|Clip art: Clker|
A number of posts have referred to the neurological "overlapping" in visual and haptic process in the brain. In other words, sight and touch are intricately interwoven. In the 2007 review by Pelli and TiIlman summarized by Science Daily.com from the journal, Nature, the concept of "critical spacing" is used to highlight the fact that spacing beween visual entities is apparently much more important to visual discrimination than is size. (Other research suggests the same for color as well.)
What that implies for our work is that establishing the optimal visual and haptic distance between vowels such as high-front-tense 'i' and high-front-lax 'I' should be very important for anchoring, encoding and recall. (How that then relates to resonance, tongue and jaw movement, and vowel quality is, of course, a very interesting question, as well!) In recent work I have begun to very carefully reassess the relative locations of all PMPs.
That focus has been very revealing. Some of it was motivated by learners who reported being seriously confused when, in an instructional video, my execution of the PMP and contact node for one of the vowels, the "critical space," varied by a couple of inches. A "feel" for visual space is potentially a very powerful tool, indeed.