The Relationship between Social Cognition and Executive Functions in Alzheimer’s Disease: A Systematic Review

Abstract

Introduction: Social cognition (SC) is a complex construct that reflects a wide variety of implicit and explicit cognitive processes. Many neurocognitive domains are associated with SC and the executive function (EF) is the most representative one. We conducted a systematic review aiming at clarifying whether SC impairments are associated with dysfunction on EF in people with Alzheimer Disease (AD). Methods: The search, based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA), was undertaken between January 2007 and December 2019 using Pubmed, SciELO, BIREME and Thomson Reuters Web of Science electronic databases. The keywords were SC, AD, EF, Neuropsychological functioning and Executive Disorder. Results: One hundred thirty-six articles were identified and fifteen were included. These studies are not in agreement about the extent of SC deficits in AD, mainly in the mild stage of the disease. EF deficits, specifically inhibition and the ability to manipulate verbal information, are associated with the impairment in SC in AD. SC decreases with the disease progression, a relationship explained by global cognition impairment and SC specific symptoms. Conclusion: SC impairment is associated with disease progression, mainly because of the decline in EF. Studies on SC components are unequal, contributing to a frequent generalization of Theory of Mind results, and often hampering the investigation of other components, mainly empathy. More precise knowledge about SC functioning in AD may contribute to a better understanding of the behavioral changes and interpersonal interactions.

The Role of the NRF2 Pathway in Maintaining and Improving Cognitive Function

“…When reviewing some reflections related to the available clinical literature on the effects of NRF2 activators in human cognition, it is important to mention that cognitive decline, which represents an expected consequence even among relatively healthy “successful agers”, is associated with structural, functional, and metabolic brain changes whose mechanisms involve oxidative stress and neuroinflammation [ 148 ]. Moreover, cognitive decline is commonly more intense in dementia frontotemporal and with Lewy bodies but also in individuals with specific diseases, such Alzheimer’s disease [ 149 ], Parkinson’s disease [ 150 , 151 ], type 2 diabetes mellitus [ 152 ], and Huntington’s disease [ 153 ], among others. Based on the well-known antioxidant and anti-inflammatory events resulting from NRF2 activation [ 154 ], some of the aforementioned clinical evidence on the beneficial effects of NRF2 in human cognition strongly suggest that the described NRF2-based interventions were able to prevent cognitive decline rather than directly improve cognition.…”

The Assessment of the Socioemotional Disorder in Neurodegenerative Diseases with the Revised Self-Monitoring Scale (RSMS)

“…Social cognition deficits in AD are related to the progression of the disease and lead to global cognition deterioration [9]. Social cognition is mainly associated with declines in executive functions [10].…”

A Longitudinal Evaluation of the Pattern of Social Cognition Impairment in Brazilians With Alzheimer’s Disease

“…ToM is defined as the capacity to make inferences about other people’s behavior. Such inferences may be associated with cognitive states, beliefs, and thoughts without any personal or emotional involvement (cognitive ToM) or may also include the emotional states of others (feelings, emotions) (affective ToM) 7–9 . Meanwhile, empathy involves understanding the experiences of others.…”

“…Duclos et al (2018) proposed that poor social perception may present difficulties in discriminating emotions expressed by faces, body posture, or prosody 2 . Social behavior is directly related to understanding the social situation and awareness of the best social choices and their consequences 6,7 . Therefore, impairments include the presence of inadequate behaviors, such as failure to respect social rules, thereby leading to inappropriate social functioning 2 …”

“…Such inferences may be associated with cognitive states, beliefs, and thoughts without any personal or emotional involvement (cognitive ToM) or may also include the emotional states of others (feelings, emotions) (affective ToM). [7][8][9] Meanwhile, empathy involves understanding the experiences of others. Affective empathy occurs specifically when there is an emotional response to the perceived situations of others.…”