Jill D. Waring

Aging memory for pictures : Using high-density event-related potentials to understand the effect of aging on the picture superiority effect

High-density event-related potentials (ERPs) were used to understand the effect of aging on the neural correlates of the picture superiority effect. Pictures and words were systematically varied at study and test while ERPs were recorded at retrieval. Here, the results of the word-word and picture-picture study-test conditions are presented. Behavioral results showed that older adults demonstrated the picture superiority effect to a greater extent than younger adults. The ERP data helped to explain these findings. The early frontal effect, parietal effect, and late frontal effect were all indistinguishable between older and younger adults for pictures. In contrast, for words, the early frontal and parietal effects were significantly diminished for the older adults compared to the younger adults. These two old/new effects have been linked to familiarity and recollection, respectively, and the authors speculate that these processes are impaired for word-based memory in the course of healthy aging. The findings of this study suggest that pictures allow older adults to compensate for their impaired memorial processes, and may allow these memorial components to function more effectively in older adults.

Effects of emotional valence and arousal upon memory trade-offs with aging.

Attention can be attracted faster by emotional relative to neutral information, and memory also can be strengthened for that emotional information. However, within visual scenes, often there is an advantage in memory for central emotional portions at the expense of memory for peripheral background information, called an emotion-induced memory trade-off. The authors examined how aging impacts the trade-off by manipulating valence (positive, negative) and arousal (low, high) of a central emotional item within a neutral background scene and testing memory for item and background components separately. They also assessed memory after 2 study-test delay intervals, to investigate age differences in the trade-off over time. Results revealed similar patterns of performance between groups after a short study-test delay, with both age groups showing robust memory trade-offs. After a longer delay, young and older adults showed enhanced memory for emotional items but at a cost to memory for background information only for young adults in negative arousing scenes. These results emphasize that attention and consolidation stage processes interact to shape how emotional memory is constructed in young and older adults.

Preserved frontal memorial processing for pictures in patients with mild cognitive impairment.

Amnestic mild cognitive impairment (aMCI) has been conceptualized as a transitional stage between healthy aging and Alzheimers disease (AD). Therefore, understanding which aspects of memory are impaired and which remain relatively intact in these patients can be useful in determining who will ultimately go on to develop AD, and subsequently designing interventions to help patients live more engaged and independent lives. The dual-process model posits that recognition memory decisions can rely on either familiarity or recollection. Whereas research is fairly consistent in showing impaired recollection in patients with aMCI, the results have been mixed regarding familiarity. A noted difference between these studies investigating familiarity has been stimulus type. The goal of the current investigation was to use high-density event-related potentials (ERPs) to help elucidate the neural correlates of recognition decisions in patients with aMCI for words and pictures. We also hoped to help answer the question of whether patients can rely on familiarity to support successful recognition. Patients and controls participated in separate recognition memory tests of words and pictures while ERPs were recorded during retrieval. Results showed that ERP components typically associated with familiarity and retrieval monitoring were similar between groups for pictures. However, these components were diminished in the patient group for words. Based on recent work, the authors discuss the possibility that implicit conceptual priming could have contributed to the enhanced ERP correlate of familiarity. Further, the authors address the possibility that enhanced retrieval monitoring may be needed to modulate increased familiarity engendered by pictures.

Impact of individual differences upon emotion-induced memory trade-offs

After seeing a scene containing an emotional component (e.g., a snake in a forest) people often demonstrate a “trade-off” in memory, where memory for the emotional component (e.g., the snake) is good, but memory for the non-emotional elements (e.g., the forest) is poor. The result is an incomplete memory retaining central emotional information at the expense of neutral background information. Though almost everyone demonstrates the trade-off, there may be individual differences in the magnitude of the effect. We investigated whether differences in the strength of the trade-off would correlate with anxiety levels, working memory capacity, and executive functioning abilities. Sixty-four participants studied scenes comprised of a negative or neutral item placed on a neutral background, and memory was later tested for items and backgrounds separately. The magnitude of the trade-off correlated positively with anxiety and negatively with visuospatial working memory and executive function. These results suggest that greater anxiety, poor visuospatial working memory, and poor executive function may inhibit formation of complete mental representations of these complex emotional scenes.

Response bias for picture recognition in patients with Alzheimer disease.

ObjectiveTo investigate whether changing recognition stimuli from words to pictures would alter response bias in patients with Alzheimer disease (AD). BackgroundResponse bias is an important aspect of memory performance in patients with AD, as they show an abnormally liberal response bias compared with healthy older adults. We have previously found that despite changes in discrimination produced by varying the study and test list length, response bias remained remarkably stable in both patients with AD and older adult controls. MethodsPatients with mild AD and healthy older adults underwent two separate study-test sessions of pictures and words. For both pictures and words, increasing study-test list lengths were used to determine whether bias changed as a factor of discrimination or task difficulty. ResultsConsistent with apriori hypotheses, healthy older adults showed increased discrimination and shifted to a more liberal response bias for pictures compared with words. In contrast, despite their higher level of discrimination for pictures, patients with AD showed a similar response bias for both pictures and words. Bias was consistent across varying study-test lengths for both groups. ConclusionsThese results suggest that response bias is a relatively invariant factor of an individual with AD that remains liberal regardless of discrimination or stimulus type.

MEMORY FOR THE SEPTEMBER 11, 2001, TERRORIST ATTACKS ONE YEAR LATER IN PATIENTS WITH ALZHEIMER'S DISEASE, PATIENTS WITH MILD COGNITIVE IMPAIRMENT, AND HEALTHY OLDER ADULTS

Although there are many opportunities to study memory in patients with Alzheimers disease (AD) in the laboratory, there are few opportunities to study memory for real world events in these patients. The September 11, 2001 terrorist attacks provided one such opportunity. Patients with AD, patients with mild cognitive impairment (MCI), and healthy older adults were given a telephone questionnaire in the initial weeks after the event, again three to four months later, and finally one year afterwards to evaluate their memory for the September 11, 2001 terrorist attacks. We were particularly interested in using the attacks as an opportunity to examine the decline of episodic memory in patients with AD, patients with MCI, and older adult controls over a period of months. We found that compared to healthy older adults, patients with AD and MCI showed impaired memory at the initial time point, more rapid forgetting from the initial to the three-month time point, and very similar changes in memory from the three-month to the one-year time point. We speculated that these findings were consistent with patients with AD and MCI showing initial impaired encoding and a more rapid rate of forgetting compared with healthy older adults, but that once the memories had been consolidated, their decay rate became similar to that of healthy older adults. Lastly, although memory distortions were common among all groups, they were greatest in the patients with AD.

Effects of Distinctive Encoding on Source-based False Recognition: Further Examination of Recall-to-Reject Processes in Aging and Alzheimer Disease

ObjectiveTo examine the use of distinctive materials at encoding on recall-to-reject monitoring processes in aging and Alzheimer disease (AD). BackgroundAD patients, and to a lesser extent older adults, have shown an impaired ability to use recollection-based monitoring processes (eg, recall-to-reject) to avoid various types of false memories, such as source-based false recognition. MethodYounger adults, healthy older adults, and AD patients engaged in an incidental learning task, in which critical category exemplars were either accompanied by a distinctive picture or were presented as only words. Later, participants studied a series of categorized lists in which several typical exemplars were omitted and were then given a source memory test. ResultsBoth older and younger adults made more accurate source attributions after picture encoding compared with word-only encoding, whereas AD patients did not exhibit this distinctiveness effect. ConclusionsThese results extend those of previous studies showing that monitoring in older adults can be enhanced with distinctive encoding, and suggest that such monitoring processes in AD patients many be insensitive to distinctiveness.

Disentangling cognition and emotion in older adults: the role of cognitive control and mental health in emotional conflict adaptation.

Recent research suggests cognition has a bidirectional relationship with emotional processing in older adults, yet the relationship is still poorly understood. We aimed to examine a potential relationship between late‐life cognitive function, mental health symptoms, and emotional conflict adaptation. We hypothesized that worse cognitive control abilities would be associated with poorer emotional conflict adaptation. We further hypothesized that a higher severity of mental health symptoms would be associated with poorer emotional conflict adaptation.

Impact of 5-HTTLPR on hippocampal subregional activation in older adults.

Studies have shown that a functional polymorphism of the serotonin transporter gene (5-HTTLPR) impacts performance on memory-related tasks and the hippocampal structures that subserve these tasks. The short (s) allele of 5-HTTLPR has been linked to greater susceptibility for impaired memory and smaller hippocampal volume compared to the long allele (l). However, previous studies have not examined the associations between 5-HTTLPR allele and activation in subregions of the hippocampus. In this study, we used functional magnetic resonance imaging (fMRI) to measure activation in hippocampal and temporal lobe subregions in 36 elderly non-clinical participants performing a face–name encoding and recognition task. Although there were no significant differences in task performance between s allele carriers and l homozygotes, right CA1 and right parahippocampal activation during recognition errors was significantly greater in individuals bearing the s allele. In an exploratory analysis, we determined that these effects were more pronounced in s allele carriers with the apolipoprotein ɛ4 allele. Our results suggest that older individuals with the s allele inefficiently allocate neural resources while making errors in recognizing face–name associations, which could negatively impact memory performance during more challenging tasks.

Effects of mild cognitive impairment on emotional scene memory

ABSTRACT Young and older adults experience benefits in attention and memory for emotional compared to neutral information, but this memory benefit is greatly diminished in Alzheimers 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. HIGHLIGHTSOlder adults with full or divided attention showed selective emotional scene memory.Both groups remembered emotional items while forgetting paired scene backgrounds.MCI patients had poorer accuracy than older adults.Higher‐performing MCI patients showed a similar memory pattern as older adults.However, emotional scene memory patterns differed in lower‐performing MCI patients.