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Predictability matters: role of the hippocampus and prefrontal cortex in disambiguation of overlapping sequences
Previous research has demonstrated that areas in the medial temporal lobe and prefrontal cortex (PFC) show increased activation during retrieval of overlapping sequences. In this study, we designed a task in which degree of overlap varied between conditions in order to parse out the contributions of...
Autores principales: | , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Cold Spring Harbor Laboratory Press
2018
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6049392/ https://www.ncbi.nlm.nih.gov/pubmed/30012878 http://dx.doi.org/10.1101/lm.047175.117 |
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author | Cohen, Justine E. Ross, Robert S. Stern, Chantal E. |
author_facet | Cohen, Justine E. Ross, Robert S. Stern, Chantal E. |
author_sort | Cohen, Justine E. |
collection | PubMed |
description | Previous research has demonstrated that areas in the medial temporal lobe and prefrontal cortex (PFC) show increased activation during retrieval of overlapping sequences. In this study, we designed a task in which degree of overlap varied between conditions in order to parse out the contributions of hippocampal and prefrontal subregions as overlap between associations increased. In the task, participants learned sequential associations consisting of a picture frame, a face within the picture frame, and an outdoor scene. The control condition consisted of a single frame-face-scene sequence. In the low overlap condition, each frame was paired with two faces and two scenes. In the high overlap condition, each frame was paired with four faces and four scenes. In all conditions the correct scene was chosen among four possible scenes and was dependent on the frame and face that preceded the choice point. One day after training, participants were tested on the retrieval of learned sequences during fMRI scanning. Results showed that the middle and posterior hippocampus (HC) was active at times when participants acquired information that increased predictability of the correct response in the overlapping sequences. Activation of dorsolateral PFC occurred at time points when the participant was able to ascertain which set of sequences the correct response belonged to. The ventrolateral PFC was active when inhibition was required, either of irrelevant stimuli or incorrect responses. These results indicate that areas of lateral PFC work in concert with the HC to disambiguate between overlapping sequences and that sequence predictability is key to when specific brain regions become active. |
format | Online Article Text |
id | pubmed-6049392 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2018 |
publisher | Cold Spring Harbor Laboratory Press |
record_format | MEDLINE/PubMed |
spelling | pubmed-60493922019-08-01 Predictability matters: role of the hippocampus and prefrontal cortex in disambiguation of overlapping sequences Cohen, Justine E. Ross, Robert S. Stern, Chantal E. Learn Mem Research Previous research has demonstrated that areas in the medial temporal lobe and prefrontal cortex (PFC) show increased activation during retrieval of overlapping sequences. In this study, we designed a task in which degree of overlap varied between conditions in order to parse out the contributions of hippocampal and prefrontal subregions as overlap between associations increased. In the task, participants learned sequential associations consisting of a picture frame, a face within the picture frame, and an outdoor scene. The control condition consisted of a single frame-face-scene sequence. In the low overlap condition, each frame was paired with two faces and two scenes. In the high overlap condition, each frame was paired with four faces and four scenes. In all conditions the correct scene was chosen among four possible scenes and was dependent on the frame and face that preceded the choice point. One day after training, participants were tested on the retrieval of learned sequences during fMRI scanning. Results showed that the middle and posterior hippocampus (HC) was active at times when participants acquired information that increased predictability of the correct response in the overlapping sequences. Activation of dorsolateral PFC occurred at time points when the participant was able to ascertain which set of sequences the correct response belonged to. The ventrolateral PFC was active when inhibition was required, either of irrelevant stimuli or incorrect responses. These results indicate that areas of lateral PFC work in concert with the HC to disambiguate between overlapping sequences and that sequence predictability is key to when specific brain regions become active. Cold Spring Harbor Laboratory Press 2018-08 /pmc/articles/PMC6049392/ /pubmed/30012878 http://dx.doi.org/10.1101/lm.047175.117 Text en © 2018 Cohen et al.; Published by Cold Spring Harbor Laboratory Press http://creativecommons.org/licenses/by-nc/4.0/ This article is distributed exclusively by Cold Spring Harbor Laboratory Press for the first 12 months after the full-issue publication date (see http://learnmem.cshlp.org/site/misc/terms.xhtml). After 12 months, it is available under a Creative Commons License (Attribution-NonCommercial 4.0 International), as described at http://creativecommons.org/licenses/by-nc/4.0/. |
spellingShingle | Research Cohen, Justine E. Ross, Robert S. Stern, Chantal E. Predictability matters: role of the hippocampus and prefrontal cortex in disambiguation of overlapping sequences |
title | Predictability matters: role of the hippocampus and prefrontal cortex in disambiguation of overlapping sequences |
title_full | Predictability matters: role of the hippocampus and prefrontal cortex in disambiguation of overlapping sequences |
title_fullStr | Predictability matters: role of the hippocampus and prefrontal cortex in disambiguation of overlapping sequences |
title_full_unstemmed | Predictability matters: role of the hippocampus and prefrontal cortex in disambiguation of overlapping sequences |
title_short | Predictability matters: role of the hippocampus and prefrontal cortex in disambiguation of overlapping sequences |
title_sort | predictability matters: role of the hippocampus and prefrontal cortex in disambiguation of overlapping sequences |
topic | Research |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6049392/ https://www.ncbi.nlm.nih.gov/pubmed/30012878 http://dx.doi.org/10.1101/lm.047175.117 |
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