Sleep facilitates learning a new linguistic rule

Abstract

Natural languages contain countless regularities. Extraction of these patterns is an essential component of language acquisition. Here we examined the hypothesis that memory processing during sleep contributes to this learning. We exposed participants to a hidden linguistic rule by presenting a large number of two-word phrases, each including a noun preceded by one of four novel words that functioned as an article (e.g., gi rhino). These novel words (ul, gi, ro and ne) were presented as obeying an explicit rule: two words signified that the noun referent was relatively near, and two that it was relatively far. Undisclosed to participants was the fact that the novel articles also predicted noun animacy, with two of the articles preceding animate referents and the other two preceding inanimate referents. Rule acquisition was tested implicitly using a task in which participants responded to each phrase according to whether the noun was animate or inanimate. Learning of the hidden rule was evident in slower responses to phrases that violated the rule. Responses were delayed regardless of whether rule-knowledge was consciously accessible. Brain potentials provided additional confirmation of implicit and explicit rule-knowledge. An afternoon nap was interposed between two 20-min learning sessions. Participants who obtained greater amounts of both slow-wave and rapid-eye-movement sleep showed increased sensitivity to the hidden linguistic rule in the second session. We conclude that during sleep, reactivation of linguistic information linked with the rule was instrumental for stabilizing learning. The combination of slow-wave and rapid-eye-movement sleep may synergistically facilitate the abstraction of complex patterns in linguistic input.

Sleep-based memory processing facilitates grammatical generalization: Evidence from targeted memory reactivation

“…Most importantly, these TMR results show that sleep provides benefits for generalization learning. Most previous support for this idea has come from wake-versus-sleep comparisons (e.g., Fenn et al, 2003; Gomez et al, 2006; Nieuwenhuis et al, 2013; Gaskell et al, 2014; Wagner et al, 2004; Durrant et al, 2011; Djonlagic et al, 2009), or from sleep-physiology and behavioral correlations (Batterink et al, 2014; Durrant et al, 2011; Djonlagic et al, 2009). By directly manipulating processing during sleep, our study provides novel evidence for this idea (e.g., avoiding limitations due to greater interference during wake in studies with wake-versus-sleep comparisons).…”

“…Sleep has been shown to facilitate generalization processes involved in a number of different aspects of language, including speech perception (Fenn et al, 2003), grammar learning (Gomez et al, 2006; Nieuwenhuis et al, 2013; Batterink et al 2014), and speech production (Gaskell et al, 2014). These experimental results have often implicated generalization above and beyond any improvement in rote or exemplar-based learning.…”

Sleep promotes analogical transfer in problem solving

“…Though sleep has been found to improve explicit knowledge about structure of sequences in serial reaction time tests (Wilhelm et al, 2013) and linguistic material (Batterink, Oudiette, Reber, & Paller, 2014) it may be that complex structural mappings do not become consciously available. We thus suggest that the effect of sleep appears to be more likely due to information restructuring.…”

System Consolidation During Sleep – A Common Principle Underlying Psychological and Immunological Memory Formation

“…The redistribution proceeds alongside a qualitative transformation of the representation and the abstraction of invariants, regularities, and gist. Thus, sleep was found to enhance false but generalized, abstract memories in the Deese-Roediger-McDermott paradigm [27] to facilitate insight into hidden rules underlying stimulus sequences [28][29][30][31], to improve distant inferential judgment [32], to favor the abstraction of categories from similar objects [33], and to de-contextualize memories from the original context in which they were learned [34][35][36].…”