The Effect of Task-Irrelevant Fearful-Face Distractor on Working Memory Processing in Mild Cognitive Impairment versus Healthy Controls: An Exploratory fMRI Study in Female Participants.

Amer M Burhan,Jun Ku Chung,Amanda Arena,Udunna C Anazodo,Derek G V Mitchell,Ariel Graff-Guerrero

doi:10.1155/2016/1637392

Abstract

In mild cognitive impairment (MCI), a risk state for Alzheimer's disease, patients have objective cognitive deficits with relatively preserved functioning. fMRI studies have identified anomalies during working memory (WM) processing in individuals with MCI. The effect of task-irrelevant emotional face distractor on WM processing in MCI remains unclear. We aim to explore the impact of fearful-face task-irrelevant distractor on WM processing in MCI using fMRI. Hypothesis. Compared to healthy controls (HC), MCI patients will show significantly higher BOLD signal in a priori identified regions of interest (ROIs) during a WM task with a task-irrelevant emotional face distractor. Methods. 9 right-handed female participants with MCI and 12 matched HC performed a WM task with standardized task-irrelevant fearful versus neutral face distractors randomized and counterbalanced across WM trials. MRI images were acquired during the WM task and BOLD signal was analyzed using statistical parametric mapping (SPM) to identify signal patterns during the task response phase. Results. Task-irrelevant fearful-face distractor resulted in higher activation in the amygdala, anterior cingulate, and frontal areas, in MCI participants compared to HC. Conclusions. This exploratory study suggests altered WM processing as a result of fearful-face distractor in MCI.

Highlights

Mild cognitive impairment (MCI) is a transitional risk state between cognitive aging and Alzheimer’s disease (AD)
The MCI group demonstrated an increase in brain activation in the anterior cingulate and amygdala area as compared to healthy controls (HC), while a decrease in brain activation was seen in the superior parietal and prefrontal areas in MCI patients
Within the regions of interest (ROIs), a main effect of loading was found in the left precuneus (BA7), superior parietal cortex, and right anterior cingulate cortex (BA 32/24)

Summary

Introduction

Mild cognitive impairment (MCI) is a transitional risk state between cognitive aging and Alzheimer’s disease (AD). This state is defined as a “cognitive concern,” with patients demonstrating deficits in one or more cognitive domains on objective testing while maintaining relatively preserved daily functioning. In addition to cognitive deficits, patients with MCI often present with significant emotional symptoms including dysphoria, anxiety, and irritability [2]; these symptoms are associated with an increased risk for conversion from MCI to dementia and AD [3]. A recent study suggests that high level anxiety is a predictor of cognitive decline in a preclinical sample positive for betaamyloid, a marker for AD risk [4]. Neuropsychological testing has identified a marked impairment in episodic memory, which is a defining clinical feature of this prodromal state [5] and can be identified up to 7 years before

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Discussion

Conclusion