TABLE OF CONTENTS
INTRODUCTION
15
ATTENTIONAL SYSTEMS AND COGNITIVE CONTROL 17
1. ALERTING 18
2. ORIENTING 21
3. EXECUTIVE ATTENTION OR COGNITIVE CONTROL 23
3. 1. The categorical and taxonomical approach of cognitive control 25
3. 2. Neurocomputational and neurobiological models of cognitive control 30
3. 2. 1. The expected value of control (EVC) model 31
3. 2. 2. Hierarchical (rostro caudal) organization of PFC 40
3. 3. Temporal dynamics of cognitive control 42
3. 3. 1. The dual mechanism of control (DMC) model 42
3. 3. 2. The dual-‐networks control architecture and the Default Mode Network 45
3. 4. Conclusions on cognitive control 48
TASK SWITCHING 49
1. THE CONCEPT OF TASK SET 51
2. THE ROLE OF TASK SETS 53
3. THE MEASUREMENT OF SWITCH COST 56
3. 1. Task switching paradigms 56
3. 1. 1. The list procedure (mixed-‐task blocks vs. single-‐task blocks) 56
3. 1. 2. Alternating runs (predictable task switching) 57
3. 1. 3. The cuing procedure (task cuing) 58
3. 1. 4. Voluntary Task Switching (voluntary task selection) 60
3. 2. Calculation of switch cost 62
4. THEORIES IN TASK SWITCHING 65
4. 1. The reconfiguration view 65
4. 2. The interference view 66
4. 3. The importance of preparation time duration 67
4. 4. Residual switch cost 68
4. 5. Integrative accounts and the importance of strategy 69
4. 6. A more global proactive control mechanism 72
4. 7. Task-‐goal and task-‐rule switching 73
4. 8. Stimulus-‐response rules in task switching 74
4. 9. Failure to engage in preparation and task-‐goal neglect 81
4. 10. Task set decay 83
4. 11. The repetition benefit view 84
5. ADDITIONAL PHENOMENA IN TASK SWITCHING 85
5. 1. Congruency effects 85
5. 2. Switch-‐cost asymmetries 86
5. 3. Task inhibition and n-‐2 task-‐repetition costs. 86
5. 4. Response repetition effects 87
6. THE NEUROIMAGING OF TASK SWITCHING 88
7. DOPAMINE AND SPONTANEOUS EYE BLINK RATE IN TASK SWITCHING 96
CONCLUSIONS ON TASK SWITCHING 99
OBJECTIVES AND OVERVIEW OF THE THESIS 101
EXPERIMENTAL SECTION
103
THE CUED MATCH-‐TO-‐SAMPLE TASK 105
STUDY 1 111
TOWARD SHARED MECHANISMS OF PROACTIVE AND REACTIVE CONTROL: 111
THE CASE OF TASK SWITCHING AND CONTINUOUS PERFORMANCE 111
ABSTRACT 112
METHODS 118
Participants 118
Material and procedure 118
AX-‐CPT 119
Task-‐goal switching 121
RESULTS 123
Data analysis 123
AX-‐CPT 124
Task switching 125
Associations between reactive/proactive modes of control in the AX-‐CPT and task-‐switching
paradigm 126
DISCUSSION 128
STUDY 2 133
THE IMPACT OF LANGUAGE ON TASK-‐GOAL SWITCHING 133
ABSTRACT 134
EXPERIMENT 1: LANGUAGE AND TASK-‐GOAL ACTIVATION IN TASK SWITCHING 142
Method 142
Participants 142
The cued match-‐to-‐sample task 143
Apparatus and Stimuli 145
Procedure 146
Data analysis 148
Results 149
Discussion of Experiment 1 152
EXPERIMENT 2. LANGUAGE AS AN ATTENTIONAL TRIGGER 154
Method 155
Participants 155
Apparatus and stimuli 155
Procedure 156
Data analysis 156
Results 157
Discussion of Experiment 2 159
EXPERIMENT 3 : TASK-‐SET INERTIA, DOPAMINE AND WORKING MEMORY 160
Method 161
Apparatus and stimuli 162
Procedure 163
Data analysis 164
Results 164
Discussion of Experiment 3 168
GENERAL DISCUSSION 170
Language modulation of local switch costs 171
How language modulates attentional processes 173
The impact of arbitrary S-‐R mappings on task switching 175
Goal-‐neglect switch cost 177
Task-‐goal activation and EBR 178
Implications for cognitive models of task switching 179
Conclusions and perspectives 180
STUDY 3 183
AFTERNOON NAP AND BRIGHT LIGHT EXPOSURE IMPROVE COGNITIVE FLEXIBILITY POST LUNCH 183
INTRODUCTION 187
MATERIAL AND METHODS 191
Participants and Protocol 191
Cognitive measures 194
Data analysis 198
RESULTS 200
Participants 200
Sleep variables 200
Sleepiness, fatigue and alertness 201
Task-‐switching speed (latency switch-‐cost score) 202
Task-‐switching accuracy (accuracy switch-‐cost score) 203
DISCUSSION 206
SUPPORTING INFORMATION 211
S1 File. Supplementary analyses 211
Data analysis 211
Response latencies 212
Accuracy 216
STUDY 4 219
SLEEP DEPRIVATION TRIGGERS COGNITIVE CONTROL IMPAIRMENTS IN TASK-‐GOAL SWITCHING ASSOCIATED
WITH CHANGES IN ALERTNESS AND SPONTANEOUS EYE BLINK RATE 219
ABSTRACT 220
MATERIAL AND METHODS 226
Participants 226
Procedure 227
Fatigue, sleepiness, alertness and vigilance, and eye blink rate (EBR) 228
Working memory and inhibition tasks 229
Working memory N-‐back task 229
Inhibition Stop Signal task 230
Task-‐goal switching 231
RESULTS 234
Sleep prior to the experiment 234
Working memory and Inhibition 237
Working memory N-‐back task 237
Inhibition Stop Signal task 239
Spontaneous Eye Blink Rate (EBR) 239
Task-‐goal switching 240
Relationships between impairments in task-‐goal switching and other variables 245
DISCUSSION 247
APPENDICES 254
STUDY 5 255
EXPERTISE AND COGNITIVE FLEXIBILITY: A MUSICIAN’S TALE 255
ABSTRACT 256
METHOD 264
Participants 264
Material and procedure 265
The musical-‐switching task 265
RESULTS 268
Data analysis 268
Switch costs 269
Mixing costs 271
DISCUSSION 273
GENERAL DISCUSSION
279
GENERAL DISCUSSION 281
1. THE IMPACT OF ARBITRARY S-‐R RULES ON TASK SWITCHING 281
2. PROACTIVE AND REACTIVE MODES OF CONTROL IN TASK-‐GOAL SWITCHING 284
2. 1. Goal maintenance and the balance between reactive and proactive control modes 284
2. 2. The unity and diversity of cognitive control 285
2. 3. Task-‐goal switching and the goal-‐neglect switch cost 286
2. 3. The importance of stimulus-‐rule correspondences 287
2. 4. The importance of participants’ motivation and fatigue 287
3. THE IMPACT OF LANGUAGE ON TASK-‐GOAL SWITCHING 289
4. THE IMPACT OF ALERTNESS ON TASK-‐GOAL SWITCHING 291
4. 1. Task-‐goal switching after napping and bright light exposure 291
4. 2. Task goal switching after sleep deprivation 292
4. 3. Task-‐goal switching and alertness 293
5. THE IMPACT OF EXPERTISE ON TASK-‐GOAL SWITCHING 294
6. TASK-‐GOAL ACTIVATION AND EBR 297
6. 1. EBR and the goal-‐neglect switch cost 297
6. 2. EBR and attentional variability during task-‐goal switching 298
6. 3. EBR and cognitive-‐control functions 299
7. SWITCH COST OR REPEAT BENEFIT 301
LIMITATIONS 301
GENERAL CONCLUSION 303
PERSPECTIVES 304
