Explicit contamination contributes to aging effects in episodic priming: behavioral and ERP evidence

We examined the impact of explicit contamination on age-related changes in episodic priming. We recorded event-related brain potentials (ERPs) from older and younger adults to primed and unprimed nouns tested in a recognition memory task. Results revealed that the magnitude of priming was greater in the younger adults. ERPs revealed a priming effect in the younger adults that was absent in older adults. Findings suggest that explicit contamination may account for the reported aging effect: Item memory was correlated with episodic priming and ERP priming in younger adults, but not older adults; item memory was associated with episodic priming after aging effects were controlled for; and the topographies of the young's priming and item memory effects were indistinguishable. Given the apparent vulnerability to contamination by explicit memory, we suggest caution when researchers use an episodic priming paradigm to assess aging effects in implicit memory.