Negative Bias in the Perception and Memory of Emotional Information in Alzheimer Disease

Rumination in dementia and its relationship with depression, anxiety, and attentional biases

Rumination (self-referential and repetitive thinking), attentional biases (AB), and impaired cognitive control are theorized as being integral factors in depression and anxiety. Yet, research examining the relationship between rumination, mood, and AB for populations with reduced cognitive control, e.g., people living with dementia (PwD), is lacking. To explore whether literature-based relationships are demonstrated in dementia, PwD (n = 64) and healthy controls (HC) (n = 75) completed an online self-report survey measuring rumination and mood (twice), and a telephone cognitive status interview (once). Rumination was measured as an emotion-regulation style, thinking style, and response to depression. We examined the test-retest reliability of PwD's (n = 50) ruminative-scale responses, ruminative-scale internal consistency, and correlations between rumination, age, cognitive ability, and mood scores. Also, nine participants (PwD = 6, HC = 3) completed an AB measure via eye-tracking. Participants fixated on a cross, naturally viewed pairs of facial images conveying sad, angry, happy, and neutral emotions, and then fixated on a dot. Exploratory analyses of emotional-face dwell-times versus rumination and mood scores were conducted. Except for the HC group's reflective response to depression measure, rumination measures were reliable, and correlation strengths between rumination and mood scores (.29 to .79) were in line with literature for both groups. For the AB measure subgroup, ruminative thinking style scores and angry-face metrics were negatively correlated. The results of this study show that literature-based relationships between rumination, depression, and anxiety are demonstrated in dementia, but the relationship between rumination and AB requires further investigation.

Webcam-Based Eye-Tracking of Attentional Biases in Alzheimer's Disease: A Proof-Of-Concept Study

OBJECTIVES

To measure home-based older adults' attentional biases (AB) using webcam-based eye-tracking (WBET) and examine internal consistency.

METHODS

Twelve participants with and without cognitive impairment completed online self-report anxiety and depression screens, and a 96-trial dot-probe task with eye-gaze tracking. For each trial, participants fixated on a cross, free-viewed sad-neutral, sad-angry, sad-happy, angry-neutral, angry-happy, and happy-neutral facial expression pairings, and then fixated on a dot. In emotional-neutral pairings, the time spent looking (dwell-time) at neutral was averaged and subtracted from the emotional average to indicate biases "away from" (negative score) and "toward" (positive score) each emotional face. Internal consistency was estimated for dwell-times and bias scores using Cronbach's alpha and Spearman - Brown corrected split-half coefficients.

RESULTS

The full-cohort and a comorbid anxious and depressed sub-group (n = 6) displayed AB away from sad faces, and toward angry and happy faces, with happy-face AB being more pronounced. AB indices demonstrated low reliability except sub-group happy-face indices. Happy-face AB demonstrated the highest reliability.

CONCLUSIONS

AB measures were in-line with lab-based eye-tracking literature, providing some support for WBET-based measurement.

CLINICAL IMPLICATIONS

Establishing the feasibility of WBET-based measures is a step toward an objective home-based clinical tool. Literature-based suggestions are provided to improve reliability.

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.

Antidepressant medications in dementia: evidence and potential mechanisms of treatment-resistance

Depression in dementia is common, disabling and causes significant distress to patients and carers. Despite widespread use of antidepressants for depression in dementia, there is no evidence of therapeutic efficacy, and their use is potentially harmful in this patient group. Depression in dementia has poor outcomes and effective treatments are urgently needed. Understanding why antidepressants are ineffective in depression in dementia could provide insight into their mechanism of action and aid identification of new therapeutic targets. In this review we discuss why depression in dementia may be a distinct entity, current theories of how antidepressants work and how these mechanisms of action may be affected by disease processes in dementia. We also consider why clinicians continue to prescribe antidepressants in dementia, and novel approaches to understand and identify effective treatments for patients living with depression and dementia.

Emotional Valence Affects Word Retrieval During Verb Fluency Tasks in Alzheimer's Dementia

Individuals with amnestic Alzheimer's disease (AD) often demonstrate preserved emotional processing skills despite the neurodegenerative disease that affects their limbic system. Emotional valence encompasses the encoding and retrieval of memory and it also affects word retrieval in healthy populations, but it remains unclear whether these effects are preserved in individuals with amnestic AD. Previous studies used a variety of encoding procedures and different retrieval methods that resulted in mixed findings. Therefore, the purpose of the current study is to investigate whether emotional enhancement of memory effects is observed in an experimental condition where the memory encoding process is not required, namely verb (action) fluency tasks. Seventeen participants who were cognitively healthy older adults (CHOA) and 15 participants with amnestic AD were asked to complete verb fluency tasks, and the relative degree of emotional valence observed in their responses was compared between the two groups. A neuropsychological test battery was administered to determine the participants' cognitive and linguistic profiles, and correlational analyses were conducted to delineate relationships between emotional valence, verbal memory, and learning abilities. The results indicated that the participants with amnestic AD produced words with higher emotional valence (i.e., more pleasant words) compared to CHOA during action fluency testing. In addition, the degree of emotional valence in the words was negatively correlated with verbal memory and learning skills, showing that those with poorer memory skills tend to retrieve words with higher emotional valence. The findings are consistent with those previous studies that stressed that individuals with AD have preserved emotional enhancement of memory effects and may benefit from them for retrieval of information, which may offer some insight into the development of novel rehabilitative strategies for this population.

Effects of stress on emotional memory in patients with Alzheimer's disease and in healthy elderly

ABSTRACTObjective:We aimed at examining the relation between stress markers (cortisol levels and state anxiety) with memory for emotional information in AD patients and in healthy elderly.

DESIGN, SETTING, AND PARTICIPANTS

Baseline and changes in stress markers during memory testing were assessed in a sample of 98 elderly (46 mild-to-moderate Alzheimer's disease patients and 52 controls) recruited from dementia day centers and adult day centers, respectively.

MEASUREMENTS

Salivary cortisol, state anxiety, and measures of immediate recall and delayed recognition using the International Affective Pictures System.

RESULTS

Patients' performance in memory tasks was not associated with either cortisol levels or anxiety. In controls, quadratic and linear associations were found between cortisol and immediate recall scores (total and bias, respectively). Besides, quadratic and linear associations were observed between anxiety and delayed recognition scores (total and bias, respectively).

CONCLUSIONS

The emotional memory of patients with Alzheimer´s disease is not related to stress markers as healthy older adults' is. Future studies that include moderating variables are needed to explain the lack of association.