Abstract
Electroencephalographic (EEG) and sensory evoked potential (EP) measures provide some of the most direct methods for assessing central nervous system function. However, despite considerable research demonstrating systematic differences between normals and patients, 1 cognitive event-related brain potentials (ERPs) as yet have not been employed in a clinically routine fashion. The P300 component in particular has been widely applied in the scientific study of cognitive dysfunction, because it reflects attentional and memory processes. 2 The clinical utility of the P300 is currently considered an index of “cognitive efficiency”—i.e., how well an individual's CNS can process incoming information. Such a measure can be a highly useful metric for neurologic/psychiatric evaluation, especially with respect to evaluating therapeutic strategies involving CNS medications. Comparison of P300 assessment with standard clinical assays indicates that this component is as reliable as other biomedical measures, 3 with standardized cognitive ERP methods being developed. 4,5 An objective, comparatively easy, and inexpensive tool for assessing cognitive efficiency should prove exceptionally useful and can help address a wide variety of clinical questions.
This special issue of Clinical EEG was developed with the intent of providing an overview into this research world. The present papers were solicited to reflect the diversity of ERP applications to different neuropsychological, neurologic, and psychiatric problem areas. The topics include: P3 assessment of HIV patients on anti-viral medications (Polich and Basho); clinical integration of neuropsychological testing and P300 evaluation of head trauma victims (Solbackk, Reinvang, and Andersson); a rare ERP report of how temporal lobe epilepsy affects semantic processing (Olichney, Riggins, Hillert, Nowacki, Tecoma, Kutas, and Iragui); a comprehensive P300 study of depressive and anxiety patients (Bruder, Kayser, Tenke, Leite, Schneier, Stewart, and Quitkin), and an important assessment of paradigm effects when ERPs are used to assess patients with schizophrenia (Mathalon and Ford). Each of these studies presents a unique portrait that reflects state-of-the-art ERP applications and findings. The papers also highlight the critical details of clinical ERP research: (1) use of well-defined patient and control samples, (2) appropriate neuroelectric methodology, analysis, and data presentation, and (3) the thoughtful interpretation of results in a clinical context. Thus, the findings provide an intriguing snapshot of the direction and breadth of contemporary clinical ERP research.
I sincerely thank Dr. Norman C. Moore for his gracious invitation to edit this special issue. The project has been very rewarding and fun. I am very grateful to all of the authors for their contributions, scientific acumen, and collegiality. Special thanks are due also to Ms. Catherine Demeter, the journal's technical editor, for her unflagging support, optimistic advice, and wonderful good humor.