Enhanced Feedback-Related Negativity in Alzheimer's Disease.

Eri Nitta,Fuminori Ishitobi,Atsushi Nagai,Shuhei Yamaguchi,Ryota Okazaki,Keiichi Onoda,Seiji Mishima

doi:10.3389/fnhum.2017.00179

Abstract

Alzheimer’s disease (AD), the most common cause of dementia in the elderly, results in the impairment of executive function, including that of performance monitoring. Feedback-related negativity (FRN) is an electrophysiological measure reflecting the activity of this monitoring system via feedback signals, and is generated from the anterior cingulate cortex. However, there have been no reports on FRN in AD. Based on prior aging studies, we hypothesized that FRN would decrease in AD patients. To assess this, FRN was measured in healthy individuals and those with AD during a simple gambling task involving positive and negative feedback stimuli. Contrary to our hypothesis, FRN amplitude increased in AD patients, compared with the healthy elderly. We speculate that this may reflect the existence of a compensatory mechanism against the decline in executive function. Also, there was a significant association between FRN amplitude and depression scores in AD, and the FRN amplitude tended to increase insomuch as the Self-rating Depression Scale (SDS) was higher. This result suggests the existence of a negative bias in the affective state in AD. Thus, the impaired functioning monitoring system in AD is a more complex phenomenon than we thought.

Highlights

Executive function is a set of cognitive processes including attentional control, working memory and planning, and so on, and is necessary for selecting and successfully monitoring behavior (Alvarez and Emory, 2006; Chan et al, 2008; Diamond, 2013)
There were no significant differences in age and gender ratios between Alzheimer’s disease (AD) and healthy older subjects (HO)
Independent t tests revealed that there were significant differences between AD and HO on the cognitive function scores (MMSE, Frontal Assessment Battery (FAB), Word Fluency Test (WFT)), and that AD showed reduced cognitive function compared to HO (ts (45) > 5.0, ps < 0.001)

Summary

Introduction

Executive function is a set of cognitive processes including attentional control, working memory and planning, and so on, and is necessary for selecting and successfully monitoring behavior (Alvarez and Emory, 2006; Chan et al, 2008; Diamond, 2013). FRN has been shown to be elicited by feedback stimuli ( negative stimuli) in a gambling task (Gehring, 2002; Hajcak et al, 2006; Holroyd et al, 2006) and a time production task (Miltner et al, 1997; Wild-Wall et al, 2009; Becker et al, 2014) This negative potential appears at a latency of 200–300 ms after feedback (Miltner et al, 1997; Falkenstein et al, 2000; Gehring, 2002; Holroyd and Coles, 2002; Nieuwenhuis et al, 2004), and is primarily distributed over the frontal-central scalp area. No reports have investigated the changes in FRN in AD patients

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