The Impact of Alzheimer’s Disease on Emotional Processing

Abstract

Background: Emotional processing involves the ability of the individual to infer emotional information. There is no consensus about how Alzheimer’s disease (AD) affects emotional processing. Objective: We aim to systematically review the impact of AD on emotion processing Method: We conducted a search based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). The literature search was performed using the electronic databases MEDLINE (Pubmed) and Science Citation Index (ISI). The following descriptors were used in the review process: emotion or emotional processing, cognition or cognitive functions and Alzheimer disease or Alzheimer’s disease. This systematic review was recorded in the International Prospective Register of Systematic Reviews (PROSPERO) under the number CRD42018115891. Results: We identified 425 articles, 19 of which met our criteria. Visual emotional stimuli were the most used among studies. Most studies used tasks of emotional naming, discrimination, identification and correspondence. The results were contradictory. Many studies reported that individuals with AD were impaired on emotional perception tasks, while others results reported preserved skills. The relationship between emotional processing and cognition is also unclear. Some studies suggested that general cognitive performance affects performance in emotional perception tasks among people with AD, but other studies have shown deficits in recognizing emotion, regardless cognitive performance. Conclusions: Studies are scarce, present contradictory results, and report impairment in emotional processing in relation to cognition. Moreover, analyzes of correlation between emotion processing and cognitive functioning failed to reveal clear relationships.