Brain potentials during sentence verification: late negativity and long-term memory strength.

Subjects decided whether self-referential statements were true or false. Event-related potentials (ERPs) associated with final words creating false statements displayed a late negativity (N340) relative to ERPs for true completions. The size of this difference between true and false statements was greater for highly familiar statements (e.g. "My name is Ira") than for less familiar ones (e.g. "I go to bed late") even after all the statements had been practised a number of times. The late negativity appears to be associated with a discrepancy between presented and remembered information, and its magnitude reflects the long-term familiarity or strength of the remembered information.