Age-dependent and coordinated shift in performance between implicit and explicit skill learning

Abstract

It has been reported recently that while general sequence learning across ages conforms to the typical inverted-U shape pattern, with best performance in early adulthood, surprisingly, the basic ability of picking up in an implicit manner triplets that occur with high vs. low probability in the sequence is best before 12 years of age and it significantly weakens afterwards. Based on these findings, it has been hypothesized that the cognitively controlled processes coming online at around 12 are useful for more targeted explicit learning at the cost of becoming relatively less sensitive to raw probabilities of events. To test this hypothesis, we collected data in a sequence learning task using probabilistic sequences in five age groups from 11 to 39 years of age (N = 288), replicating the original implicit learning paradigm in an explicit task setting where subjects were guided to find repeating sequences. We found that in contrast to the implicit results, performance with the high- vs. low-probability triplets was at the same level in all age groups when subjects sought patterns in the sequence explicitly. Importantly, measurements of explicit knowledge about the identity of the sequences revealed a significant increase in ability to explicitly access the true sequences exactly around the age where the earlier study found the significant drop in ability to learn implicitly raw probabilities. These findings support the conjecture that the gradually increasing involvement of more complex internal models optimizes our skill learning abilities by compensating for the performance loss due to down-weighting the raw probabilities of the sensory input, while expanding our ability to acquire more sophisticated skills.

Procedural learning across the lifespan: A systematic review with implications for atypical development

“…Findings suggested a stronger learning effect in the young groups (4‐ to 12‐year‐olds) which gradually declined over the older groups (14‐ to 85‐year‐olds). These findings were confirmed by a second paper of the same group, using partly the same group of participants (Németh, Janacsek, & Fiser, ), and are in line with a previous study (Fischer, Wilhelm, & Born, ). Janacsek et al .…”

The impact of signal-to-noise ratio on contextual cueing in children and adults

“…We know that children are able to explicitly understand the concept of probability by 9 or 10 years of age (e.g., Nikiforidou & Pange, 2010;Piaget & Inhelder, 1975). However, their ability to extract and explicitly express statistical probabilities continues to develop for many more years (e.g., Eppinger, Mock, & Kray, 2009;Hämmerer, Li, Müller, & Lindenberger, 2011;Janacsek, Fiser, & Nemeth, 2012;Nemeth, Janacsek, & Fiser, 2013). If these differences in processing probabilistic information also apply to implicitly extracting information about environmental regularities, then we would expect to find that acquiring contextual cueing by children is more affected by the introduction of noise than is the contextual cueing of adults.…”

Children retain implicitly learned phonological sequences better than adults: a longitudinal study

“…Interestingly, the authors observed a peak in task performance before the age of 12, after which performance dropped significantly. In another version of the task, however, where participants were explicitly made aware of the repetition, using instructions and visual cues, they found no age‐dependent change in learning (Nemeth, Janacsek, & Fiser, ). Nonetheless, in this latter case, additional measures of explicit knowledge concerning the repeating sequence (using verbal reports) revealed a different age‐effect, with significantly better scores on explicit knowledge of the sequence after the age of 12.…”

“…Based on these findings, Nemeth et al. () argued that children's superiority in various skills might have its basis in underlying implicit‐learning abilities that shift to explicit‐learning mechanisms later in life (Poldrack & Packard, ). This might, in turn, be attributed to a neurological change at the level of two separate long‐term memory systems, namely an early developed basal‐ganglia system (the procedural memory system), that is involved in implicit skill learning, and the late maturing frontal/medial‐temporal circuits (the declarative memory system), that is assumed to rely on explicit attention processes (Perez, Peynircioglu, & Blaxton, ; Robertson, ; Squire, ).…”

“…In the present study, participants were made explicitly aware of only one of two Hebb sequences (i.e., the sequences and their co‐presented pictures) by the use of intentional encoding instructions issued prior to training (Gagnon et al., ), as well as by use of explicit cuing during the task (similar to Nemeth, Janacsek, & Fiser, ). The other Hebb sequence remained implicit, in the sense that its presence was unannounced to participants.…”