Another study also challenges the notion of working memory being
deficient in people who are deaf because HEARING people who used
British Sign Language had the same inability to reach the
magical 7 +/-2 level of serial recall. This doesn't answer the
OP - but the point is: our phonological loop (which is where the
speaking-words-in-our-mind) is not terribly important in
measures of intellectual ability. What does this imply for the
OP? Not much, except we give our "thinking in spoken words" part
of our mind perhaps a little more credit than it might be due.
Or rather: We *too* do not think exclusively in auditory words.
[1]
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4419661/ "A
disadvantage for serially-presented linguistic material is also
found when deaf participants undertake the digit span or letter
span task in a sign language. Deaf native American Sign Language
(ASL) signers recall on average only 5 * 1 digits in forward
tasks, compared to hearers who recall an average of 7 * 2 digits
(Boutla et al., 2004; Bavelier et al., 2006). Hall and Bavelier
(2010, p. 54) have concluded that *speech-based representations
are better suited for the specific task of perception and memory
encoding of a series of unrelated verbal items in serial order
through the phonological loop.* Conway et al. (2009) go further
and propose the *auditory scaffolding hypothesis,* whereby one's
experience with sound helps provide a scaffold for the
development of those general cognitive abilities that are
required for the representation of temporal or sequential
patterns. However, Bavelier and colleagues' work shows that
hearing English-ASL bilingual adults also show the same
disadvantage for sign span compared to spoken span (Bavelier et
al., 2008), which challenges the auditory scaffolding hypothesis
because these individuals have had rich auditory input since
birth. In any case, it is clear that performance on spoken
serial recall tasks may not be directly comparable to
performance on signed serial recall tasks." ===
[2]
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2945821/ Among
hearing people, the phonological loop is partially relied upon
for working memory but not exclusively. There's a heuristic - a
"rule of thumb" that's used as a baseline, of 7 distinct items
in working memory, +/- two, but according to this study, people
born deaf do not have diminished working memory capacity,
although they DO have fewer "items" available to recall in a
serial fashion - at least *seem-to*. IN this article the
rule-of-thumb itself is questioned because the 7 +/-2 was rather
over-reaching... and in fact people who have hearing, their
levels of serial item recall is typically at the same levels as
ASL users with only minor adjustments to lab study. So, point
is: The "extra two" that are sometimes measured are _likely_
echoing in the phonological loop. Meaning: There's not much
significance to the phonological loop to working memory.
References
Visible links
1.
https://l.facebook.com/l.php?u=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fpmc%2Farticles%2FPMC4419661%2F&h=qAQHtap0U
2.
https://l.facebook.com/l.php?u=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fpmc%2Farticles%2FPMC2945821%2F&h=tAQHB8qcH
