Behavioural and cognitive relevance of evoked gamma-band responses in ADHD patients and healthy children [Elektronische Ressource] / von Daniel Lenz

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• Gesundheit

Informations

• Publié par: otto-von-guericke-universitat_magdeburg
• Publié le: 01 janvier 2009
• Nombre de lectures: 20
• Langue: English
• Poids de l'ouvrage: 3 Mo

Extrait

Behavioural and cognitive
relevance of evoked gamma-band
responses in ADHD patients and
healthy children
Dissertation
zur Erlangung des akademischen Grades
doctor rerum naturalium
(Dr. rer. nat.)
genehmigt durch die Fakultät für Naturwissenschaften
der Otto-von-Guericke-Universität Magdeburg
von Dipl.-Psych. Daniel Lenz
geb. am 8. Dezember 1979 in Magdeburg
Gutachter: Prof. Dr. Christoph S. Herrmann
Prof. Dr. Canan Ba?ar-Eroglu
eingereicht am: 28. Juli 2009
verteidigt am: 29. Oktober 2009iiIamamongthosewhothinkthatscience hasgreatbeauty.Ascientist
in his laboratory is not only a technician: he is also a child placed
before natural phenomena which impress him like a fairy tale.
Marie CurieivContents
1 Introduction 1
2 Theoretical background 5
2.1 Attention-Deficit/Hyperactivity Disorder . . . . . . . . . . . . . . 5
2.1.1 Prevalence and primary symptoms . . . . . . . . . . . . . 5
2.1.2 Neurobiological and cognitive models . . . . . . . . . . . . 8
2.1.3 Neurophysiology . . . . . . . . . . . . . . . . . . . . . . . 11
2.2 Oscillatory activity in the gamma-band of human EEG . . . . . . 15
2.2.1 Gamma-band activity during cognitive processing . . . . . 15
2.2.2 Direct links of GBRs to perception and behaviour . . . . . 19
3 Research questions 23
4 General methods 25
4.1 Electroencephalogram . . . . . . . . . . . . . . . . . . . . . . . . 25
4.2 Event-related potentials . . . . . . . . . . . . . . . . . . . . . . . 27
4.3 Oscillatory brain activity . . . . . . . . . . . . . . . . . . . . . . . 28
4.3.1 Classification of brain oscillations . . . . . . . . . . . . . . 28
4.3.2 Time-frequency analysis based on Morlet wavelets . . . . . 30
5 Experiment I: Behavioural relevance of evoked GBRs in ADHD chil-
dren and healthy participants 33
5.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
5.2 Experimental procedure . . . . . . . . . . . . . . . . . . . . . . . 35
5.2.1 Participants . . . . . . . . . . . . . . . . . . . . . . . . . . 35
5.2.2 Stimuli and task . . . . . . . . . . . . . . . . . . . . . . . 36
5.2.3 Data acquisition . . . . . . . . . . . . . . . . . . . . . . . . 38
5.2.4 Data analysis . . . . . . . . . . . . . . . . . . . . . . . . . 39
vContents
5.3 Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
5.3.1 Behavioural performance . . . . . . . . . . . . . . . . . . . 42
5.3.2 Evoked gamma-activity . . . . . . . . . . . . . . . . . . . . 42
5.3.3 Associations between behavioural performance and evoked
GBR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
5.4 Discussion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
5.4.1 Group differences in evoked GBRs. . . . . . . . . . . . . . 45
5.4.2 AssociationbetweenevokedGBRsandsubsequent memory
performance . . . . . . . . . . . . . . . . . . . . . . . . . . 46
5.4.3 Possible interactions of ADHD neurobiology and evoked
GBRs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
5.5 Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
6 Experiments II & III: Cognitive relevance of evoked GBRs in ADHD
children and healthy participants 51
6.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
6.2 Experiment II: Pilot study on evoked GBRs in healthy children . 53
6.3 Experiment III: Altered evoked GBRs reveal impaired early visual
processing in ADHD children . . . . . . . . . . . . . . . . . . . . 56
6.3.1 Experimental procedure . . . . . . . . . . . . . . . . . . . 56
6.3.2 Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
6.4 Discussion of Experiments II & III . . . . . . . . . . . . . . . . . 62
6.5 Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
7 General discussion 69
8 Conclusions and implications for future studies 77
Bibliography 79
Appendices 105
A Curriculum vitae 105
B Eigene Publikationen 109
C Danksagung 113
D Selbstständigkeitserklärung 117
viList of Figures
2.1 Evoked GBRs in response to memory matches . . . . . . . . . . . 18
4.1 Frequency analysis of an ERP . . . . . . . . . . . . . . . . . . . . 30
4.2 Calculation of evoked and total activity . . . . . . . . . . . . . . . 32
5.1 Experiment I: Temporal sequence of the paradigm . . . . . . . . . 38
5.2 Experiment I: Illustration of individual peak frequencies . . . . . 41
5.3 Experiment I: Evoked GBRs depicted as time-frequency plots,
time-courses, and topographical maps . . . . . . . . . . . . . . . . 43
5.4 Experiment I: Correlation between evoked GBRs and recognition
performance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
6.1 ExperimentII:ComparisonbetweenevokedGBRsofhealthyadults
and healthy children employing the same as well as modified stim-
ulus material . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
6.2 Experiment III: Temporal sequence of the paradigm . . . . . . . . 58
6.3 Experiment III: Time-frequency plots of four representative par-
ticipants . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
6.4 Experiment III: Time-frequency plots and time-courses of evoked
GBRs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
6.5 Experiment III: Event-related potentials at selected electrodes . . 63
7.1 Model of the association between evoked GBRs and an early dys-
function in visual processing in ADHD patients . . . . . . . . . . 73
viiList of Figures
viiiList of Tables
5.1 Experiment I: Group characteristics . . . . . . . . . . . . . . . . . 37
5.2 Experiment I: Behavioural performance . . . . . . . . . . . . . . . 42
6.1 Experiment III: Group characteristics . . . . . . . . . . . . . . . . 57
ixList of Tables
x