Setback in sensory adaptation

To get a glimpse into how people adapt to new sensory information, I started brushing my teeth with my left hand instead of my right. My brain now had to adapt to new sensory information, especially from proprioception, touch, and the vestibular sense (see our blog for Growing into one’s own body and Sensory Adaptation). Drawing on previous research on people who have recently lost their vision, including some of my own work, I expected to:

– Do well on my first attempt, then struggle to adapt to sensory information from my left hand

– Have slip-ups – old habits die hard – that would set me back in my progress

– Try different routines before fully adapting to sensory information from my left hand

Week 13: My expectations were largely met. Except that I had experienced fewer slip-ups than I had feared, and no major setbacks – not even when I had deliberately returned to right-hand brushing in week seven. I had indeed settled into a consistent left-hand brushing routine (see our blog for Sensory Adaptation). Then, very unexpectedly, everything changed.

I was on a short spring holiday – and then, bang, the setback hit me! The toothbrush I use when travelling has a different handle and bristles from the one at home, and there were separate hot and cold water taps instead of the mixer tap in my flat. And now the slip-ups came one after another.

girl brushing teeth with beach backdrop
AI-generated illustration for SmartSense

As before, I caught the slip-ups early: first by how I moved the brush and then by the feel of it on my gums. After the third slip-up, I again started telling myself out loud to brush with my left hand (see our blog for Sensory Adaptation). But this had little effect. I even forgot to remind myself …

Four consecutive slip-ups later, I had to change tactics: I moved my reminder to brush with my left hand earlier in the habit-chain – from applying toothpaste to entering the bathroom. This helped, but it did not put an end to the slip-ups. Then I tried my other strategy from before – paying close attention to what I was doing from the moment I applied toothpaste (see our blog for Sensory Adaptation). It turned out that while I was on holiday, the entire sequence was being led by my right hand. With the toothbrush in my right hand, I applied toothpaste with my left hand, then fastened the cap on the toothpaste tube, turned on the cold water tap, and brushed with my right hand. At home, I switched the toothbrush over to my left hand before turning on the water tap and brushing my teeth. I now started to deliberately switch my toothbrush over to my left hand and turn on the cold water tap with my right. This helped too, but my movements with the toothbrush and the feel of it on my gums were both awkward. The holiday slip-ups had set me back to about week three (see our blog for Sensory Adaptation). At least my teeth felt clean.

After six more brushings while on holiday, with slip-ups in two of them, it was time to return home. Then what happened?

I struggled. And one week later, with three slip-ups, I still brushed as if I were in week three, or perhaps four (see our blog for Sensory Adaptation). Interestingly, though, my right-hand brushing also felt awkward. It was as if I no longer had a good hand for brushing my teeth.

I wonder whether this setback was caused by the different way of moving my hands when turning on the cold water tap and the feel of the toothbrush handle while on holiday. If so, then it seems that adaptation to new sensory information, at least from proprioception, touch, and the vestibular sense, is sensitive to context. At least in my case. And that context has a stronger influence on sensory adaptation than my strategy of telling myself out loud to brush with my left hand. Although my strategy became more effective when employed earlier in the habit-chain, it was still not stronger than context. At home, in my familiar surroundings, my strategy worked well again – even when used at the point of applying toothpaste.

Further in this vein, I wonder whether this sensitivity to context is high only until the brain has fully adapted to the new sensory information. Did the context cause slip-ups because my left-hand brushing routine was not yet as fully formed as I had thought? Indeed, even when I was aware of what I did differently on holiday and at home, and I knew how to correct it, I still had slip-ups. Back home after my holiday, the deliberate switching of the toothbrush from my right to my left hand before turning on the water tap and brushing my teeth worked well again.

group of children brushing teeth
AI-generated illustration for SmartSense

Some of my friends have joined me in brushing their teeth with the opposite hand. And they too have experienced setbacks in unfamiliar contexts. One of them also reported setbacks caused by too many simultaneous activities drawing her attention while brushing her teeth at home. For example, listening to the radio and planning what to wear the next day.

At home and back on track

  • Day seven: For the first time after my holiday, I automatically switched the toothbrush over to my left hand before turning on the water tap and brushing my teeth. The brushing itself, however, still felt a little awkward.
  • Day 10: My left-hand brushing routine was finally on course again. But it still felt both natural and fragile at the same time.
  • Day 12: Brushing with my left hand now felt much as it did in week seven before the holiday (see our blog for Sensory Adaptation).
  • Day 13: I just had to try. My friends were sceptical, but I had to see what would happen if I deliberately returned to right-hand brushing. And it felt completely wrong! My right hand seemed to be trying to flex and move the brush the way my left hand does. But it felt stiff and clumsy … (see our blog for Sensory Adaptation).
  • Day 14: Back to left-hand brushing. This now felt completely right: no setback!

 

My adaptation to new sensory information should by no means be taken as representative of how people adapt when every aspect of their life has to change. For example, after total sight loss (see our blog for Sensory mismatch, Decay and maintenance of sensory memories, Visual memories and sensory experiences, and Sensory Adaptation). The sensory adaptation required of me was limited to a single activity, lasting just two to three minutes twice a day. Even so, I hope my experience helps us all understand a little better that context matters, habit-chain matters, simultaneous activities matter, and probably many more factors besides. It takes persistence to adapt to new sensory information. And a fair bit of courage too!

See our blog for Activities; especially 97-99.

Blog post author: Dr Torø Graven

Sensory adaptation

When sighted people ask about being blind, they often wonder:

Is it like seeing black all the time?

My favourite conversation about this took place on the metro in Oslo. I was doing research on blindness. And the person who asked seemed to be sleeping rough. I answered, ‘No, because there is nothing there to see black with’. She lifted her index finger into the air and cut straight to the chase: ‘So, like seeing with my index finger. Or my big toe.’

Is it better to have had vision or to be born blind?

But people seem to know, intuitively, that there is no single answer to this. My response is usually: ‘It depends.’ Then people, often spontaneously, talk about recognising friends by their faces; yet they soon realise that voices are just as important – as are the skills needed to identify them. Some also talk about the smell of colours, mostly ocean blue and grass green. (See our blog for the scientific approach, the crossmodal correspondences between the senses, Crossmodal brain plasticity and empowering of sensory abilities, and Multisensory processing.)

How long does it take to adapt to being blind?

Again, my answer usually is: ‘It depends’ – on when and how vision was lost, the use of other senses before and after, and overall health. The brain must adapt to recognise sensory information without vision. And new habits take on average 66 days to become automatic. (See our blog for Decay and maintenance of sensory memories, Visual memories and sensory experiences, Reading braille in colour, and My vision, my identity.) I wonder, therefore, if it would be better to ask not how long it takes to adapt, but rather: how to adapt?

In an attempt to explore this question – how do people adapt to new sensory information? – I started brushing my teeth with my left hand instead of my right. Doing this meant adapting to new sensory information, especially from proprioception, touch, and the vestibular sense (see our blog for Growing into one’s own body). Drawing on previous research on people who have lost vision, including some of my own work, I expected to:

– Do well on my first attempt, then struggle to adapt to sensory information from my left hand

– Have slip-ups – old habits die hard – that would set me back in my progress

– Try different routines before fully adapting to sensory information from my left hand

My first attempt went well, but then came the second and the third – and they felt strange. Holding the brush was awkward, and I did not really know how to move it properly. It felt as if the brush was sliding around with no clear purpose. And I was certainly not convinced my teeth were clean afterwards, but I resisted the temptation to go back to using my right hand.

Then, attempt five – and my first slip-up. I suddenly realised that my movements with the brush were different, and next came the feel of it against my gums. Judging from the position of the brush this was my usual right-hand brushing routine, I had at least caught my slip-up early.

For the next attempt, I reminded myself – even said it out loud – to use my left hand. I was expecting this brushing to be more difficult, but I did not notice any real setback. And I wondered if this was because I had not yet formed a routine for brushing with my left hand.

young child smiling and brushing teeth
AI-generated illustration for SmartSense

To stay on track, I decided to pay close attention to what I was doing from the moment I applied toothpaste to the brush. I noticed the difference in how I used my two hands. With my right hand, I used a full-hand grip to hold the brush. My wrist was often stiff, and the pressure on my gums was quite hard. With my left hand, I flexed the brush in my grip: I held it almost as if I were holding a pen, sometimes adding my middle finger; I gripped it between my index finger and thumb, again sometimes bringing in the middle finger, and my wrist bent, stretched, and turned. The pressure on my gums was much lighter than with my right hand.

Over the next three to four weeks, I began to establish a routine for how I brushed – moving from the left upper teeth, across to the right, then down to the right lower teeth, and over to the left, before returning to the middle for an extra clean. My grip on the brush became firmer, and the pressure on my gums more constant. It no longer felt as if the brush was sliding around with no clear purpose. And I was almost convinced my teeth were clean afterwards. I had had three slip-ups, but I caught them early and carried on brushing with my left hand. It was time to try a deliberate right-hand brushing again.

Week seven, day one: return to right-hand brushing. At this point, I had a consistent routine for my left-hand brushing: the movement and feel of the brush were the same every time. Returning to my right hand was a bit of a shock. My right hand now felt inferior to my left: the handling of the brush was less flexible, the pressure on my gums was harder, and my teeth did not feel any cleaner than with my left-hand brushing. Next time, I brushed with my left hand again, without noticing any setbacks in my progress. In fact, left-hand brushing now felt more natural to me.

I have continued with my left-hand brushing, and if you asked me which hand I used this morning, I would not be able to tell you. But it was most likely my left.

My required adaptation was both minimal and reversible – only two to three minutes in the morning and evening, and it could be stopped at any time – and so should by no means be taken as representative of how people adapt when every aspect of their life has to change. For example, after total sight loss. There is also a little twist to my experience. I am “a leftie” who was trained to use my right hand. So, I wonder if my adaptation to new sensory information was facilitated by some pre-existing left-hand architecture in my brain. Still, I hope my experience offers a glimpse into how people adapt to new sensory information.

See our blog for Activities; especially 94-96.

Blog post author: Dr Torø Graven