INTRACRANIAL TOPOGRAPHY OF EVENT-RELATED POTENTIALS (N400/P600) ELICITED DURING A CONTINUOUS RECOGNITION MEMORY TASK

To isolate the anatomical locus of the neural activity most important for generating or modulating the scalp-recorded N400 and P600 components elicited during continuous recognition memory tasks, intracranial event-related potentials (ERPs) were recorded from medial and lateral aspects of the temporal, frontal, parietal, and occipital lobes in 25 patients undergoing stereoelectroencephalography for seizure localization. Large-amplitude and polarity-inverted ERPs were recorded from various temporal, frontal, and parietal structures, whereas the memory-related ERP modulation assessed by the ERP repetition effect was present only in those brain areas that play the most important role in memory processing. These data suggest that the scalp-recorded N400 and P600 components may represent the most readily observable aspect of synchronous activity occurring across widely distributed brain structures and neural systems underlying different cognitive mechanisms, which all contribute to some aspect of information processing during recognition memory.