The processing of low-frequency spatial cues [Elektronische Ressource] : a behavioral approach / vorgelegt von Andrea Lingner

Andrea Lingner

Sujets

• Biologie

Informations

• Publié par: ludwig-maximilians-universitat_munchen
• Publié le: 01 janvier 2010
• Nombre de lectures: 5
• Langue: English
• Poids de l'ouvrage: 29 Mo

Extrait

The Processing of
Low-Frequency Spatial Cues
– A Behavioral Approach –
Andrea Lingner
Dissertation
an der Fakultät für Biologie
der Ludwig–Maximilians–Universität
München
vorgelegt von
Andrea Lingner
München, September 2010Erstgutachter: ..........................Prof. Dr. Benedikt Grothe
Zweitgutachter: .......................... Prof. Dr. Lutz Wiegrebe
Tag der mündlichen Prüfung: ...........................02.12.2010Contents
1 Introduction 19
1.1 Sound Detection and Localization . . . . . . . . . . . . . . . . . . . 19
1.2 Aim of the Current Study . . . . . . . . . . . . . . . . . . . . . . . 34
1.3 Mongolian Gerbils and Auditory Research . . . . . . . . . . . . . . 36
2 Material & Methods 39
2.1 Azimuthal Sound Localization . . . . . . . . . . . . . . . . . . . . . 39
2.2 Release from Masking . . . . . . . . . . . . . . . . . . . . . . . . . 42
2.2.1 Gerbils . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
2.2.2 Humans . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
2.2.3 Simulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
2.3 Azimuthal Sound Localization and the MNTB . . . . . . . . . . . . 50
3 Results 55
3.1 Azimuthal Sound Localization . . . . . . . . . . . . . . . . . . . . . 55
3.2 Release from Masking . . . . . . . . . . . . . . . . . . . . . . . . . 57
3.3 Azimuthal Sound Localization and the MNTB . . . . . . . . . . . . 62
4 Discussion 79
5 Concluding Remarks 95
Bibliography 97
Contributions to the Manuscript 111
Acknowledgment 113
Curriculum Vitæ 114
5Abbreviations
AVCN anterior part of the ventral cochlear nucleus
BMLD binaural masking level difference
CN cochlear nucleus
DAS dorsal acoustic stria
DCN dorsal cochlear nucleus
DNLL dorsal nucleus of the lateral lemniscus
ERB equivalent rectangular bandwidth
GABA gamma-amino-butyric acid
IAS intermediate acoustic stria
IC inferior colliculus
ILD interaural level difference
ITD in time
KA kainic acid
LNTB lateral nucleus of the trapezoid body
LSO lateral superior olive
MNTB medial nucleus of the trapezoid body
MRA minimal resolvable angle
MSO medial superior olive
NL nucleus laminaris
PVCN posterior part of the ventral cochlear nucleus
SNR signal-to-noise ratio
SOC superior olivary complex
TB trapezoid body
VCN ventral cochlear nucleus
2-AFC two-alternative, forced-choice
6-AFC six-alternative,hoice
7List of Figures
1.1 Duplex Theory of Sound Localization. . . . . . . . . . . . . . . . . 23
1.2 Schematic Innervation Pattern of LSO and MSO. . . . . . . . . . . 26
1.3 Jeffress-Model. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
1.4 Effect of Strychnine on a MSO Neuron. . . . . . . . . . . . . . . . . 32
1.5 Maturation of Inhibitory Synapses in Gerbils. . . . . . . . . . . . . 33
1.6 Gerbil. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
2.1 Setup of Experiment 1. . . . . . . . . . . . . . . . . . . . . . . . . . 40
2.2 Setup of Experiment 2 (Gerbils). . . . . . . . . . . . . . . . . . . . 43
2.3 Setup of Experiment 2 (Human). . . . . . . . . . . . . . . . . . . . 46
2.4 Block Diagram of the Model. . . . . . . . . . . . . . . . . . . . . . . 48
2.5 Analyzing Time Schedule. . . . . . . . . . . . . . . . . . . . . . . . 52
3.1 Azimuthal Sound Localization. . . . . . . . . . . . . . . . . . . . . . 56
3.2 Exemplary Psychometric Function. . . . . . . . . . . . . . . . . . . 57
3.3 Detection Threshold and Release from Masking. . . . . . . . . . . . 58
3.4 Thresholds and Release from Masking Compared to the
Model. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
3.5 Simulated Masker-Only and Signal Templates. . . . . . . . . . . . . 60
3.6 Effect of Low-Pass Frequency. . . . . . . . . . . . . . . . . . . . . . 62
3.7 Listing of the different Lesioning Effects. . . . . . . . . . . . . . . . 62
3.8 Histological Verification of the Lesion (Control Animals). . . . . . . 64
3.9 Azimuthal Sound Localization Before and After Saline Injection. . . 65
3.10 Histological Verification of the Lesion (Unilateral Injected Animal). 67
3.11 Azimuthal Sound Localization Before and After Unilateral KA In-
jection. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68
3.12 Histological Verification of the Lesion (Bilaterally Injected Animals). 70
8List of Figures
3.13 AzimuthalSoundLocalizationBeforeandAfterBilateralKAInjection. 71
3.14 Histological Verification of the Lesion (Bilaterally Injected Animals). 73
3.15 AzimuthalSoundLocalizationBeforeandAfterBilateralKAInjection. 74
3.16 Mean MRA Before and After Injection for all Animals. . . . . . . . 76
4.1 Localization Ability of Different Small Rodents. . . . . . . . . . . . 83
9