Recognition memory and familiarity judgments in severe amnesia: No evidence for a contribution of repetition priming

The amnesic patient E.P. has demonstrated normal levels of repetition primi ng and at-chance recognition performance (S. B. Hamann & L. R. Squire, 1997 ), suggesting that the sense of familiarity used to make a recognition memo ry judgment is not based on the same mechanism responsible for repetition p riming. However, the recognition tests previously used may have discouraged the use of familiarity and encouraged reliance on episodic memory. This is sue was addressed in 5 experiments with E.P., 3 other amnesic patients with hippocampal damage, and 8 healthy controls. In Experiments 1-3, which were designed to discourage the use of episodic memory, the amnesic patients we re impaired and E.P. performed at chance. In Experiments 4 and 5A, a stem-c ompletion priming task was combined with a recognition memory task on each trial. E.P.'s priming was intact, yet his recognition memory performance wa s at chance. This suggests that although recognition memory judgments may b e made on the basis of familiarity, repetition priming is not the source of this feeling of familiarity.