EMOTIONAL STROOP PERFORMANCE: FURTHER EVIDENCE FOR DISTINCT COGNITIVE PATTERNS IN DEPRESSED AND NON-DEPRESSED AMCI

Abstract

Listen

Translate article

It is well-established that individuals with amnestic mild cognitive impairment (aMCI) or late-life depression (LLD) are at high risk for developing dementia. aMCI is a highly heterogeneous syndrome: patients may manifest a variety of different cognitive and neuropsychiatric symptoms, some of which may resemble those of LLD. Emerging research suggests that patients with aMCI and concomitant depressive symptoms (aMCI/D+) may be an identifiable subtype of prodromal dementia that is distinct from that of non-depressed aMCI and LLD. Indeed, these groups perform differently on tests of episodic memory (Callahan et al., 2012a), semantic memory (Brunet et al., 2011; Callahan et al., 2012b) and inhibition (Hudon et al., 2008). Furthermore, aMCI and aMCI/D+ evolve differently over time (Steffens, 2012). The present study aimed to further characterize aMCI/D+ by investigating patients' cognitive processing of emotional stimuli. Twenty-nine MCI, 14 aMCI/D+, 10 LLD and 15 healthy elderly controls (CONT) performed an emotional Stroop task in which blocks of different-colored positive, negative and neutral words were presented on a computer screen. Participants were instructed to name the color of each word as quickly as possible. Response time (RT) to name each color was recorded. Afterward, subjects were asked to rate the emotional intensity of each word on a scale from 1 (not intense) to 9 (very intense) to verify whether task performance is modulated by stimulus intensity. All three patient groups were slower than CONT in completing the emotional Stroop task. CONT subjects had longer RTs on negative compared to neutral blocks. Latencies of aMCI/D+ patients were longer on negative than neutral and positive blocks. Performance of aMCI and LLD groups were similar on emotional and neutral blocks. These results were independent of words' intensity ratings. This study is the first to investigate emotional Stroop performance in participants with probable prodromal dementia. The results converge with those of prior studies to support the notion that aMCI/D+ may represent an identifiable subgroup distinct from aMCI and LLD. Increasing our understanding of the features of aMCI/D+ through additional research is essential to elucidate the heterogeneity of prodromal dementia and to optimize preven tion and treatment plans.