Alterations in Intra- and Interregional Intrinsic Brain Connectivity Are Differentially Associated with Memory Performance in Amnestic Mild Cognitive Impairment

2018 ◽  
Vol 46 (3-4) ◽  
pp. 229-242 ◽  
Author(s):  
Dong Woo Kang ◽  
Hyun Kook Lim ◽  
Soo-Hyun Joo ◽  
Na Rae Lee ◽  
Chang-Uk Lee
Keyword(s):  
Cognitive Impairment ◽  
Mild Cognitive Impairment ◽  
Functional Connectivity ◽  
Brain Connectivity ◽  
Memory Performance ◽  
Amnestic Mild Cognitive Impairment ◽  
Connectivity Pattern ◽  
Inferior Temporal Gyrus ◽  
Amci Group ◽  
With Memory

Background: Previous research has separated spatial patterns of intra- and interregional intrinsic brain connectivity, as evaluated by regional homogeneity (ReHo) and functional connectivity (FC), respectively, in prodromal Alzheimer’s disease (AD). Moreover, the intra- and interregional intrinsic brain connectivities have been demonstrated to have a significant relationship with each other. Objective: To explore FCs from brain regions which display a difference in ReHo between an amnestic mild cognitive impairment (aMCI) group and healthy controls (HC) and to examine the relationship of intra- and interregional intrinsic brain connectivity to cognitive function in both groups. Methods: Thirty-four subjects with aMCI and 38 HC underwent 3T MRI scanning and a battery of neuropsychological tests. Results: The aMCI group exhibited significantly higher ReHo in the left putamen and lower ReHo in the left inferior temporal gyrus than the HC. Furthermore, both groups showed a distinctive functional connectivity pattern seeded from 2 regions of interest which exhibited significant ReHo differences between the groups. In the HC group, only ReHo exhibited significant associations with memory performance, but in the aMCI group, only FC seeded from the left inferior temporal gyrus showed significant correlations with memory performance. Conclusions: By approaching both intra- and interregional intrinsic brain activities in the early stages of AD, the findings of this research provide insights into the early pathogenesis of AD as related to memory performance.

Errorless learning and elaborative self-generation in healthy older adults and individuals with amnestic mild cognitive impairment: Mnemonic benefits and mechanisms

2009 ◽  
Vol 15 (5) ◽  
pp. 704-716 ◽  
Author(s):  
TOBI LUBINSKY ◽  
JILL B. RICH ◽  
NICOLE D. ANDERSON
Keyword(s):  
Older Adults ◽  
Cognitive Impairment ◽  
Mild Cognitive Impairment ◽  
Memory Performance ◽  
Amnestic Mild Cognitive Impairment ◽  
Cued Recall ◽  
Errorless Learning ◽  
Healthy Older Adults ◽  
Elaborative Processing ◽  
Amci Group

AbstractErrorless learning is an intervention that benefits memory performance in healthy older adults and a variety of clinical populations. A limitation of the errorless learning technique is that it is passive and does not involve elaborative processing. We report two studies investigating the added benefits of elaborative, self-generated learning to the errorless learning advantage. We also explored the mnemonic mechanisms of the errorless learning advantage. In both studies, older adults and individuals with amnestic mild cognitive impairment (aMCI) completed four encoding conditions representing the crossing of errorless/errorful learning and self-generated/experimenter-provided learning. Self-generation enhanced the errorless learning benefit in cued recall and cued recognition, but not in free recall or item recognition. An errorless learning advantage was observed for priming of target words, and this effect was amplified for participants with aMCI after self-generated learning. Moreover, the aMCI group showed significant priming of prior self-generated errors. These results demonstrate that self-generation enhances the errorless learning advantage when study and test conditions match. The data also support the argument that errorless learning eliminates the misleading implicit influence of prior errors, as well as the need for explicit memory processes to distinguish targets from errors. (JINS, 2009, 15, 704–716.)

The Anterior-posterior Functional Connectivity Disconnection in the Elderly with Subjective Memory Impairment and Amnestic Mild Cognitive Impairment

2020 ◽  
Vol 17 (4) ◽  
pp. 373-381
Author(s):  
Wuhai Tao ◽  
Jinping Sun ◽  
Xin Li ◽  
Wen Shao ◽  
Jing Pei ◽  
...  
Keyword(s):  
Cognitive Impairment ◽  
Mild Cognitive Impairment ◽  
Functional Connectivity ◽  
Memory Impairment ◽  
Amnestic Mild Cognitive Impairment ◽  
Magnetic Resonance Imaging Scan ◽  
Subjective Memory ◽  
Long Distance ◽  
Whole Brain ◽  
Subjective Memory Impairment

Background: Subjective Memory Impairment (SMI) may tremendously increase the risk of Alzheimer’s Disease (AD). The full understanding of the neuromechanism of SMI will shed light on the early intervention of AD. Methods: In the current study, 23 Healthy Controls (HC), 22 SMI subjects and 24 amnestic Mild Cognitive Impairment (aMCI) subjects underwent the comprehensive neuropsychological assessment and the resting-state functional magnetic resonance imaging scan. The difference in the connectivity of the Default Mode Network (DMN) and Functional Connectivity (FC) from the Region of Interest (ROI) to the whole brain were compared, respectively. Results: The results showed that HC and SMI subjects had significantly higher connectivity in the region of the precuneus area compared to aMCI subjects. However, from this region to the whole brain, SMI and aMCI subjects had significant FC decrease in the right anterior cingulum, left superior frontal and left medial superior frontal gyrus compared to HC. In addition, this FC change was significantly correlated with the cognitive function decline in participants. Conclusion: Our study indicated that SMI subjects had relatively intact DMN connectivity but impaired FC between the anterior and posterior brain. The findings suggest that long-distance FC is more vulnerable than the short ones in the people with SMI.

scholarly journals Semantic knowledge for famous names in mild cognitive impairment

2009 ◽  
Vol 15 (1) ◽  
pp. 9-18 ◽  
Author(s):  
MICHAEL SEIDENBERG ◽  
LESLIE GUIDOTTI ◽  
KRISTY A. NIELSON ◽  
JOHN L. WOODARD ◽  
SALLY DURGERIAN ◽  
...  
Keyword(s):  
Cognitive Impairment ◽  
Mild Cognitive Impairment ◽  
Memory Performance ◽  
Memory Deficits ◽  
Semantic Knowledge ◽  
Person Identification ◽  
Healthy Elderly ◽  
Amnestic Mci ◽  
Amci Group ◽  
Stored Information

AbstractPerson identification represents a unique category of semantic knowledge that is commonly impaired in Alzheimer’s disease (AD), but has received relatively little investigation in patients with mild cognitive impairment (MCI). The current study examined the retrieval of semantic knowledge for famous names from three time epochs (recent, remote, and enduring) in two participant groups: 23 amnestic MCI (aMCI) patients and 23 healthy elderly controls. The aMCI group was less accurate and produced less semantic knowledge than controls for famous names. Names from the enduring period were recognized faster than both recent and remote names in both groups, and remote names were recognized more quickly than recent names. Episodic memory performance was correlated with greater semantic knowledge particularly for recent names. We suggest that the anterograde memory deficits in the aMCI group interferes with learning of recent famous names and as a result produces difficulties with updating and integrating new semantic information with previously stored information. The implications of these findings for characterizing semantic memory deficits in MCI are discussed. (JINS, 2009, 15, 9–18.)

scholarly journals Sex differences in cortisol and memory following acute social stress in amnestic mild cognitive impairment

2019 ◽  
Author(s):  
Kelly J. Murphy ◽  
Travis E. Hodges ◽  
Paul A.S. Sheppard ◽  
Angela K. Troyer ◽  
Elizabeth Hampson ◽  
...  
Keyword(s):  
Working Memory ◽  
Cognitive Impairment ◽  
Mild Cognitive Impairment ◽  
Episodic Memory ◽  
Social Stress ◽  
Spatial Working Memory ◽  
Memory Function ◽  
Amnestic Mild Cognitive Impairment ◽  
Amci Group ◽  
The Relationship

AbstractObjectiveOlder adults with amnestic mild cognitive impairment (aMCI) develop Alzheimer’s type dementia approximately ten times faster annually than the normal population. Adrenal hormones are associated with aging and cognition. We investigated the relationship between acute stress, cortisol, and memory function in aMCI with an exploratory analysis of sex.MethodSalivary cortisol was sampled diurnally and during two test sessions, one session with the Trier Social Stress Test (TSST), to explore differences in the relationship between cortisol and memory function in age-normal cognition (NA) and aMCI. Participants with aMCI (n=6 women, 9 men; mean age=75) or similarly aged NA (n=9 women, 7 men, mean age=75) were given tests of episodic, associative, and spatial working memory with a psychosocial stressor (TSST) in the second session.ResultsThe aMCI group performed worse on the memory tests than NA as expected, and males with aMCI had elevated cortisol levels on test days. Immediate episodic memory was enhanced by social stress in NA but not in the aMCI group, indicating that stress-induced alterations in memory are different in individuals with aMCI. High cortisol was associated with impaired performance on episodic memory in aMCI males only. Cortisol in Session 1 moderated the relationship with spatial working memory, whereby higher cortisol was associated with worse performance in NA, but better spatial working memory in aMCI. In addition, effects of aMCI on perceived anxiety in response to stress exposure were moderated by stress-induced cortisol in a sex-specific manner.ConclusionsWe show effects of aMCI on Test Session cortisol levels and effects on perceived anxiety, and stress-induced impairments in memory in males with aMCI in our exploratory sample. Future studies should explore sex as a biological variable as our findings suggests that effects at the confluence of aMCI and stress can be obfuscated without sex as a consideration.

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