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Associative memory for conceptually unitized word pairs in mild cognitive impairment is related to the volume of the perirhinal cortex

Delhaye, Emma ; Mechanic-Hamilton, Dawn ; Saad, Laura ; Das, Sandhitsu R ; Wisse, Laura E M LU orcid ; Yushkevich, Paul A ; Wolk, David A and Bastin, Christine (2019) In Hippocampus 29(7). p.630-638
Abstract

Unitization, that is, the encoding of an association as one integrated entity, has been shown to improve associative memory in populations presenting with associative memory deficit due to hippocampal dysfunction, such as amnesic patients with focal hippocampal lesions and healthy older adults. One reason for this benefit is that encoding of unitized associations would rely on the perirhinal cortex (PrC) and thus minimize the need for hippocampal recruitment. Mild cognitive impairment (MCI) is accompanied by a deficit in associative memory. However, unitization has never been studied to explore the potential benefit in associative memory in MCI, maybe because MCI is characterized by PrC pathology. However, the PrC may potentially still... (More)

Unitization, that is, the encoding of an association as one integrated entity, has been shown to improve associative memory in populations presenting with associative memory deficit due to hippocampal dysfunction, such as amnesic patients with focal hippocampal lesions and healthy older adults. One reason for this benefit is that encoding of unitized associations would rely on the perirhinal cortex (PrC) and thus minimize the need for hippocampal recruitment. Mild cognitive impairment (MCI) is accompanied by a deficit in associative memory. However, unitization has never been studied to explore the potential benefit in associative memory in MCI, maybe because MCI is characterized by PrC pathology. However, the PrC may potentially still function sufficiently to allow for the successful adoption of unitization. In this study, we aimed at assessing whether unitization could attenuate MCI patients' associative memory deficit, and whether the ability to remember unitized associations would be modulated by the integrity of the PrC in MCI patients. Unitization was manipulated at a conceptual level, by encouraging participants to encode unrelated word pairs as new compound words. Participants also underwent a structural MRI exam, and measures of PrC were extracted (Brodmann Areas [BA] 35 and 36). Results showed that, contrary to healthy controls, MCI patients did not benefit from unitization. Moreover, their memory performance for unitized associations was related to the measure of PrC integrity (BA35), while it was not the case in controls. This finding thus suggests that unitization does not help to attenuate the associative deficit in MCI patients, and brings support to the literature linking unitization to the PrC function.

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author
; ; ; ; ; ; and
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Aged, Aged, 80 and over, Association Learning/physiology, Case-Control Studies, Cognitive Dysfunction/diagnostic imaging, Female, Functional Neuroimaging, Hippocampus/diagnostic imaging, Humans, Magnetic Resonance Imaging, Male, Memory/physiology, Perirhinal Cortex/diagnostic imaging
in
Hippocampus
volume
29
issue
7
pages
630 - 638
publisher
John Wiley & Sons Inc.
external identifiers
  • scopus:85059070204
  • pmid:30588714
ISSN
1050-9631
DOI
10.1002/hipo.23063
language
English
LU publication?
no
additional info
© 2018 Wiley Periodicals, Inc.
id
5b190bd2-4d07-4102-9f28-9e289ad6f9f9
date added to LUP
2024-02-28 14:46:14
date last changed
2024-04-14 00:19:03
@article{5b190bd2-4d07-4102-9f28-9e289ad6f9f9,
  abstract     = {{<p>Unitization, that is, the encoding of an association as one integrated entity, has been shown to improve associative memory in populations presenting with associative memory deficit due to hippocampal dysfunction, such as amnesic patients with focal hippocampal lesions and healthy older adults. One reason for this benefit is that encoding of unitized associations would rely on the perirhinal cortex (PrC) and thus minimize the need for hippocampal recruitment. Mild cognitive impairment (MCI) is accompanied by a deficit in associative memory. However, unitization has never been studied to explore the potential benefit in associative memory in MCI, maybe because MCI is characterized by PrC pathology. However, the PrC may potentially still function sufficiently to allow for the successful adoption of unitization. In this study, we aimed at assessing whether unitization could attenuate MCI patients' associative memory deficit, and whether the ability to remember unitized associations would be modulated by the integrity of the PrC in MCI patients. Unitization was manipulated at a conceptual level, by encouraging participants to encode unrelated word pairs as new compound words. Participants also underwent a structural MRI exam, and measures of PrC were extracted (Brodmann Areas [BA] 35 and 36). Results showed that, contrary to healthy controls, MCI patients did not benefit from unitization. Moreover, their memory performance for unitized associations was related to the measure of PrC integrity (BA35), while it was not the case in controls. This finding thus suggests that unitization does not help to attenuate the associative deficit in MCI patients, and brings support to the literature linking unitization to the PrC function.</p>}},
  author       = {{Delhaye, Emma and Mechanic-Hamilton, Dawn and Saad, Laura and Das, Sandhitsu R and Wisse, Laura E M and Yushkevich, Paul A and Wolk, David A and Bastin, Christine}},
  issn         = {{1050-9631}},
  keywords     = {{Aged; Aged, 80 and over; Association Learning/physiology; Case-Control Studies; Cognitive Dysfunction/diagnostic imaging; Female; Functional Neuroimaging; Hippocampus/diagnostic imaging; Humans; Magnetic Resonance Imaging; Male; Memory/physiology; Perirhinal Cortex/diagnostic imaging}},
  language     = {{eng}},
  number       = {{7}},
  pages        = {{630--638}},
  publisher    = {{John Wiley & Sons Inc.}},
  series       = {{Hippocampus}},
  title        = {{Associative memory for conceptually unitized word pairs in mild cognitive impairment is related to the volume of the perirhinal cortex}},
  url          = {{http://dx.doi.org/10.1002/hipo.23063}},
  doi          = {{10.1002/hipo.23063}},
  volume       = {{29}},
  year         = {{2019}},
}