Event-related EEG/MEG synchronization and desynchronization: basic principles.

The event-related potential (ERP) technique in cognitive neuroscience allows scientists to observe human brain activity that reflects specific cognitive processes. In An Introduction to the Event-Related Potential Technique, Steve Luck offers the first comprehensive guide to the practicalities of conducting ERP experiments in cognitive neuroscience and related fields, including affective neuroscience and experimental psychopathology. The book can serve as a guide for the classroom or the laboratory and as a reference for researchers who do not conduct ERP studies themselves but need to understand and evaluate ERP experiments in the literature. It summarizes the accumulated body of ERP theory and practice, providing detailed, practical advice about how to design, conduct, and interpret ERP experiments, and presents the theoretical background needed to understand why an experiment is carried out in a particular way. Luck focuses on the most fundamental techniques, describing them as they are used in many of the world's leading ERP laboratories. These techniques reflect a long history of electrophysiological recordings and provide an excellent foundation for more advanced approaches. The book also provides advice on the key topic of how to design ERP experiments so that they will be useful in answering questions of broad scientific interest. This reflects the increasing proportion of ERP research that focuses on these broader questions rather than the "ERPology" of early studies, which concentrated primarily on ERP components and methods. Topics covered include the neural origins of ERPs, signal averaging, artifact rejection and correction, filtering, measurement and analysis, localization, and the practicalities of setting up the lab.

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An Introduction to the Event-Related Potential Technique

Spherical splines for scalp potential and current density mapping

The mismatch negativity (MMN) in basic research of central auditory processing: a review.

Event-related potentials ~ERPs! recorded from the human scalp can provide important information about how the human brain normally processes information and about how this processing may go awry in neurological or psychiatric disorders. Scientists using or studying ERPs must strive to overcome the many technical problems that can occur in the recording and analysis of these potentials. The methods and the results of these ERP studies must be published in a way that allows other scientists to understand exactly what was done so that they can, if necessary, replicate the experiments. The data must then be analyzed and presented in a way that allows different studies to be compared readily. This paper presents guidelines for recording ERPs and criteria for publishing the results.

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Guidelines for using human event-related potentials to study cognition: Recording standards and publication criteria

The neurophysiological mechanisms underlying mismatch negativity (MMN) can be inferred from an examination of some of the brain generators involved in the process of this event-related potential (ERP) component. ERPs were recorded in two studies in which the subjects were involved in a selective dichotic listening task. Subjects were required to silently count rare stimuli deviating in pitch from a sequence of standard stimuli in one ear, while ignoring all the stimuli (standards and deviants) delivered randomly to the other ear. The results showed that, in all cases, the negative wave elicited by the deviant stimuli showed the highest amplitudes over the right hemiscalp irrespective of the ear of stimulation or the direction of attention. Scalp radial current density analysis showed that this asymmetric potential distribution could be attributed to the sum of activities of two sets of neural generators: one temporal, located in the vicinity of the primary auditory cortex, predominantly activated in the hemisphere contralateral to the ear of stimulation, and the other frontal, involving mainly the right hemisphere.



The results are discussed in light of Naatanen's model: we suggest the dissociation of two functional processes on the basis of activity of distinct brain areas: a sensory memory mechanism related to the temporal generators, and an automatic attention-switching process related to the frontal generators.

Brain generators implicated in the processing of auditory stimulus deviance: a topographic event-related potential study.

Mapping of scalp potentials by surface spline interpolation.

Scalp current density (SCD) makes possible the identification of scalp sources and sinks of current. SCD is reference independent and its peaks and troughs are sharper than those of the scalp potential (SP). SCD, by comparison to SP, reflects mainly the activity of cortical generators. SCD mapping appears to be a valuable tool to spatially split smeared SP distribution due to simultaneously active generators. The SCD map may be computed from any sufficiently smooth mathematical SP map. An evaluation of the error of SCD estimation is given for a surface spline method of interpolation of SP. An example of the simultaneous use of SP and SCD in the analysis of somatosensory evoked data is given.

Francois Perrin

Papers

Spherical splines for scalp potential and current density mapping

Brain generators implicated in the processing of auditory stimulus deviance: a topographic event-related potential study.

Mapping of scalp potentials by surface spline interpolation.

Scalp Current Density Mapping: Value and Estimation from Potential Data

A theoretical justification of the average reference in topographic evoked potential studies.