Second language processing of english past tense morphology

Abstract

In the present study, highly proficient second language (L2) speakers’ processing of English past tense morphology was investigated in order to understand whether their processing routes (i.e., decomposition, storage or a dual-route) were comparable with native (L1) speakers of English. To this end, two instruments were developed. In the masked priming task, the reaction times (RT) for regular and irregular verbs were measured. The prime-target pairs were presented in three prime conditions: i) Identity (save-SAVE; build-BUILD), (ii) Test (saved-SAVE; built-BUILD), and (iii) Unrelated (carry-SAVE; share-BUILD). In the sentence reading task, the same regular and irregular verbs used in the masked priming task were inserted in sentences and the participants’ fixation durations for each verb type were compared. The study also sought to explore whether working memory (WM) has any relationship with L2 morphological processing. In addition to these, two WM measures, Automated Reading Span (ARSPAN) and Automated Operation Span (AOSPAN) tasks were adopted in order to discern whether WM correlates with the RTs in the masked priming task and fixation durations in the eye tracking task. The L2 speakers also received a Turkish version of the ARSPAN so that any confounding effects of language on WM performance could be ruled out. The findings of the masked priming task showed that L2 speakers had slower RTs than native speakers. In addition, the regular verbs were responded to slower than irregular verbs in both groups. Further analyses revealed a partial priming pattern across the conditions for regular verbs (identityRT < testRT < unrelatedRT), which is interpreted as reduced decomposition and full priming pattern for the irregular verbs (identityRT = testRT < unrelatedRT), which is interpreted as decomposition, in both groups. In the eye tracking task, major significant differences were not found between the participant groups and verb types in terms of early (first-fixation duration, gaze duration) and late (second fixation duration, total fixation duration) processing measures. Regular and irregular verbs yielded significantly different fixation durations only in the native speaker group with regard to gaze duration, with slower durations for regular verbs. The correlation analyses did not point to any relationship between WM and masked priming and eye tracking results in either group. The extreme-groups analysis, whereby high and low WM subgroups in each participant group were compared, also did not result in significant between-group differences in terms of morphological processing. Comparable processing patterns in native and nonnative groups obtained in the present study oppose to earlier views that L2 learners are less sensitive to the morphological structure of the target language compared to native speakers. It seems that high proficiency L2 English speakers can employ the decomposition route in accessing inflected forms in the L2 similar to native speakers. Thus, our findings suggest that real-time processing of morphologically complex words can ultimately be native-like for adult L2 learners. Despite the lack of qualitative differences in processing, quantitative differences were found in the form of slower RTs in the L2 English group. These differences could not be accounted for by differences in WM.