Languages, Literatures, & Cultures Theses and Dissertations

Permanent URI for this collectionhttp://hdl.handle.net/1903/2785

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Modeling the effects of entrenchment and memory development on second language acquisition
(2019) Osthus, Peter Daniel; DeKeyser, Robert; Second Language Acquisition and Application; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
The observation that language learning outcomes are less consistent the older one becomes has motivated a large portion of second language acquisition research (e.g., Hartshorne, Tenenbaum, & Pinker, 2018; DeKeyser, 2012). Hypotheses about the underlying mechanisms which lead to age-related declines are traditionally tested with human subjects; however, many hypotheses cannot be fully evaluated in the natural world due to maturational and environmental constraints. In these scenarios, computational simulations provide a convenient way to test these hypotheses. In the present work, recurrent neural networks are used to study the effects of linguistic entrenchment and memory development on second language acquisition. Previous computational studies have found mixed results regarding these factors. Three computational experiments using a range of languages were conducted to understand better the role of entrenchment and memory development in learning several linguistic sub-tasks: grammatical gender assignment, grammatical gender agreement, and word boundary identification. Linguistic entrenchment consistently had a negative, but marginal, influence on second language learning outcomes in the gender assignment experiment. In the gender agreement and word boundary experiments, entrenchment rarely affected learning outcomes. Starting with fewer memory resources consistently led to poorer outcomes across learning tasks and languages. The complexity of the learning task and the regularity of the formal cues present in the linguistic input affected outcomes. In the gender assignment experiment, the first language influenced second language outcomes, especially when the second language had fewer gender classes than the first language. These results suggest that the effects of entrenchment and memory development on second language learning may be dependent upon the language pairs and the difficulty of the modeling task.
THE COMPARISON OF L1 AND L2 CASE PROCESSING: ERP EVIDENCE FROM TURKISH
(2019) KARATAS, NUR BASAK; Gor, Kira; Second Language Acquisition and Application; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
This dissertation investigates the morphological and morphosyntactic processing of case-marking by native and nonnative speakers of Turkish, through behavioral and electrophysiological responses. The study explores the locus of case processing costs during first (L1) and second language (L2) word recognition both in isolation and in sentences. It identifies the factors leading to persistent problems that late L2 learners face in attaining native-like processing of case assignment. To this end, the first experiment (a visual lexical decision task) examines whether different case forms generate differential processing costs, based on four main comparisons that reflect case properties and its status in the inflectional paradigm: 1) structural (genitive, accusative) vs. lexical (dative) case; 2) argument (accusative, dative) vs. non-argument (genitive); 3) higher (genitive) vs. lower type frequency (accusative, dative), and 4) citation form (nominative) vs. oblique cases (genitive, accusative, dative). The behavioral findings show significantly larger processing costs (i.e., longer reaction times and lower accuracy rates) for the genitive than the nominative case (citation form) across both subject groups, and than other oblique cases in L2 group only. ERP findings show significantly larger processing costs for the genitive than the accusative, and for the dative than the accusative only in L2 group. When the same case-inflected nouns were placed in a sentence context, larger N400 effects were found for the genitive, compared to the nominative and accusative in L1 group only. Together, these results suggest that different case forms generate differential processing costs in both subject groups, and L2 learners’ difficulty with the non-argument genitive and lexical dative oblique cases are at the level of form rather than sentence structure. The second (sentence) experiment also examined the processing of case errors (i.e., substitution of the accusative for the dative or vice versa on the object). ERP findings show a qualitative difference between L1 and L2 morphosyntactic patterns: P600 was missing while early negativities (N400 and left anterior negativity, LAN) were present in L2 group. These results suggest that advanced L2 learners evaluate the verb argument structure (LAN) and semantic fit (N400), but do not attempt to reparse the sentence (P600), unlike native speakers.
The Interactive Effects of Task Complexity, Task Condition, and Cognitive Individual Differences on L2 Writing
(2018) Lee, Jiyong; Long, Michael; Second Language Acquisition and Application; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
Second language (L2) researchers, L2 teachers, and textbook designers have shown great interest in the relationship between task characteristics and interlanguage development. Although the literature is inundated with research on the effects of task complexity on speech, less attention has been paid to its effects on writing. To this end, the present study investigated how increasing task complexity led to changes in cognitive load, and in turn, changes in L2 written performance. It also explored whether limiting the number of acceptable solutions to a task, i.e., task closure, had an effect on writing. Finally, the roles of working memory capacity (WMC) and aptitudes for implicit and explicit learning in task performance were investigated as well. Eighty-three Korean learners of English and seven L2 teachers deemed as experts were recruited for the study. The L2 learners were randomly assigned to one of two conditions: the Open condition, in which participants carried out open task versions, and the Closed condition, in which they carried out closed versions. Participants carried out two tasks, each with a simple and complex version. Learner self-ratings, expert judgments, and time-on-task were used to obtain independent evidence that increasing task complexity led to changes in cognitive load. An Ospan task and the LLAMA D and F were used to measure WMC and aptitudes for implicit and explicit learning, respectively. A series of mixed effects models revealed that tasks intended to be more complex were perceived as such by both learners and experts. While significant task complexity effects were found on lexical diversity and one measure of accuracy, its effects on syntactic complexity measures were not significant. Task closure effects were only found for lexical diversity, such that open versions elicited more diverse vocabulary than complex versions. Cognitive individual differences also played a role, such that higher WMC was related to greater lexical diversity, and higher aptitude for implicit learning was associated with greater accuracy in writing.
SECOND LANGUAGE LEXICAL REPRESENTATION AND PROCESSING OF MANDARIN CHINESE TONES
(2018) Pelzl, Eric; DeKeyser, Robert; Second Language Acquisition and Application; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
This dissertation investigates second language (L2) speech learning challenges by testing advanced L2 Mandarin Chinese learners’ tone and word knowledge. We consider L2 speech learning under the scope of three general hypotheses. (1) The Tone Perception Hypothesis: Tones may be difficult for L2 listeners to perceive auditorily. (2) The Tone Representation Hypothesis: Tones may be difficult for L2 listeners to represent effectively. (3) The Tone Processing Hypothesis: Tones may be difficult for L2 listeners to process efficiently. Experiments 1 and 2 test tone perception and representation using tone identification tasks with monosyllabic and disyllabic stimuli with L1 and advanced L2 Mandarin listeners. Results suggest that both groups are highly accurate in identification of tones on isolated monosyllables; however, L2 learners have some difficulty in disyllabic contexts. This suggests that low-level auditory perception of tones presents L2 learners with persistent long-term challenges. Results also shed light on tone representations, showing that both L1 and L2 listeners are able to form abstract representations of third tone allotones. Experiments 3 and 4 test tone representation and processing through the use of online (behavioral and ERP) and offline measures of tone word recognition. Offline results suggest weaknesses in L2 learners’ long-term memory of tones for specific vocabulary. However, even when we consider only trials for which learners had correct and confident explicit knowledge of tones and words, we still see significant differences in accuracy for rejection of tone compared to vowel nonwords in lexical recognition tasks. Using a lexical decision task, ERP measures in Experiment 3 reveal consistent L1 sensitivity to tones and vowels in isolated word recognition, and individual differences among L2 listeners. While some are sensitive to both tone and vowel mismatches, others are only sensitive to vowels or not at all. Experiment 4 utilized picture cues to test neural responses tied directly to tone and vowel mismatches. Results suggest strong L1 sensitivity to vowel mismatches. No other significant results were found. The final chapter considers how the three hypotheses shed light on the results as a whole, and how they relate to the broader context of L2 speech learning.
Explicit and Implicit Cognitive Aptitudes, L2 Outcome Measures, and Learning of Morphosyntax under an Incidental Condition
(2018) Maie, Ryo; DeKeyser, Robert M; Second Language Acquisition and Application; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
This study is the first to combine recent methodological advances to the measurement of explicit and implicit knowledge in an investigation of learning under incidental exposure. Participants were exposed to a semi-artificial language, Japlish, and subsequently tested as to the extent to which they had developed explicit and/or implicit knowledge. Subjective measures of awareness, objective measures of linguistic knowledge, and explicit and implicit cognitive aptitudes were employed to triangulate learning outcomes at two testing sessions. Overall results shed new light on the complexity of explicit and implicit learning under incidental conditions. Both learning types were confirmed in the experiment, but they occurred to a different degree and extent. Furthermore, the study identifies clear discrepancies among the four approaches to measuring explicit and implicit knowledge, with some being rigorous and others tending to underestimate or overestimate. The study calls for future research with more longitudinal and situated analyses of the phenomena.
TEMPORAL DISTRIBUTION OF PRACTICE AND INDIVIDUAL DIFFERENCES IN THE ACQUISITION AND RETENTION OF L2 MANDARIN TONAL WORD PRODUCTION
(2017) Li, Man; DeKeyser, Robert M; Second Language Acquisition and Application; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
This dissertation investigated the effects of temporal distribution of practice (relatively massed vs. distributed) on the learning and retention of oral Mandarin tonal word production by native English-speaking adults within the theoretical framework of skill acquisition and retention theories. The present study focused on oral production of Mandarin two-syllable words as a function of temporal distribution of practice. It also explored whether the effects of this distribution differ depending on the type of knowledge to be acquired or retained (declarative word knowledge vs. skills in oral production) and on individual differences in cognitive aptitudes (including working memory, phonological short-term memory, declarative memory, procedural memory, and musical aptitude). Eighty native English-speaking adults who did not have any prior knowledge of a tonal language completed all sessions of the study and provided data for analysis. These participants were randomly assigned to four experimental conditions, i.e., Condition A with a 1-day ISI (intersession interval) and a 1-week RI (retention interval), Condition B with a 1-day ISI and a 4-week RI, Condition C with a 1-week ISI and a 1-week RI, and Condition D with a 1-week ISI and a 4-week RI. Each participant came in for five sessions. All participants completed a set of cognitive aptitude tests and underwent the same number and content of training sessions, which differed only on training or testing schedules. The results showed that the effects of ISI and RI differed depending on the type of knowledge/skill to be retained, declarative versus procedural. For the retention of declarative knowledge, RI had a robust effect: the longer the RI, the worse the retention. Spacing, or distributed practice seemed to improve long-term retention of declarative knowledge; however, this ISI effect was much weaker. With regard to procedural knowledge retention, ISI seems to play a role, but not RI, and it was massed practice that had an advantage over distributed practice. Musical aptitude, working memory, and declarative memory ability were found to play facilitative roles in L2 learning of Mandarin tonal word productions. Procedural memory ability was found to interact with ISI and RI for various RT outcome measures.
An Examination of the Influence of Age on L2 Acquisition of English Sound-Symbolic Patterns
(2017) Mueller, Jeansue; Jiang, Nan; Second Language Acquisition and Application; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
A number of researchers (DeKeyser, 2012; J. S. Johnson & Newport, 1989; Long, 1990) have argued that age is a critical factor in second language acquisition. This conclusion is based on extensive research over the last two decades that has demonstrated age-related effects in learners’ nonnativelike acquisition of phonology, morphosyntax, pragmatics, and discourse-level features of language. In the wake of such findings, there has recently been an increased interest in determining the precise linguistic areas that are difficult for adult learners and the cognitive mechanisms implicated in age-related effects. Because implicit learning plays a key role in first-language (L1) acquisition, particularly in the acquisition of statistical patterns in language, it has been proposed that age effects may be the result of attenuated implicit learning capabilities in late-teen and adult learners (DeKeyser, 2000; Janacsek, Fiser, & Nemeth, 2012). If this is true, age-related effects should be significant in linguistic areas that are not readily amenable to conscious learning processes and explicit instruction. To determine whether this is in fact the case, this study examined the linguistic knowledge of native speakers (NSs), early L2 learners, and learners who acquired English as adults. In particular, it examined these groups’ knowledge related to an area of English that is hypothesized to be difficult to learn explicitly, namely, English sound-symbolic (SS) patterns. Participants were composed of English NSs (n = 20) and three NNS groups with L1 Korean and L2 of English. The NNS groups were divided into three groups based on age of onset (AO) , with an AO range from 3 to 9 years of age (n = 20), 10 to 16 (n = 20), and > 17 (n = 20). Three experiments were performed that tested the participants’ English magnitude SS sensitivities when forming assumptions about nonce words (Experiment 1 and 2) and their ability to utilize English SS patterns to bootstrap their learning of new vocabulary (Experiment 3). The two late L2 learner groups (AO 10-16; 17+) were found to have significantly reduced levels of SS knowledge compared to the early L2 learners (AO 3-9) and NSs in all experiments. Only in Experiment 1 and 2, the early L2 learners had diminished magnitude SS sensitivities compared to NSs, but not for Experiment 3. Explicit and implicit aptitudes as measured by LLAMA (Meara, 2005) were also tested for potential relationships with test scores. Explicit aptitudes (LLAMA B, E, and F) did not have a significant effect on the performance of all AO groups, whereas implicit aptitude (LLAMA D) did have a moderate to strong correlation for test scores in only the two late learner groups. The early learner group was not affected by language aptitude levels during the experiments. In sum, the study has found that there is evidence for SPE in the areas of magnitude and English phonesthemic SS patterns. Implicit language-learning aptitudes appeared to have a facilitative effect on the acquisition of these SS sensitivities for the two late L2 learner groups, but not for the early L2 learners.
EXPLICIT WRITTEN CORRECTIVE FEEDBACK AND LANGUAGE APTITUDE IN SLA: IMPLICATIONS FOR IMPROVEMENT OF LINGUISTIC ACCURACY
(2016) Benson, Susan Dianne; DeKeyser, Robert; Second Language Acquisition and Application; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
Most second language researchers agree that there is a role for corrective feedback in second language writing classes. However, many unanswered questions remain concerning which linguistic features to target and the type and amount of feedback to offer. This study examined two new pieces of writing by 151 learners of English as a Second Language (ESL), in order to investigate the effect of direct and metalinguistic written feedback on errors with the simple past tense, the present perfect tense, dropped pronouns, and pronominal duplication. This inquiry also considered the extent to which learner differences in language-analytic ability (LAA), as measured by the LLAMA F, mediated the effects of these two types of explicit written corrective feedback. Learners in the feedback groups were provided with corrective feedback on two essays, after which learners in all three groups completed two additional writing tasks to determine whether or not the provision of corrective feedback led to greater gains in accuracy compared to no feedback. Both treatment groups, direct and metalinguistic, performed better than the comparison group on new pieces of writing immediately following the treatment sessions, yet direct feedback was more durable than metalinguistic feedback for one structure, the simple past tense. Participants with greater LAA proved more likely to achieve gains in the direct feedback group than in the metalinguistic group, whereas learners with lower LAA benefited more from metalinguistic feedback. Overall, the findings of the present study confirm the results of prior studies that have found a positive role for written corrective feedback in instructed second language acquisition.
THE RELATIVE SIGNIFICANCE OF SYNTACTIC KNOWLEDGE AND VOCABULARY KNOWLEDGE IN SECOND LANGUAGE LISTENING COMPREHENSION
(2016) Vafaee, Payman; Ross, Steve; Second Language Acquisition and Application; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
The main purpose of the current study was to examine the role of vocabulary knowledge (VK) and syntactic knowledge (SK) in L2 listening comprehension, as well as their relative significance. Unlike previous studies, the current project employed assessment tasks to measure aural and proceduralized VK and SK. In terms of VK, to avoid under-representing the construct, measures of both breadth (VB) and depth (VD) were included. Additionally, the current study examined the role of VK and SK by accounting for individual differences in two important cognitive factors in L2 listening: metacognitive knowledge (MK) and working memory (WM). Also, to explore the role of VK and SK more fully, the current study accounted for the negative impact of anxiety on WM and L2 listening. The study was carried out in an English as a Foreign Language (EFL) context, and participants were 263 Iranian learners at a wide range of English proficiency from lower-intermediate to advanced. Participants took a battery of ten linguistic, cognitive and affective measures. Then, the collected data were subjected to several preliminary analyses, but structural equation modeling (SEM) was then used as the primary analysis method to answer the study research questions. Results of the preliminary analyses revealed that MK and WM were significant predictors of L2 listening ability; thus, they were kept in the main SEM analyses. The significant role of WM was only observed when the negative effect of anxiety on WM was accounted for. Preliminary analyses also showed that VB and VD were not distinct measures of VK. However, the results also showed that if VB and VD were considered separate, VD was a better predictor of L2 listening success. The main analyses of the current study revealed a significant role for both VK and SK in explaining success in L2 listening comprehension, which differs from findings from previous empirical studies. However, SEM analysis did not reveal a statistically significant difference in terms of the predictive power of the two linguistic factors. Descriptive results of the SEM analysis, along with results from regression analysis, indicated to a more significant role for VK.
Comparing Second Language Learners' Sensitivity to Arabic Derivational and Inflectional Morphology at the Lexical and Sentence Levels
(2015) Freynik, Suzanne Marie; Gor, Kira; Second Language Acquisition and Application; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
While L2 learners are less sensitive than native speakers to morphological structure in general (Clahsen & Felser, 2006; Jiang, 2007; Neubauer & Clahsen, 2009), researchers disagree about the roles different features of morphological systems play in determining the timecourse and accuracy of their acquisition by L2 learners. Some studies suggest that L2 learners process derivational morphemes in a more native-like manner than inflectional ones (Silva & Clahsen, 2008; Kirkici & Clahsen, 2013). Other research demonstrates accurate acquisition of L2 inflectional morphology as well (Gor & Jackson, 2013; Hopp, 2003; Jackson, 2008; Sagarra & Herschensohn, 2010). To date, few studies have directly compared L2 acquisition of inflectional and derivational morphology (Silva & Clahsen, 2008; Kirkici & Clahsen, 2013). Arabic verbs exhibit a system of derivational morphology whose function in constraining event structures and theta roles allows for comparably direct comparison with inflectional morphemes at the sentence level. Forty-four L2 learners and thirty-three native speakers of Arabic participated in the current study, which used three behavioral tasks: a primed lexical decision task, an acceptability judgment task, and a self-paced reading task, to triangulate a picture of L1 and L2 Arabic learners' commands of derivational and inflectional morphology at the lexical and sentential levels. Results of the lexical decision and self-paced reading tasks indicated that both L2 learners and native speakers alike made use of Arabic derivational and inflectional morphological structure during lexical access and sentence processing. However, the acceptability judgment task found that L2 learners made far more accurate judgments about Arabic inflectional errors than about derivational errors. By contrast, native speakers made accurate judgments about both kinds of morphological errors. Thus, L2 learners' behavior regarding Arabic inflectional morphology was at least as native-like as their behavior regarding derivational morphology, if not more so, across tasks. This pattern of results accords with previous research that found accurate processing of inflectional morphology in proficient L2 learners. It also adds to a growing body of research suggesting that the distinction between derivational and inflectional morphology in Semitic languages may be more graded than it is in Indo-European languages (Boudelaa & Marslen-Wilson, 2000; Frost, Forster, Deutsch, 1997).

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