Medial prefrontal cortex and hippocampal activity differentially contribute to ordinal and temporal context retrieval during sequence memory
- 1Cognitive Neuroscience Program, Department of Psychology, Florida International University, Miami, Florida 33199, USA
- 2Department of Environmental Health Sciences, Florida International University, Miami, Florida 33199, USA
- 3Center for Children and Families, Florida International University, Miami, Florida 33199, USA
- Corresponding author: amattfel{at}fiu.edu
Abstract
Remembering sequences of events defines episodic memory, but retrieval can be driven by both ordinality and temporal contexts. Whether these modes of retrieval operate at the same time or not remains unclear. Theoretically, medial prefrontal cortex (mPFC) confers ordinality, while the hippocampus (HC) associates events in gradually changing temporal contexts. Here, we looked for evidence of each with BOLD fMRI in a sequence task that taxes both retrieval modes. To test ordinal modes, items were transferred between sequences but retained their position (e.g., AB3). Ordinal modes activated mPFC, but not HC. To test temporal contexts, we examined items that skipped ahead across lag distances (e.g., ABD). HC, but not mPFC, tracked temporal contexts. There was a mPFC and HC by retrieval mode interaction. These current results suggest that the mPFC and HC are concurrently engaged in different retrieval modes in support of remembering when an event occurred.
Footnotes
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Article is online at http://www.learnmem.org/cgi/doi/10.1101/lm.052365.120.
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Freely available online through the Learning & Memory Open Access option.
- Received July 7, 2020.
- Accepted January 20, 2021.
This article, published in Learning & Memory, is available under a Creative Commons License (Attribution-NonCommercial 4.0 International), as described at http://creativecommons.org/licenses/by-nc/4.0/.
