P.J. Durka Matching Pursuit and Unification in EEG Analysis Table of Contents
Foreword ix
Preface xi
I Some Basic Notions 1
Chapter 1 Signal: Going Digital 3
1.1 Sampling 4
1.2 Drawback: Aliasing 5
1.3 Advantage: Checksums 8
Chapter 2 Analysis 11
2.1 Inner Product—A Measure of Fit 15
2.2 Orthogonality 15
2.3 Frequency and Phase 16
Chapter 3 Spectrum 19
3.1 Example Calculations 21
3.2 Uncertainty Principle and Resolution 25
3.3 Real-World Spectra 26
Chapter 4 Between Time and Frequency 29
4.1 Spectrogram 29
4.2 Interpretation of the Spectrogram 32
4.3 Wavelets 33
4.4 Wigner Transform and Cross-Terms 35
References 38
Chapter 5 Choosing the Representation 39
5.1 Gabor Dictionary 39
5.2 Adaptive Approximation 41
5.3 Matching Pursuit 43
5.4 Time-Frequency Energy Density 44
References 46
Chapter 6 Advantages of Adaptive Approximations 47
6.1 Explicit Parameterization of Transients 47
6.2 Automatic Negotiation of Time-Frequency Tradeoff 50
6.3 Freedom from Arbitrary Settings 52
6.4 A Unified Framework 53
Chapter 7 Caveats and Practical Issues 55
7.1 Dictionary Density 55
7.2 Number of Waveforms in the Expansion 57
7.3 Statistical Bias 58
7.4 Limitations of Gabor Dictionaries 59
References 60
II EEG Analysis 61
Chapter 8 Parameterization of EEG Transients 63
8.1 Selecting Relevant Structures 66
8.2 Sleep Spindles and Slow Waves 68
8.3 Real-World Problems 72
8.4 Hypnogram and Continuous Description of Sleep 75
8.5 Sensitivity to Phase and Frequency 77
8.6 Nonoscillating Structures 79
8.7 Epileptic EEG Spikes 82
References
Chapter 9 Epileptic Seizures 87
9.1 Series of Spikes 88
9.2 Periodicity and Greedy Algorithms 89
9.3 Evolution of Seizures
9.4 Gabor Atom Density 95
References 99
Chapter 10 Event-Related Desynchronization and Synchronization 101
10.1 Conventional ERD/ERS Quantification 102
10.2 A Complete Time-Frequency Picture 104
10.3 ERD/ERS in the Time-Frequency Plane 105
10.4 Other Estimates of Signal’s Energy Density 108
References 112
Chapter 11 Selective Estimates of Energy 115
11.1 ERD/ERS Enhancement 117
11.2 Pharmaco EEG 117
References 129
Chapter 12 Spatial Localization of Cerebral Sources 131
12.1 EEG Inverse Solutions 132
12.2 Is It a Tomography? 133
12.3 Selection of Structures for Localization 134
12.4 Localization of Sleep Spindles 137
References 139
III Equations and Technical Details 141
Chapter 13 Adaptive Approximations and Matching Pursuit 143
13.1 Notation 143
13.2 Linear Expansions 144
13.3 Time-Frequency Distributions 145
13.4 Adaptive Time-Frequency Approximations 146
13.5 Matching Pursuit Algorithm 147
13.6 Orthogonalization 148
13.7 Stopping Criteria 149
13.8 Matching Pursuit with Gabor Dictionaries 151
13.9 Statistical Bias 153
13.10 MP-Based Estimate of Signal’s Energy Density 155
13.11 An Interesting Failure of the Greedy Algorithm 157
13.12 Multichannel Matching Pursuit 158
References 163
Chapter 14 Implementation: Details and Tricks 167
14.1 Optimal Phase of a Gabor Function 168
14.2 Product Update Formula 170
14.3 Sin, Cos, and Exp: Fast Calculations and Tables 170
References 172
Chapter 15 Statistical Significance of Changes in the Time-Frequency Plane 173
15.1 Reference Epoch 173
15.2 Resolution Elements 174
15.3 Statistics 175
15.4 Resampling 176
15.5 Parametric Tests 177
15.6 Correction for Multiple Comparisons 177
References 179
About the Author 181
Index 183