umu.sePublikasjoner
Endre søk
RefereraExporteraLink to record
Permanent link

Direct link
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annet format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annet språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf
Longitudinal association between hippocampus atrophy and episodic-memory decline
Umeå universitet, Samhällsvetenskapliga fakulteten, Handelshögskolan vid Umeå universitet, Statistik. (Stat4Reg)ORCID-id: 0000-0003-2135-9963
Umeå universitet, Medicinska fakulteten, Umeå centrum för funktionell hjärnavbildning (UFBI). Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB).
Umeå universitet, Samhällsvetenskapliga fakulteten, Handelshögskolan vid Umeå universitet, Statistik. Umeå universitet, Medicinska fakulteten, Umeå centrum för funktionell hjärnavbildning (UFBI).ORCID-id: 0000-0003-1524-0851
Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper.
Vise andre og tillknytning
2017 (engelsk)Inngår i: Neurobiology of Aging, ISSN 0197-4580, E-ISSN 1558-1497, Vol. 51, s. 167-176Artikkel i tidsskrift (Fagfellevurdert) Published
Abstract [en]

There is marked variability in both onset and rate of episodic-memory decline in aging. Structural magnetic resonance imaging studies have revealed that the extent of age-related brain changes varies markedly across individuals. Past studies of whether regional atrophy accounts for episodic-memory decline in aging have yielded inconclusive findings. Here we related 15-year changes in episodic memory to 4-year changes in cortical and subcortical gray matter volume and in white-matter connectivity and lesions. In addition, changes in word fluency, fluid IQ (Block Design), and processing speed were estimated and related to structural brain changes. Significant negative change over time was observed for all cognitive and brain measures. A robust brain-cognition change-change association was observed for episodic-memory decline and atrophy in the hippocampus. This association was significant for older (65-80 years) but not middle-aged (55-60 years) participants and not sensitive to the assumption of ignorable attrition. Thus, these longitudinal findings highlight medial-temporal lobe system integrity as particularly crucial for maintaining episodic-memory functioning in older age. 

sted, utgiver, år, opplag, sider
2017. Vol. 51, s. 167-176
Emneord [en]
Aging, cognitive decline, episodic memory, hippocampus, longitudinal changes, non-ignorable attrition
HSV kategori
Identifikatorer
URN: urn:nbn:se:umu:diva-128725DOI: 10.1016/j.neurobiolaging.2016.12.002ISI: 000397168600018PubMedID: 28089351OAI: oai:DiVA.org:umu-128725DiVA, id: diva2:1056866
Forskningsfinansiär
Swedish Research CouncilKnut and Alice Wallenberg FoundationRagnar Söderbergs stiftelseTilgjengelig fra: 2016-12-15 Laget: 2016-12-13 Sist oppdatert: 2019-01-25bibliografisk kontrollert
Inngår i avhandling
1. Methods for longitudinal brain imaging studies with dropout
Åpne denne publikasjonen i ny fane eller vindu >>Methods for longitudinal brain imaging studies with dropout
2019 (engelsk)Doktoravhandling, med artikler (Annet vitenskapelig)
Alternativ tittel[sv]
Metoder för longitudinella hjärnavbildningsstudier med bortfall
Abstract [en]

One of the challenges in aging research is to understand the brain mechanisms that underlie cognitive development in older adults. Such aging processes are investigated in longitudinal studies, where the within-individual changes over time are observed. However, several methodological issues exist in longitudinal analyses.  One of them is loss of participants to follow-up, which occurs when individuals drop out from the study. Such dropout should be taken into account for valid conclusions from longitudinal investigations, and this is the focus of this thesis. The developed methods are used to explore brain aging and its relation to cognition within the Betula longitudinal study of aging.

Papers I and II consider the association between changes in brain structure and cognition. In the first paper, regression analysis is used to establish the statistical significance of brain-cognition associations while accounting for dropout. Paper II develops interval estimators directly for an association as measured by partial correlation, when some data are missing. The estimators of Paper II may be used in longitudinal as well as cross-sectional studies and are not limited to brain imaging. 

Papers III and IV study functional brain connectivity, which is the statistical dependency between the functions of distinct brain regions. Typically, only brain regions with associations stronger than a predefined threshold are considered connected. However, the threshold is often arbitrarily set and does not reflect the individual differences in the overall connectivity patterns.  Paper III proposes a mixture model for brain connectivity without explicit thresholding of associations and suggests an alternative connectivity measure. Paper IV extends the mixture modeling of Paper III to a longitudinal setting with dropout and investigates the impact of ignoring the dropout mechanism on the quality of the inferences made on longitudinal connectivity changes.

sted, utgiver, år, opplag, sider
Umeå: Umeå universitet, 2019. s. 20
Serie
Statistical studies, ISSN 1100-8989 ; 54
Emneord
Missing data, nonignorable dropout, sensitivity analysis, uncertainty intervals, pattern-mixture models, aging, cognition, MRI, brain structure, resting-state functional connectivity
HSV kategori
Forskningsprogram
statistik
Identifikatorer
urn:nbn:se:umu:diva-155680 (URN)978-91-7855-011-1 (ISBN)
Disputas
2019-02-22, Hörsal 1031, Norra Beteendevetarhuset, Umeå University, Umeå, 10:15 (engelsk)
Opponent
Veileder
Tilgjengelig fra: 2019-02-01 Laget: 2019-01-25 Sist oppdatert: 2019-04-26bibliografisk kontrollert

Open Access i DiVA

fulltext(4183 kB)218 nedlastinger
Filinformasjon
Fil FULLTEXT01.pdfFilstørrelse 4183 kBChecksum SHA-512
8c0f2934d247a4193d4d30aedfb105a87f3032eb1a566c365994cc1ff64f9588bd1867daa4ec09be895c21f7ceac8baa7f71ae3de61c8762eb1a38cfa264edfd
Type fulltextMimetype application/pdf

Andre lenker

Forlagets fulltekstPubMed

Personposter BETA

Gorbach, TetianaPudas, SaraLundquist, AndersOrädd, GregerJosefsson, MariaSalami, Alirezade Luna, XavierNyberg, Lars

Søk i DiVA

Av forfatter/redaktør
Gorbach, TetianaPudas, SaraLundquist, AndersOrädd, GregerJosefsson, MariaSalami, Alirezade Luna, XavierNyberg, Lars
Av organisasjonen
I samme tidsskrift
Neurobiology of Aging

Søk utenfor DiVA

GoogleGoogle Scholar
Totalt: 218 nedlastinger
Antall nedlastinger er summen av alle nedlastinger av alle fulltekster. Det kan for eksempel være tidligere versjoner som er ikke lenger tilgjengelige

doi
pubmed
urn-nbn

Altmetric

doi
pubmed
urn-nbn
Totalt: 1221 treff
RefereraExporteraLink to record
Permanent link

Direct link
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annet format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annet språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf