Summarizing a recent study:
…the tactile disadvantage extends to the conceptual domain. That is, we seem to be slower at recognising when a word is tactile in nature than we are at recognising whether words are visual, to do with taste, sound, or smell.
The researchers had dozens of participants look at words on a screen, presented one at a time, and press a button to say if they were related to the tactile modality (e.g. ‘itchy’) or not. Some words were tactile-related whilst others were fillers and related to the other senses.
The same task was then repeated but with participants judging whether the words were visual-related, auditory and so on, with each sense dealt with by a new block of trials. The key finding is that participants were much slower at this task in the tactile condition than for the other senses. This was the case even when words were presented for just 17ms, which is too fast for conscious detection but long enough for accurate responding.
Connell and Lynott say their findings provide further evidence for the tactile sense having a processing disadvantage relative to the other senses. They think this is because there’s little evolutionary advantage to sustaining attention to the tactile modality whereas there are obvious survival advantages with the other senses, for example: ‘…in hunting, where efficacious looking, listening and even smelling for traces of prey could afford an advantage.’ You may think of pain and damage detection as reasons for paying sustained attention to the tactile domain, but remember these are served by spinal reflexes. ‘We do not wait for the burning or stinging sensation to register with the attentional system before responding,’ the researchers said.
I can think of lots of reasons for sustained attention to tactile sensation, but they probably don’t have any evolutionary purpose.
“Staring into the blaze had been a tonic for me, confirming tendencies that I had always had but never cultivated. Gradually some of them were becoming comprehensible to me.
Even as a young boy I had been in the habit of gazing at bizarre natural phenomena, not so much observing them as surrendering to their magic, their confused, deep language. Long gnarled tree roots, colored veins in rocks, patches of oil floating on water, light-refracting flaws in glass — all these things had held great magic for me at one time: water and fire particularly, smoke, clouds, and dust, but most of all the swirling specks of color that swam before my eyes the minute I closed them.
To the few experiences which helped me along the way toward my life’s true goal I added this new one: the observation of such configurations. The surrender to Nature’s irrational, strangely confused formations produces in us a feeling of inner harmony with the force responsible for these phenomena. We soon fall prey to the temptation of thinking of them as being our own moods, our own creations, and see the boundaries separating us from Nature begin to quiver and dissolve. We become acquainted with that state of mind in which we are unable to decide whether the images on our retina are the results of impressions from without or from within.”
– from Demian by Hermann Hesse