Reading – Touch by David Linden
Strolling through a local foreign language library, I stumbled onto TOUCH, by David Linden. Looked through, found it to be of interest and decided to have a go at it.
I was looking for a translation of all the science into everyday behaviors, something practical for my work. The expectations were met; however, you need to be patient if you choose to read this book because 90% of it is medical science (in English, in the version I read!).
Difficult as it may have been to read “Touch”, I did come out of it with some very interesting observations and learning. All text in inverted commas in the following text is a direct quotation from the book TOUCH, by David Linden.
How touch works
Touch is so much more than facts, objects and circuits which allow information to move from the sensors to the brain and back to the parts which can perform the needed action, like withdrawal.
We have “two separate touch systems in the skin, operating in parallel, which report fundamentally different aspects of our tactile world”: the facts and the emotions they trigger within us.
“Our perception of a sensory stimulus is crucially dependent upon our expectations, as they have been formed by our life experience up to that moment. When there’s a mismatch between expectation and sensation, it’s a sign that something weird is happening, and our perception of that sensation is fundamentally altered.”
While making sense of the touch information, context is key. The sensory experience itself is altered by the context.
It’s all blended
We experience touch as a unified sensation. The map our brain interprets as “touch” is built through parallel information transmission, interpretation, and sometimes with interventions.
“When pain occurs, we don’t experience it as a series of distinct sensory-discriminative and emotional-affective components: we experience it as a unified, unpleasant sensation. The emotional and the sensory are completely blended. “
Interior vs. Exterior
This fun fact you probably have already experienced. We feel more of them (touch sensations including pleasurable and unpleasurable ones) when they originate from outside our own body. We are more sensitive to pain (or other touch sensations) inflicted by someone else than by ourselves.
This state of facts is strongly related to the interpretation of the touch sensation and to the action- information the brain extracts from it. Am I in danger? What is the necessary action to keep this body safe?
It also corelates with the knowledge available before the sensation. If I have prior knowledge of what is going to happen I experience less emotional negative sense attached to the touch information.
In case you were wondering: the answer is “yes”: meditation helps reduce the unpleasantness of pain.
Self and others
Our emotional touch interpretation skills refer not only to what we come in direct contact with but also to what we observe in others. “We are highly sensitive to reading such signals [emotional-touch] between other people. This is an important feature of social cognition, helping us to track changes in affiliations, coalitions, and status within our social groups.”
Our brain tunes the touch information
This is a confirmation of what we know from other topics. Our brain filters, tunes and alters input-information before we experience it as perception and afterwards. It’s one of the mechanisms which allows us to go back into our memories and attribute them new interpretations and meaning.
In terms of touch sensations, there have been several studies which have documented the way our brain alters what we feel, when we feel and how we feel before we even feel it.
It’s always good to remember that we are not as objective as we think we are and I find it very interesting that the research investigated the touch mechanisms because I would have expected it to be “more fact based” than other senses.
Enjoy the reading!