This special issue of Cognitive Neuroscience focuses on the roles of the hippocampus during long-term memory. A discussion paper by Tallman, Clark, and Smith (this issue) found that functional connectivity of the hippocampus with the parahippocampal cortex and fusiform gyrus decreased with memory age, providing support for systems consolidation. Commentaries were received by Berdugo-Vega and Gräff (this issue), Feld and Gerchen (this issue), Gellersen and Simons (this issue), Gobbo, Mitchell-Heggs, and Tse (this issue), Gilmore, Audrain, and Martin (this issue), Kirwan (this issue), Manns (this issue), Runyan and Brooks (this issue), Santangelo (this issue), and Yang (this issue). The author response considered the content and context of memorial information along with neuroanatomy and functional specialization and conducted new analyses to clarify their findings. An empirical fMRI paper by Thakral, Yu, and Rugg (this issue) reported that the hippocampus was sensitive to the amount of contextual information retrieved, regardless of remember-know status. Another empirical study by Bjornn, Van, and Kirwan (this issue) found that hippocampal activation changes were correlated with the number of fixations at study for correct but not incorrect mnemonic discrimination judgments. A second discussion paper (Slotnick, this issue) concluded that no fMRI studies have provided evidence that the hippocampus is associated with working memory. Commentaries were received by Courtney (this issue), Kessels and Bergmann (this issue), Peters and Reithler (this issue), Rose and Chao (this issue), Stern and Hasselmo (this issue), and Wood, Clark, and Nee (this issue). The articles in this special issue illustrate that the roles of the hippocampus in long-term memory (and other types of memory) are under active investigation and provide many directions for research in the immediate future.
Keywords: Consolidation; fMRI; medial temporal lobe; review; working memory.