Feature Topography and Sound Intensity Level Encoding in Primary Auditory Cortex

......................................................................................................................................... ii Acknowledgments ..................................................................................................................... iv List of Tables .............................................................................................................................. ix List of Figures ............................................................................................................................. x 1 General Introduction .......................................................................................................... 1 2 Experimental Methods ...................................................................................................... 5 2.1 A Computational Framework for Topographies of Cortical Areas...................... 6 2.1.1 Self-Organizing Feature Map........................................................................ 6 2.1.2 Unit Grid Initialization .................................................................................. 8 2.1.3 Metrics of Topographical Characteristics ................................................... 9 2.1.4 Conditions Driving Dominance and Global Orthogonality ..................18 2.2 Neuronal Responses to Sound Intensity Level......................................................21 2.2.1 Electrophysiology .........................................................................................21 2.2.2 Acoustic Stimuli ............................................................................................23 2.2.3 Data Analysis.................................................................................................24 2.3 Neuronal Adaptation to Sound Intensity Level.....................................................30 2.3.1 Acoustic Stimuli ............................................................................................30 2.3.2 Data Analysis.................................................................................................34 2.4 Time Course of Neuronal Adaptation to Sound Intensity Level........................39 2.4.1 Acoustic Stimuli ............................................................................................39 2.4.2 Data Analysis.................................................................................................44 3 A Computational Framework for Topographies of Cortical Areas .....................64 3.