Poorer Theory of Mind in Amnestic Mild Cognitive Impairment Is Associated with Decreased Functional Connectivity in the Default Mode Network

2021 ◽  
pp. 1-13
Author(s):  
Johannes C. Michaelian ◽  
Shantel L. Duffy ◽  
Loren Mowszowski ◽  
Adam J. Guastella ◽  
Donna McCade ◽  
...  
Keyword(s):  
Older Adults ◽  
Cognitive Impairment ◽  
Mild Cognitive Impairment ◽  
Functional Connectivity ◽  
Theory Of Mind ◽  
Default Mode Network ◽  
Amnestic Mild Cognitive Impairment ◽  
Default Mode ◽  
Left And Right ◽  
The Right

Background: Older adults living with amnestic mild cognitive impairment (aMCI) not only demonstrate impairments in Theory of Mind (ToM), relative to adults with non-amnestic MCI (naMCI), but are also at a higher risk of developing dementia. Objective: Our primary objective was to ascertain whether default mode network (DMN) functional connectivity was differentially associated with ToM abilities between MCI subgroups. Methods: Using functional magnetic resonance imaging, we investigated alterations in resting-state functional connectivity within the brain’s DMN in a sample of 43 older adults with aMCI (n = 19) and naMCI (n = 24), previously reported to demonstrate poorer ToM abilities. Results: Compared to naMCI, the aMCI subgroup revealed a significant association between poorer ToM performance and reduced functional connectivity between the bilateral temporal pole (TempP) and the left lateral temporal cortex (LTC) (LTC_L-TempP_L: b = –0.06, t(33) = –3.53, p = 0.02; LTC_L-TempP_R: b = –0.07,t(33) = –3.20, p = 0.03); between the right TempP and the dorsal medial prefrontal cortex (dMPFC) (b = –0.04, t(33) = –3.02, p = 0.03) and between the left and right TempP (b = –0.05, t(33) = –3.26, p = 0.03). In the naMCI subgroup, the opposite relationship was present between the bilateral TempP and the left LTC (Combined correlation: r = –0.47, p = 0.02), however, not between the right TempP and the dMPFC (r = –0.14, p = 0.51) or the left and right TempP (r = –0.31, p = 0.14). Conclusion: Our findings suggest that alterations in functional connectivity within the DMN involving temporal and frontal lobe regions are associated with ToM deficits in aMCI.

Altered intrinsic default mode network functional connectivity in patients with remitted geriatric depression and amnestic mild cognitive impairment

2021 ◽  
pp. 1-12
Author(s):  
Chengbin Guan ◽  
Nousayhah Amdanee ◽  
Wenxiang Liao ◽  
Chao Zhou ◽  
Xin Wu ◽  
...  
Keyword(s):  
Cognitive Impairment ◽  
Mild Cognitive Impairment ◽  
Functional Connectivity ◽  
Default Mode Network ◽  
Posterior Cingulate Cortex ◽  
Amnestic Mild Cognitive Impairment ◽  
Geriatric Depression ◽  
Cross Sectional ◽  
Default Mode ◽  
Increased Risk

ABSTRACT Objectives: Patients with geriatric depression exhibit a spectrum of symptoms ranging from mild to severe cognitive impairment which could potentially lead to the development of Alzheimer’s disease (AD). The aim of the study is to assess the alterations of the default mode network (DMN) in remitted geriatric depression (RGD) patients and whether it could serve as an underlying neuropathological mechanism associated with the risk of progression of AD. Design: Cross-sectional study. Participants: A total of 154 participants, comprising 66 RGD subjects (which included 27 patients with comorbid amnestic mild cognitive impairment [aMCI] and 39 without aMCI [RGD]), 45 aMCI subjects without a history of depression (aMCI), and 43 matched healthy comparisons (HC), were recruited. Measurements: All participants completed neuropsychological tests and underwent resting-state functional magnetic resonance imaging (fMRI). Posterior cingulate cortex (PCC)-seeded DMN functional connectivity (FC) along with cognitive function were compared among the four groups, and correlation analyses were conducted. Results: In contrast to HC, RGD, aMCI, and RGD-aMCI subjects showed significant impairment across all domains of cognitive functions except for attention. Furthermore, compared with HC, there was a similar and significant decrease in PCC-seed FC in the bilateral medial superior frontal gyrus (M-SFG) in the RGD, aMCI, and RGD-aMCI groups. Conclusions: The aberrations in rsFC of the DMN were associated with cognitive deficits in RGD patients and might potentially reflect an underlying neuropathological mechanism for the increased risk of developing AD. Therefore, altered connectivity in the DMN could serve as a potential neural marker for the conversion of geriatric depression to AD.

scholarly journals AEROBIC TRAINING, THE DEFAULT MODE NETWORK, AND COGNITION IN OLDER ADULTS WITH MILD VASCULAR COGNITIVE IMPAIRMENT

2019 ◽  
Vol 3 (Supplement_1) ◽  
pp. S55-S55
Author(s):  
Rachel A Crockett ◽  
Chun Liang Hsu ◽  
Cindy Barha ◽  
Ging-Yuek Robin Hsiung ◽  
Teresa Liu-Ambrose
Keyword(s):  
Older Adults ◽  
Cognitive Impairment ◽  
Cognitive Function ◽  
Functional Connectivity ◽  
Default Mode Network ◽  
Resting State ◽  
Aerobic Training ◽  
Vascular Cognitive Impairment ◽  
Default Mode ◽  
Global Cognitive Function

Abstract Aerobic training has been shown to be effective at improving cognitive and brain outcomes in older adults with mild subcortical ischemic vascular cognitive impairment (SIVCI). However, uncertainty remains regarding the underlying neurobiological mechanisms by which exercise elicits these improvements in cognition. Increased aberrant functional connectivity of the default mode network has been highlighted as a factor contributing to cognitive decline in older adults with cognitive impairment. Greater connectivity of the DMN at rest is associated with poorer performance on attention-demanding tasks, indicative of a lack of ability to deactivate the network on task. Our previous work on a randomized controlled trial of participants with mild SIVCI, demonstrated that 6-months of thrice weekly aerobic training led to improved global cognitive function, as measured by Alzheimer’s disease Assessment Scale-Cognitive subscale (ADAS-Cog), compared with a health education program. Thus, we conducted secondary analyses to investigate whether these changes in global cognitive function were associated with changes in resting state DMN connectivity. A subsample of 21 participants underwent a resting state functional magnetic resonance imaging (fMRI) scan before and after trial completion. Change in resting state DMN connectivity was found to significantly predict change in ADAS-Cog score (β = -.442, p=.038) after controlling for age, intervention group, and baseline functional capacity (R2=.467, F(4,16)= 3.507, p=.031). These findings suggest that functional connectivity of the DMN may underlie changes in global cognitive function. Furthermore, aerobic exercise is a promising intervention by which to elicit these changes in older adults with mild SIVCI.

scholarly journals Theory of Mind in mild cognitive impairment: Relationship with the default mode network (DMN)

2020 ◽  
Vol 16 (S4) ◽  
Author(s):  
Johannes Carapiet Michaelian ◽  
Andrew C McKinnon ◽  
Loren Mowszowski ◽  
Shantel L Duffy ◽  
Adam Guastella ◽  
...  
Keyword(s):  
Cognitive Impairment ◽  
Mild Cognitive Impairment ◽  
Theory Of Mind ◽  
Default Mode Network ◽  
Default Mode
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