Positivity effect specific to older adults with subclinical memory impairment

The limited roles of cognitive capabilities and future time perspective in contributing to positivity effects

When compared to younger adults, older adults tend to favor positive over negative information in attention and memory. This is known as the positivity effect. Although this is a robust phenomenon, there is still debate about how it relates to individual differences in cognitive capabilities and future time perspective (FTP). To address this, we investigated how measures of fluid cognitive capabilities and FTP related to positivity effects within the domains of episodic memory, visual attention, and autobiographical memory. Cognitive capabilities were assessed using the National Institute of Health Toolbox Cognition battery, and included assessments of executive function, working memory, episodic memory, and processing speed. FTP was assessed via the Carstensen and Lang (1996) scale. Within our final sample (N = 196), we replicated positivity effects in all three task domains, which were all driven by age differences in how people responded to negative (but not positive) information. However, there was limited evidence that the magnitude of these age-related reductions in negativity varied as a function of individual differences in older adults' cognitive capabilities or FTP. Furthermore, when FTP did emerge as a predictor, the pattern was not in line with expectations based upon socioemotional selectivity theory. Thus, the positivity effect may be less reliant on cognitive capabilities and self-reported FTP than is often assumed. Given that there was also very little consistency in the extent to which participants displayed positivity effects across the task domains, these results also raise the possibility that there may be multiple mechanisms underlying positivity effects.

Age differences in emotion-induced blindness: Positivity effects in early attention

Compared with younger adults, older adults tend to favor positive information more than negative information in their attention and memory. This "positivity effect" has been observed in various paradigms, but at which stage it impacts cognitive processing and how it influences processing other stimuli appearing around the same time remains unclear. Across 4 experiments, we examined how older adults prioritize emotional information in early attention. Both younger and older adults demonstrated emotion-induced blindness-identifying targets in a rapid serial display of pictures with less accuracy after emotional compared with neutral distractors-but older adults demonstrated a positivity bias at this early attentional level. Moreover, the bias toward positive but not negative information in older adults was reduced when they had a working memory load. These results suggest that a selective bias toward positive, but not negative, information occurs early in visual processing, and the bias relies on cognitive control resources. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Stereotype Threat Reduces the Positivity of Older Adults' Recall

OBJECTIVES

As people get older, they show a relative preference to remember positive information over negative information. In two experiments, we tested whether the positivity of older adults' memory is affected by stereotype threat about age-related cognitive declines. We also tested whether highlighting a positive aging stereotype (older adults are wise) would inoculate older adults from stereotype threat's adverse effects.

METHOD

In Experiments 1 and 2, we manipulated whether stereotypes about age-related cognitive decline were highlighted (stereotype threat) or mitigated (stereotype alleviation). In Experiment 2, we included a third condition (intervention + stereotype threat), which highlighted positive and negative aging stereotypes. Participants then saw emotionally evocative pictures and completed a memory test.

RESULTS

In both experiments, stereotype threat selectively reduced older adults' memory for positive pictures but did not affect their memory for negative pictures. This eliminated the positivity effect (i.e., the Age × Valence interaction; Experiment 1). Our positive stereotype intervention did not reduce stereotype threat's adverse effect (Experiment 2).

DISCUSSION

Our findings show that the positivity effect is more robust when testing situations minimize stereotype threat. They also suggest that health interventions designed to capitalize on the positivity effect should ensure that ageist stereotypes are mitigated in the environment.

Low Arousal Positive Emotional Stimuli Attenuate Aberrant Working Memory Processing in Persons with Mild Cognitive Impairment

Emotional enhancement effects on memory have been reported to mitigate the pathophysiology of Alzheimer's disease (AD). However, relative to their manifestation in persons without pathologic aging, these effects may be reduced in magnitude or even deleterious, especially in tasks that more closely model ecologic memory performance. Based upon a synthesis of such reports, we hypothesized that in persons with AD low arousal positive stimuli would evoke relatively intact emotional enhancement effects, but that high arousal negative stimuli would evoke disordered emotional enhancement effects. To assess this, participants with and without mild cognitive impairment (MCI) presumed to be due to AD performed an emotionally-valenced short-term memory task while encephalography was recorded. Results indicated that for persons with MCI, high arousal negative stimuli led to working memory processing patterns previously associated with MCI presumed due to AD and dementia of the Alzheimer-type. In contrast, low arousal positive stimuli evoked a processing pattern similar to MCI participants' unaffected spouses. Our current findings suggest that low arousal positive stimuli attenuate working memory deficits of MCI due to AD.

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

Relative to younger adults, older adults attend to and remember positive information more than negative information. This shift from a negativity bias in younger age to a preference for positive information in later life is termed the 'positivity effect.' Based on nearly two decades of research and recent evidence from neuroscience, we argue that the effect reflects age-related changes in motivation that direct behavior and cognitive processing rather than neural or cognitive decline. Understanding the positivity effect, including conditions that reduce and enhance it, can inform effective public health and educational messages directed at older people.

Disruption of amygdala-entorhinal-hippocampal network in late-life depression

Episodic memory deficits are evident in late-life depression (LLD) and are associated with subtle synaptic and neurochemical changes in the medial temporal lobes (MTL). However, the particular mechanisms by which memory impairment occurs in LLD are currently unknown. We tested older adults with (DS+) and without (DS-) depressive symptoms using high-resolution fMRI that is capable of discerning signals in hippocampal subfields and amygdala nuclei. Scanning was conducted during performance of an emotional discrimination task used previously to examine the relationship between depressive symptoms and amygdala-mediated emotional modulation of hippocampal pattern separation in young adults. We found that hippocampal dentate gyrus (DG)/CA3 activity was reduced during correct discrimination of negative stimuli and increased during correct discrimination of neutral items in DS+ compared to DS- adults. The extent of the latter increase was correlated with symptom severity. Furthermore, DG/CA3 and basolateral amygdala (BLA) activity predicted discrimination performance on negative trials, a relationship that depended on symptom severity. The impact of the BLA on depressive symptom severity was mediated by the DG/CA3 during discrimination of neutral items, and by the lateral entorhinal cortex (LEC) during false recognition of positive items. These results shed light on a novel mechanistic account for amygdala-hippocampal network changes and concurrent alterations in emotional episodic memory in LLD. The BLA-LEC-DG/CA3 network, which comprises a key pathway by which emotion modulates memory, is specifically implicated in LLD. © 2017 Wiley Periodicals, Inc.

Effects of mild cognitive impairment on emotional scene memory

Young and older adults experience benefits in attention and memory for emotional compared to neutral information, but this memory benefit is greatly diminished in Alzheimer's disease (AD). Little is known about whether this impairment arises early or late in the time course between healthy aging and AD. This study compared memory for positive, negative, and neutral items with neutral backgrounds between patients with mild cognitive impairment (MCI) and healthy older adults. We also used a divided attention condition in older adults as a possible model for the deficits observed in MCI patients. Results showed a similar pattern of selective memory for emotional items while forgetting their backgrounds in older adults and MCI patients, but MCI patients had poorer memory overall. Dividing attention during encoding disproportionately reduced memory for backgrounds (versus items) relative to a full attention condition. Participants performing in the lower half on the divided attention task qualitatively and quantitatively mirrored the results in MCI patients. Exploratory analyses comparing lower- and higher-performing MCI patients showed that only higher-performing MCI patients had the characteristic scene memory pattern observed in healthy older adults. Together, these results suggest that the effects of emotion on memory are relatively well preserved for patients with MCI, although emotional memory patterns may start to be altered once memory deficits become more pronounced.