Functional and structural connectivity of the amygdala underpins locus of control in mild cognitive impairment

Abstract

Locus of control (LOC) is an important personality trait. LOC over cognitive competency reflects an individual's perceived control of desired cognitive outcomes, which is critical for maintaining successful cognitive aging. It is important to understand the neural substrates of LOC over cognitive competency in older adults, especially for individuals at high risk of dementia. Here, we characterized a cohesive functional and structural connectivity profile underlying LOC among 55 older adults with amnestic mild cognitive impairment (aMCI), combining resting-state functional magnetic resonance imaging and diffusion tensor imaging. The results showed that both functional and structural connectivity between the medial prefrontal cortex and amygdala were significantly correlated with external LOC. The functional connectivity mediated the correlation between structural connectivity and external LOC. In addition, aging-associated neurodegeneration moderated the relationship between structural connectivity and external LOC, showing that the structural connectivity was positively correlated with external LOC in low, but not high neurodegeneration. Our results suggest a critical role of the functional amygdala-frontal network, which may serve as a bridge between its white matter tract and LOC over cognitive competency in groups at high risk for dementia.

Abnormal Functional Connectivity of the Amygdala in Mild Cognitive Impairment Patients With Depression Symptoms Revealed by Resting-State fMRI

“…Almeida and colleagues reported reduced amygdala-orbitofrontal cortex (OFC) FC during the processing of happy and sad faces in medicated patients with MDD (20). Using fMRI and diffusion tensor imaging data from 55 older adults with amnestic MCI, another study found that both functional and structural connectivities between the medial prefrontal cortex and amygdala were significantly correlated with external LOC (21). Using the coherence regional homogeneity method, we previously reported that D-MCI patients had abnormal temporal homogeneity compared with patients with no depression with MCI (nD-MCI) in the mPFC, post-central gyrus, and thalamus (22).…”

“…Alterations of the amygdala-mPFC circuit have been widely reported in patients with depression (15)(16)(17)(18)(19)(20)(21). Using data from 100 fMRI experiments, one meta-analysis showed that hyperactivation of the mPFC is associated with diminished right amygdala activity during the regulation of negative emotions (12).…”

“…The aim of the present study was to examine alterations in amygdala FC in D-MCI patients using rsfMRI and seed-point FC by comparing with nD-MCI patients and healthy controls (HCs). Based on previous findings of abnormal amygdala FC in those with depression (15)(16)(17)(18)(19)(20)(21), we hypothesized that, relative to the nD-MCI and HC groups, the D-MCI group would display altered amygdala FC in regions of the mPFC that are critical to emotion regulation (23).…”

An update on magnetic resonance imaging markers in AD

“…and premorbid personality traits (such as internal or externa locus of control) in addition to the severity of AD pathology assessed with CSF. 34 , 87 , 88 …”