title: Distinct neural mechanisms for remembering when an event occurred.
abstract: Events are often remembered as having occurred in a specific order, but almost nothing is known about how the brain encodes this temporal information. It is commonly assumed that temporal information is encoded via a single mechanism, based either on the temporal context in which the event occurred or inferred from the strength of the memory trace itself. By analyzing time-dependent changes in activity patterns, we show that the distinctiveness of contextual representations in the hippocampus and anterior and medial prefrontal cortex was associated with accurate recency memory. In contrast, overall activation in the perirhinal and lateral prefrontal cortices predicted whether an object would be judged more recent, regardless of accuracy. These results demonstrate that temporal information was encoded through at least two complementary neural mechanisms.
authors: Department of Psychology, University of Wisconsin, Milwaukee, Wisconsin, 53201.
authors: Lucas J
authors: LJ
authors: Jenkins
authors: Department of Psychology, University of California, 135 Young Hall, One Shields Ave. Davis, Davis, California, 95616.|Center for Neuroscience, University of California, 1544 Newton Ct. Davis, Davis, California, 95618.
authors: Charan
authors: C
authors: Ranganath
mesh_terms: D000328:Adult; D001921:Brain / Q000000981:diagnostic imaging / Q000502:physiology*; D001931:Brain Mapping; D004192:Discrimination, Psychological; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008568:Memory / Q000502:physiology*; D015999:Multivariate Analysis; D010364:Pattern Recognition, Visual; D010775:Photic Stimulation; D055815:Young Adult
keywords: episodic memory; functional MRI; recency discrimination; temporal context; temporal order memory