Can we use our visual cortex to decode tactile input?

[Diane]

I thought this was an interesting post at Deric Bownds Mindblog: We can use our visual cortex for touch (http://mindblog.dericbownds.net/2008/09/we-can-use-our-visual-cortex-for-touch.html). I plan to chase down the article too, to see how it may apply to manual therapy. I've always said that if people can learn to read braille they can learn to use their hands appropriately for manual therapy, can learn to feel the nervous system as it responds to touch and handling and particularly skin stretching.

Here is the article, open access. (http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0003046)

Rapid and Reversible Recruitment of Early Visual Cortex for Touch

Lotfi B. Merabet, Roy Hamilton, Gottfried Schlaug, Jascha D. Swisher, Elaine T. Kiriakopoulos, Naomi B. Pitskel, Thomas Kauffman, Alvaro Pascual-Leone*

Department of Neurology, Berenson-Allen Center for Noninvasive Brain Stimulation, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts, United States of America
Abstract
Background

The loss of vision has been associated with enhanced performance in non-visual tasks such as tactile discrimination and sound localization. Current evidence suggests that these functional gains are linked to the recruitment of the occipital visual cortex for non-visual processing, but the neurophysiological mechanisms underlying these crossmodal changes remain uncertain. One possible explanation is that visual deprivation is associated with an unmasking of non-visual input into visual cortex.

It would be nice to examine sighted people and see if their brains can respond in a like manner, with eyes either open or closed. ;)

[Gustavo Pacheco de Souza Cruz]

HI Diane,

This subject is very interesting, and there are some papers showing that, when a congenitally blind subject reads in braille, his visual cortex shows any activation near sulcus calcarinus (primary visual cortex). THese studies were made with fMRI.

I'll find them and send you.

[Barrett Dorko]

Diane,

This concept is reminiscent of the essay A Sense of Things ( http://www.barrettdorko.com/articles/a_sense_of_things.htm).

The visual deprivation anyone obliged to palpate the body in order to feel subtle but meaningful alterations in temperature and position as it moves will predictably light up the visual cortex, I think. This seems confirmed by Bach-y-Rita’s highly regarded work years ago and I’ve been getting images in my head for ages, it seems.

I’m I right? Is this related?

[Diane]

I’m I right? Is this related?
Yup, pretty sure it would be.
Would be nice if sighted people who practice manual terapy for a living were fMRI'ed while working to find out if their visual cortices were active, with their eyes closed, don't you think?
I'd like to find out something like that, anyway...