Item memory, context memory and the hippocampus: fMRI evidence

• Published in: Neuropsychologia Vol. 50; no. 13; pp. 3070 - 3079
• Main Authors: Rugg, Michael D., Vilberg, Kaia L., Mattson, Julia T., Yu, Sarah S., Johnson, Jeffrey D., Suzuki, Maki
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.11.2012; Elsevier
• Subjects: Beginning Reading; Brain Hemisphere Functions; Context Effect; Correlation; Diagnostic Tests; Episodic memory; Evidence; Familiarity; Hippocampus - physiology; Humans; Image Processing, Computer-Assisted; Magnetic Resonance Imaging; Memory; Memory - physiology; Memory strength; Mental Processes - physiology; Mental Recall - physiology; Recognition (Psychology); Recollection; Remember-know; Memory strength; Remember-know; Familiarity; Episodic memory; Recollection
• ISSN: 0028-3932; 1873-3514
• DOI: 10.1016/j.neuropsychologia.2012.06.004

Dual-process models of recognition memory distinguish between the retrieval of qualitative information about a prior event (recollection), and judgments of prior occurrence based on an acontextual sense of familiarity. fMRI studies investigating the neural correlates of memory encoding and retrieval conducted within the dual-process framework have frequently reported findings consistent with the view that the hippocampus selectively supports recollection, and has little or no role in familiarity-based recognition. An alternative interpretation of these findings has been proposed, however, in which it is argued that the hippocampus supports the encoding and retrieval of ‘strong’ memories, regardless of whether the memories are recollection- or familiarity-based. Here, we describe the findings of eight fMRI studies from our laboratory: one study of source memory encoding, four studies of the retrieval of contextual information, and three studies of continuous recognition. Together, the findings support the proposal that hippocampal activity co-varies with the amount of contextual information about a study episode that is encoded or retrieved, and not with the strength of an undifferentiated memory signal. ► Item memory strength is not a major determinant of hippocampal encoding- or retrieval-related activity. ► Hippocampal activity co-varies positively with the amount of contextual information encoded or retrieved. ► Hippocampal activity co-varies negatively with familiarity strength.