I found and read the Jaeggi study for the first time last night. I was
shocked; I had always assumed that g was essentially fixed. This study
is groundbreaking in its implications.
But the literature on this topic is a little larger than might be
expected. Several studies (
http://www.nature.com/neuro/journal/v7/n1/
abs/nn1165.html,
http://lib.bioinfo.pl/pmid:17597168) have
demonstrated that working memory can be improved dramatically with
training, and that this improvement is largely attributable to long-
lasting brain changes. Allow me to share some information that you may
find useful:
Posttraining sleep may improve working memory. It is best to train at
night, preferably immediately before sleep.
http://www.jneurosci.org/cgi/content/abstract/28/40/10145
"Working memory (WM) performance, which is an important factor for
determining problem-solving and reasoning ability, has been firmly
believed to be constant. However, recent findings have demonstrated
that WM performance has the potential to be improved by repetitive
training. Although various skills are reported to be improved by
sleep, the beneficial effect of sleep on WM performance has not been
clarified. Here, we show that improvement in WM performance is
facilitated by posttraining naturalistic sleep. A spatial variant of
the n-back WM task was performed by 29 healthy young adults who were
assigned randomly to three different experimental groups that had
different time schedules of repetitive n-back WM task sessions, with
or without intervening sleep. Intergroup and intersession comparisons
of WM performance (accuracy and response time) profiles showed that n-
back accuracy after posttraining sleep was significantly improved
compared with that after the same period of wakefulness, independent
of sleep timing, subject's vigilance level, or circadian influences.
On the other hand, response time was not influenced by sleep or
repetitive training schedules. The present study indicates that
improvement in n-back accuracy, which could reflect WM capacity,
essentially benefits from posttraining sleep."