The Weakened Relationship Between Prestimulus Alpha Oscillations and Response Time in Older Adults With Mild Cognitive Impairment.

Yuehong Qiu,Wei Feng,Li Hu,Yuejia Luo,Hao He,Pengfei Xu,Yiqi Chen,Qing Guan,Jing Wang

doi:10.3389/fnhum.2020.00048

Abstract

Background: Prestimulus alpha oscillations associated with preparatory attention have an impact on response time (RT). However, little is known about whether there is a deficit in the relationship between prestimulus alpha oscillations and RT in older adults with mild cognitive impairment (MCI).Method: We collected electroencephalography (EEG) data from 28 older adults with MCI and 28 demographically matched healthy controls (HCs) when they were performing an Eriksen flanker task. For each participant, single-trial prestimulus alpha power was calculated for combinations of congruency (congruent vs. incongruent) and response speed (fast vs. slow).Result: Statistical analysis indicated that prestimulus alpha power was significantly lower for fast trials than slow trials in HCs but not in older adults with MCI. The Fisher’s z scores of the within-subject correlation coefficients between single-trial prestimulus alpha power and RT were significantly larger in HCs than in older adults with MCI. In addition, machine learning analyses indicated that prestimulus alpha power and its correlation with RT could serve as features to distinguish older adults with MCI from HCs and to predict performance on some neuropsychological tests.Conclusion: The reduced correlation between prestimulus alpha activity and RT suggests that older adults with MCI experience impaired preparatory attention.

Highlights

Mild cognitive impairment (MCI) refers to an intermediate stage between normal cognitive decline due to aging and a more severe decline due to dementia (Albert et al, 2011; Petersen et al, 2018)
error rate (ER) in the congruent condition (M = 5%, SD = 7%) was significantly lower than that in the incongruent condition (M = 10%, SD = 13%), which was observed in older adults with mild cognitive impairment (MCI) (p < 0.05) rather than in healthy controls (HCs)
The trained classifiers had the mean accuracy of 80.4%, the mean area under the receiver operating characteristic (ROC) curve was 0.77, the mean sensitivity of 80.3%, the mean specificity of 80.4%, the mean positive predictive values (PPV) of 82.0%, and the mean negative predictive values (NPV) of 79.4%

Summary

Introduction

Mild cognitive impairment (MCI) refers to an intermediate stage between normal cognitive decline due to aging and a more severe decline due to dementia (Albert et al, 2011; Petersen et al, 2018). Previous studies have demonstrated that participants with MCI show impaired preparatory attention in choice reaction time tasks and cued target detection tasks (Levinoff et al, 2005; Tales et al, 2005, 2011). In these tasks with cues, participants with MCI, compared to those with normal cognition, were less sensitive to prestimulus cues that induced a decrease in the power of prestimulus alpha oscillations and a shorter response time (RT; van den Berg et al, 2014). Little is known about whether there is a deficit in the relationship between prestimulus alpha oscillations and RT in older adults with mild cognitive impairment (MCI)

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