The influence of the level of alertness on spatial and non-spatial components of visual attention in healthy subjects and neglect patients [Elektronische Ressource] / vorgelegt von Ellen Matthias

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• Publié par: ludwig-maximilians-universitat_munchen
• Publié le: 01 janvier 2008
• Nombre de lectures: 5
• Langue: English

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The influence of the level of alertness on
spatial and non-spatial components of visual
attention in healthy subjects and neglect
patients



Inaugural-Dissertation
zur Erlangung des Doktorgrades der Philosophie
an der Ludwig-Maximilians-Universität
München




vorgelegt von
Ellen Matthias
aus
Bad Aibling





März 2008

















Erster Gutachter: Prof. Dr. Hermann J. Müller
Zweiter Gutachter: Prof. Dr. Werner X. Schneider
Tag der mündlichen Prüfung: 04.07.2008
Table of Contents


Table of Contents ............................................................................................................... 3
Acknowledgements............................................................................................................. 6
Chapter 1: Introduction..................................................................................................... 7
1.1 The Theoretical Framework of Bundesen´s Theory of Visual Attention (TVA) .... 8
1.1.1 Basic Assumptions .............................................................................................. 8
1.1.2 Stages of Processing.......................................................................................... 10
1.1.3 Single Stimulus Identification.......................................................................... 12
1.1.4 Selection from Multi-element Displays ............................................................ 14
1.1.4.1 Equation 1: Rate Equation (Hazard Function) .......................................... 15
1.1.4.2 Equation 2: Weight Equation ..................................................................... 16
1.1.4.3 Limited Processing Capacity C ................................................................. 17
1.1.5 Short Summary of TVA Basics........................................................................ 18
1.1.6 Mechanisms of Selection .................................................................................. 18
1.1.6.1 Filtering ...................................................................................................... 19
1.1.6.2 Pigeonholing............................................................................................... 20
1.1.6.3 Combining Filtering and Pigeonholing...................................................... 20
1.1.7 A Neural Theory of Visual Attention (NTVA)................................................. 21
1.1.8 Applications of TVA......................................................................................... 23
1.1.8.1 Whole-Report Paradigm............................................................................. 23
1.1.8.2 Partial-Report Paradigm 24
1.2 The Theory of Visual Attention and the Concept of Alertness.............................. 26
1.3 The Concept of Alertness ........................................................................................ 27 1.3.1 Basic Definition................................................................................................. 27
1.3.2 Neural Correlates............................................................................................... 28
Chapter 2: Synopsis ......................................................................................................... 30
Chapter 3: The Influence of the Level of Alertness in Healthy Subjects.................... 33
3.1 Introduction............................................................................................................. 33
3.2 Study 1: The Influence of Increased Phasic Alertness on Visual Attention....... 35
3.2.1 Abstract 35
3.2.2 Introduction and Scope...................................................................................... 36
3.2.3 General Method................................................................................................. 38
3.2.4 Experiment 1 ..................................................................................................... 40
3.2.4.1 Method ....................................................................................................... 40
3.2.4.2 Results and Discussion............................................................................... 42
3.2.5 Experiment 2 48
3.2.5.1 Method 49
3.2.5.2 Results and Discussion 51
3.2.6 Experiment 3 ..................................................................................................... 66
3.2.6.1 Method ....................................................................................................... 67
3.2.6.2 Results and Discussion............................................................................... 68
3.2.7 General Discussion............................................................................................ 72
3.3 Study 2: The Influence of Decreased Intrinsic Alertness on Visual Attention..... 78
3.3.1 Abstract ............................................................................................................. 78
3.3.2 Scope of the Study............................................................................................. 79
3.3.3 Method .............................................................................................................. 81
3.3.4 Results ............................................................................................................... 85
3.3.5 Discussion ......................................................................................................... 96
Chapter 4: The Influence of the Level of Alertness in Neglect Patients...................... 99 4.1 The Influence of Increased Phasic Alertness ........................................................ 99
4.1.1 Abstract ............................................................................................................. 99
4.1.2 Introduction ..................................................................................................... 100
4.1.3 Scope of the Study........................................................................................... 102
4.1.4 Method ............................................................................................................ 103
4.1.5 Results 110
4.1.6 Discussion ....................................................................................................... 118
Chapter 5: General Conclusion .................................................................................... 121
Deutsche Zusammenfassung (Abstract in German) ................................................... 123
References ....................................................................................................................... 129
Curriculum Vitae ........................................................................................................... 136

Acknowledgements 6


Acknowledgements


This Ph.D. thesis was written at the Ludwig-Maximilians University in Munich and was
supported by a grant of the German Research Foundation (Deutsche Forschungsgemeinschaft;
MU773/6-1).
A number of people have contributed to the successful completion of this work. First of
all, I would like to thank my Ph.D. supervisor Prof. Dr. Hermann J. Müller for his support
over the last 21/2 years. In addition, I am grateful to Dr. Kathrin Finke for her time, encour-
agement and effort in accomplishing this thesis. I also thank Prof. Dr. Werner X. Schneider,
Prof. i.K. Dr. Peter Bublak, and Prof. Dr. Joseph Krummenacher for discussing results of ex-
periments with me. I also would like to thank the colleagues at the Neurological Clinic Bad
Aibling, especially PD Dr. Ingo Keller and Gudrun Lefin-Rank for their assistance and kind-
ness during the neglect patients study.
I want to thank all my friends, especially Lea and Melissa. I am really grateful that I met
you and that I could gain your friendship. Together we were strong. I deeply hope that we will
keep in touch in the future.
Special thanks go to my parents, Birgitt and Michael, and to my two younger brothers,
Arne and Martin, for their endless support during the past years. We went through good and
bad times and we fortunately always stood together.

I thank you all!
Ellen Matthias
Bad Aibling, März 2008 Chapter 1: Introduction 7


Chapter 1: Introduction


It is widely accepted that attention is a multi-dimensional cognitive ability which consists
of separable components supported by overlapping, but independent, neural networks
(Desimone & Duncan, 1995; Fan, McCandliss, Fossella, Flombaum, & Posner, 2005; Fernan-
dez-Duque & Posner, 1997; Posner & Boies, 1971). Current theoretical conceptions bridging
the behavioral and neuroanatomical levels of analysis such as the ‘Theory of Visual Atten-
tion’ (TVA; Bundesen, 1990, 1998a) or the ‘attentional-networks’ model (Fan, McCandliss,
Sommer, Raz, & Posner, 2002) consider both spatially lateralized and non-lateralized compo-
nents of visual attention to be critical determinants of attentional performance. A currently
widely debated question concerns whether and, if yes