Cognitive Investigations of Comprehension Processes

1. Cognitive Investigations of Comprehension Processes 曾玉村 Yuhtsuen Tzeng Learning & Cognition Lab, National Chung Cheng University Presented at GSME, NCYU, May, 04, 2011

2. To understand is human nature • Comprehension/understanding rests on memory • Comprehension promote reasoning, problem solving, creation… • To understand is to activate old knowledge • To understand is to a first step of learning • Education should aim at understanding

3. What is comprehension/understanding? • Language • Non-language

4. What is language comprehension? • Complex cognitive processes • The construction of a coherent mental representation of the text (e.g., Kintsch, 1988; Graesser & Clark, 1985; Trabasso & van den Broek, 1985) The reader identifies meaningful relations • between parts of the text • between text and background knowledge

5. What is comprehension?Text input provides raw elements for comprehension

6. What is comprehension?Readers connect text elements to build a network representation

7. What do the LS models say? How do readers achieve comprehension? • As readers proceed through the text, they attempt to maintain coherence for each new text segment (sentence) • (Re)activate information from prior text or background knowledge • E.g., referential and causal coherence • Naming/lexical decision/speeded recognition as well as reading time studies (e.g., O’Brien & Myers, 1989; McKoon & Ratcliff, 1990) • Inferences are crucial to go beyond text inputs

8. Formalization of the LS model • Attentional/Working memory limitations • Comprehension involves fluctuation of activation from • Text input • Carry over • Reinstatement (from representation of prior text) • Activation of background knowledge • Cohort activation (see below) •  landscape of activations

10. The LS model: Constructing a memory representation • Connections are identified between text items that are activated simultaneously • The episodic memory representation is updated as a result of each new activation vector, via an asymptotic (delta) rule

11. LS model: Dynamic interaction between activation and representation • Co-activated elements form a cohort in the episodic representation • Cohort activation provides additional activation during reading process • Consistent with current models (e.g., Construction-Integration model, Kintsch 1988; Resonance model,O’Brien & Myers)

13. Mathematical Formalizations of LS model • Three phases of LS model • Determine input • Compute cohort • Update episodic memory

14. Determine Input

15. Compute Cohort Activation- Equation 1

16. Transform Connection Strengths-Equation 2

17. Sigmoid Transformation

18. Compute Expectancy-Equation 3

19. Update Connection Strengths- Equation 4

20. Partial Memory Representation at Reading Cycle 3

21. Partial Memory Representation at Reading Cycle 13

22. The LS program: Input

23. The LS program: Input

24. The LS program: Output of activation patterns

25. The LS program: Output of connection patterns

28. Offline memory representation of text comprehension (Tzeng & Chen, 2006) Textbase Situation model

29. Offline memory representation of text comprehension (曾玉村＆陳秋芬，修改中)

30. How does causal structure of text affect online reading processes? • A minimalist view: readers make minimum amount inferences (McKoon & Ratcliff, 1992) • A bottom up approach of inference makings • Many “inferences” are passive memory activation processes • Readers will make inferences only if • No readily available information in WM • Coherence breaks in texts

31. How does causal structure of text affect online reading processes? • A constructionist view: readers would search for meaning (Graesser, Singer, & Trabasso, 1994) • Readers would make many (but not all) types of inferences to satisfy coherence assumption and explanation assumption • Coherence assumption: need local & global coherence to build situation models • Explanation assumption: to explain why certain event occur

32. A contrasting prediction • A minimalist view predicts no inferences will be made if texts have local coherence • A constructionist view predicts that inferences will be made even if texts have local coherence but do not have global coherence

34. Do readers make online global inferences? • Procedures • 22 college students • 32 stories were constructed out of 16 scenarios, half sequential & half hierarchical • Participants engaged in self-paced reading while recording their eye movements using Eyelink II

35. Eye tracking system

36. Eye tracking system

37. Results of eye movement data • Focusing on two types of sentences • Major goals & consequences (i.e., 3th、5th、8th、11th & 14th sentences) • Spill over effects of them (i.e., 4th、6th、9th & 12th sentences)

38. Results of eye movement data • First Gaze:the sum of time a reader’s first look of a sentence to the first time s/he exits that sentence • no differences on both versions except for outcome 3 • longer duration for sequential than hierarchical stories (889 vs. 777 ms respectively, t = 2.56, p = .011) • all other ps > .05

39. Results of eye movement data • Second Gaze: the sum of time readers’ fixations on their second pass of a sentence • longer for sequential version than hierarchical version on outcome 1 (1159 vs. 818 ms, t = 2.61, p = .009)

40. Results of eye movement data • Total duration: the sum of first-gaze and second-gaze • longer for sequential version than for hierarchical version on outcome 1 (2258 vs. 1789 ms, t = 2.65, p = .009) • longer for Action 1 for sequential version (a spillover region of Goal 1) (2350 vs. 1968 ms, t = 2.06, p = .04)

41. Results of eye movement data • Pattern of first Gaze • Cognitive loading for both version is the same since the wordings and syntax are almost identical

42. Results of eye movement data • Pattern of second gaze • Longer fixation time for sequential versions on Outcome 1 • Readers attempt to go back to integrate sentences to build a coherent representation since it start a new episode after this sentence (i.e., lack of global coherence)

43. Results of eye movement data • Pattern of total gaze • Outcome 1 marks the first difference between two versions of text therefore readers pay different amount of time • this effect spill back to Action 1 • There is a coherence break between the first and the second episode • Lack of global coherence in sequential stories causes readers spend more time on the first episode

44. Conclusions of eye movement data • Causal structure affect online reading times • Fixation time increase if texts lack of cross-episode (global) coherence • High causal coherent texts result in fewer looking back behaviors • Support a constructionist view

45. Key Issues of comprehension research • Successful decoding • Form text-based representations • extract propositions from texts (Kintsch & van Dijk, 1978) • Form situation model: • what the text is about • Go beyond text • Adding background kknowledge (van Dijk & Kintsch, 1983; Kintsch, 1988)

46. Inferences are crucial for constructing situation model Three turtles floating on a log. Several fish swimming under the log.

47. What are inferences • Information not explicit in text & readers retrieve from memory（Kintsch, 1998; Graesser, Singer, & Trabasso, 1994; Till, Mross & Kintsch, 1988) • 「他把鎖好的門打開」 • 「鑰匙」 • 「氣憤的老婆把杯子往地板上摔」 • 「碎掉」

48. 閱讀理解的推論能力 • Weaver 與 Kintsch (1991)估計讀者每讀一則文章之敘述，平均必須進行上打的推論才能真正 完全理解文意 • 理解需要多少推論以及何種推論有待釐清

49. 閱讀理解的推論能力 • 最小量論（minimalist） ( McKoon & Ratcliff, 1992） • 若文本具有局部連貫性，讀者則沒有進行整體推論連貫之必要，除非相關訊息可免費取得 • 建構論（constructivist） ( Graesser, Singer, & Trabasso, 1993） • 讀者會進行必要之推論以獲取文章整體意義，滿足讀者尋求意義的需求

50. 閱讀理解的推論能力發展 • 傳統閱讀發展停留於整體能力指標描述 • 傳統閱讀能力發展研究往往缺乏理論 • 推論能力發展研究較具特定性 • 推論能力發展研究有潛力提早診斷閱讀理解困難