The encoding/retrieval flip: interactions between memory performance and memory stage and relationship to intrinsic cortical networks

J Cogn Neurosci. 2013 Jul;25(7):1163-79. doi: 10.1162/jocn_a_00366. Epub 2013 Feb 5.

Abstract

fMRI studies have linked the posteromedial cortex to episodic learning (encoding) and remembering (retrieval) processes. The posteromedial cortex is considered part of the default network and tends to deactivate during encoding but activate during retrieval, a pattern known as the encoding/retrieval flip. Yet, the exact relationship between the neural correlates of memory performance (hit/miss) and memory stage (encoding/retrieval) and the extent of overlap with intrinsic cortical networks remains to be elucidated. Using task-based fMRI, we isolated the pattern of activity associated with memory performance, memory stage, and the interaction between both. Using resting-state fMRI, we identified which intrinsic large-scale functional networks overlapped with regions showing task-induced effects. Our results demonstrated an effect of successful memory performance in regions associated with the control network and an effect of unsuccessful memory performance in the ventral attention network. We found an effect of memory retrieval in brain regions that span the default and control networks. Finally, we found an interaction between memory performance and memory stage in brain regions associated with the default network, including the posteromedial cortex, posterior parietal cortex, and parahippocampal cortex. We discuss these findings in relation to the encoding/retrieval flip. In general, the findings demonstrate that task-induced effects cut across intrinsic cortical networks. Furthermore, regions within the default network display functional dissociations, and this may have implications for the neural underpinnings of age-related memory disorders.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Analysis of Variance
  • Brain Mapping*
  • Cerebral Cortex / blood supply
  • Cerebral Cortex / physiology*
  • Female
  • Functional Laterality / physiology
  • Humans
  • Image Processing, Computer-Assisted
  • Linear Models
  • Magnetic Resonance Imaging
  • Male
  • Mental Recall / physiology*
  • Neural Pathways / blood supply
  • Neural Pathways / physiology*
  • Neuropsychological Tests
  • Oxygen / blood
  • Recognition, Psychology / physiology*
  • Young Adult

Substances

  • Oxygen