Sleep Underpins the Plasticity of Language Production

Abstract

The constraints that govern acceptable phoneme combinations in speech perception and production have considerable plasticity. We addressed whether sleep influences the acquisition of new constraints and their integration into the speech-production system. Participants repeated sequences of syllables in which two phonemes were artificially restricted to syllable onset or syllable coda, depending on the vowel in that sequence. After 48 sequences, participants either had a 90-min nap or remained awake. Participants then repeated 96 sequences so implicit constraint learning could be examined, and then were tested for constraint generalization in a forced-choice task. The sleep group, but not the wake group, produced speech errors at test that were consistent with restrictions on the placement of phonemes in training. Furthermore, only the sleep group generalized their learning to new materials. Polysomnography data showed that implicit constraint learning was associated with slow-wave sleep. These results show that sleep facilitates the integration of new linguistic knowledge with existing production constraints. These data have relevance for systems-consolidation models of sleep.

Bedding down new words: Sleep promotes the emergence of lexical competition in visual word recognition

“…In demonstrating for the first time a sleep effect on visual word learning, the current study extends research on the influence of sleep on oral vocabulary learning (Dumay & Gaskell, 2007;Gaskell et al, 2014;Henderson et al, 2012;but cf. Szmalec et al, 2012).…”

Rapid generalization in phonotactic learning

“…In these experiments, participants are presented with individual words in a miniature artificial language, and are then tested on novel words to determine what knowledge they have extracted from the language. Adult participants have shown evidence of learning the phonotactics of artificial languages in such diverse tasks as acceptability judgments (Richtsmeier, 2011), speech error patterns in production (Gaskell et al, 2014;Warker & Dell, 2006) and familiarity judgments (Cristia et al, 2013). Related findings have been reported in artificial language studies of morphological alternations (Finley & Badecker, 2009;Peperkamp et al, 2006;Wilson, 2003).…”

“…In a study that assessed phonotactic learning using speech errors in production, participants only generalized phonotactic constraints to new sounds if a period of sleep intervened between the exposure and test sessions (Gaskell et al, 2014). Two studies that examined phonotactic learning in the context of a morphological alternation also did not report generalization to new segments (Peperkamp et al, 2006;Peperkamp & Dupoux, 2007).…”

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

“…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.…”