Dataset Information

A Working Memory Buffer in Parahippocampal Regions: Evidence from a Load Effect during the Delay Period.

ABSTRACT: Computational models have proposed that the entorhinal cortex (EC) is well suited for maintaining multiple items in working memory (WM). Evidence from animal recording and human neuroimaging studies show that medial temporal lobe areas including the perirhinal (PrC), EC, and CA1 hippocampal subfield may contribute to active maintenance during WM. Previous neuroimaging work also suggests CA1 may be recruited transiently when encoding novel information, and EC and CA1 may be involved in maintaining multiple items in WM. In this study, we tested the prediction that a putative WM buffer would demonstrate a load-dependent effect during a WM delay. Using high-resolution fMRI, we examined whether activity within the hippocampus (CA3/DG, CA1, and subiculum) and surrounding medial temporal cortices (PrC, EC, and parahippocampal cortex-PHC) is modulated in a load-dependent manner. We employed a delayed matching-to-sample task with novel scenes at 2 different WM loads. A contrast between high- and low-WM load showed greater activity within CA1 and subiculum during the encoding phase, and greater EC, PrC, and PHC activity during WM maintenance. These results are consistent with computational models and suggest that EC/PrC and PHC act as a WM buffer by actively maintaining novel information in a capacity-dependent manner.

SUBMITTER: Schon K

PROVIDER: S-EPMC4830282 | biostudies-literature | 2016 May

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

A Working Memory Buffer in Parahippocampal Regions: Evidence from a Load Effect during the Delay Period.

Schon Karin K Newmark Randall E RE Ross Robert S RS Stern Chantal E CE

Cerebral cortex (New York, N.Y. : 1991) 20150206 5

Computational models have proposed that the entorhinal cortex (EC) is well suited for maintaining multiple items in working memory (WM). Evidence from animal recording and human neuroimaging studies show that medial temporal lobe areas including the perirhinal (PrC), EC, and CA1 hippocampal subfield may contribute to active maintenance during WM. Previous neuroimaging work also suggests CA1 may be recruited transiently when encoding novel information, and EC and CA1 may be involved in maintainin ...[more]

PMID: 25662713

Similar Datasets

Project description:PurposeThis study evaluated the effects of a linguistic characteristic, typicality, and a processing variable, working memory on the abilities of people with aphasia (PWA) and neurologically intact adults to process semantic representations. This was accomplished using a newly developed assessment task, the Category Typicality Test, which was created for the Temple Assessment of Language and Short-Term Memory in Aphasia.MethodA post hoc quasi-experimental design was used. Participants included 27 PWA and 14 neurologically intact adults who completed the picture and word versions of the Category Typicality Test, which required them to determine if two items are in the same category. Memory load was altered by increasing the number of items to be compared, and the typicality of items was altered to increase linguistic complexity.ResultsA four-way mixed analysis of covariance was conducted. There was a significant interaction between working memory load and category typicality with performance accuracy decreasing as working memory load increased and category typicality decreased. There was also a significant interaction for typicality and stimuli with better performance in the picture condition and a significant interaction for working memory and group with lower performance accuracy for PWA. Post hoc pairwise comparisons revealed differences between memory load, typicality, stimuli conditions, and group. PWA also showed greater magnitude of change than neurologically intact adults when comparing high and low working memory load conditions, but not typicality conditions.DiscussionIncreasing working memory load had the most substantial impact on the accuracy of category judgments in PWA, but the interaction between increased working memory load and decreased category typicality of items to be compared resulted in reduced accuracy in both groups. These findings suggest that manipulation of processing and linguistic variables in assessment will provide insight into the nature of linguistic breakdown in aphasia. Supplemental Material https://doi.org/10.23641/asha.14781996.

Dataset Information

A Working Memory Buffer in Parahippocampal Regions: Evidence from a Load Effect during the Delay Period.

Publications

A Working Memory Buffer in Parahippocampal Regions: Evidence from a Load Effect during the Delay Period.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets