Relative sparing of emotionally influenced memory in Alzheimer's disease

Memory biases in Alzheimer's disease and mild cognitive impairment. A systematic review and metanalysis

Several studies demonstrated that individuals are more likely to remember emotional than neutral information; this phenomenon is known as emotional enhancement of memory (EEM). Adults generally tend to remember negative information more efficiently than neutral or positive items. In contrast, healthy elders seem to show an opposite bias for positive information, but results are inconsistent, also because during aging, elaboration of emotional information could change as a consequence of cognitive impairment. In this systematic review and meta-analysis, we conducted literature search of studies investigating emotion memory biases in mild cognitive impairment (MCI) and Alzheimer's disease (AD) on PubMed, Scopus and PsycINFO databases following PRISMA guidelines. The findings showed that emotional memory biases are still present despite the presence of cognitive impairment, both in MCI and at least in early stages of AD. However, the direction of emotion memory biases is not consistent across studies. These results suggest that patients with cognitive impairment might still benefit from EEM and help to define targets of intervention for cognitive rehabilitation in pathological aging.

Knowledge gains and intent to change practice patterns after the Leveraging Existing Abilities in Dementia (LEAD)™ Training Program

Few investigations have examined dementia training programs for rehabilitation professionals. To address this, the Leveraging Existing Abilities in Dementia (LEAD) program was developed and examined with a pilot study. LEAD addressed dementia knowledge; the Strength-Based Approach; strategies for communication, recognizing behaviors, and learning techniques; and documentation. Participants completed pre-program, post-program, and three-month follow-up questionnaires assessing confidence, practice patterns, and dementia knowledge. Confidence and use of treatment strategies increased through the three-month follow-up and dementia knowledge significantly increased following training. LEAD positively impacted rehabilitation professionals' knowledge, confidence, and use of evidence-based treatment strategies. Implications of LEAD and future research are discussed.

The Pattern of Mu Rhythm Modulation During Emotional Destination Memory: Comparison Between Mild Cognitive Impairment Patients and Healthy Controls

Leading theories of affect development and empirical studies suggest that emotion can enhance memory in older adults. Destination memory which is defined as the ability to remember to whom we told a piece of information is being found to be compromised in aging. In the present study, we sought to assess destination memory using emotional stimuli (Emotional Destination Memory, EDM) in 16 older adults with mild cognitive impairment (MCI) and 16 healthy controls and shed light onto its potential neurophysiological aspects. We measured Mu suppression in frontal and temporal regions via EEG in real time while participants performed the task of EDM. Results showed no group differences in task performance but significant differences in fronto-temporal activations, specifically in electrodes F7 and F8. Differential Mu rhythm pattern was observed between healthy controls and MCI with the first exhibiting Mu suppression and the last Mu enhancement. Furthermore, Mu enhancement in temporal electrodes within the MCI group was associated with lower scores on EDM. The absence of group differences in the task can be explained by the fact that even if there are underlying structural or functional deficits in the MCI group, these deficits are manifested only at neurophysiological level and not at a behavioral level, which is a common pattern in the process of cognitive decline in its initial phases. The overall findings reveal that, even if there are not any behavioral decrements in MCI patients, they show reduced activations in fronto-temporal regions and this can be attributed to general impairment in emotional destination memory due to possible mirror neuron deficiency.

Early life stress amplifies fear responses and hippocampal synaptic potentiation in the APPswe/PS1dE9 Alzheimer mouse model

Cognitive deficits and alterations in emotional behaviour are typical features of Alzheimer's disease (AD). Moreover, exposure to stress or adversity during the early life period has been associated with an acceleration of cognitive deficits and increased AD pathology in transgenic AD mouse models. Whether and how early life adversity affects fear memory in AD mice remains elusive. We therefore investigated whether exposure to early life stress (ELS) alters fear learning in APPswe/PS1dE9 mice, a classic mouse model for AD, and whether this is accompanied by alterations in hippocampal synaptic potentiation, an important cellular substrate for learning and memory. Transgenic APPswe/PS1dE9 mice were subjected to ELS by housing the dams and her pups with limited nesting and bedding material from postnatal days 2-9. Following a fear conditioning paradigm, 12-month-old ELS-exposed APPswe/PS1dE9 mice displayed enhanced contextual freezing behaviour, both in the conditioning context and in a novel context. ELS-exposed APPswe/PS1dE9 mice also displayed enhanced hippocampal synaptic potentiation, even in the presence of the GluN2B antagonist Ro25-6981 (which prevented synaptic potentiation in control mice). No differences in the level of PSD-95 or synaptophysin were observed between the groups. We conclude that in APPswe/PS1dE9 mice, ELS increases fear memory in the conditioning context as well as a novel context, which is accompanied by aberrant hippocampal synaptic potentiation. These results may help to understand how individual differences in the vulnerability to develop AD arise and emphasise the importance of the early postnatal time window in these differences. This article is part of Special Issue entitled: Lifestyle and Brain Metaplasticity.

Cognitive Benefits From a Musical Activity in Older Adults

The aging population is growing rapidly. Proposing interventions that enhance the cognitive functions or strategies that delay the onset of disabilities associated with age is a topic of capital interest for the biopsychosocial health of our species. In this work, we employed musical improvisation as a focal environmental activity to explore its ability to improve memory in older adults. We present two studies: the first one evaluated neutral memory using the Rey Complex Figure (RCF) and the second one evaluated emotional memory using International Affective Picture System (IAPS). A group of 132 volunteers, between the ages of 60 and 90, participated in this investigation. Fifty-one of them were musicians with more than 5 years of formal musical training. After acquisition of neutral (Study 1) or emotional (Study 2) information, the groups of older adults were exposed to music improvisation (experimental intervention) or music imitation (control intervention) for 3 min. We then evaluated memory through two tasks (free recall and recognition), by means of immediate and deferred measures (after a week). We found a significant improvement in memory among participants involved in music improvisation, who remembered more items of the RCF and images from IAPS than the imitation group, both in the immediate and deferred evaluation. On the other hand, participants who had musical knowledge had a better performance in neutral visual memory than non-musicians. Our results suggest that a focal musical activity can be a useful intervention in older adults to promote an enhancement in memory.

Communication technology adoption among older adult veterans: the interplay of social and cognitive factors

OBJECTIVES

InTouch is an electronic communication platform designed to be accessible by computer-naive seniors. The present study explored the process of adoption and use of the application by seniors with and without mild cognitive impairment (MCI) through the lens of Social Cognitive Theory (SCT).

METHOD

We studied adoption and use of InTouch for social communication over a 12-week period in a 475-bed Veteran's care facility at Sunnybrook Health Sciences Centre in Toronto, Canada. Eleven older adult veterans participated, six of whom had MCI, as indicated by their Montreal Cognitive Assessment score. Veterans were partnered with volunteers, each was provided with an iPad with the InTouch application. Qualitative data were collected through interviews, field notes, and direct observation. Quantitative data were collected from data logging of the software and medical charts. Data types and sources were triangulated and examined through the lens of SCT.

RESULTS

A total of 2361 messages (102 videos, 359 audios, 417 photos, 1438 texts) were sent by 10 of the 11 veterans over the 12-week study period. There was no apparent difference in extent of adoption or use, between participants with and without MCI. Participants used various resources and techniques to learn, provided that they felt motivated to connect with others using the app.

CONCLUSION

This pilot illustrates both the accessibility of InTouch and the promise of using extrinsic motivators such as social bonding to promote learning in institutionalized older adults with and without cognitive impairment, whose intrinsic motivation and self-efficacy may well be suffering.

The Efficacy of Emotion Recognition Rehabilitation for People with Alzheimer's Disease

BACKGROUND

The ability to recognize emotional expression is essential for social interactions, adapting to the environment, and quality of life. Emotion recognition is impaired in people with Alzheimer's disease (AD), thus rehabilitation of these skills has the potential to elicit significant benefits.

OBJECTIVE

This study sought to establish whether emotion recognition capacity could be rehabilitated in people with AD.

METHODS

Thirty-six participants with AD were assigned to one of three conditions: an experimental group (EG) that received 20 sessions of rehabilitation of emotion recognition and 20 sessions of cognitive stimulation therapy (CST), a control group (CG) that received 40 sessions of CST, and a treatment as usual group (TAU).

RESULTS

A positive treatment effect favoring the EG was found; participants were better able to correctly identify emotions (p = 0.021), made fewer errors of commission (p = 0.002), had greater precision of processing (p = 0.021), and faster processing speed (p = 0.001). Specifically, the EG were better able to identify sadness (p = 0.016), disgust (p = 0.005), and the neutral expression (p = 0.014), with quicker processing speed for disgust (p = 0.002). These gains were maintained at one month follow-up with the exception of processing speed for surprise, which improved.

CONCLUSION

Capacity to recognize facial expressions of emotions can be improved through specific rehabilitation in people with AD, and gains are still present at a one month follow up. These findings have implications for the design of rehabilitation techniques for people with AD that may lead to improved quality of life and social interactions for this population.

Frontal activity during a verbal emotional working memory task in patients with Alzheimer's disease: A functional near-infrared spectroscopy study

Emotional working memory (EWM) is suggested as a working memory (WM) type, distinguished to process emotional stimuli, and may or may not be spared in Alzheimer's disease (AD). The aim was to compare patients with AD and healthy older adults (HC) on verbal EWM performance and accompanying prefrontal cortex activity. Twenty AD patients along with 20 HC individuals are required to complete an emotional one-back task in three conditions (neutral, positive and negative word lists). Prefrontal oxyhemoglobin (oxyHb) concentrations were measured simultaneously by a 24- channel functional near infrared spectroscopy device. Correct response rates were similar in two groups in all conditions. Reaction times were comparable in the EWM positive condition but longer in the AD group in EWMneutral and negative conditions. In the HC group, emotional words had no significant effect on WM. On the other hand, positive compared to neutral words led to greater activation in the left ventral prefrontal cortex (VPFC) in AD group. When compared to HCs, activity in the VPFC was significantly higher in AD patients during the positive condition. Positive words facilitated WM performance in participants with AD. Activity in VPFC may be the functional correlate of this phenomenon.

An evaluation of shared reading groups for adults living with dementia: preliminary findings

Purpose

– Although there is a growing evidence base for the value of psychosocial and arts-based strategies for enhancing well-being amongst adults living with dementia, relatively little attention has been paid to literature-based interventions. The purpose of this paper is to assess the impact of shared reading (SR) groups, a programme developed and implemented by The Reader Organisation, on quality of life for care home residents with mild/moderate dementia.

Design/methodology/approach

– In total, 31 individuals were recruited from four care homes, which were randomly assigned to either reading-waiting groups (three months reading, followed by three months no reading) or waiting-reading groups (three months no reading, followed by three months reading). Quality of life was assessed by the DEMQOL-Proxy and psychopathological symptoms were assessed by the Neuropsychiatric Inventory Questionnaire.

Findings

– Compared to the waiting condition, the positive effects of SR on quality of life were demonstrated at the commencement of the reading groups and were maintained once the activity ended. Low levels of baseline symptoms prevented analyses on whether the intervention impacted on the clinical signs of dementia.

Research limitations/implications

– Limitations included the small sample and lack of control for confounding variables.

Originality/value

– The therapeutic potential of reading groups is discussed as a positive and practical intervention for older adults living with dementia.

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

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.

Impaired and preserved aspects of feedback learning in aMCI: contributions of structural connectivity

Distinct lines of research demonstrated that patients with amnestic mild cognitive impairment (aMCI), a potential precursor of Alzheimer disease (AD), are particularly impaired in remembering relations between items and that the use of emotional targets can facilitate memory in patients with AD. We link these findings by examining learning through positive and negative feedback in patients with aMCI, and explore its anatomic underpinnings with diffusion tensor imaging and tractography. Compared to healthy controls, patients with single-domain aMCI were impaired in learning from positive feedback, while learning from negative outcomes was preserved. Among pathways within the brain circuit involved in feedback learning, abnormal white matter microstructure was observed in tracts, which connect left-hemispheric amygdala with hippocampus and entorhinal cortex. In all participants, reduced white matter integrity in this left fiber tract was specifically associated with learning from positive outcomes. Microstructure of right-hemispheric tracts between amygdala and entorhinal cortex was related to learning from negative feedback, and was not compromised in aMCI patients. Our results provide new insight into how anatomical connections might contribute to impaired and preserved aspects of learning behaviors in the early AD process and indicate potential compensatory mechanisms.

The Positivity Effect on the Intensity of Experienced Emotion and Memory Performance in Mild Cognitive Impairment and Dementia

AIMS

We examined the 'positivity effect' on memory performance in mild cognitive impairment (MCI) and dementia patients.

METHODS

In 109 subjects (28 controls, 32 with MCI, 27 with mild and 32 with moderate dementia), we investigated free recalls (immediate and delayed) and recognition of 12 pictures. Moreover, the emotional valence of the pictures perceived and the emotions evoked in the subjects were evaluated.

RESULTS

Patients with mild and moderate dementia recalled fewer pictures than those with MCI or the healthy controls. Across the groups, the positive pictures were better memorized and induced a higher arousal than the negative or neutral ones.

CONCLUSIONS

Our findings indicate a positivity effect on memory performance and intensity of experience not only in healthy elderly patients but also in those with MCI or mild and moderate dementia. This effect does not refer to the compliance of the patients investigated since they perceived and experienced the pictures in the expected way.

Impaired emotional autobiographical memory associated with right amygdalar-hippocampal atrophy in Alzheimer's disease patients

We studied the influence of emotions on autobiographical memory (AbM) in patients with Alzheimer’s disease (AD), characteristically triggering atrophy in the hippocampus and the amygdala, two crucial structures sustaining memory and emotional processing. Our first aim was to analyze the influence of emotion on AbM in AD patients, on both the proportion and the specificity of emotional memories. Additionally, we sought to determine the relationship of emotional AbM to amygdalar-hippocampal volumes. Eighteen prodromal to mild AD patients and 18 age-matched healthy controls were included. We obtained 30 autobiographical memories per participant using the modified Crovitz test (MCT). Analyses were performed on global scores, rates and specificity scores of the emotional vs. neutral categories of memories. Amygdalar-hippocampal volumes were extracted from 3D T1-weighted MRI scans and tested for correlations with behavioral data. Overall, AD patients displayed a deficit in emotional AbMs as they elicited less emotional memories than the controls, however, the specificity of those memories was preserved. The deficit likely implied retrieval or storage as it was extended in time and without reminiscence bump effect. Global scores and rates of emotional memories, but not the specificity scores, were correlated to right amygdalar and hippocampal volumes, indicating that atrophy in these structures has a central role in the deficit observed. Conversely, emotional memories were more specific than neutral memories in both groups, reflecting an enhancement effect of emotion that could be supported by other brain regions that are spared during the early stages of the disease.

Feelings without memory in Alzheimer disease

Background:

Patients with Alzheimer disease (AD) typically have impaired declarative memory as a result of hippocampal damage early in the disease. Far less is understood about AD’s effect on emotion.

Objective:

We investigated whether feelings of emotion can persist in patients with AD, even after their declarative memory for what caused the feelings has faded.

Methods:

A sample of 17 patients with probable AD and 17 healthy comparison participants (case-matched for age, sex, and education) underwent 2 separate emotion induction procedures in which they watched film clips intended to induce feelings of sadness or happiness. We collected real-time emotion ratings at baseline and at 3 post-induction time points, and we administered a test of declarative memory shortly after each induction.

Results:

As expected, the patients with AD had severely impaired declarative memory for both the sad and happy films. Despite their memory impairment, the patients continued to report elevated levels of sadness and happiness that persisted well beyond their memory for the films. This outcome was especially prominent after the sadness induction, with sustained elevations in sadness lasting for more than 30 minutes, even in patients with no conscious recollection for the films.

Conclusions:

These findings indicate that patients with AD can experience prolonged states of emotion that persist well beyond the patients’ memory for the events that originally caused the emotion. The preserved emotional life evident in patients with AD has important implications for their management and care, and highlights the need for caretakers to foster positive emotional experiences.

Frontal and temporal lobe contributions to emotional enhancement of memory in behavioral-variant frontotemporal dementia and Alzheimer's disease

Emotional events gain special priority in how they are remembered, with emotionally arousing events typically recalled more vividly and with greater confidence than non-emotional events. In dementia, memory and emotion processing are affected to varying degrees, however, whether emotional enhancement of memory for complex ecologically-valid events is differentially affected across dementia syndromes remains unclear, with previous studies examining effects of emotion on simple visual recognition only. Here, we examined memory for an emotionally arousing short story and a closely matched, emotionally neutral story in behavioral-variant frontotemporal dementia (bvFTD) (n = 13) and Alzheimer's disease (AD) (n = 14), and contrasted their performance with healthy controls (n = 12). Multiple-choice recognition memory for specific details of the story was assessed after a 1-h delay. While AD and control groups showed enhanced memory for the emotional story, the bvFTD group recalled a similar number of details from the emotional and neutral stories. Voxel-based morphometry analyses revealed emotional enhancement of memory correlated with distinct brain regions in each patient group. In AD, emotional enhancement was associated with integrity of the bilateral hippocampus, parahippocampal gyri, temporal fusiform gyrus and frontal pole, regions typically implicated in memory processes. In contrast in bvFTD, integrity of emotion processing regions, including the orbitofrontal cortex, right amygdala and right insula, correlated with the extent emotion enhanced memory. Our results reveal that integrity of frontal and temporal regions determine the quality and nature of emotional memories. While emotional enhancement of memory is present in mild AD, in bvFTD emotion does not facilitate memory retrieval for complex realistic events. This attenuation of emotional enhancement is due to degradation of emotion processing regions, which may be important for modulating levels of arousal in response to emotional events in these patients.

Social influence on associative learning: double dissociation in high-functioning autism, early-stage behavioural variant frontotemporal dementia and Alzheimer's disease

INTRODUCTION

Most of our learning activity takes place in a social context. I examined how social interactions influence associative learning in neurodegenerative diseases and atypical neurodevelopmental conditions primarily characterised by social cognitive and memory dysfunctions.

METHODS

Participants were individuals with high-functioning autism (HFA, n = 18), early-stage behavioural variant frontotemporal dementia (bvFTD, n = 16) and Alzheimer's disease (AD, n = 20). The leading symptoms in HFA and bvFTD were social and behavioural dysfunctions, whereas AD was characterised by memory deficits. Participants received three versions of a paired associates learning task. In the game with boxes test, objects were hidden in six candy boxes placed in different locations on the computer screen. In the game with faces, each box was labelled by a photo of a person. In the real-life version of the game, participants played with real persons.

RESULTS

Individuals with HFA and bvFTD performed well in the computer games, but failed on the task including real persons. In contrast, in patients with early-stage AD, social interactions boosted paired associates learning up to the level of healthy control volunteers. Worse performance in the real life game was associated with less successful recognition of complex emotions and mental states in the Reading the Mind in the Eyes Test. Spatial span did not affect the results.

CONCLUSIONS

When social cognition is impaired, but memory systems are less compromised (HFA and bvFTD), real-life interactions disrupt associative learning; when disease process impairs memory systems but social cognition is relatively intact (early-stage AD), social interactions have a beneficial effect on learning and memory.

Distinct neural systems underlying reduced emotional enhancement for positive and negative stimuli in early Alzheimer's disease

Emotional information is typically better remembered than neutral content, and previous studies suggest that this effect is subserved particularly by the amygdala together with its interactions with the hippocampus. However, it is not known whether amygdala damage affects emotional memory performance at immediate and delayed recall, and whether its involvement is modulated by stimulus valence. Moreover, it is unclear to what extent more distributed neocortical regions involved in e.g., autobiographical memory, also contribute to emotional processing. We investigated these questions in a group of patients with Alzheimer's disease (AD), which affects the amygdala, hippocampus and neocortical regions. Healthy controls (n = 14), patients with AD (n = 15) and its putative prodrome amnestic mild cognitive impairment (n = 11) completed a memory task consisting of immediate and delayed free recall of a list of positive, negative and neutral words. Memory performance was related to brain integrity in region of interest and whole-brain voxel-based morphometry analyses. In the brain-behavioral analyses, the left amygdala volume predicted the immediate recall of both positive and negative material, whereas at delay, left and right amygdala volumes were associated with performance with positive and negative words, respectively. Whole-brain analyses revealed additional associations between left angular gyrus integrity and the immediate recall of positive words as well as between the orbitofrontal cortex and the delayed recall of negative words. These results indicate that emotional memory impairments in AD may be underpinned by damage to regions implicated in emotional processing as well as frontoparietal regions, which may exert their influence via autobiographical memories and organizational strategies.

Emotional reactivity to film material in Alzheimer's disease

AIMS

To explore emotional reactivity in mild to moderate Alzheimer's disease (AD) using film material, investigating the influence of dementia-related material and awareness of condition.

METHODS

Twenty-two patients with AD and 21 healthy older adults viewed films with positive, neutral or negative content, including a film about dementia. Reactivity was measured through a self-report questionnaire and filming of facial expressions. Awareness of condition was assessed contrasting patients' versus informants' versions of an anosognosia questionnaire.

RESULTS

The AD patients showed reduced self-reported reactivity to negative films, but exhibited a pattern of facial responses similar to controls for all films. Awareness was associated with frequency of negative facial expressions during the dementia film.

CONCLUSIONS

AD patients may have impairments in self-reported reactivity to negative stimuli. Awareness may mediate responses to dementia-related material.

Preserved and impaired emotional memory in Alzheimer's disease

Patients with early atrophy of both limbic structures involved in memory and emotion processing in Alzheimer's disease (AD) provide a unique clinical population for investigating how emotion is able to modulate retention processes. This review focuses on the emotional enhancement effect (EEE), defined as the improvement of memory for emotional events compared with neutral ones. The assessment of the EEE for different memory systems in AD suggests that the EEE could be preserved under specific retrieval instructions. The first part of this review examines these data in light of compelling evidence that the amygdala can modulate processes of hippocampus-dependent memory. We argue that the EEE could be a useful paradigm to reduce impairment in episodic memory tasks. In the second part, we discuss theoretical consequences of the findings in favor of an EEE, according to which a compensatory mechanism in patients with AD solicits greater amygdala functioning or additional networks, even when amygdala atrophy is present. These considerations emphasize the relevance of investigating patients with AD to understand the relationship between emotion and memory processes.

Emotional memory in patients with Alzheimer's disease: a report of two cases

Highly emotional events in daily life can be preserved in memory and such memory is generally referred to as emotional memory. Some reports have demonstrated that emotional memory is also found in patients with Alzheimer's disease (AD). However, to our knowledge, there have been no reports about how long memory retention for emotional events can continue in patients with AD. In this paper, we present two patients with AD who lost an immediate family member during followup and retained the memory over a long period despite progression of the AD.

Does emotional memory enhancement assist the memory-impaired?

We review recent work on emotional memory enhancement in older adults and patients with mild cognitive impairment (MCI) or Alzheimer dementia (AD) and evaluate the viability of incorporating emotional components into cognitive rehabilitation for these groups. First, we identify converging evidence regarding the effects of emotional valence on working memory in healthy aging. Second, we introduce work that suggests a more complex role for emotional memory enhancement in aging and identify a model capable of unifying disparate research findings. Third, we survey the neuroimaging literature for evidence of a special role for the amygdala in MCI and early AD in emotional memory enhancement. Finally, we assess the theoretical feasibility of incorporating emotional content into cognitive rehabilitation given all available evidence.

Affective learning and psychophysiological reactivity in dementia patients

We examined the association of faces with biographical information that varied in emotional content in patients with Alzheimer's disease and a healthy control group. During two experimental sessions, participants rated neutral male faces on dimensions of hedonic valence and emotional arousal, later paired with fictitious biographical information. Both groups changed their ratings of the faces according to the biographical content. Free recall and recognition were tested in the second session. Patients neither recalled the biographical information nor recognized the faces, whereas the controls did. In addition, psychophysiological measures were taken in response to the face stimuli. Patients showed significant heart rate modulation as a function of their emotion ratings, whereas the controls did not. No correlation of rating changes with skin conductance was found in any group. Results suggest that psychophysiological reactions such as heart rate changes may indicate preserved affective associative learning in dementia patients despite impaired explicit memory.

Effects of emotional arousal on memory binding in normal aging and Alzheimer's disease

Previous research suggests that associative memory declines in normal aging and is severely affected by Alzheimer's disease (AD); however, it is unclear whether and how this deficit can be minimized. The present study investigated whether emotional arousal improves associative memory in healthy younger and older adults and patients with probable AD. We examined the effect of arousal on memory for item-location associations. Arousal improved memory for item location similarly across the three groups, whereas valence had no effect in any groups. Overall, our results suggest that arousal has beneficial effects on associative memory in healthy older adults and patients with AD, as previously observed in younger adults.

Memory for emotional pictures in patients with Alzheimer's dementia: comparing picture-location binding and subsequent recognition

Emotional content typically facilitates subsequent memory, known as the emotional enhancement effect. We investigated whether emotional content facilitates spatial and item memory in patients with Alzheimer's dementia (AD). Twenty-three AD patients, twenty-three healthy elderly, and twenty-three young adults performed a picture relocation task and a delayed recognition task with positive, negative, and neutral stimuli. AD patients showed a benefit in immediate spatial memory for positive pictures, while healthy young and older participants did not benefit from emotional content. No emotional enhancement effects on delayed item recognition were seen. We conclude that AD patients may have a memory bias for positive information in spatial memory. Discrepancies between our findings and earlier studies are discussed.

Familiar smiling faces in Alzheimer's disease: understanding the positivity-related recognition bias

Recent research has revealed a recognition bias favoring positive faces and other stimuli in older compared to younger adults. However, it is yet unclear whether this bias reflects an age-related preference for positive emotional stimuli, or an affirmatory bias used to compensate for episodic memory deficits. To follow up this point, the present study examined recognition of emotional faces and current mood state in patients with mild Alzheimer disease (AD) and healthy controls. Expecting lower overall memory performance, more negative and less positive mood in AD patients, the critical question was whether the positivity-related recognition bias would be increased compared to cognitively unimpaired controls. Eighteen AD patients and 18 healthy controls studied happy, neutral, and angry faces, which in a subsequent recognition task were intermixed with 50% distracter faces. As expected, the patient group showed reduced memory performance, along with a less positive and more negative mood. The recognition bias for positive faces persisted. This pattern supports the view that the positivity-induced recognition bias represents a compensatory, gist-based memory process that is applied when item-based recognition fails.

Remembering relationships: preserved emotion-based learning in Alzheimer's disease

Research into Alzheimer's disease has long focused on cognitive impairments. Advocates of the person-centered approach argue that emotions and interpersonal responses may remain intact. The answer to this paradox may derive from the neuropsychology of emotion, demonstrating preserved ability on simple emotion learning tasks, though this may not capture the complex interpersonal interactions that some patients appear able to manage in everyday life. This study demonstrates, for the first time, preserved complex emotion-based learning capacity, despite profound episodic memory impairment in Alzheimer's disease. These findings offer a starting point for the development of a solid neuropsychological and neuroanatomical account for the person-centered approach.

Implicit learning of affective responses in dementia patients: a face-emotion-association paradigm

The aim of the present study was to develop and evaluate an ecologically valid approach to assess implicit learning of affective responses in dementia patients. We designed a Face-Emotion-Association paradigm (FEA) that allows to quantify the influence of stimuli with positive and negative valence on affective responses. Two pictures of neutral male faces are rated on the dimensions of valence and arousal before and after aversive versus pleasant fictitious biographical information is paired with each of the pictures. At the second measurement time point, memory for pictures and biographical content is tested. The FEA was tested in 21 patients with dementia and 13 healthy controls. Despite severely impaired explicit memory, patients changed valence and arousal ratings according to the biographical content and did not differ in their ratings from the control group. The results demonstrate that our FEA paradigm is a valid instrument to investigate learning of affective responses in dementia patients.

Emotion processing for arousal and neutral content in Alzheimer's disease

Objective. To assess the ability of Alzheimer's disease (AD) patients to perceive emotional information and to assign subjective emotional rating scores to audiovisual presentations. Materials and Methods. 24 subjects (14 with AD, matched to controls for age and educational levels) were studied. After neuropsychological assessment, they watched a Neutral story and then a story with Emotional content. Results. Recall scores for both stories were significantly lower in AD (Neutral and Emotional: P = .001). CG assigned different emotional scores for each version of the test, P = .001, while ratings of AD did not differ, P = .32. Linear regression analyses determined the best predictors of emotional rating and recognition memory for each group among neuropsychological tests battery. Conclusions. AD patients show changes in emotional processing on declarative memory and a preserved ability to express emotions in face of arousal content. The present findings suggest that these impairments are due to general cognitive decline.

Free recall and learning of emotional word lists in very elderly people with and without dementia

An emotional memory advantage has been found across the life span where recall is better for emotional (as opposed to neutral) stimuli. Our goal was to design emotionally valent word lists for easy use by practitioners and to test whether demented and healthy elderly participants showed an emotional memory advantage with these lists. Three new word lists (a positive, a negative, and a neutral list) were constructed. Thirty-eight controls, 37 with mild cognitive impairment and 20 Alzheimer's dementia participants' free recall was tested. Unsurprisingly, controls had better recall overall. Emotionally valent words were recalled better in comparison to neutral words in all 3 groups. No recall advantage for positive versus negative words emerged. Learning differed among the groups with the Alzheimer's dementia participants showing flatter learning curves. The results tentatively suggest that emotional memory may stay intact longer but that learning of such lists becomes more difficult as dementia progresses.

Emotional valence and semantic relatedness differentially influence false recognition in mild cognitive impairment, Alzheimer's disease, and healthy elderly

This study examined whether patients with mild cognitive impairment (MCI) who are at higher risk for later Alzheimer disease (AD) display deficits comparable to patients with diagnosed dementia. We assessed 27 patients with MCI, 36 patients with AD, and 20 healthy older adults with an emotional variant of the Deese-Roediger-McDermott-paradigm. Participants studied four lists that were semantically related to a nonpresented critical theme word. These theme words were either depression-related (i.e., loneliness) or delusion-related (betrayal) or had a positive (holidays) or neutral (window) valence. Despite a normal overall emotional memory and a normal corrected overall false recognition, patients with MCI, as predicted, produced as many false memories as patients with AD. On closer examination, both patient groups showed enhanced false memories to unrelated stimuli and a significant bias to falsely remember stimuli with a positive valence. We conclude that although patients with MCI are not distinguishable from healthy older adults in terms of their overall emotional recognition, positively valenced memories and more specifically false positive memories may represent the signature of a breakdown of emotional memory along the continuum between normal aging and AD.

Bedeutung der emotionalen Valenz beim emotionalen Gedächtniseffekt bei Demenzpatienten

Die Verbesserung der Gedächtnisleistung für emotional erregende gegenüber neutralen Informationen wird als „emotionaler Gedächtniseffekt“ bezeichnet. Inwiefern die emotionale Valenz des Materials die Erinnerungsleistung bei Demenzpatienten beeinflußt, ist bislang unklar und wurde in der vorliegenden Studie untersucht. Allen Versuchsteilnehmern wurden ein Text (emotional positiv, negativ und neutral beurteilter Abschnitt) und mehrere Bilder (emotional positiv, negativ und neutral beurteilte Bilder) präsentiert, es erfolgte ein unmittelbarer und ein verzögerter freier Abruf (30 min.). Während beim non-verbalen Material die Kontrollgruppe emotional positive und negative Informationen in gleichem Masse erinnerte, zeigte sich bei der Gruppe der Alzheimer Patienten eine verbesserte Abrufleistung für emotional negatives Material. Die vermehrte Erinnerung von emotional negativem Material trat nicht nur bei depressiven Patienten auf und ist folglich nicht durch einen „Stimmungskongruenzeffekt“ zu erklären. Beim verbalen Gedächtnistest wiesen beide Stichproben eine Tendenz zur vermehrten Erinnerung von emotional negativen Informationen auf. Die Studie zeigt, daß die emotionale Valenz des Materials die explizite Gedächtnisleistung von Demenzpatienten beeinflusst. Die Ergebnisse sind für die Therapie von und den Umgang mit Demenzpatienten von besonderer Bedeutung.

Nonpharmacological cognitive interventions in aging and dementia

There have been increasing efforts to develop cognitive interventions to ameliorate cognitive problems experienced by older adults. In healthy elderly populations, cognitive training has centered on the enhancement of memory and speed of processing, with the goal of maximizing current function and reducing the risk of cognitive decline. Among elderly persons with nonprogressive neurological conditions such as traumatic brain injury (TBI) and stroke, there has been an emphasis on rehabilitation to help restore function. Most recently, there has been increased attention on the development of new cognitive techniques to treat persons with progressive neurodegenerative conditions such as Alzheimer disease. The literature is reviewed on current approaches to cognitive interventions in elderly healthy populations, and a particular emphasis is placed on the most recent strides in progressive neurocognitive conditions, particularly Alzheimer disease. Important issues such as study design, the use of ecologically and functionally valid outcome measures, the need to examine heterogeneous populations and cross-cultural variables, and the incorporation of technologically based systems are examined. It is concluded that cognitive interventions in the elderly show considerable promise and deserve further study.

Neural correlates of emotional working memory in patients with mild cognitive impairment

Emotional stimuli can have beneficial effects on memory in healthy aged subjects and partly on patients with dementia. So far, no experimental study has explored the effects of memory for emotional stimuli in patients with mild cognitive impairment (MCI), a concept that describes a transitional state between normal aging and dementia. The present fMRI study explored working memory for emotional stimuli in 16 patients with amnestic MCI (aMCI) and 16 healthy aged participants. Subjects performed an n-back task (2-back) with neutral, positive, and negative emotional pictures. The analysis focused on target processing. Results showed that groups did not differ in working memory performance. In healthy aged participants emotional targets had no significant impact on working memory. In patients with aMCI a negativity bias was observed, indicating that negative targets were better remembered compared to neutral and positive targets. Regarding fMRI results, both groups showed an increase in functional activity in prefrontal and lateral parietal brain regions associated with target processing. As a key result, we observed significant group by emotion interaction effects in the precuneus. Healthy aged participants showed a signal decrease in the left precuneus for positive compared to neutral targets. The precuneus deactivation in healthy aged participants may indicate a disengagement of self-referential processes towards task-related processes. Patients with aMCI revealed a signal increase in the right precuneus for negative compared to neutral targets. This increase in precuneus activity, combined with a behavioural facilitation effect, may indicate a mechanism to compensate disease related processes in aMCI.

Preserved implicit memory in dementia: a potential model for care

A growing body of evidence supports the presence of a preserved implicit memory (PIM) system for persons with Alzheimer's disease (AD). This article describes a new approach to dementia care, the PIM model, which translates evidence from implicit memory research into a practice model of dementia care. The PIM model predicts that function can be sustained longer for persons with AD through interventions and environments that activate an individual's PIM. Activation of PIM can occur with perceptual priming of familiar objects and reinforcement of learned motor skill memories within tasks. This practice model provides a new framework for planning and implementing dementia care that may preserve function for persons with Alzheimer's dementia.

Neutral and emotional episodic memory: global impairment after lorazepam or scopolamine

RATIONALE

Benzodiazepines and anticholinergic drugs have repeatedly been shown to impair episodic memory for emotionally neutral material in humans. However, their effect on memory for emotionally laden stimuli has been relatively neglected.

OBJECTIVE

We sought to investigate the effects of the benzodiazepine, lorazepam, and the anticholinergic, scopolamine, on incidental episodic memory for neutral and emotional components of a narrative memory task in humans.

MATERIALS AND METHODS

A double-blind, placebo-controlled independent group design was used with 48 healthy volunteers to examine the effects of these drugs on emotional and neutral episodic memory.

RESULTS

As expected, the emotional memory advantage was retained for recall and recognition memory under placebo conditions. However, lorazepam and scopolamine produced anterograde recognition memory impairments on both the neutral and emotional components of the narrative, although floor effects were obtained for recall memory. Furthermore, compared with placebo, recognition memory for both central (gist) and peripheral (detail) aspects of neutral and emotional elements of the narrative was poorer after either drug.

CONCLUSIONS

Benzodiazepine-induced GABAergic enhancement or scopolamine-induced cholinergic hypofunction results in a loss of the enhancing effect of emotional arousal on memory. Furthermore, lorazepam- and scopolamine-induced memory impairment for both gist (which is amygdala dependent) and detail raises the possibility that their effects on emotional memory do not depend only on the amygdala. We discuss the results with reference to potential clinical/forensic implications of processing emotional memories under conditions of globally impaired episodic memory.

False recognition of emotional word lists in aging and Alzheimer disease

OBJECTIVE

To examine 3 different aspects of the emotional memory effect in aging and Alzheimer disease (AD): item-specific recollection, gist memory, and recognition response bias.

METHOD

Younger adults, older adults, and patients with AD performed a false recognition memory test in which participants were tested on "lure" items that were not seen at study, but were semantically related to the study items. Participants were tested on 5 emotional and 5 non-emotional lists.

RESULTS

In addition to finding an increase in true recognition for emotional versus non-emotional items in healthy younger and older adults but not in patients with AD, and confirming that emotional items led younger adults to shift their response bias to a more liberal one, 3 novel findings were observed. First, the emotional effect on response bias was also observed in healthy older adults. Second, the opposite emotional effect on response bias was observed in patients with AD. Third, emotional items did not lead to an improvement in item-specific recollection or gist memory.

CONCLUSIONS

Although healthy older adults show the normal amygdala-modulated criterion shift for emotional items-influencing their subjective feeling that information has been previously encountered, the amygdala pathology present in early AD may disrupt this influence.

Acquisition of affective dispositions in dementia patients

In this study, we investigated the acquisition of affective dispositions towards neutral faces in patients with Alzheimer's disease and mixed dementia. Participants viewed four affectively neutral male faces from the International Affective Picture System. Biographical information about the depicted persons was presented, which described them in terms of positive or negative traits varying in intensity. Participants were asked to rate the pictures with respect to emotional valence, arousal, and preference prior to and after the presentation of the biographical information. Following a retention interval of 180 min, pictures were rated again and the biographical information was presented once more. Final ratings were obtained after another interval of 1300 min. As expected, healthy control participants identified the faces and recalled parts of the information in the delayed recall test. They showed pronounced changes in affective ratings. Patients did not recognize the faces in a recognition test after the retention intervals, but valence, arousal, and preference ratings were systematically altered by the affective content of biographies. The results suggest that acquisition and maintenance of implicit affective dispositions are preserved in dementia even when explicit memory is impaired.

Chronic dietary alpha-lipoic acid reduces deficits in hippocampal memory of aged Tg2576 mice

Oxidative stress may play a key role in Alzheimer's disease (AD) neuropathology. Here, the effects of the antioxidant, alpha-lipoic acid (ALA) were tested on the Tg2576 mouse, a transgenic model of cerebral amyloidosis associated with AD. Ten-month old Tg2576 and wild type mice were fed an ALA-containing diet (0.1%) or control diet for 6 months and then assessed for the influence of diet on memory and neuropathology. ALA-treated Tg2576 mice exhibited significantly improved learning, and memory retention in the Morris water maze task compared to untreated Tg2576 mice. Twenty-four hours after contextual fear conditioning, untreated Tg2576 mice exhibited significantly impaired context-dependent freezing. ALA-treated Tg2576 mice exhibited significantly more context freezing than the untreated Tg2576 mice. Assessment of brain soluble and insoluble beta-amyloid levels revealed no differences between ALA-treated and untreated Tg2576 mice. Brain levels of nitrotyrosine, a marker of nitrative stress, were elevated in Tg2576 mice, while F2 isoprostanes and neuroprostanes, oxidative stress markers, were not elevated in the Tg2576 mice relative to wild type. These data indicate that chronic dietary ALA can reduce hippocampal-dependent memory deficits of Tg2576 mice without affecting beta-amyloid levels or plaque deposition.

Emotionen und Gedächtnis bei Patienten mit Alzheimer-Demenz

Zusammenfassung: Dieser Übersichtsartikel hat das Ziel, Zusammenhänge von Emotionen und Gedächtnisleistungen bei Alzheimerpatienten aufzuzeigen und dabei auf Ressourcen der Patienten in diesem Bereich einzugehen. Neurophysiologische Veränderungen durch die Alzheimerdemenz werden kurz diskutiert und mit neuroanatomischen Strukturen, die an der Verarbeitung von Emotionen beteiligt sind, in Verbindung gebracht. Auf dieser Grundlage wird ein Überblick über Studien mit Alzheimerpatienten gegeben, die (a) den emotionalen Gedächtniseffekt erforschen, oder (b) Emotionen als Gedächtnisinhalte bei Alzheimerpatienten untersuchen. Abschließend werden offene Forschungsfragen mit Blick auf Konsequenzen dieser Befunde für die nichtmedikamentöse Therapie diskutiert.

Emotional enhancement of perceptual priming is preserved in aging and early-stage Alzheimer's disease

Perceptual priming for emotionally-negative and neutral scenes was tested in early-stage Alzheimer's disease (AD) patients and healthy younger, middle-aged and older adults. In the study phase, participants rated the scenes for their arousal properties. In the test phase, studied and novel scenes were initially presented subliminally, and the exposure duration was gradually increased until a valence categorization was made. The difference in exposure duration required to categorize novel versus studied items was the dependent measure of priming. Aversive content increased the magnitude of priming, an effect that was preserved in healthy aging and AD. Results from an immediate recognition memory test showed that the priming effects could not be attributable to enhanced explicit memory for the aversive scenes. These findings implicate a dissociation between the modulatory effect of emotion across implicit and explicit forms of memory in aging and early-stage AD.

Inference of mental states in patients with Alzheimer's disease

INTRODUCTION

The ability to determine what someone thinks or knows often requires an individual to infer the mental state of another person, an ability typically referred to as one's "theory of mind". The present study tests this ability in patients with mild-to-moderate Alzheimer's disease (AD).

METHODS

Three theory of mind tests and three standardised neuropsychological tests were presented to a group of patients with AD (n = 25) and a group of healthy elderly controls (n = 15).

RESULTS

On the first two theory of mind tasks, the performance of the AD patients was nearly perfect and did not differ from that of the controls: AD patients showed no difficulties in either attributing a false belief to another person, or in recognising their own previous false beliefs. On the third theory of mind task, where the key information was embedded in a story narrative, AD patients per formed significantly worse than controls. However, their performance on this task was similar to the control condition, which used a similar story but which did not involve beliefs.

CONCLUSIONS

These results, as well as those involving correlations between the neuropsychological tests and performance on the third task, suggest that the AD patients' difficulty may be secondary to their cognitive impairments, rather than a primary impairment in theory of mind.

Memory and emotions for the september 11, 2001, terrorist attacks in patients with Alzheimer's disease, patients with mild cognitive impairment, and healthy older adults

National traumatic events can produce extremely vivid memories. Using a questionnaire administered during telephone interviews, the authors investigated emotional responses to, and memory for. the September 11, 2001, terrorist attacks in patients with Alzheimer's disease (AD), patients with mild cognitive impairment (MCI), and healthy older adults in the initial weeks following the event and again 3-4 months later. There were several notable findings. First, patients with AD showed less memory than patients with MCI and older adults. Second, patients with AD, but not patients with MCI or older adults, appeared to retain more memory for personal versus factual information. Third, patients with AD and older adults did not differ in the intensity of their reported emotional responses to the attacks, whereas patients with MCI reported relatively less intense emotional responses. Last, distortions of memory for personal information were frequent for all participants but were more common in patients with AD.

Improving the functioning of individuals with Alzheimer's disease: emergence of behavioral interventions

Alzheimer's disease (AD) is a neurodegenerative process that invariably results in diminished communicative functioning. Historically, it was thought that little could be done to improve the functioning of affected individuals. However, in recent years the value of behavioral interventions has increasingly been explored, resulting in a changing perspective. Some of the factors contributing to this changing view include: understanding that memory is not a unitary phenomenon, recognizing that certain types of memory are relatively spared in AD, a growing realization that conceptual knowledge is largely intact, and a greater understanding of how people learn and remember. Intervention techniques that capitalize on spared memory systems and take advantage of principles of learning and remembering have been successful in teaching individuals with AD new information and allowing them to maintain better functioning throughout the disease course.

LEARNING OUTCOMES

(1) The participant will be able to describe the historical perspective on behavioral interventions, and four factors that have contributed to a changing perspective. (2) The participant will be able to list behavioral strategies that clinicians can use in order to improve functioning of individuals with AD.

Impaired fear conditioning in Alzheimer's disease

Classical conditioning of the fear response is a basic form of nondeclarative (nonconscious) memory that mediates both normal and pathological responses to aversive stimuli. Because fear conditioning critically depends on the amygdala, a medial temporal lobe structure that frequently undergoes significant pathological changes early in the course of Alzheimer's disease (AD), we hypothesized that fear conditioning would be impaired in patients with mild to moderate AD. We examined simple classical fear conditioning in a group of 10 patients with probable AD and 14 demographically matched, neurologically intact elderly controls. During conditioning, one stimulus (e.g. a green rectangle, the conditioned stimulus (CS+)), was paired with an aversive stimulus (a loud noise, the unconditioned stimulus (US)) using a partial reinforcement conditioning schedule. The opponent color (e.g. red rectangle), the CS-, was never paired with the US. The elderly controls acquired robust fear responses as demonstrated by their differential skin-conductance responses to the CS+ and CS-. In contrast, the AD group showed a marked impairment in conditioning, failing to exhibit significant conditioned fear responses. This failure to acquire conditioned responses could not be attributed to diminished responding by patients, relative to controls, to the aversive US. The results indicate that fear conditioning, an amygdala-dependent form of memory, is impaired in AD. These findings complement previous reports of impairments in declarative emotional memory in AD by demonstrating that a basic form of nondeclarative emotional memory is also impaired in AD.