| Credit: Clker/|
Library of Congress
In essence, they found that the brain seems to have two parallel learning management systems in sensory-motor learning. One is the Experiencer, learning the new skill; the other, something like "the Coach," that uses previous motor patterns in adjusting and perfecting the target skill. And the "surprising" finding: the two systems appear to be much more independent than previously thought, and furthermore, "the memories of errors foster faster learning!"
Wow. Does that mean that drawing attention to a learner's L1-influenced errors in pronunciation may, in fact, be a good thing? Apparently. Exactly how and when that is done is the question, of course. Most experienced speech professionals, especially speech pathologists, are very comfortable with occasional focus on the "error" as a point of departure, but until very recently, use of L1 pronunciation in L2 pronunciation instruction in this field has been, at least, not discussed formally in the literature.
I recently posted a question on a discussion board of pronunciation researchers and methodologists related to L1 use in pronunciation instruction--and got no response, other than some off-list comments to the effect that it is generally not done--probably a holdover from earlier Behaviourist notions of avoiding errors at all costs.
As noted in several earlier posts, in haptic pronunciation work, especially with vowels and intonation, anchoring of L1 structures and pronunciation is often key to quick, effective change. The Herzfield et al. study may help to explain why: haptic work is probably more strongly positioned or experienced on the sensory-motor side or track of the brain, allowing the L1 to be "used" somewhat more in isolation, causing less potential "interference" there than typical auditory/visual processing and practice.
Now that may be wrong, but (hopefully) helpful, nonetheless!
Citation: Johns Hopkins Medicine. "Memories of errors foster faster learning." ScienceDaily. ScienceDaily, 14 August 2014.