sensory systems

Masterpost: Sensory differences

If you know a bit about autism, or have been following this blog for some time, you must be aware that one of the autistic traits which has the most consequences on our daily lives is our sensory differences. They have an impact on all spheres of our lives: on what we can and cannot do, on where we can and cannot go, on what we can eat, wear, listen to, on our ways to feel good and on what makes us feel bad.

Such a wide subject definitely warrants a masterpost. So, here we go!

First, let’s take a look at the human sensory system, to understand the different areas in which there can be differences. It’s actually more complicated than the traditional five senses! Our sensory system is divided into three parts:

  • Exteroception : sensing what comes from the environment outside your body.
  • Interoception : sensing the internal physiological condition of your body
  • Proprioception : sensing the position your limbs and body are in

These three main areas encompass different senses (note that this is one model and others exist):

  • Exteroception: sight, hearing, smell, taste, touch, but also thermoception (sensation of heat/cold) and nociception (sensation of pain)
  • Interoception: nociception (internal pain), feelings of hunger, lack of oxygen, thirst, need to pee, as well as monitoring of the respiratory rate and heart rate.
  • Proprioception: the kinesthetic sense (knowledge of the movement and relative positions of your body parts) and the vestibular sense (knowledge of body movement, direction and acceleration)

For all of these senses, autistic people can have them work typically, be hyposensitive (less sensitive than most people), be hypersensitive (more sensitive than most people) or have sensory processing differences which do not fall under the hypo/hyper system.

The clinical term which encompasses these differences is “Sensory Processing Disorder”. One can have SPD without being autistic, but all or almost all autistic people have SPD.

It should be noted, however, that some autistic people don’t like to think of it as a disorder and prefer simply talking about sensory processing differences.

Something very important to understand is that hypersensitivity and hyposensitivity CAN coexist in any one person’s sensory system. For example, they might be hypersensitive to smell and hyposensitive to touch. They can also be hyper/hypo sensitive to only one aspect of one sense (for instance, pressure or texture or bright lights or sweet tastes). They can also be sometimes hyposensitive to something, and sometimes hypersensitive to it.

Being hypersensitive to a stimulus and being exposed to it can cause what is called “sensory overload”, which usually translates to pain, discomfort, and impaired cognitive functions (in other words, trouble thinking properly). If pushed further (very intense stimuli or very long exposition), it can lead to a shutdown or meltdown.

Being hyposensitive to something and lacking stimulation can translate to restlessness, discomfort, and even pain, as well as an intense craving for the stimuli.

Here are some examples of what hypersensitivity to different senses can translate to, on a behavioral and subjective level:

  • Sight: The person wears sunglasses, maybe even indoors. They avoid places with fluorescent lightning, blinking lightning or too bright lightning. They dislike looking at brightly colored surfaces. They may have trouble with visually cluttered spaces, such as crowds and supermarkets. They may find any kind of flickering or movement around them painful to see.

  • Hearing: They may hear sounds no one else can hear (and some have been tested to hear outside the normal human range). They may have to wear headphones/ear defenders in noisy places. They may avoid crowds and events with lots of people/loud music/shouting. They may have difficulty with the noise of the vacuum, of the construction work on the other side of the street, of the clock ticking in the next room. They may develop tinnitus eventually.

  • Smell: They’ll probably dislike places with strong smells such as perfume shops, farms, or crowded public transportation. They may need to wash themselves, their clothes and their sheet very often to keep body odors to a minimum. They may not tolerate scented soap, shampoo or deodorant (and it’s sometimes difficult to find an unscented one!). They may struggle with the smell of food in general, or with particular smells.

  • Taste: They may be very picky eaters, only tolerating a couple of very bland-tasting food such as mashed potatoes or pasta. They may have difficulty having diverse enough diets with all the nutrients they need. They may always eat the exact same thing.

  • Touch: They may have trouble finding clothing with a texture that they can tolerate. They may need to cut all the tags off their clothing. They may absolutely hate anyone touching them. They may be ok with firm touch, but find light brushy touches painful. They may have trouble wearing specific items of clothing, such as socks/shoes, headphones or hats. They may hate people touching their hair, or find brushing their hair very difficult. They may find brushing their teeth nearly impossible because of the scratching sensation. They may have trouble with the texture of many foods, and be a picky eater because of that.

  • Thermoception: They may be very sensitive to cold, and always wearing loads of clothing and turning the heating up even when other people don’t think it’s that cold. They may be very sensitive to heat, finding summer very hard to cope with, especially if they don’t have access to AC. They may be hyper-aware of tiny changes in temperature, feeling cold when it is dropping and hot when it is rising regardless of the actual temperature.

  • Nociception: They may be more sensitive to pain than most people, and find very painful what most people would shrug off. (They’re not being a drama queen! They really do feel more pain!)

  • Vestibular sense: They may get motion sickness very easily.

And here are some examples for hyposensitivity:

  • Sight: The person may have trouble finding things in visually crowded environments. They may enjoy looking at bright colored lights or at objects in motion (spinning top/twirling fingers…)

  • Hearing: They may not notice being called or being talked to, especially when focused. They may enjoy listening to very loud music, singing, or making lots of noises.

  • Smell: They may not notice smells which other people do. They may enjoy strong smells such as perfume, essential oils or body odor. They may enjoy sniffing a favorite blanket, a significant other, a pet, or anything they like.

  • Taste: They may be able to ingest an impressive amount of spicy food, and may crave strong tasting food (pepper, lemon, salt, sugar…).

  • Touch: They may love rubbing/touching favorite textures, rubbing their hands together… They may love and crave deep pressure, such as having heavy weights on top of them.

  • Thermoception: They may be outside in winter with just a T-shirt, or not be bothered by the heat in summer and even wear a sweater. They may enjoy touching very hot things such as radiators or very hot water, or very cold things like ice cubes or snow.

  • Nociception: They may be less sensitive to pain than most people and not notice it when they’ve been hurt.

  • Vestibular sense: They may love roller coasters, boat rides when there’s a lot of waves… They may never get motion sickness of any sort. They may spend time rocking or like to chill upside down.

  • Kinesthetic sense: They may be very clumsy since they have a poor sense of the position of their body in space. They may stumble a lot and be generally bad at sports. They may have trouble with fine motor skills such as handwriting or sewing. They may enjoy doing repetitive motions such as hand flapping.

  • Interoception: They may have trouble noticing  when they are hungry, thirsty, tired, or when they need to go to the bathroom. They may need to set alarms or to have self-care at set times as part of their routine.

These are of course only examples and hyper or hyposensitivity can express themselves in as many ways are there are people who experience them.

Here are some examples of other sensory differences autistic people can experience:

  • Synesthesia seems more frequent among autistic people than in the general population. It is defined as a transfer from one sensory modality to another: for example, seeing sounds or hearing tastes. It can also mean associating colors or personalities to numbers/letters. In autistic people specifically, it can be a very positive thing (you can now stim with two senses at the same time!) or something painful (these bright lights are awful, well now they’re harsh noises too).

  • We often struggle with processing sensory information, especially speech, which can mean we can have a lot of trouble understanding what people say, might take a lot of time to process speech (which results in conversations such as” “Hey, will you get me this thing please?” “What?” “I said, will-” “Oh yeah, sure”), and might need subtitles to be able to understand movies. Processing information from two different senses at a time can also be difficult, which often translates as “I can either look at the images or understand what’s being said”. This is one of the causes of our struggle with eye contact.

That’s all for today. We hope this helped. We are currently preparing a masterpost on stimming which will be quite related to this one. Happy writing!

Honestly I really love it when my friend asks me questions about ADHD randomly whenever she thinks of them. 

Like we were listening to Sail by AWOLNATION while studying one time and at the line “Maybe it’s my ADD” she paused it just to ask what the difference between ADD and ADHD was and listened to me ramble on for like five minutes about the different classifications of ADHD and which classification I have (and actually laughed at my shitty joke that having Combined time is “the best of both worlds” oh my God what a champ) and then asked more questions about how each type would have an effect on someone’s life. 

And another time I made a joke about my medication being a Class 2 controlled substance in the Criminal Code of Canada (aka one of the Super Serious Drugs) so she asked me how my medication actually affects me and how it makes my life easier, and when I listed off how it helps control my impulsive decisions, evens out my moods and emotions, and generally helps to keep me more evened out as a person, she said she would try to help me however she can to make things easier and look out for me if ever I get too impulsive or get sensory overloaded or something. 

And every time she asks me a question, she always says “I’m sorry if this is rude or too invasive” and she’s just really nice and supportive about it and I love it??? Because it’s someone who cares about me trying to understand my disorder and how it affects me and makes me feel and how she can help??? And it’s such a nice change from the usual “just focus, just sit still, just be quiet, it’s not that hard!!!” kind of bullshit people usually give me as “”””advice”””” on how to handle my ADHD I just I don’t know I love it I love her she’s wonderful and it makes me so happy. 


Laural Virtues Wauters - 1: Serpent – Root Chakra – Base of Spine, 2013  2: Islam - Crown Chakra - Top Of Head, 2013  3: Third Eye – Sensory System, 2013  4: Intention of Self – Container of Life – Root Chakra, 2013  5: Soul Body – Sacral Chakra – Caduceus, 2013  6: Soul Sound – Throat Chakra – Sri Yantra Aum, 2013  7: Hinduism  – Solar Plexus Chakra – Stomach Area, 2013  8: Root Chakra – Muscular Skeletal System, 2013  9: Awakened Self – Crown Chakra – Star of Life, 2013  Mixed Media

Can plants talk to each other? It certainly doesn’t seem that way: They don’t have complex sensory or nervous systems, like animals do, and they look pretty passive. But odd as it sounds, plants can communicate with each other — especially when they’re under attack. 

From the TED-Ed Lesson Can plants talk to each other? - Richard Karban

Animation by Yukai Du / @yukaidu 

When the Physical World is Unreliable

A new study in the journal Translational Psychiatry sheds further light on the idea that schizophrenia is a sensory disorder and that individuals with the condition are impaired in their ability to process stimuli from the outside world. The findings may also point to a new way to identify the disease at an early stage and before symptoms become acute.

Because one of the hallmarks of the disease is auditory hallucinations, such as hearing voices, researchers have long suspected a link between auditory processing and schizophrenia. The new study provides evidence that the filtering of incoming visual information, and also of simple touch inputs, is also severely compromised in individuals with the condition.  

“When we think about schizophrenia, the first things that come to mind are the paranoia, the delusions, the disorganized thinking,” said John Foxe, Ph.D., the chair of the University of Rochester Medical Center Department of Neuroscience and senior author of the study. “But there is increasing evidence that there is something fundamentally wrong with the way these patients hear, the way they feel things through their sense of touch, and in the way in which they see the environment.”  

The researchers conducted a series of experiments in which they presented visual and touch stimuli to 15 schizophrenia patients and 15 controls while they recorded the brain’s response via electrodes placed on the surface of the scalp. What scientists have known for years is that when encountering a series of inputs, such as successive flashes of light, the brain’s initial response is large and strong. However, as the flash is repeated the reaction quickly fades in intensity.  

This response reduction is known as sensory “adaptation” and is an essential mechanism which enables the brain to filter out repetitive and irrelevant information. Researchers believe that adaptation allows the brain to free itself up to respond to new events and stimuli that may be more important.  

The research team found that adaptation was substantially weaker in the patients with schizophrenia, and this was the case for both repeated visual stimulation and for repeated touch stimulation.

“If you can’t properly filter the information at the basic sensory input stage, then it is not too hard to imagine how the external world could begin to be experienced as bizarre and unreliable,” said Gizely Andrade, Ph.D. with the Albert Einstein College of Medicine and a co-author of the study. “A fundamental aspect of the way our minds operate is that they can rely on the fact that the external world remains constant. If it doesn’t, then reality itself could become distorted.”

The team is hopeful that this discovery might lead to simple and basic measures of sensory adaptation that could be used to diagnose schizophrenia or identify individuals at risk of developing the condition before the disease has had a chance to fully establish itself.  

“A key point with this study is that we find these dramatic differences in patients who are already suffering from full-blown schizophrenia,” said Foxe. “Schizophrenia is a disease that typically strikes during late adolescence or early adulthood, but what we also know is that long before a person has their first major psychotic episode, there are subtle changes occurring that precede the full manifestation of the disease. Our hope is that these new measures can allow us to pick up on these people before they ever become seriously ill.”

Choir practice really “unclogged” my sensory system. Being able to sing full voice and hear chords all around me smoothed things out kinda like combing hair gets rid of tangles.

I’m still cranky and bleh, but I feel regulated too. It’s like there’s a peaceful center under all the grumpy storms happening in my nerves. (Audio only, no visual.)

someone asked me what stimming is and i thought i’d share my answer here

stimming is a too-limited word for basically anything we do that feeds our nervous systems with sensory input that feels nice and calming.

allistic people like to say we’re stimming when they notice us doing repetitive things that they don’t understand

like rocking or whatever. like i looked up examples just now and some australian parenting website defined it as “repetitive or unusual body movement or noises.”

parenting websites love pathologizing autistic stuff lol

so it’s a really wide range even in their world. fiddling with a pen, tapping your foot or your fingers, chewing on things, humming, meowing, listening to the same song over and over, etc

i know someone whose about says “reading is stimming” which makes perfect sense to me but it’s hard to explain why

or people will stim by just looking at really nice pictures or colors, or stroking a blanket or shirt they like, or eating something that they really like the texture of, or…

i think we need more words for different kinds of stimming. i wrote a post once where i proposed calling it “basking” or “luxuriating” when we’re just soaking in the things we like. 

i like the word “stimming” for repetitive stuff, like rocking or tapping or knitting. it seems like a better fit for the way the word sounds, to me.

  • Modern/Radical Feminist: All men are terrible people and should die!
  • Me, a Feminist: Is it ok for me to tell others that you think that all men are awful?
  • Modern/Radical Feminist: Yes! The world should know how horrible they are!
  • Me: Alright, then. Everyone, listen up! This person thinks that all black, Muslim, Jewish, and trans men are terrible and should die!
  • Modern/Radical Feminist: Wait, no, what?
  • Me: You generalized men, you made statements as if men are inferior and are all the same, so unless you're racist and transphobic, you include those men in that opinion, right?
  • Modern/Radical Feminist: System malfunction, sensory overload, computation cancelled, failure in transaction of regurgitating sexist statements *explodes*
Thanks for checking your facts
  • So I student taught at an elementary school in NYC and during my 5th grade placement, I was pretty open about being autistic. During the 5th grade lunch period, one of the other fifth grade teachers came in the room. Paraphrasing a bit because I only remember the gist of the conversation and not every single word said.
  • Other teacher: You're autistic right?
  • Me: nods
  • Other teacher: How would you explain autism to a class of fifth graders? A character in a book we are reading has autism and I don't know enough about autism to try to explain it to them.
  • Me: The basic points is that each person experiences it differently, that they typically have issues with communication and social interactions and that their sensory system doesn't perceive the world like they do.
  • Other teacher: That is what I thought but I wasn't sure and didn't want to tell the kids the wrong information.
  • I was just surprised that her first thought besides realizing that she wasn't sure of what she knew was to go ask an autistic to make sure she was explaining it correctly. This is not how most educators I have interacted with deal with this situation.

So policy is his cerebellum, which contributes to coordination, precision, and accurate timing. It receives input from sensory systems of the spinal cord and from other parts of the brain, and integrates these inputs to fine tune motor activity. In other words, Obama’s policies are necessary for effectively and efficiently carrying out his goals, and coordinating them with external reality. A good cartoon. - Abyssal Squid

why are people so mad that everyone keeps talking about the dress picture???? i think it’s fascinating. millions and millions of people are all curious about the same thing!!! how often does that happen??? this one strange, fuzzy, dimly lit picture of an ugly dress has not only sparked global debate and discussion, but also demonstrated the dramatic variability in the way our sensory systems perceive things. lighten up, the dress meme is fucking cool. 

Researchers Find Brain Area That Integrates Speech’s Rhythms

Duke and MIT scientists have discovered an area of the brain that is sensitive to the timing of speech, a crucial element of spoken language.

Timing matters to the structure of human speech. For example, phonemes are the shortest, most basic unit of speech and last an average of 30 to 60 milliseconds. By comparison, syllables take longer: 200 to 300 milliseconds. Most whole words are longer still.

To understand speech, the brain needs to somehow integrate this rapidly evolving information.

(Image credit)

The auditory system, like other sensory systems, likely takes shortcuts to cope with the onslaught of information – by, for example, sampling information in chunks similar in length to that of an average consonant or syllable, says study co-author Tobias Overath, an assistant research professor of psychology and neuroscience at Duke. The other corresponding author is Josh McDermott from MIT.

In a study appearing May 18 in the journal Nature Neuroscience, Overath and his collaborators cut recordings of foreign speech into short chunks ranging from 30 to 960 milliseconds in length, and then reassembled the pieces using a novel algorithm to create new sounds that the authors call ‘speech quilts’.

The shorter the pieces of the resulting speech quilts, the greater the disruption was to the original structure of the speech.

To measure the activity of neurons in real time, the scientists played speech quilts to study participants while scanning their brains in a functional magnetic resonance imaging machine. The team hypothesized that brain areas involved in speech processing would show larger responses to speech quilts made up of longer segments.

Indeed, a region of the brain called the superior temporal sulcus (STS) became highly active during the 480- and 960-millisecond quilts compared with the 30-millisecond quilts.

In contrast, other areas of the brain involved in processing sound did not change their response as a result of the differences in the sound quilts.

“That was pretty exciting. We knew we were onto something,” said Overath, who is a member of the Duke Institute for Brain Sciences

The superior temporal sulcus is known to integrate auditory and other sensory information. But no one has shown that the STS is sensitive to time structures in speech.

To rule out other explanations for the activation of the STS, the researchers tested numerous control sounds they created to mimic speech. One of the synthetic sounds they created shared the frequency of speech but lacked its rhythms. Another removed all the pitch from the speech. A third used environmental sounds.

They quilted each of these control stimuli, chopping them up in either 30- or 960-millisecond pieces and stitching them back together, before playing them to participants. The STS didn’t seem responsive to the quilting manipulation when it was applied to these control sounds.

“We really went to great lengths to be certain that the effect we were seeing in STS was due to speech-specific processing and not due to some other explanation, for example, pitch in the sound or it being a natural sound as opposed to some computer-generated sound,” Overath said.

The group plans to study whether the response in STS is similar for foreign speech that is phonetically much different than English, such as Mandarin, or quilts of familiar speech that is intelligible and has meaning. For familiar speech they might see stronger activation on the left side of the brain, which is thought to be dominant in processing language.