Comparison of conventional P3 determination with global field power in epilepsy patients

The usefulness of global field power (GFP) determinations in assessing the cognitive event-related potential latency to an auditory "odd-ball" discrimination paradigm was explored in thirty epileptic patients. Relationships to measurements of intellectual and neuropsychologic test parameters were compared between conventional peak determinations and those obtained by GFP. Latencies as determined by GFP showed a greater number and more consistent relationships with neuropsychologic test measures than those obtained by conventional peak determinations. In some instances, GFP gave however also ambiguous results and the method cannot be substituted for conventional peak determinations, but must be used in conjunction in order to avoid spurious results.