Patterns of memory impairment in patients with amnesia suggest that memory for facts and episodes depends on a process of "cross-cortical storage" that is not required for other forms of memory. This neuropsychological evidence provides a theoretical foundation for understanding memory phenomena like recollection (the conscious experience of remembering facts and events) and priming (an instance of item-specific implicit memory). Building on this foundation, electrophysiological measures of brain activity can provide additional evidence relevant for understanding the processes responsible for these fundamentally different types of memory. In particular, distinct brain potentials have been associated with recollection of episodic memories and with certain types of priming. This approach is thus useful for exploring the neurocognitive events that make remembering with awareness so different from remembering without awareness.