Executive Functioning and the Emergence of Conversational Understanding
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Contents Executive Functioning and the Emergence of Conversational Understanding. Clair Pond A thesis submitted for the degree of Doctor of Philosophy Department of Psychology September 2009 Contents 11 Abstract Conversational understanding (CU) refers to the ability to accurately interpret the meaning of discourse-embedded language. Siegal and Surian (2007) have suggested that the developmental expression of CU often reflects the unmasking of a cognitive competence obscured by processing biases associated with a shortage of computational resources. This thesis sought to investigate the relationship between developing computational resources (conceptualized in terms of executive functioning (EF)) and CU in 3- to 6-year-old children. According to Miyake et al. (2000), EF can be considered to reflect three main skills - inhibition and updating of mental representations, and mental set shifting. This thesis investigated the independent contribution of these three aspects ofEF to CU. Experiments 1 and 2 investigated whether a relationship exists between the three components ofEF and a narrow, scalar implicature (SI) measure of CO. Updating ability was found to demonstrate significant relations with SI scores. Experiment 3 revealed that shifting ability is significantly related to a broad, conversational violations task (CVT) measure of CU. Experiment 4 used training to significantly enhance children's shifting ability. However, this did not lead to a corresponding improvement in CVT perfonnance. Experiment 5 investigated the relationship between EF and CU in bilingual children. Bilinguals demonstrated a non-significant shifting advantage relative to monolingual controls, but did not demonstrate a CO superiority. Experiment 6 provided a more detailed analysis of the relationship between EF and CO by presenting monolingual children with both the narrow and broad CO measures previously presented, along with the updating, inhibitory and shifting EF measures used in Experiments 2-5 and three new measures of these EF components. All three EF components were found to demonstrate relations with CVT perfonnance after the effects of age and verbal intelligence had been controlled for. The consistent demonstration of significant relationships between EF components and CU revealed in this thesis provides partial support for Siegal and Surian's masked competence model of the developmental expression of CU. Contents 11l Acknowledgements I would like to thank my primary supervisor, Professor Michael Siegal, for providing direction and criticism where required and helping me to expand my understanding of the field focused upon in this thesis. I am also grateful for the support provided by my second supervisor, Professor Richard Eiser. My family and friends also deserve mention for their ceaseless patience and encouragement. I would also like to express gratitude to the ESRC who provided the funding which enabled me to conduct the research reported in this thesis and all the children who took part in my studies along with their teachers, schools and parents. Contents IV Table of Contents page Executive Functioning and the Emergence of Conversational Understanding ............ i Abstract. ........................................................................................... ii Acknowledgements .............................................................................. iii Table of Contents ................................................................................ .iv Table of Tables ........................................................................................ vii Table of Figures ...................................................................................... xiv Chapter 1: Conversational understanding in young children 1.1 Focus of this thesis ........................................................................... 1 1.2 Conversational understanding in childhood .............................................. 2 1.3 The Gricean framework and the Relevance approach .................................. 6 1.4 Cognitive development and the conceptual change approach ........................ 12 1.5 Recent directions in conversational understanding research ..........................22 1.5.1 Explicit vs. implicit conversational understanding .................................22 1.5.2 The role of informational processing ................................................28 1.6 Theory of mind and conversational understanding ................................... .45 1.7 Summary .................................................................................... 52 Chapter 2: Executive functioning and conversational understanding 2.1 Elucidating the concept of "executive functioning" ................................... 53 2.2 Development of executive functioning in young children ............................. 58 2.3 Executive functioning and theory of mind ............................................... 67 2.4 Conversational understanding and executive functioning: A working model. ............................................................................................. 71 Chapter 3: Experiment 1 - Investigating the relationships between executive functioning, a narrow scalar implicature measure of conversational understanding and theory of mind. 3.1 Introduction ................................................................................. 74 3.2 Method ....................................................................................... 81 3.3 Results ........................................................................................ 91 3.4 Discussion .................................................................................. 103 Contents v 3.5 Conclusions ................................................................................ 111 Chapter 4: Experiment 2 - Using new measures to investigate the relationships between executive functioning, scalar implicatures and theory of mind. 4.1 Introduction ................................................................................ 113 4.2 Method ..................................................................................... 115 4.3 Results ....................................................................................... 126 4.4 Discussion .................................................................................. 146 4.5 Conclusions ................................................................................. 153 Chapter 5: Experiment 3 - Investigating the relationships between executive functioning, conversational understanding and theory of mind using a broad measure of conversational understanding: The Conversational Violations Task. 5.1 Introduction ................................................................................ 154 5.2 Method ..................................................................................... 157 5.3 Results ....................................................................................... 160 5.4 Discussion .................................................................................. 173 5.5 Conclusions ................................................................................ 184 Chapter 6: Experiment 4 - Effects of executive functioning training on conversational understanding. 6.1 Introduction ................................................................................. 185 6.2 Method ..................................................................................... 190 6.3 Results ....................................................................................... 198 6.4 Discussion ..................................................................................252 6.5 Conclusions ................................................................................ 259 Chapter 7: Experiment 5 - Effects of bilingualism on executive functioning and conversational understanding 7.1 Introduction .................................................................................260 7.2 Comparison of the language skills of monolingual and bilingual children. .. .. .. .. .. ...................................................262 7.3 Executive functioning and bilingualism ................................................ 265 7.4 Aim of Experiment 5 ...................................................................... 274 Contents VI 7.5 Method ..................................................................................... 277 7.6 Results ....................................................................................... 280 7.7 Discussion ................................................................................. 293 7.8 Conclusions ................................................................................ 301 Chapter 8: Experiment 6 - A further examination of the relationship between executive functioning and conversational understanding 8.1 Introduction ................................................................................. 302 8.2 Method ..................................................................................... 306 8.3 Results ...................................................................................... 314 8.4 Discussion .................................................................................. 347 8.5 Conclusions ................................................................................ 358 Chapter 9: Summary of findings regarding the relationship between executive functioning and conversational understanding