Table of Contents

Title Page *
Dedication *
Table of Contents *
List of Tables *
List of Figures *
Acknowledgements *
Curriculum Vitae *
Abstract of the dissertation *
I. INTRODUCTION *

A Physiological Framework for Understanding Information Processing Biases in Depression *
Tasks to Evaluate Attention in Depression *
The Need for Assessment Using Personally Relevant Information *
Using Pupil Dilation to Measure Attention Continuously in Depressed Individuals *
    Pupil Dilation as a Measure of Cognitive Load *
    Appropriateness of Using Pupil Dilation to Study Depressed Individuals *
Identification of Sustained Attention with Rumination *
The Need for Simulation Before Prediction * II. A NEURAL NETWORK MODEL OF EMOTIONAL INFORMATION PROCESSING * A Short Introduction to Computational Neural Networks *
Why Computer Simulations of Neural Networks are Particularly Appropriate for Investigating Depression *
A Computational Framework for Investigating Affective Information Processing *
    Representation of Valence *
    Simulation of Normal and Depressed Experiences in the Model *
    Simulating Attention and Recognition Processes *
Reproducing Valence Rating Data *
Use of the Network to Predict the Time Course of Attention to Emotional Information *
    Predictions for Reaction Times *
    Predictions for Error Rates *
    Predictions for Pupil Dilation *
Summary of Predictions Based on the Performance of the Neural Network Model *
Experimental Design Based on the Network’s Behavior * III. METHOD * Research Participants *
Self-Report Measures *
Apparatus *
    Target Stimulus Materials *
Tasks *
    Lexical Decision Task *
    Valence Identification Task *
    Warned Reaction Time Task *
    Gaze Task *
    Counterbalancing of Conditions *
Procedure *
Statistical Power *
Selection of Relevant Stimuli for Analysis *
Methods of Analysis - Reaction Times *
    Data Aggregation *
    Data Cleaning *
    Analytic Techniques *
Methods of Analysis - Signal Detection *
    Data Cleaning *
    Analytic Techniques *
Methods of Analysis - Pupil Dilation *
    Data Cleaning *
    Data Aggregation - Principal Components Analysis *
Type I Error Control *
Type II Error Control and Exploratory Analyses * IV. RESULTS * Reaction Times *
    Lexical Decision Task Planned Contrasts *
Valence Identification Task Planned Contrasts *
Planned Analyses Exploring the Relationship of Ruminative Coping to Reaction Time Measures *
Signal Detection Rates * Valence Identification Task Response Biases *
Lexical Decision Task False Alarms * Pupil Dilation *
    Aggregate Curves *
    Principal Components Analysis *
    Planned Contrasts *
    Interpretation of the late pupil dilation factor *
Brief Summary *
Personal Relevance * V. DISCUSSION * What This Experiment Could Say About Depressed People *
What this Experiment Suggests about Depression: Depressed People Have Sustained Attentional Responses to Many Things *
Operationalizing Rumination *
Evaluation of Predictions from the Neural Network Model Based on the Empirical Data * Predictions Consistent With the Data: Seeing Things Negatively, and Sustaining Attention *
Predictions Not Consistent with the Data: Attending Differently to Different Valences * Take Home Lessons *
Potential Treatment Implications *
Limitations * Limitations of the Neural Network Model *
Limitations of the Sample of Research Participants *
Limitations of the Sample of Stimuli *
Limitations of the Analyses *
Limitations of the Design *
Other Generalizability Concerns * Future Directions *
The Big Picture * Appendices * APPENDIX A -- TECHNICAL DETAILS OF THE NEURAL NETWORK * Construction of the Hebb trained network *
Construction of the BackPropagation Network *
Differences between Hebb and Backpropagation learning rules * APPENDIX B: GRAPHS OF NETWORK ACTIVATION IN RESPONSE TO EACH VALENCE *
APPENDIX C: SELF-REPORT MEASURES * Beck Depression Inventory (BDI) *
Beck Anxiety Inventory (BAI) *
State Trait Anxiety Inventory (STAI) *
Response Styles Questionnaire (RSQ) * APPENDIX D: WORD LISTS USED IN THE EXPERIMENT *
APPENDIX E: WORD GENERATION FORM *
APPENDIX F: CONSENT FORMS * SDSU form *
UCSD form for non-veterans *
UCSD form for veterans * APPENDIX G: INSTRUCTIONS FOR TASKS * Initial Directions *
Lexical Decision Task—Practice *
Lexical Decision Task—Task *
Valence Identification Task—Practice *
Valence Identification Task—Task *
Word Rating Task *
Warned Reaction Time Task *
Gaze Task * APPENDIX H: SOFTWARE USED FOR DATA COLLECTION AND ANALYSIS *
APPENDIX I: Examples of a few selected pupil dilation curves *
APPENDIX J: Robustness of PCA analyses *
APPENDIX K: ANOVA planned contrasts on differences between pupil dilation factors * References *