Large scale neurocognitive networks underlying episodic memory.

Journal Article (Journal Article)

Large-scale networks of brain regions are believed to mediate cognitive processes, including episodic memory. Analyses of regional differences in brain activity, measured by functional neuroimaging, have begun to identify putative components of these networks. To more fully characterize neurocognitive networks, however, it is necessary to use analytical methods that quantify neural network interactions. Here, we used positron emission tomography (PET) to measure brain activity during initial encoding and subsequent recognition of sentences and pictures. For each type of material, three recognition conditions were included which varied with respect to target density (0%, 50%, 100%). Analysis of large-scale activity patterns identified a collection of foci whose activity distinguished the processing of sentences vs. pictures. A second pattern, which showed strong prefrontal cortex involvement, distinguished the type of cognitive process (encoding or retrieval). For both pictures and sentences, the manipulation of target density was associated with minor activation changes. Instead, it was found to relate to systematic changes of functional connections between material-specific regions and several other brain regions, including medial temporal, right prefrontal and parietal regions. These findings provide evidence for large-scale neural interactions between material-specific and process-specific neural substrates of episodic encoding and retrieval.

Full Text

Duke Authors

Cited Authors

  • Nyberg, L; Persson, J; Habib, R; Tulving, E; McIntosh, AR; Cabeza, R; Houle, S

Published Date

  • January 2000

Published In

Volume / Issue

  • 12 / 1

Start / End Page

  • 163 - 173

PubMed ID

  • 10769313

Electronic International Standard Serial Number (EISSN)

  • 1530-8898

International Standard Serial Number (ISSN)

  • 0898-929X

Digital Object Identifier (DOI)

  • 10.1162/089892900561805


  • eng