PREFACE PREAMBLE SECTION 1 CHAPTER 1: INTRODUCTION MEG and EEG Setups Comparison of MEG and EEG Structure of this Primer CHAPTER 2: INSIGHTS INTO THE HUMAN BRAIN Overview of the Human Brain How to Obtain Information About Brain Function Timing in Human Behavior Functional Structure of the Human Cerebral Cortex Communication Between Brain Areas Thalamocortical Connections Intra-Brain Connectivity Electric Signaling in Neurons Membrane Potential Action Potentials Postsynaptic Potentials CHAPTER 3: BASIC PHYSICS AND PHYSIOLOGY OF MEG AND EEG An Overview of MEG and EEG Signal Generation Charges and Electric Current Ohm's and Kirchoff's Laws Relationship Between Current and Magnetic Field Superconductivity Inverse Problem Source Currents Primary Current Layers, Open Fields, and Closed Fields Intracortical Cancellation Volume Conduction Spherical Head Model Some General Points About Source Localization CHAPTER 4: AN OVERVIEW OF EEG AND MEG Historical Aspects Early EEG Recordings Early MEG Recordings Brain Rhythms Evoked and Event-Related Responses SECTION 2 CHAPTER 5: INSTRUMENTATION FOR MEG AND EEG EEG Instrumentation Electrodes EEG Amplifiers Differential Amplifiers, Common Mode Rejection, and Amplifier Input Impedances Standard Electrode Positions Effects of Reference Electrode on Potential Distribution Re-Referencing Relative to an Average Reference MEG Instrumentation Squids and Squid Electronics Flux Transformers and Their Configuration Shielding Other Means to Maintain a Noise-Free Environment Stimulators and Monitoring Devices Auditory Stimulators Visual Stimulators Somatosensory Stimulators Stimulators for Inducing Acute Pain Passive-Movement Stimulators (Proprioception Stimulation) Monitoring Devices Future Developments of EEG and MEG Instrumentation Developments in EEG Developments in MEG CHAPTER 6. PRACTICALITIES OF DATA COLLECTION General Principles of Good Experimentation Replicability Checks EEG Recordings: The Practice Electrodes, Skin Preparation, and Electrode-Impedance Measurement Post-Recording Infection Control MEG Recordings: The Practice Measurement of MEG Sensor and EEG Electrode Positions Locations of MEG Sensors and EEG Electrodes Electrical Safety CHAPTER 7: DATA ACQUISITION AND PREPROCESSING Filtering Data Sampling (Analog-To-Digital Conversion) CHAPTER 8: ARTIFACTS General Artifact-Removal Methods Blind Source Separation and Independent-Component Analysis Signal-Space Projection (SSP) and Temporal Signal-Space Separation Tsss (For MEG) Eye-Related Artifacts Generation and Recognition of Eye Movement and Eye Blink Artifacts Saccadic and Microsaccade Artifacts Electroretinogram and Magnetoretinogram Removal of Eye-Related Artifacts Muscle Artifacts Generation and Recognition Removal Cardiac Artifacts Generation and Recognition Removal Respiration-Related Artifacts Generation and Recognition Sweating Generation, Recognition, and Removal Non-Physiological Artifacts Power-Line Noise and its Removal Response-Box Artifacts EEG-Electrode and MEG-Sensor-Related Artifacts How to be Sure that the Signals come from the Brain CHAPTER 9: ANALYZING THE DATA General Data Inspection and Pre-Processing Signal Averaging of MEG/EEG Data Signal-To-Noise Considerations Segmentation Amplitude and Latency Measures Issues Related to Cross-Group Averaging and Assessment of Group Differences Topographic Maps of EEG and MEG Activity Whole-Head Statistical Analysis of EEG Data Analysis of Spontaneous Activity and Single-Trial Data General Evoked Versus Induced Activity MEG/EEG Signal Level and Power Event-Related Desynchronization and Synchronization, and Temporal Spectral Evolution Time-Frequency Analyses Phase Resetting and Models of Evoked Activity Coherence and Other Measures of Association Cross-Frequency Coupling Global Field Power, Dissimilarity, and Brain Microstates Source Modeling The Forward and Inverse Problems in MEG and EEG Head Models Single-Dipole Model and Model Validity Goodness-of-Fit and Confidence Limits of the Model Spatial Resolution Source Extent Multidipole Models, Distributed Models, and Beamformers Hypothesis Testing with Predetermined Source Locations Effect of Synchrony Changes in Orientation/Tilting Assessments of Effective Connectivity Common Pitfalls in Data Analysis and Interpretation Interpretation of MEG/EEG Data SECTION 3 CHAPTER 10: BRAIN RHYTHMS General Alpha Rhythm of the Posterior Cortex Mu Rhythm of the Sensorimotor Cortex Tau Rhythm in the Auditory Cortex Beta Rhythm Theta Rhythm Gamma Rhythms Delta-Band Activity and Ultra-Slow Oscillations Coupling Between Different Brain Rhythms Changes in Brain Rhythms During Sleep Effects of Anesthesia and Other Drugs on EEG/MEG CHAPTER 11: EVOKED AND EVENT-RELATED RESPONSES General An Initial Example Nomenclature of Evoked Responses and Brain Rhythms Effects of Interstimulus Interval and Stimulus Timing Effects of Other Stimulus Parameters CHAPTER 12: AUDITORY RESPONSES Aspects of Auditory Stimulation Auditory Brainstem Responses Middle-Latency Auditory-Evoked Responses Long-Latency Auditory Evoked Responses Auditory Steady-State Responses Frequency Tagging CHAPTER 13: VISUAL RESPONSES Visual Stimuli Transient Visual Responses Assessing the Ventral Visual Stream Assessing the Dorsal Visual Stream Steady-State Visual Responses CHAPTER 14: SOMATOSENSORY RESPONSES 304 Compound Action Potentials and Fields of Peripheral Nerves Responses from SI Cortex Responses from Posterior Parietal Cortex Responses from SII Cortex Somatosensory Steady-State Responses High-Frequency Oscillations (Hfos) in SI Pain and Nociceptive Responses CHAPTER 15: OTHER SENSORY RESPONSES & MULTISENSORY INTERACTIONS Visceral Responses Olfactory and Gustatory Responses Multisensory Interaction General Audiotactile Interaction: An MEG Case Study Multisensory Integration of Human Communication Multisensory Integration Reflected in Spontaneous MEG/EEG Activity CHAPTER 16: MOTOR FUNCTION Movement-Related Readiness Potentials and Fields Coherence Between Brain Activity and Movements/Muscles General Cortex-Muscle Coherence Corticokinematic Coherence Corticovocal Coherence CHAPTER 17: BRAIN SIGNALS RELATED TO CHANGE DETECTION General Contingent Negative Variation (CNV) Mismatch Negativity and Field (MMN, MMF) P300 Responses N400 Responses Error-Related Negativity (ERN) CHAPTER 18: THE SOCIAL BRAIN Theoretical Framework Responses to Emotions Depicted by Faces and Bodies Action Viewing and Mirroring Hyperscanning Verbal Communication CHAPTER 19: BRAIN DISORDERS General Remarks Epilepsy Preoperative Mapping Functional Identification of the Central Sulcus Anatomical Identification of the Central Sulcus Hemispheric Dominance for Speech and Language Stroke Critically Ill Patients Coma Brain Death CHAPTER 20: MEG/EEG IN THE STUDY OF BRAIN FUNCTION Advantages of MEG and EEG Disadvantages of MEG and EEG Combining MEG and EEG Combining MEG/EEG with MRI/fMRI EEG During Non-Invasive Brain Stimulation CHAPTER 21: LOOKING TO THE FUTURE Decoding of Brain States Travelling Light Data Governance Better Analysis of Behavior Modeling at Different Levels How Your MEG and EEG Work Can Make an Impact on Science Index
Riitta Hari MD, PhD researches systems neuroscience and neuroimaging. She has pioneered the use of MEG in the study of the spatiotemporal dynamics of sensory, motor, cognitive and social brain functions both in health and disease. Her background training is in medicine, with specialization in clinical neurophysiology. Aina Puce, PhD is a social neuroscientist with research interests in the brain bases of human non-verbal communication. Her studies in basic and clinical human neuroscience have used scalp and intracranial EEG, and functional MRI methods. Her formal training was in biophysics and functional brain mapping/neurophysiology.
"This Primer fulfills a gap in the human neurophysiology literature where no book exists dealing with MEG and EEG in equal terms. This is important since both methodologies are, in essence, complementary and jointly can be used to answer specific scientific questions with respect to a variety of brain functions. Special attention is paid to comparisons of findings obtained using both MEG and EEG modalities, what can yield important new insights, particularly in the growing field of cognitive neuroscience. Written in an appealing style, this Primer embraces the whole field of human neurophysiology." -Fernando Lopes Da Silva, MD, PhD, Emeritus Professor, Center of Neuroscience, Swammerdam Institute for Life Sciences, Amsterdam, The Netherlands "The two non-invasive electrophysiological recording methods, magnetoencephalography (MEG) and electroencephalography (EEG), are closely related due to their common neural sources. They are usually discussed separately in the literature, which makes it difficult to optimize the use MEG and EEG to target specific neuroscience or clinical questions. This engaging Primer is a welcome addition because it covers all aspects of both methods on equal footing. This volume covers the physiological and physical point of view, the path from data acquisition to analysis and interpretation, and discusses many different types of data that can be acquired. It is useful reading for newcomers, for experts of one method or the other, and developers of new methods to give them a thorough understanding of the physiological and physical underpinnings of MEG/EEG." --Matti Hamalainen, PhD, Associate Professor of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, MA