Z. Dienes et al., UNCONSCIOUS KNOWLEDGE OF ARTIFICIAL GRAMMARS IS APPLIED STRATEGICALLY, Journal of experimental psychology. Learning, memory, and cognition, 21(5), 1995, pp. 1322-1338
The criteria by which incidentally acquired knowledge of an artificial
grammar (A. S. Reber, 1967) could be unconscious was explored in 5 ex
periments. Participants trained on an artificial grammar lacked metakn
owledge of their knowledge: Participants classified substantially abov
e chance even when they believed that they were literally guessing, an
d, under some conditions, participants' confidence in incorrect decisi
ons was just as great as their confidence in correct decisions. Howeve
r, participants had a large degree of strategic control over their kno
wledge: Participants trained on 2 grammars could decide which grammar
to apply in a test phase, and there was no detectable tendency for par
ticipants to apply the other grammar.