Interindividual differences of medial temporal lobe activation during encoding in an elderly population studied by fMRI

Vandenbroucke, Myriam W. G.; Goekoop, Rutger; Duschek, Erik J J; Netelenbos, J. C.; Kuijer, Joost P.A.; Barkhof, Frederik; Scheltens, Philip; Rombouts, Serge A.R.B.

doi:10.1016/j.neuroimage.2003.09.043

Cited by 34 publications

(29 citation statements)

References 29 publications

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“…Previous studies from our laboratory [4,20] also have consistently reported increased MTL signal associated with the APOE ε4 allele, and ROI analyses involving the hippocampus in these and other former studies have typically been based on a standardized anatomic atlas [12], thus not allowing for consideration of individual variation with respect to hippocampal size and consequent individual hippocampal BOLD activity. In fact, most fMRI studies average groups of different subjects into standard coordinate space, and anatomic differences in brain structure create additional variance and loss of registration accuracy [46]. We utilized native space manual outlining of individual hippocampi as structural masks for functional overlays, thereby allowing for better anatomic accuracy of hippocampal activity (see Vandenbroucke et al [46] for discussion).…”

Section: Resultsmentioning

confidence: 99%

“…In fact, most fMRI studies average groups of different subjects into standard coordinate space, and anatomic differences in brain structure create additional variance and loss of registration accuracy [46]. We utilized native space manual outlining of individual hippocampi as structural masks for functional overlays, thereby allowing for better anatomic accuracy of hippocampal activity (see Vandenbroucke et al [46] for discussion).…”

Section: Resultsmentioning

confidence: 99%

“…A few studies have investigated the relationship between APOE genotype and functional neuroimaging of memory processes in non-demented elderly, but the interpretation of these results has been confounded by a number of factors. These include: (1) poorer memory in the ε4 group than in the non-ε4 group [6], (2) questions of interpretability of signal change via the subtraction method, particularly when contrasting two higher-level conditions such as novel versus familiar items, (3) no assessment for differential atrophy [6,20], or (4) the use of general standard space region of interest (ROI) analyses rather than specific individualized native space renderings [4,20] (see also Vandenbroucke et al [46] for discussion).…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Verbal paired-associate learning by APOE genotype in non-demented older adults: fMRI evidence of a right hemispheric compensatory response

Han

Houston

Jak

et al. 2007

Neurobiology of Aging

139

114

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Previous studies of episodic memory report a greater extent of blood-oxygenation-level-dependent (BOLD) response in non-demented older adults with the apolipoprotein E epsilon-4 (APOE ε4) allele than in those without the allele. We conducted a functional MRI study to investigate whether APOE genotype is related to brain response to verbal paired-associate encoding and consolidation, particularly in the right hemisphere, among non-demented older adults. Structurally segmented volumes and BOLD response were measured in 13 non-ε4 and 12 ε4 subjects. The ε4 group displayed greater activation than the non-ε4 group in multiple right hemisphere regions for previously encoded word pairs relative to fixation. Activation within manually outlined hippocampal regions of interest also displayed genotype-specific dissociations consistent with whole brain analyses. Furthermore, this differential BOLD response occurred in the presence of equivalent behavioral and neuropsychological performances as well as comparable hippocampal and overall structural segmentation volumes between groups. Results implicate a widely distributed and interconnected network of right hemisphere brain regions that may be involved in compensating for APOE ε4-related deficiencies associated with verbal episodic memory encoding and consolidation.

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Verbal paired-associate learning by APOE genotype in non-demented older adults: fMRI evidence of a right hemispheric compensatory response

Han

Houston

Jak

et al. 2007

Neurobiology of Aging

139

114

View full text Add to dashboard Cite

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“…Many studies have found that fMRI activation patterns may considerably differ among subjects even within the same group. For example, Sugihara et al (2006) found three of the five regions related to writing were inconsistently activated among subjects; in Vandenbroucke et al (2004)'s study, eighteen of twenty nine subjects showed activation varied in both location and size. These results suggest that the similarity and diversity among group members should be balanced in group models, rather than either over-emphasized or neglected.…”

Section: Introductionmentioning

confidence: 94%

Dynamic Bayesian network modeling of fMRI: A comparison of group-analysis methods

Wang

Palmer

et al. 2008

NeuroImage

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Bayesian network (BN) modeling has recently been introduced as a tool for determining the dependencies between brain regions from functional-magnetic-resonance-imaging (fMRI) data. However, studies to date have yet to explore the optimum way for meaningfully combining individually determined BN models to make group inferences. We contrasted the results from three broad approaches: the "virtual-typical-subject" (VTS) approach which pools or averages group data as if they are sampled from a single, hypothetical virtual typical subject; the "individual-structure" (IS) approach that learns a separate BN for each subject, and then finds commonality across the individual structures, and the "common-structure" (CS) approach that imposes the same network structure on the BN of every subject, but allows the parameters to differ across subjects. To explore the effects of these three approaches, we applied them to an fMRI study exploring the motor effect of L-dopa medication on ten subjects with Parkinson's disease (PD), as the profound clinical effects of this medication suggest that fMRI activation in PD subjects after medication should start approaching that of age-matched controls. We found that none of these approaches is generally superior over the others, according to Bayesian-information-criterion (BIC) scores, and that they led to considerably different group-level results. The IS approach was more sensitive to the normalization effect of the L-dopa medication on brain connectivity. However, for the more homogeneous control population, the VTS approach was superior. Group-analysis approaches should be selected carefully with consideration of both statistical and biomedical evidence.

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“…Some studies have reported evidence of age-related activation decreases in the MTL and adjacent ventral temporal regions during visual perception and encoding (Park et al, 2004), in working memory function (Mencl et al, 2000;Vandenbroucke et al, 2004), and in the binding of visuospatial information (Mitchell et al, 2000). These results have generally been interpreted as an age-related regional loss of function or specialization.…”

Section: Introductionmentioning

confidence: 99%

Healthy aging attenuates task-related specialization in the human medial temporal lobe

Ramsøy

Liptrot

Skimminge

et al. 2012

Neurobiology of Aging

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Recent research on aging has established important links between the neurobiology of normal aging and age-related decline in episodic memory, yet the exact nature of this relationship is still unknown. Functional neuroimaging of regions such as the medial temporal lobe (MTL) have produced conflicting findings. Using functional magnetic resonance imaging (fMRI), we have recently shown that young healthy individuals show a stronger activation of the MTL during encoding of objects as compared with encoding of positions. Using the same encoding task, the present study addressed the question whether this greater MTL activation during encoding of objects varies with age. Fifty-four healthy individuals aged between 18 and 81 years underwent functional magnetic resonance imaging while they encoded and subsequently made new-old judgments on objects and positions. Region of interest (ROI) analysis of task related changes in the blood oxygen level-dependent (BOLD) signal was performed in native space after correction for gender effects and individual differences in cerebral blood flow. The hippocampus, amygdala, and parahippocampal, perirhinal, entorhinal, and temporopolar cortices of right and left hemisphere were defined as ROIs. Aging had an adverse effect on memory performance that was similar for memorizing objects or positions. In left and right MTL, relatively greater activation for object stimuli was attenuated in older individuals. Age-related attenuation in content specificity was most prominent in the recognition stage. During recognition, the larger response to objects gradually decreased with age in all ROIs apart from left temporopolar and entorhinal cortex. An age-related attenuation was also present during encoding, but only in right parahippocampus and amygdala. Our results suggest that memory-related processing in the MTL becomes gradually less sensitive to content during normal aging.

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Interindividual differences of medial temporal lobe activation during encoding in an elderly population studied by fMRI

Cited by 34 publications

References 29 publications

Verbal paired-associate learning by APOE genotype in non-demented older adults: fMRI evidence of a right hemispheric compensatory response

Verbal paired-associate learning by APOE genotype in non-demented older adults: fMRI evidence of a right hemispheric compensatory response

Dynamic Bayesian network modeling of fMRI: A comparison of group-analysis methods

Healthy aging attenuates task-related specialization in the human medial temporal lobe

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