Positivity effect specific to older adults with subclinical memory impairment

Abstract

Numerous studies have suggested that older adults preferentially remember positive information ("positivity effect"), however others have reported mixed results. One potential source of conflict is that aging is not a unitary phenomenon and individual differences exist. We modified a standard neuropsychological test to vary emotional content and tested memory at three time points (immediate/20 min/1 wk). Cognitively normal older adults were stratified into those with and without subclinical memory impairment. We found that the positivity effect was limited to those with subclinical memory impairment, suggesting that consideration of subclinical memory impairment is necessary for understanding age-related emotional memory alterations.[Supplemental material is available for this article.]Increasing age is the greatest risk factor for developing mild cognitive impairment (MCI) and Alzheimer's disease (AD) (Thies and Bleiler 2011). Thus, it is vital to understand neurocognitive changes that occur during the aging process to identify early phenotypes that may be associated with later cognitive decline. Memory impairment is one of the hallmark cognitive dysfunctions in healthy aging and is a major symptom of MCI and AD. There is extensive evidence that episodic memory, or memory for events, generally declines with age (Craik and Simon 1980;Glisky 2007). However, some studies suggest that there is a "positivity effect," where older adults may be more likely to attend to and remember positive information (Mather and Carstensen 2005;Wong et al. 2012). On the other hand, some studies have suggested that older adults are biased toward remembering negative details (Kensinger et al. 2007) or show no evidence of such an age-related positivity bias (Grühn et al. 2005;Fernandes et al. 2008). One potential source of conflict is that aging is not a uniform phenomenon and individual differences are frequently observed in older adults.There are numerous approaches to examining individual differences with age. One such approach dichotomizes older rats into two groups (Gallagher et al. 1993). One group of older rats performs on par with young rats on the Morris Water Maze (i.e., "aged-unimpaired"-AU), while another group performs outside of the range of young rat performance (i.e., "aged-impaired"-AI). This approach has been used to examine the aged brain in which this dichotomy maps onto neurobiological alterations associated with medial temporal lobe dysfunction, including synaptic loss in the perforant path (Smith et al. 2000), loss of inhibitory tone (Spiegel et al. 2013), hyperexcitability in the CA3 subregion of the hippocampus (Wilson et al. 2004(Wilson et al. , 2005, as well as loss of reelin and increased phosphorylated tau expression in the lateral entorhinal cortex (Stranahan et al. 2011). In humans, we have used a similar approach and have found that individual differences in age-related memory impairment (as defined by performance on the Rey Auditory Verbal Learning Test-RAVLT, a word-list learning task) was associated w...

Effects of mild cognitive impairment on emotional scene memory

“…2B, comparing positive-high arousal and negative-low arousal bars). In a broader sense, these results contribute to the literature of preserved emotion processing in late life, and memory preferences for positive information in healthy older adults (reviewed by Reed, Chan, and Mikels, 2014), and individuals with MCI (Callahan et al, 2016; Gorenc-Mahmutaj et al, 2015; Leal et al, 2016). …”

“…Moreover, examining recall in addition to recognition could further probe the nuances of memory decline in healthy older adults and MCI patients. A recent study reported that individuals with below-average episodic memory preferentially recalled the gist of positive stories relative to individuals with above-average episodic memory, although this effect did not extend to memory for story details (Leal et al, 2016). This raises the question of whether the patterns of emotional scene memory in healthy older adults and MCI patients would appear to differ if recall or gist were assessed as well as recognition of specific scene items and backgrounds.…”

The positivity effect: a negativity bias in youth fades with age

“…We suspected that our experimental approaches tapped into ubiquitous goals in daily life; in other words, all things being equal, older people favor positive material. In studies where experimenters assigned new goals, however, and participants were asked to attend specifically to certain types of information and operate on the information (for example, [55]), preferential processing of positive materials was diminished (see [9]).…”

How Emotional Arousal Enhances Episodic Memory

“…An emotional or a neutral narrative is played over the slides to color participants` interpretation of what they are seeing: In the emotional version, the child is hit by a car en route. Other materials following a similar logic have also been developed (Leal et al, 2016). Available stimuli of these nature are, however, often limited to one neutral version and one emotional version (although for a recent innovation, see Kim et al, 2013).…”