The role of attention in emotional memory enhancement in pathological and healthy aging

Abstract

After short delays between encoding and retrieval, healthy young participants have better memory performance for emotional stimuli than for neutral stimuli. Divided-attention paradigms suggest that this emotional enhancement of memory (EEM) is due to different attention mechanisms involved during encoding: automatic processing for negative stimuli, and controlled processing for positive stimuli. As far as we know, no study on the influence of these factors on EEM in Alzheimer's disease (AD) and mild cognitive impairment (MCI) patients, as compared to healthy young and older controls, has been conducted. Thus, the goal of our study was to ascertain whether the EEM in these populations depends on the attention resources available at encoding. Participants completed two encoding phases: full attention (FA) and divided attention (DA), followed by two retrieval phases (recognition tasks). There was no EEM on the discrimination accuracy, independently of group and encoding condition. Nevertheless, all participants used a more liberal response criterion for the negative and positive stimuli than for neutral ones. In AD patients, larger numbers of false recognitions for negative and positive stimuli than for neutral ones were observed after both encoding conditions. In MCI patients and in healthy older and younger controls this effect was observed only for negative stimuli, and it depended on the encoding condition. Thus, this effect was observed in young controls after both encoding conditions, in older controls after the DA encoding, and in MCI patients after the FA encoding. In conclusion, our results suggest that emotional valence does not always enhance discrimination accuracy. Nevertheless, in certain conditions related to the attention resources available at encoding, emotional valence, especially the negative one, enhances the subjective feeling of familiarity and, consequently, engenders changes in response bias. This effect seems to be sensitive to the age and the pathology of participants.

Effects of mild cognitive impairment on emotional scene memory

“…To our knowledge, this is the first study examining selective memory for emotional scenes in patients with MCI (but see Gorenc-Mahmutaj et al (2015) and Sava et al (2016)) for memory for complete emotional images in patients with MCI or dementia). The primary goal of the study was to examine the effect of emotion on selective scene memory between MCI patients and healthy older adults.…”

“…Some studies of working memory for emotional images have revealed a negativity bias in the memories of MCI patients (but the negative items were also more arousing than positive items, making it impossible to attribute these differences to valence (how positive or negative) alone (Dohnel et al, 2008, 2007)). Another investigation of MCI patients’ recognition memory for emotional and neutral IAPS images showed higher true recognition and false alarms for negative compared to positive or neutral images, and also that dividing attention did not impact discrimination ability (Sava et al, 2016). In other studies MCI patients have shown a memory benefit for positive or negative words (Brueckner and Moritz, 2009; Callahan et al, 2016), but impaired memory for faces studied with emotional expressions (Wang et al, 2013; Werheid et al, 2010).…”

False memories in patients with mild cognitive impairment and mild Alzheimer’s disease dementia: Can cognitive strategies help?

“…Further, patients with AD committed more causal errors for positive and negatively valanced scripts than for neutral scripts, which suggests that their memory for pictorial information is vulnerable to distortions due to emotional valence. This finding that patients with AD demonstrate increased memory errors to emotionally valanced pictures has been replicated when attention at encoding was manipulated (Sava, Paquet, Dumurgier, Hugon, & Chainay, 2016).…”

Effect of emotional enhancement of memory on recollection process in young adults: the influence factors and neural mechanisms

“…On the contrary, incidental encoding occurs under divided attention (Trivedi et al 2011). For instance, young adults discriminated equally between old and new images in the full and divided attention condition; however, this pattern was altered in normal aging and neurodegenerative disease according to the attention resources available at encoding (Sava et al 2016). Other studies have shown that dividing attention during encoding can disrupt memory enhancement for nonarousing emotional items but not emotionally arousing items for reasons that are not well understood (Kensinger 2004).…”

“…The latter is particularly relevant when retrieval occurs immediately after encoding, thereby eliminating the influence of consolidation. A previous study has shown that EEM in healthy young adults is due to different attention mechanisms activated during encoding: automatic processing (incidental) for negative stimuli and controlled processing (intentional) for positive stimuli (Sava et al 2016). Intentional encoding refers to self-directed or controlled situations where there is an explicit attempt made and full attention devoted to encoding new episodic information.…”