Implicit probabilistic sequence learning is independent of explicit awareness

Abstract

Studies into interactions between explicit and implicit motor sequence learning have yielded mixed results. Some of these discrepancies have been attributed to difficulties in isolating implicit learning. In the present study, the effect of explicit knowledge on implicit learning was investigated using a modified version of the Alternating Serial Response Time (ASRT) task, a probabilistic sequence learning paradigm that yields continuous and relatively pure measures of implicit learning. Results revealed that implicit learning occurred to the same extent, whether or not subjects had explicit knowledge. Some evidence, however, indicated that explicit knowledge could interfere with the expression of implicit learning early in training. In addition, there were dissociations between learning measures, in that reaction time and accuracy were differentially affected by explicit knowledge. These findings indicate that implicit sequence learning occurs independently of explicit knowledge, and help to explain previous discrepant findings.

Offline consolidation in implicit sequence learning

“…For example, when learning was assessed in young adults across three sessions with equivalent intervals of wakefulness or sleep, Song et al (2007) andHoward, 1997, Romano, Howard, and, they found no sequencespecific improvements from an a.m. to p.m. session or a p.m. to a.m. session. Similarly, when Nemeth and Janacsek (2011) tested participants on probabilistic sequence learning, before and after a 12-hr, 24-hr, or a 1-week interval, they found an improvement in general motor skill (i.e.…”

“…Sequence-specific learning refers to faster responses as a result of the acquisition of sequence-specific knowledge. Many serial reaction time task (SRTT) studies to date have not distinguished between these two components of performance (but see Hallgato et al, 2013;Németh et al, 2010;Song, Howard, & Howard, 2007, for exceptions).…”

“…To test probabilistic sequence learning we used an alternating serial reaction time task (ASRTT) in which every alternate component is sequenced according to a predictable rule with pseudorandom trials in between (see Howard & Howard, 1997;Németh et al, 2010;Romano, Howard, & Howard, 2010). The main reason for using a probabilistic sequence was to avoid the emergence of explicit knowledge, which might alter performance (Cleeremans & Jiménez, 1998;Destrebecqz & Cleeremans, 2001;Perruchet, Bigand, & Benoit-Gonin, 1997;Remillard, 2008;Remillard & Clark, 2001;Song et al, 2007). We tested whether consolidation would OFFLINE CONSOLIDATION 7 differ for the learning of probabilistic and deterministic sequences, in particular, whether it might be stronger for deterministic sequences (see Deroost, Zeeuws, & Soetens, 2006;Destrebecqz & Cleeremans, 2001;Wilkinson & Jahanshahi, 2007).…”

“…active online training) is all that is useful for the consolidation of implicit memory traces (Della-Maggiore, 2005;Press et al, 2005;Robertson et al, 2004;. In fact, offline consolidation, in the sense of "silent" improvement, may play no role at all in implicit sequence-specific learning (Hallgato et al, 2013;Németh & Janacsek, 2011;Németh et al, 2010;Siengsukon & Boyd, 2009;Song et al, 2007;Spencer, Gouw, & Ivry, 2007).…”

“…Sequence-specific learning refers to faster responses as a result of the acquisition of sequence-specific knowledge. Many serial reaction time task (SRTT) studies to date have not distinguished between these two components of performance (but see Hallgato et al, 2013;Németh et al, 2010;Song, Howard, & Howard, 2007, for exceptions).Evidence of offline motor memory consolidation in conjunction with explicit sequence learning was found when participants performed a finger-tapping task with two training sessions (Doyon et al, 2009;Walker, Brakefield, Morgan, Hobson, & Stickgold, 2002;Walker, Brakefield, Seidman, et al, 2003). Specifically, after one night's sleep, with no further practice between sessions, participants showed marked improvements in speed and accuracy.…”