The use of brain electrical potentials (BEP) to study localization of human brain function

Various techniques such as neuropsychological diagnosis of individuals with focal lesions, stimulation of neurosurgery patients, and regional cerebral blood flow have been used to elucidate the major anatomical and functional divisions of the human cerebral cortex. Because of insufficient spatial sampling and other limitations, only minor support for these divisions comes from brain electrical potential (BEP) experimentation. The use of EEG to localize different neuropathologies and to screen and track the evolution of seizure disorders is fairly reliable and still widely practiced. Its use, however, in localizing higher cognitive functions is much more complicated and has not stood the test of scientific scrutiny because of methodological problems. More specifically, the failure to control for the stimulus, response and performance related properties of tasks in experiments has rendered ambiguous the results of most EEG studies of higher cognitive functions. Those studies which actually controlled for these properties did not find and differences between tasks.