For nearly forty years the study of human event-related brain
dynamics was dominated by the study of averaged event-related
potentials (ERPs) and fields (ERFs) recorded and averaged time
locked to classes of experimental events. ERPs and ERFs provide
unequivocal evidence of direct linkage between cognitive events
and electrochemical brain events in a wide range of cognitive
paradigms. However, collapsing a set of complex, multidimensional
data epochs to a skeleton set of peak amplitude and latency measures
of a response average actually conceals, rather than reveals,
many important types of event-related EEG brain dynamics. The unfortunate
side effects of the averaging era include, first, a near-complete
divorce between the innately related sub-fields of ERP and of EEG research,
and second, an enduring separation between the fields of human electrophysiology
and animal neurophysiology, the latter potentiated by the near-total neglect
of local field potentials by neurophysiologists who record them.
The recent millenary,
however, coincides with the emergence of a field I propose to call
cognitive event-related brain dynamics. The availability of
ever-increasing computational resources allow new generations of
cognitive neuroscientists to study the dynamics of the scalp-recorded
electromagnetic field using combinations of complex and sophisticated
methods including source imaging, time/frequency analysis,
event-related coherence, non-linear dynamics and independent
component analysis. Applying these new techniques reveals that the
EEG and MEG data contain a great deal of yet unappreciated information
about mechanisms of neural synchronization within and between brain
areas. Further, this information appears to be convergent with new
findings in cellular neuroscience. These and related views of
event-related brain dynamics may soon combine to give a much richer
picture of the brain processes supporting human cognition and
consciousness.