The Impact of Cognitive Processes on Input Enhancement Techniques: studying Chinese Students with English as their Second Language

Student thesis: Doctoral Thesis


This thesis investigates the effects of an instructed second language acquisition method called Input Enhancement: textual using boldface, and audio enhancement, using intonation and stress and explicit rules aimed at facilitating gender pronoun grammar structures in English as a second language. Previous research on visual input enhancement has found mixed effects, and there is a scarcity of audio enhancement research thereby requiring more empirical studies. The relationship with cognitive processes is also explored in this investigation to provide a contribution to the understanding of cognitive load in instructed second language acquisition. There has been a long debate of how effective input enhancement is (typically visual input enhancement) and to what degree cognitive processes play a role in this instructed second language acquisition method.

The present thesis reports on a methodological synthesis with a meta-analysis and two experimental studies. First, the synthesis on visual input enhancement and grammar learning was performed on available studies (published and grey literature) in a 35-year period. 29 studies were included and focused on the method and design to help explain some of the variability in findings in this group of studies. A quantitative review of these 29 studies calculating and aggregating effect sizes using Cohen’s d values. The results indicate mixed effect sizes ranging from small to large, d = 0.34, 95% CI [0.142, 0.542. The pre to post-test results focus on the how learners have performed from with 0.78 pre, 95% CI [0.496, 1.07]. This is a large effect and shows that students with the enhanced input texts improve from their pre-test scores to post-tests scores. Results demonstrates that second language learners with enhanced texts in the studies rarely outperform with in their comparison groups (control group/unenhanced or only text groups). Conclusions from the analysis highlight the need for an improvement in methodological practices in visual input enhancement for grammar learning including reporting research design and measures more thoroughly.

In total, two experiments were then designed and conducted with a total of 416 second language learners of English participants (Experiment 1– 311, Experiment 2 – 105) participated in voluntary sessions. Experiment 1 was a four-week study which focused on the extent to which increased textually salient enhancements to a grammar form with intermediate second language learners of English in a middle school in China. With a total of six study conditions, participants were exposed to their study condition twice in two weeks and performed immediate and delayed post-tests a week later. The magnitude of visual input enhancement in Experiment 1 revealed that the rules only group performed best in the immediate short-term and that learners with rules and enhancement created possible cognitive overload.

Experiment 2 was a seven-week study which focused on the impact of modality (visual or audio-visual) on input enhancement and grammatical rules on intake with pre-sessional Chinese students. Audio input enhancement was designed and tested whereby the grammar form was emphasised naturally through native speaker stress and intonation. Again, in six conditions, participants studied for three sessions a week lasting a total of two weeks with immediate post-tests and then three weeks later with delayed post-tests. In both experimental studies, the participants were Chinese learners of English. Experiment 2 found no difference between audio and visual input enhancement but may have demonstrated cognitive load in audio and explicit rules condition.

Overall, the results of the studies in this thesis shed light on the notion that input enhancement may be impacted by cognitive processes and using this method does not always achieve long-term learning. Therefore, the statistical analyses demonstrate mixed findings from both input enhancement studies but do uncover how cognitive load plays a role in situations where the learner becomes overloaded with too much implicit and explicit information. This thesis concludes by suggesting that there is a relationship between cognitive processes and input enhancement techniques. Careful design of materials and staging needs to be considered before providing this form of instructed second language acquisition method to second language learners of English. In the future, there should also be more studies on audio input enhancement.
Date of AwardDec 2020
Original languageEnglish
Awarding Institution
  • University of Northampton
SupervisorChris Roe (Supervisor), Steve Kilpatrick (Supervisor) & Catherine Fritz (Supervisor)


  • Textual Enhancement
  • Input Enhancement
  • Audio Enhancement
  • Noticing and Awareness
  • Explicit and Implicit Instruction

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