Explicit and implicit aptitude effects on second language speech learning: Scrutinizing segmental and suprasegmental sensitivity and performance via behavioural and neurophysiological measures

Abstract

The current study examines the role of cognitive and perceptual individual differences (i.e., aptitude) in second language (L2) pronunciation learning, when L2 learners' varied experience background is controlled for. A total of 48 Chinese learners of English in the UK were assessed for their sensitivity to segmental and suprasegmental aspects of speech on explicit and implicit modes via behavioural (language/music aptitude tests) and neurophysiological (electroencephalography) measures. Subsequently, the participants' aptitude profiles were compared to the segmental and suprasegmental dimensions of their L2 pronunciation proficiency analyzed through rater judgements and acoustic measurements. According to the results, the participants' segmental attainment was associated not only with explicit aptitude (phonemic coding), but also with implicit aptitude (enhanced neural encoding of spectral peaks). Whereas the participants' suprasegmental attainment was linked to explicit aptitude (rhythmic imagery) to some degree, it was primarily influenced by the quality and quantity of their most recent L2 learning experience. COGNITIVE CORRELATES OF LSPEECH LEARNINGUnderstanding the process and product of second language acquisition (SLA) is complex, as it can be explained not only by factors related to experience (i.e., the extent to which second language [L2] learners practice the target language), but also by those related to aptitude (i.e., the cognitive and perceptual factors which determine the extent to which L2 learners can make the most of relevant L2 experience). Whereas the previous literature has examined aptitude in reference to L2 lexicogrammar development (for reviews, see Li, 2016;Skehan, 2016), surprisingly little is known about the role of aptitude in L2 pronunciation learning. The present study aims to fill this gap by proposing a new framework of cognitive abilities relevant to the degree of success after years of explicit and implicit pronunciation learning under various L2 learning conditions. To achieve this main objective, we assessed the segmental and suprasegmental sensitivity of 48 Chinese learners of English in the UK by using a range of behavioural (language and music aptitude tests) and neurophysiological (electroencephalography) measures. Subsequently, we explored which pronunciation learning aptitude variables were linked to the segmental and suprasegmental aspects of the learners' L2 pronunciation performance, controlling for their L2 learning backgrounds (i.e., their past and recent L2 use). Background Second Language Pronunciation DevelopmentSecond language pronunciation proficiency is a composite skill which comprises the capacity to (a) pronounce new consonantal and vocalic sounds in a L2 without deleting or substituting them for L1 counterparts (segmental accuracy); (b) use adequate prosody at the word (correct assignment of word stress) and sentence (appropriate use of intonation for declarative and interrogative intensions) levels; and (c) deliver speech at an optimal tempo (...

Successful second language learning is tied to robust domain-general auditory processing and stable neural representation of sound

“…We find that individuals who encode the neural representation of the second formant of speech more robustly are also better able to perceive English vowels. This is in accordance with previous findings that vowel perception is linked to the extent to which the frequency-following response distinguishes between different vowels (Won et al, 2016), and that formant encoding in the frequency-following response tracks with the accuracy of segmental L2 production (Saito et al, 2018). Here we extend these results by showing that neural formant encoding and behavioural measurements of spectral processing explain independent variance in speech perception.…”

“…Our finding of a link between rhythm perception and production and second language acquisition is in line with our precursor research which demonstrated that adult second language learners with greater rhythmic sensitivity spoke more fluently (with faster speech rate and fewer pauses and repetitions) (Saito et al, 2018). This relationship between rhythm perception and second language learning may help explain prior findings of links between musical training and second language learning success (Slevc & Miyake, 2006;Martinez-Montes et al, 2013;Swaminathan & Gopinath, 2013;Cooper, Wang, & Ashley, 2017;Dittinger, D'Imperio, & Besson, 2018).…”

“…Even if two adults practice a target language for the same amount of time in an identical manner, their outcomes may most likely differ in various dimensions of language (Doughty, 2018). Building on first language acquisition literature (e.g., , and following our preliminary investigations (Omote et al, 2017;Saito et al, 2018), we asked whether and to what degree individual differences in auditory processing play a role in determining the degree of success among late second language learners. In the current investigation, we tested native Polish speakers living in London and found that proficient English grammatical knowledge and speech perception abilities were both linked to more precise auditory discrimination while speech perception was additionally linked to the robustness of neural responses to sound.…”

“…These studies have found that rapid speech sound learning is linked to behavioural measures of auditory processing such as spectral (Wong & Perrachione, 2007;Lengeris & Hazan, 2010) and temporal (Kempe, Thoresen, Kirk, Schaeffler, & Brooks, 2012;Kempe, Bublitz, & Brooks, 2015) discrimination acuity, as well as greater white matter density and volume in left Heschl's gyrus (Golestani, Molko, Dehaene, LeBihan, & Pallier, 2007; and the robustness of neural encoding of speech (Chandrasekaran, Kraus, & Wong, 2011). Recently, we have shown that the robustness of neural encoding of speech is linked to English speech perception ability in native Japanese speakers (Omote, Jasmin, & Tierney, 2017) and to English speech production ability in native Mandarin Chinese speakers (Saito, Sun, & Tierney, 2018) living in the UK, suggesting that individual differences in auditory encoding may relate to L2 learning outside of the laboratory as well.…”

The role of aptitude in second language segmental learning: The case of Japanese learners’ English /ɹ/ pronunciation attainment in classroom settings

“…Although the study found that the two explicit aptitude factors explained approximately 10% of variance in the participants’ L2 pronunciation attainment, it would be intriguing to replicate the findings by adopting a more comprehensive set of aptitude measures that are designed to tap into explicit and implicit learning abilities (with and without awareness), and domain-specific and domain-general abilities (associated with language learning and applicable to any general skill acquisition) in both the receptive and the productive modes (cf. Saito, Sun, & Tierney, 2018, for explicit and implicit sensitivity to segmental and suprasegmental sensitivity)…”