The Effects Of Input Enhancement And Working Memory On Incidental Vocabulary Acquisition:an Eye-tracking Study

The present thesis uses eye-tracking technology to systematically explore the effects of input enhancement and working memory on incidental vocabulary acquisition.There are three types of input enhancement: textual enhancement,first language(L1)glosses and second language(L2)glosses.Specifically,four experiments were conducted to investigate the effects of textual enhancement,L1 glosses and L2 glosses on lexical attentional processing and incidental vocabulary acquisition.The study also explored whether these effects were moderated by individual differences in working memory,and the relationship between working memory and attentional processing.Study 1 investigated the effect of textual enhancement on incidental vocabulary acquisition.The results showed that textual enhancement can promote the acquisition of word forms,but not the learning of word meanings or reading comprehension.At the same time,compared with the control condition,textual enhancement succeeded in directing learners' attention to target unknown words and promoting incidental vocabulary learning gains.Study 2 studied the effect of L1 glosses on incidental vocabulary acquisition.The results indicated that L1 glosses can promote the acquisition of word meanings and reading comprehension.Additionally,compared with the nonglossed condition,participants' attention to target unknown words was significantly reduced under L1-glossed condition,indicating that L1 glosses might distract learners' attention from target words.Noticeably,under L1-glossed condition,more reading time was associated with higher vocabulary test scores.Study 3 investigated the effect of L2 glosses on incidental vocabulary acquisition.The results showed that,similar to L1 glosses,L2 glosses can promote the acquisition of word meanings,but not the acquisition of word forms or reading comprehension.Under L2-glossed condition,participants spent less time processing the target unknown words than their matched controls,but the longer participants looked at target unknown words during reading,the more likely they were to recognize that word in an unannounced vocabulary posttest.Study 4 further investigated whether the influence of different types of input enhancement(textual enhancement,L1 glosses,L2 glosses)on incidental vocabulary acquisition was moderated by working memory,and whether individual differences in working memory affected learners' attentional processing.It was found that working memory moderated the effect of L1 glosses on incidental vocabulary acquisition.Also,working memory affects learners' attention allocation to target words under L2-glossed condition.In addition,to gain more insights into learners' perspectives,questionnaires and interviews were conducted.Consistent with the results of online eye-tracking data and offline behavioral tests,participants indicated that textual enhancement did attract their attention,but did not help them understand word meanings,and they reported that they would prefer to look directly at glosses rather than unknown words.The findings of the present study provide direct evidence for noticing hypothesis that more attention leads to more learning.Meanwhile,it shows that different types of input enhancement have different effects on vocabulary attentional processing,resulting in different performance on vocabulary posttests.Furthermore,individual differences in working memory not only affect the allocation of attentional resources,but also moderate the relationship between input enhancement and incidental vocabulary acquisition.In conclusion,this thesis systematically investigates the eye movement patterns of learners under different types of input enhancement,which helps to understand the vocabulary processing mechanism during L2 reading and provides more useful information for researchers,L2 learners and foreign language teachers.