Autism: Sensations last too long

A painful truth

Sensory stimuli can be experienced very differently by autistic individuals. Just because we may not feel something, it does not mean that they don’t. It’s something that is so simple to understand, yet not knowing anything about it makes you feel unable to help your own child.

As he grew, I began to notice more and more my son’s very acute aversion to some things we would not think twice about. Seemingly mundane tasks such as getting his hair cut or his nails clipped were surprisingly difficult.

When it came to having his nails cut, his distress was so severe that I had to start being creative to get it done. So, when he was asleep, I would have to creep quietly into his room to accomplish the task. It probably wasn’t the best option, but the only other one was for a friend (or two) to hold him down whilst I cut his nails, listening to his screaming protests. Of course, anybody could see this was a highly uncomfortable situation for my son – but nobody could tell me why he was so distressed. Was it a fear of the scissors or the sound they made, or was it the sensation of the scissors against the nail?

I needed to find out, because not understanding your own son and what puts him in such stress is hugely upsetting. Once I delved deeper, I found that for many autistic people, the sense of touch is highly acute. Not even that but the duration of this sensation can last for hours, days and even weeks.

Sensation lasts too long

Non-autistics ‘forget’ the sensation very quickly. For example, when you get dressed in the morning you can feel your clothes on your skin, but soon the feeling fades. This fading sensation is called habituation. It is the same with smell and taste, or any other sense. If the senses are exposed to a continuing stimulus, habituation soon occurs. When the stimulus changes, the feeling returns. That is why you don’t feel the clothes you are wearing and become aware of them only if you change or adjust them.

For many autistic individuals, however, the habituation process doesn’t work properly and the sensation lasts too long. For some, it takes a few days to stop feeling their clothes on the body. And unfortunately, when this comfortable feeling (or ‘no-feeling’) has been achieved it is time to wear clean ones, so the process of getting used to the sensation starts again.

And it’s not only daily clothes that can cause problems. For some, it can take weeks to get used to exposing the skin and to wearing shorts/skirts and short-sleeved tops in summer. But by the time they feel comfortable in summer outfits, it’s autumn and time to start wearing trousers and long-sleeved jumpers again!

It’s this difficulty to stop feeling sensation that explains the distressing experience of my son I described above: the sensation he felt in the process of ‘cutting’ doesn’t stop when I put the scissors away. It’s not that the feeling of nails being cut remains, but rather that the surface of the cut nail is broader and makes it felt like the air was pressing on the nails. The boy kept feeling the sensation for at least three to four days. He tried to describe how it felt, but because of his differences in using the language, the best he came up with was, ‘My nails are sticky.’ He felt better on the fifth or sixth day after the ‘traumatic event’. Unfortunately, the comfortable existence lasts only two-three more days when it is time to have his nails clipped again.

Minicolumns

I found a very convincing explanation of what causes this phenomenon in the comparative studies of minicolumns (the smallest units of the brain capable of processing information)* in the brains of non-autistic and autistic individuals.

The studies (Casanova, Buxhoeveden, Brown 2002; Casanova 2006) reveal that in non-autistic brains information is transmitted through the core of the minicolumn and is prevented from activating neighboring units by surrounding inhibitory fibres. In autism, because minicolumns are so small and their number is so big, stimuli are no longer contained within them but rather overflow to adjacent units thus creating an amplifier effect. Inhibitory fibres just do not cope with this flow.

To illustrate this phenomenon, Prof. Casanova compares inhibitory filters with shower curtain. When working properly and fully covering the bathtub, the shower curtain prevents water from spilling to the floor. In autism, ‘water is all over the bathroom’.

(I'd compare it with fire in the brain.)

Happy ending

By understanding why my son was reacting this way, I not only learned more about his experiences, but also learned to communicate with him about them. When he asked me: “Mum, will my nails be sticky when you cut them?” I replied: “Yes, your nails will be sticky, but this feeling will pass.” So, with his language and my understanding, the process has become a lot more bearable for both of us.

My son has gradually got used to these experiences, from getting dressed in new clothes to having his hair or nails cut, and he now deals with it much better than before. The sensations are still the same for him but his way of dealing with it has significantly improved. Instead of having three people holding him down, and me trying to distract him when a hairdresser started to cut his hair, we now take him to a local hairdresser who knows him well and Alyosha is able to sit through it calmly and happily. (And for the first time – at the age of 28 – he even asked the hairdresser to make “this” shorter (pointing at the unruly curl on his forehead).

Looking back, I’ve realised that over the years it wasn’t only me learning how to cope with all of this. He was, too.

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* Minicolumns are vertical columns of functionally related glutamatergic and gamma-aminobutyric acid (GABA)ergic neurons that together process thalamic input. GABAergic local circuit neurons are thought to participate in controlling the functional integrity of minicolumns and providing lateral inhibition of activity from bordering minicolumns (Casanova & Switala 2005; Lund et al. 2003; Peters & Sethares 1997; Raghanti et al. 2010).

References

Bogdashina O. (2022) Autism: Becoming a Professional Parents (1) Exploring the Sensory World of Autism. L&L