Remember/know judgments probe degrees of recollection.

Remembering and knowing are states of awareness that accompany the retrieval of facts, faces, and experiences from our past. Although originally intended to separate episodic from semantic memory, the dominant view today is that recollection-based decisions underlie remember responses, whereas familiarity-based decisions underlie know responses. Many functional magnetic resonance imaging (fMRI) studies as well as lesion studies have relied on the remember/know procedure to identify the neural correlates of recollection and familiarity. An implicit assumption of this approach is that know responses, which are thought to tap familiarity-based decisions, are devoid of recollection. We investigated this issue by using a source memory procedure and found that the accuracy of source recollection was significantly above chance for studied words that were declared to be old and known. Critically, this held true even when the source decision was made before the old/new decision (i.e., even after successful recollection had just occurred). Our results show that although recollection and familiarity may be different processes, the remember/know paradigm does not probe them directly. As such, dissociations involving remember/know judgments in fMRI studies and in studies involving amnesic patients should not be construed as dissociations between recollection and familiarity.