Measuring the bilingual advantage in young adults

263 Pages·2016·5.22 MB·English

From executive behaviors to neurophysiological markers of executive function:
Measuring the bilingual advantage in young adults

by

William Rylie Moore
BA, University of British Columbia – Okanagan, 2010
MSc, University of Victoria, 2012

A Dissertation Submitted in Partial Fulfillment
of the Requirements for the Degree of

DOCTOR OF PHILOSOPHY

in the Department of Psychology

© William Rylie Moore, 2016
University of Victoria

All rights reserved. This dissertation may not be reproduced in whole or in part, by
photocopy or other means, without the permission of the author.
ii

Supervisory Committee

From executive behaviors to neurophysiological markers of executive function:
Measuring the bilingual advantage in young adults

by

William Rylie Moore
BA, University of British Columbia – Okanagan, 2010
MSc, University of Victoria, 2012

Supervisory Committee

Dr. Mauricio Garcia-Barrera, Department of Psychology
Supervisor

Dr. Clay Holroyd, Department of Psychology
Departmental Member

Dr. Barbara Rutherford, University of British Columbia - Okanagan
Additional Member
iii

Abstract
The ease at which individuals acquire a second language is astounding.
Individuals are capable of learning a second language at any point through out their
lifespan, although it is easier to learn a second language early in life. With increasing
knowledge about linguistic neural processing and the brain’s capacity for plasticity, the
research on bilingualism has increased substantially. Researchers have become
increasingly more interested in the long-term effects of acquiring a second language,
especially the enhancement of executive function (EF). This enhancement, also known as
bilingual advantage, has been studied for a range of EFs, including inhibition, attention,
problem solving, and reasoning. Although this effect was first demonstrated in bilingual
children, researchers have extended the quest for understanding to young, middle, and
older adults; however, the research findings are mixed for young adults. In order clarify
these mixed results, the age of second language acquisition has been included as an
experimental variable, producing three relevant groups: early bilinguals, late bilinguals,
and monolinguals.
There are several ways in which EFs can be measured, including behavioral rating
scales, computerized cognitive tasks with behavioral outcomes (i.e., response times and
accuracy), and computerized event-related potential cognitive tasks. A novel multi-level
approach to measuring the bilingual advantage was developed and used as a framework
for the current dissertation; i.e., the bilingual advantage was measured at three levels of
measurement. This approach predicts that more complex levels of measurement (i.e.,
executive behaviors) would produce null findings between the three groups, while
differences between early bilinguals and the other two groups would be predicted for less
iv

complex levels of measurement (i.e., neurophysiological markers). This approach
predicts mixed results for levels of measurement that involve moderate complexity (e.g.,
computerized tasks of EF). Early bilinguals, late bilinguals, and monolinguals were
compared across three hierarchical levels of measurement: (i) executive behaviors; (ii)
information processing (i.e., computerized tasks of EF); and (iii) neurophysiology (i.e.,
event-related potential paradigm). Findings generally support the multi-level approach:
no differences were found at the executive behavior level, limited and mixed differences
were found at the information processing level, and differences between groups were
found at the neurophysiological level.
v

Table of Contents
Supervisory Committee ...................................................................................................... ii
Abstract .............................................................................................................................. iii
Table of Contents ................................................................................................................ v
List of Tables ................................................................................................................... viii
List of Figures .................................................................................................................... ix
Acknowledgments ............................................................................................................. xii
Dedication ........................................................................................................................ xiii
Prologue ........................................................................................................................... xiv
Chapter 1 ............................................................................................................................. 1
The bilingual advantage on executive function task performance in young adult: A review
and suggestions for future research ..................................................................................... 2
Executive function ....................................................................................................................... 3
The bilingual brain and the need for an executive control system .............................................. 8
The bilingual advantage ............................................................................................................. 15
Additional variables of interest .................................................................................................. 24
Opponents of the Bilingual Advantage ..................................................................................... 40
Looking forward: A multi-level approach to the measurement of the bilingual advantage ...... 42
Recommendations for future research ....................................................................................... 46
Conclusions ............................................................................................................................... 49
Chapter 2 ........................................................................................................................... 52
Examination of the bilingual advantage in young adults using two behavioral rating scale
measures of executive function ......................................................................................... 53
The Bilingual Advantage ........................................................................................................... 53
Measuring EF ............................................................................................................................ 55
Objective .................................................................................................................................... 61
Hypotheses ................................................................................................................................. 62
Method .............................................................................................................................. 63
Participants and Measures ......................................................................................................... 63
Statistical Analyses .................................................................................................................... 66
Results ............................................................................................................................... 67
Discussion ......................................................................................................................... 68
Chapter 3 ........................................................................................................................... 75
The bilingual advantage in young adults: Examining the importance of age of acquisition
when measuring executive function .................................................................................. 76
Executive function ..................................................................................................................... 77
Measuring the bilingual advantage ............................................................................................ 80
The present study ....................................................................................................................... 84
Method .............................................................................................................................. 89
vi

Participants ................................................................................................................................ 89
Materials .................................................................................................................................... 90
Stimuli & Procedure .................................................................................................................. 91
Statistical analyses ..................................................................................................................... 96
Results ............................................................................................................................... 98
Inhibition ................................................................................................................................... 98
Switching ................................................................................................................................... 99
Updating .................................................................................................................................... 99
Complex EF Tasks ..................................................................................................................... 99
Analyses with two language groups .......................................................................................... 99
Correlations ............................................................................................................................. 101
Discussion ....................................................................................................................... 103
Inhibition ................................................................................................................................. 103
Switching ................................................................................................................................. 105
Updating .................................................................................................................................. 106
Complex EF tasks .................................................................................................................... 108
Limitations ............................................................................................................................... 110
Conclusions and Future research ............................................................................................. 111
Chapter 4 ......................................................................................................................... 114
Measuring the neurophysiological markers of executive function advantages in bilingual
young adults: Inhibition, shifting, and updating working memory ................................ 115
Executive function and the bilingual advantage ...................................................................... 115
Electroencephalography/Event-related potentials ................................................................... 117
Neurophysiological differences of EF in bilinguals and monolinguals ................................... 127
Statement of the problem ......................................................................................................... 131
Hypotheses ............................................................................................................................... 133
Method ............................................................................................................................ 136
Questionnaires ......................................................................................................................... 136
Participants .............................................................................................................................. 137
Stimuli & Procedure ................................................................................................................ 139
Data acquisition & ERP analyses ............................................................................................ 145
Results ............................................................................................................................. 150
Demographic and language between-group comparisons ....................................................... 150
Behavioral data ........................................................................................................................ 151
ERP data .................................................................................................................................. 152
Discussion ....................................................................................................................... 172
Inhibition ................................................................................................................................. 173
Switching ................................................................................................................................. 178
Updating .................................................................................................................................. 181
Limitations ............................................................................................................................... 183
Conclusions and future directions ........................................................................................... 188
References ....................................................................................................................... 194
Appendix A ..................................................................................................................... 227
Appendix B ..................................................................................................................... 242
vii

Appendix C ..................................................................................................................... 247
viii

List of Tables
Table 1. Demographic Information
 ....................................................................................................
 65

Table 2. Dominant and Nondominant Language Spoken by Participants
 .............................
 65

Table 3. Mean and SD Table
 .................................................................................................................
 67

Table 4. ANOVA Table
 ............................................................................................................................
 67

Table 5. Demographic Information for Chapter 3
 .........................................................................
 90

Table 5. Table of Means, SDs, and ANOVAs Results for Three Groups
 ................................
 98

Table 7. Table of Means, SDs, and ANOVAs for Two Groups
 ...............................................
 100

Table 8. Correlation Table Between Individual EF Components
 ..........................................
 101

Table 9. Correlation Table Between Complex EF Tasks
 ..........................................................
 102

Table 10. Participant Demographics
 ..............................................................................................
 138

Table 11. Dominant and Nondominant Language Spoken by Participants
 .......................
 139

Table 12. ERP Rejection and Correction Table
 ..........................................................................
 145

Table 13. Behavioral Data: means, SDs, and one-way ANOVA results
 .............................
 151

Table 14. Midline Electrode Mean Voltages
 ................................................................................
 152

Table 15. Peak Amplitude and Latency Means and SDs
 ..........................................................
 153
ix

List of Figures
Figure 1. Adapted from Kroll (1993). It represents a cognitive processing model where
the top layer (i.e., lexical level) represents the form of the dominant (L1) and
nondominant (L2) languages and their relative connections. The conceptual level
(i.e., conceptual store) is a common system that houses semantic information and is
shared by both languages. Solid lines represent relatively stronger connections;
dotted lines represent relatively weaker connections.
 .........................................................
 10

Figure 2. Adapted from Crosbie et al., 2008 and Garcia-Barrera, Frazer, & Areshenkoff,
2012. This figure represents the relationship between genes, environment, and
executive behaviours.
 .....................................................................................................................
 44

Figure 3. This figure represents a proposed developmental trajectory of the development
of EF. The solid line represents the theoretical trajectory for monolinguals, while the
dotted line represents that of bilinguals. The difference (i.e., shaded area) represents
the bilingual advantage.
 .................................................................................................................
 50

Figure 4 represents a multilevel perspective, where multiple interactions between genes,
proteins, and structures interact with the environment during the production of
cognitive processing, ultimately resulting in executive behaviors. This model was
adapted from Crosbie et al. 2008 (model for endophenotypes) and Garcia-Barrera,
Frazer, & Areshenkoff, 2012.
 ......................................................................................................
 71

Figure 5. A schematic representation of Navon figures, where a “global” triangle is made
up of "local" circles on the right and vice versa on the left.
 ..............................................
 93

Figure 6. Illustration of the IGT, demonstrating feedback after selecting deck 'A.'
 ...........
 94

Figure 7. Illustration of the Tower of London (PEBL version, 0.12) with four disks.
 ......
 95

Figure 8. An illustration showing stimuli from the Berg Card Sorting Test (PEBL,
version 0.12).
 .....................................................................................................................................
 96

Figure 9. Schematic example of the computerized go/nogo inhibitory task. The arrow
indicates the progression of time. The first three trials are examples of “go” trials,
and the last trial is an example of a “nogo” trial.
 ...............................................................
 142

Figure 10. Represents (a) the stimulus-locked go and nogo trial grand average waveforms
for all three groups; and (b) the grand average waveforms for only nogo trials for
monolinguals, early bilinguals, and late bilinguals. Both figures represent activity at
electrode site FCz. Zero represents the onset of the stimulus; the shaded area
represents the time window for the N200.
 ...........................................................................
 154

Figure 11. Represents stimulus-locked go and nogo trial grand average waveforms for
monolinguals at electrode site FCz. Zero represents the onset of the stimulus; the
shaded area represents the time window for the N200.
 ...................................................
 154

Figure 12.
 Represents the stimulus-locked go and nogo trial grand average waveforms for
early bilinguals at electrode site FCz. Zero represents the onset of the stimulus; the
shaded area represents the time window for the N200.
 ...................................................
 155
x

Figure 13.
 Represents the stimulus-locked go and nogo trial grand average waveforms for
late bilinguals at electrode site FCz. Zero represents the onset of the stimulus; the
shaded area represents the time window for the N200.
 ...................................................
 155

Figure 14.
 Represents the go and nogo trial grand average waveforms for monolinguals at
electrode site Cz. Zero represents the onset of the stimulus; the shaded area
represents the time window for the P300.
 ............................................................................
 156

Figure 15.
 Represents the go and nogo trial grand average waveforms for early bilinguals
at electrode site Cz. Zero represents the onset of the stimulus; the shaded area
represents the time window for the P300.
 ............................................................................
 157

Figure 16.
 Represents the go and nogo trial grand average waveforms for late bilinguals
at electrode site Cz. Zero represents the onset of the stimulus; the shaded area
represents the time window for the P300.
 ............................................................................
 157

Figure 17. Represents (a) the stimulus-locked pre-switch and switch trial grand average
waveforms for all three groups; and (b) the stimulus-locked grand average
waveforms for Switch trials for monolinguals, early bilinguals, and late bilinguals.
Both figures represent activity at electrode site Cz. Zero represents the onset of the
stimulus; the shaded area represents the P3a time window. PreSw = pre-switch trials.

 ............................................................................................................................................................
 159

Figure 18. Represents the stimulus-locked pre-switch and switch trial grand average
waveforms for monolinguals at electrode site Cz. Zero represents the onset of the
stimulus; the shaded area represents the P3a time window.
 ..........................................
 159

Figure 19. Represents the stimulus-locked pre-switch and switch trial grand average
waveforms for early bilinguals at electrode site Cz. Zero represents the onset of the
stimulus; the shaded area represents the P3a time window.
 ..........................................
 160

Figure 20. Represents the stimulus-locked pre-switch and switch trial grand average
waveforms for late bilinguals at electrode site Cz. Zero represents the onset of the
stimulus; the shaded area represents the P3a time window.
 ..........................................
 160

Figure 21. Represents the grand average waveforms for switch trials for monolinguals,
early bilinguals, and late bilinguals at electrode site Pz. Zero represents the onset of
the stimulus; the shaded area represents the time window for the P3b.
 .....................
 162

Figure 22. Represents the stimulus-locked pre-switch and switch trial grand average
waveforms for monolinguals at electrode site Pz. Zero represents the onset of the
stimulus; the shaded area represents the time window for the P3b.
 ............................
 163

Figure 23. Represents the stimulus-locked pre-switch and switch trial grand average
waveforms for early bilinguals at electrode site Pz. Zero represents the onset of the
stimulus; the shaded area represents the time window for the P3b.
 ............................
 163

Figure 24. Represents the stimulus-locked pre-switch and switch trial grand average
waveforms for late bilinguals at electrode site Pz. Zero represents the onset of the
stimulus; the shaded area represents the time window for the P3b.
 ............................
 163

Figure 25. Represents (a) the 2-back target and nontarget trial grand average waveforms
for all three groups at electrode site Pz; and (b) the grand average waveforms for 2-