Subjective visual experiences of colour and form induced by temporally modulated light [Elektronische Ressource] / vorgelegt von Cordula Becker

Cordula Becker

Sujets

• Psychologie

Informations

• Publié par: ludwig-maximilians-universitat_munchen
• Publié le: 01 janvier 2005
• Nombre de lectures: 26
• Langue: English
• Poids de l'ouvrage: 13 Mo

Extrait

Subjective visual experiences of
colour and form induced by
temporally modulated light
Cordula Becker
Munchen? 2005Subjective visual experiences of
colour and form induced by
temporally modulated light
Cordula Becker
Inaugural-Dissertation
zur Erlangung des
Doktorgrades der Philosophie an der
Ludwig–Maximilians–Universit at
Munc? hen
vorgelegt von
Cordula Becker
aus Magdeburg
Munc? hen, den 21.03.2005Erstgutachter: Prof. Hermann J. Muller?
Zweitgutachter: Prof. Heiner Deubel
Tag der mundlic? hen Prufung:? 29.06.2005IchhattedieGabe,wennichdieAugenschloßundmitniedergesenktemHaupte
mir in die Mitte des Sehorgans eine Blume dachte, so verharrte sie nicht einen
Augenblick in ihrer ersten Gestalt, sondern sie legte sich auseinander, und aus
ihremInnerenentfaltetensichwiederneueBlumenausfarbigen,auchwohlgrunen?
Bl attern; es waren keine naturlichen? Blumen, sondern phantastische, jedoch regel-
m aßig wie die Rosetten der Bildhauer. Es war unm oglich, die hervorsprossende
Sch opfung zu fixieren, hingegen dauerte sie so lange, als mir beliebte, ermattete
nicht und verst arkte sich nicht. Dasselbe konnte ich hervorbringen, wenn ich
mir den Zierrat einer buntgemalten Scheibe dachte, welche dann ebenfalls aus der
MittegegendiePeripheriehinsichimmerfortver anderte,olv ligwiedieinunseren
Tagen erst erfundenen Kaleidoskope.
Johann Wolfgang von Goethe
Studien zur MorphologieI wish to express my thanks to everyone who helped me during the various phases
of writing this dissertation.
I am thankful to Hermann Mul? ler for the opportunity to do research and write a
thesis in his group in Munich. I also wish to thank him and Heiner Deubel for
their willingness to act as reviewers of this thesis.
I am especially grateful to Mark Elliott for accepting me into his Psychophysics
and Temporal Factors lab, introducing me to the paradigms employed in this
thesis, his openness for discussions and support during all stages of
experimentation, analysis, and writing of the thesis.
My thanks go to Andreas Schiegg for his help on the electronic interface of the
experimental apparatus, as well as to Sven Garbade for sharing his expertise on
the statistical programming language R.
For the revealing insights into electroencephalographic experiments, as well as for
practical help concerning EEG experiments and analyses, I wish to thank Klaus
Gramann.
This work could not have been realized without the help of my student helpers
Christine Falter, Marieluise Hupfauer, Katerina Obermeier, and Bernhard
Ostler. Many thanks to them and to all brave and patient volunteers who
participated in my experiments.
Many thanks for proofreading the German summary to Stefanie Arndt.
Special thanks go to to my Bavarian colleagues for their introduction to
Bavarian life and civilisation, in particular a primer to the Bavarian language
and induction to the ”Biergarten” culture.
I thank Johannes for proofreading and support throughout.Contents
1 Introduction 1
1.1 An overview of subjective visual experiences . . . . . . . . . . . . 4
1.1.1 Historicalandreligiousreportsofsubjectivevisualexperiences 4
1.1.2 Clinical descriptions of subjective visual experiences . . . . 6
1.1.3 Magnetically and electrically induced subjective visual ex-
periences . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
1.2 Subjective visual experiences induced by visual stimulation . . . . 12
1.2.1 Benham’s Top and Benham-like stimulation regimes . . . . 14
1.2.2 Stimulation of the visual ganzfeld . . . . . . . . . . . . . . 19
1.3 Physiologicalmechanismsofvisualperceptionrelatedtosubjective
experiences . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
1.3.1 Mechanisms of colour perception . . . . . . . . . . . . . . 24
1.3.2 Mechanisms of form p . . . . . . . . . . . . . . . 30
1.3.3 Physiological models of subjective visual experiences . . . 33
1.4 Overview of the thesis . . . . . . . . . . . . . . . . . . . . . . . . 39
2 Descriptive analysis of visually induced subjective experiences 43
2.1 Rationale . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
2.2 Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
2.3 Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
2.3.1 Reported categories of colour and form . . . . . . . . . . . 462.3.2 Analysis of the distribution of subjective experiences over
frequency . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
2.4 Discussion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
3 Interdependencies in the appearance of subjective visual experi-
ences 54
3.1 A multidimensional model of co-occurrent subjective visual expe-
riences . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
3.1.1 Rationale . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
3.1.2 Methods of analysis . . . . . . . . . . . . . . . . . . . . . . 55
3.1.3 Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58
3.1.4 Discussion . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
3.2 Progression of subjective visual experiences over time . . . . . . . 63
3.2.1 Rationale . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
3.2.2 Methods of analysis . . . . . . . . . . . . . . . . . . . . . . 63
3.2.3 Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64
3.2.4 Discussion . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
4 Relation of subjective visual experiences to the temporal charac-
teristics of the stimulation 68
4.1 Rationale . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
4.2 Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70
4.3 Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71
4.3.1 Analysis of the distributions of subjective experiences over
frequency . . . . . . . . . . . . . . . . . . . . . . . . . . . 71
4.3.2 Response time analysis . . . . . . . . . . . . . . . . . . . . 72
4.3.3 Analysis of response times over phase . . . . . . . . . . . . 73
4.4 Discussion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 765 Spontaneous visual experiences during constant ganzfeld stimu-
lation 77
5.1 Rationale . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78
5.2 Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78
5.3 Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80
5.3.1 Descriptive analysis of spontaneous visual experiences in
free report . . . . . . . . . . . . . . . . . . . . . . . . . . . 80
5.3.2 Impact of the results of Experiment 4 and 5 on the findings
of Experiment 1 . . . . . . . . . . . . . . . . . . . . . . . . 81
5.3.3 Descriptive analysis of spontaneous visual experiences in a
forced-choice paradigm . . . . . . . . . . . . . . . . . . . . 85
5.3.4 Impact of the results of Experiment 4 and 5 on the findings
of Experiment 2 and 3 . . . . . . . . . . . . . . . . . . . . 87
5.4 Discussion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89
6 Phenomenology of subjective visual experiences 91
6.1 Description of subjective colours . . . . . . . . . . . . . . . . . . . 92
6.1.1 Rationale . . . . . . . . . . . . . . . . . . . . . . . . . . . 92
6.1.2 Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92
6.1.3 Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99
6.1.4 Discussion . . . . . . . . . . . . . . . . . . . . . . . . . . . 105
6.2 Description of subjective forms . . . . . . . . . . . . . . . . . . . 107
6.2.1 Rationale . . . . . . . . . . . . . . . . . . . . . . . . . . . 107
6.2.2 Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107
6.2.3 Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108
6.2.4 Discussion . . . . . . . . . . . . . . . . . . . . . . . . . . . 112
7 Electrophysiological correlates of subjective colour 114
7.1 Rationale . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115
7.2 Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1187.3 Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123
7.4 Discussion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126
8 General Discussion 130
8.1 Summary of the experimental evidence . . . . . . . . . . . . . . . 131
8.2 A theoretical model of subjective colour . . . . . . . . . . . . . . 133
8.3 Mechanismsofsubjectiveformandtherelationbetweensubjective
colour and form . . . . . . . . . . . . . . . . . . . . . . . . . . . . 137
8.4 Future prospects . . . . . . . . . . . . . . . . . . . . . . . . . . . 139
A Form of consentment 141
B Instructions 143
C Experiment 1 - Sizer plots 162
D Experiment 1 - Kolmogorov-Smirnov-tests 165
E Experiment 1 - Multidimensional scaling 167
F Experiment 2 and 3 - Circular plots 195
G Experiment 4 and 5 - SiZer plots 198
H Experiment 7 - Drawings of subjective forms 201
I Experiment 8 - EEG regression formulas 241
German summary/Deutsche Zusammenfassung 257
Bibliography 272
Curriculum Vitae 289Chapter 1
Introduction
1