It is difficult to predict whether newly learned information will be retrievable in the future. A biomarker of long-lasting learning, capable of predicting an individual's future ability to retrieve a particular memory, could positively influence teaching and educational methods. ERPs were investigated as a potential biomarker of long-lasting learning. Prior ERP studies have supported a dual-process model of recognition memory that categorizes recollection and familiarity as distinct memorial processes with distinct ERP correlates. The late positive component is thought to underlie conscious recollection and the frontal N400 signal is thought to reflect familiarity [Yonelinas, A. P. Components of episodic memory: The contribution of recollection and familiarity. Philosophical Transactions of the Royal Society of London, Series B, Biological Sciences, 356, 1363–1374, 2001]. Here we show that the magnitude of the late positive component, soon after initial learning, is predictive of subsequent recollection of anatomical terms among medical students 6 months later.

The animal literature suggests that exposure to more complex, novel environments promotes neurogenesis and cognitive performance in older animals. Studies in humans indicate that participation in intellectually stimulating activities may serve as a buffer against mental decline and help to sustain cognitive abilities. Here, we show that across old adults, increased responsiveness to novel events (as measured by viewing duration and the size of the P3 event-related potential) is strongly linked to better performance on neuropsychological tests, especially those involving attention/executive functions. Cognitively high performing old adults generate a larger P3 response to visual stimuli than cognitively average performing adults. These results suggest that cognitively high performing adults successfully manage the task by appropriating more resources and that the increased size of their P3 component represents a beneficial compensatory mechanism rather than less efficient processing.

Event-related potentials (ERPs) were used to investigate the neural processes underlying the distinctiveness heuristic— a response mode in which participants expect to remember vivid details of an experience and make recognition decisions based on this metacognitive expectation. One group of participants studied pictures and auditory words; another group studied visual and auditory words. Studied and novel items were presented at test as words only, with all novel items repeating after varying lags. ERP differences were seen between the word and picture groups for both studied and novel items. For the novel items, ERP differences were largest in frontal and central midline electrodes. In separate analyses, the picture group showed the greatest ERP differences between item types in a parietally based component from 550 to 1000 msec, whereas the word group showed the greatest differences in a frontally based component from 1000 to 2000 msec. The authors suggest that the distinctiveness heuristic is a retrieval orientation that facilitates reliance upon recollection to differentiate between item types. Although the picture group can use this heuristic and its retrieval orientation on the basis of recollection, the word group must engage additional postretrieval processes to distinguish between item types, reflecting the use of a different retrieval orientation.