brain responsible for pain, aversion, and judging something as distinctive. This is likely why a crying baby is so easy to pick out of the commotion of a noisy room: it literally provokes a much greater reaction from your brain than the other noises.
Offhandedly near the end of the article, a researcher commented that autistic people tend to have unusual responses to sounds near the lower end of the range. They say it might be worth looking into whether you can detect autism and other conditions using a sound test. I'm honestly curious as to whether they've tested the whole range of frequencies on autistic people or not.
I have rather poor responses to, well, many sounds. My responses are to a greater degree than most people's, which makes me think I must suffer the activation of those extra parts of the brain much more often than most people. I have the usual (or more intense) reaction to a feedback loop, a baby crying, or nails on a chalkboard, of course. But I also can't stand to be near a piccolo, sudden thumps or thudding sounds make me jump (just ask my poor spouse), and the sound of dishes grating or clanking together makes me upset.
I haven't made an exhaustive list of all the noises that upset me, because in general I don't find it productive to spend time dwelling on unhappiness. But I have noticed I tend to describe things as "sharp" or "sudden" or "loud." The higher-pitched a sound is, like nails on a chalkboard, the more likely it is to be sharp. But you can still have sharp low-pitched sounds.
In any case, I would guess I have much more pronounced reactions to a broader range of sounds than most people do. Add in my brain's reduced ability to "tune out" unimportant sounds, like a police siren several roads away, or a crying baby that isn't my responsibility, and you have a whole lot of unpleasant brain activation.
(Pst! If you like seeing the latest autism-relevant research, visit my Twitter, which has links and brief comments on studies that were interesting, but didn't get a whole Reading the Research article about them.)
Today's article describes, in technical detail, why unpleasant sounds are unpleasant. I found this particularly notable due to my oversensitive hearing, a problem which many autistic people suffer from. These test subjects were neurotypical, but I bet if you hooked me up to the monitoring equipment and did the same trials, you'd get the same kind of response, only worse.
The gist of this study is this: they hooked people up to a brain scanner and played a bunch of sounds for them, including unpleasant ones that were artificially created (car horns, fire alarms) and natural ones (baby crying, human screams). They then asked the people whether the sounds were continuous or interrupted, and how unpleasant the sound was on a scale of 1-5. In the meantime, they monitored the peoples' brain reactions to the sounds.
They found that high frequency sounds blurred together in the brain. However, Lower frequency sounds, especially unpleasant ones, not only activated the hearing circuits of the brain, but also activated other parts of the brain responsible for pain, aversion, and judging something as distinctive. This is likely why a crying baby is so easy to pick out of the commotion of a noisy room: it literally provokes a much greater reaction from your brain than the other noises.
Offhandedly near the end of the article, a researcher commented that autistic people tend to have unusual responses to sounds near the lower end of the range. They say it might be worth looking into whether you can detect autism and other conditions using a sound test. I'm honestly curious as to whether they've tested the whole range of frequencies on autistic people or not.
I have rather poor responses to, well, many sounds. My responses are to a greater degree than most people's, which makes me think I must suffer the activation of those extra parts of the brain much more often than most people. I have the usual (or more intense) reaction to a feedback loop, a baby crying, or nails on a chalkboard, of course. But I also can't stand to be near a piccolo, sudden thumps or thudding sounds make me jump (just ask my poor spouse), and the sound of dishes grating or clanking together makes me upset.
I haven't made an exhaustive list of all the noises that upset me, because in general I don't find it productive to spend time dwelling on unhappiness. But I have noticed I tend to describe things as "sharp" or "sudden" or "loud." The higher-pitched a sound is, like nails on a chalkboard, the more likely it is to be sharp. But you can still have sharp low-pitched sounds.
In any case, I would guess I have much more pronounced reactions to a broader range of sounds than most people do. Add in my brain's reduced ability to "tune out" unimportant sounds, like a police siren several roads away, or a crying baby that isn't my responsibility, and you have a whole lot of unpleasant brain activation.
(Pst! If you like seeing the latest autism-relevant research, visit my Twitter, which has links and brief comments on studies that were interesting, but didn't get a whole Reading the Research article about them.)
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