Appraisal of Memory Functioning and Memory Performance in Healthy Ageing and Early-Stage Alzheimer's Disease

Anosognosia in Alzheimer's Pathology: Validation of a New Measure

OBJECTIVE

Two studies were performed to validate a brief measure of cognitive insight and compare it to an empirical model - the Cognitive Awareness Model (CAM).

METHOD

A pilot study included 31 (52% male; Mage = 69.42) patients from an outpatient neuropsychological assessment clinic. Seven patients were diagnosed with likely Alzheimer's dementia (AD), 15 mild cognitive impairment (MCI), and 9 no diagnosis (i.e., cognitively normal; CN). The Cognitive Coding Form (CCF) and several other measures were administered. Study 2 entailed archival data extraction of 240 patients (80 CN, 80 MCI, and 80 AD; 53.3% female; Mage = 72.8) to examine whether the CCF predicts memory (Wechsler Memory Scale - IV) and executive functioning (Trail-Making Test B).

RESULTS

The pilot study found preliminary evidence of convergent and discriminant validity for the 8-item CCF. Study 2 confirmed that both patient-reported cognitive concerns (F(2,237) = 10.40, p < .001, ω2 = .07, power = .99) and, more strongly, CCF informant-patient discrepancy scores (F(2,237) = 24.52, p < .001, ω2 = .16, power = .99) can distinguish CNs from those with MCI and AD. A regression indicated that depression (5.5%; β = -.38, p < .001) and TMT-B (13%; β = -.43, p < .001), together accounted for 18.5% of the variance in insight (R2 = .19, F(2,219) = 26.10, p < .001), supporting the CAM.

CONCLUSIONS

These studies establish an efficient measure of insight with high clinical utility and inform the literature on the role of insight in predicting performance in those with Alzheimer's pathology.

Subjective memory measures: Metamemory questionnaires currently in use

Subjective memory evaluation is important for assessing memory abilities and complaints alongside objective measures. In research and clinical settings, questionnaires are used to examine perceived memory ability, memory complaints, and memory beliefs/knowledge. Although they provide a structured measure of self-reported memory, there is some debate as to whether subjective evaluation accurately reflects memory abilities. Specifically, the disconnect between subjective and objective memory measures remains a long-standing issue within the field. Thus, it is essential to evaluate the benefits and limitations of questionnaires that are currently in use. This review encompasses three categories of metamemory questionnaires: self-efficacy, complaints, and multidimensional questionnaires. Factors influencing self-evaluation of memory including knowledge and beliefs about memory, ability to evaluate memory, recent metamemory experiences, and affect are examined. The relationship between subjective and objective memory measures is explored, and considerations for future development and use of metamemory questionnaires are provided.

Associations between Time Processing Ability, Daily Time Management, and Dementia Severity

This study investigated associations between time processing ability (TPA), daily time management (DTM), and dementia severity. Persons with dementia (PwDs) (n = 53) and their significant others (n = 49) participated in this cross-sectional study. Bivariate analyses were used to investigate associations between TPA and DTM and the dementia severity. Linear regression models were used to further predict the contribution of the subtests in the Mini Mental State Examination (MMSE) for TPA results. The results showed significant correlations between TPA and dementia severity, where visuospatial functions were the most highly correlated. TPA also showed a significant correlation to proxy-rated DTM. In addition, proxy-rated DTM was significantly correlated with dementia severity and PwDs' own self-ratings of their DTM. Knowledge of the association between TPA, dementia severity, and visuospatial functions can enable early detection of TPA impairments. For a comprehensive assessment of TPA and DTM, objective measures should be used in combination with self-ratings and proxy-ratings. The findings can be used in clinical research and healthcare settings to develop methods to compensate for impaired TPA and support DTM in PwDs.

"Do I Have a Memory Problem? I Can't Recall": An Evaluation of Measurement Invariance in Subjective Reporting of Memory Symptoms among Persons with and without Objective HIV-Associated Memory Impairment

OBJECTIVE

Memory symptoms and objective impairment are common in HIV disease and are associated with disability. A paradoxical issue is that objective episodic memory failures can interfere with accurate recall of memory symptoms. The present study assessed whether responses on a self-report scale of memory symptoms demonstrate measurement invariance in persons with and without objective HIV-associated memory impairment.

METHOD

In total, 505 persons with HIV completed the Prospective and Retrospective Memory Questionnaire (PRMQ). Objective memory impairment (n = 141) was determined using a 1-SD cutoff on clinical tests of episodic memory. PRMQ measurement invariance was assessed by confirmatory factor analyses examining a one-factor model with increasing cross-group equality constraints imposed on factor loadings and item thresholds (i.e., configural, weak, and strong invariance).

RESULTS

Configural model fit indicated that identical items measured a one-factor model for both groups. Comparison to the weak model indicated that factor loadings were equivalent across groups. However, there was evidence of partial strong invariance, with two PRMQ item thresholds differing across memory impairment groups. Post hoc analyses using a 1.5-SD memory impairment cutoff (n = 77) revealed both partial weak and partial strong invariance, such that PRMQ item loadings differed across memory groups for three items.

CONCLUSIONS

The PRMQ demonstrated a robust factor structure among persons with and without objective HIV-associated memory impairment. However, on select PRMQ items, individuals with memory impairment reported observed scores that were relatively higher than their latent score, while items were more strongly associated with the memory factor in a group with greater memory impairment.

Neuroanatomical correlates of self-awareness of highly practiced visuomotor skills

Metacognition is the ability to introspect and control ongoing cognitive processes. Despite the extensive investigation of the brain architectures supporting metacognition for perception and memory, little is known about the neural basis of metacognitive capacity for motor function, a vital aspect of human behavior. Here, using functional and structural magnetic resonance imaging (MRI), we examined the brain substrates underlying self-awareness of handwriting, a highly practiced visuomotor skill. Results showed that experienced adult writers generally overestimated their handwriting quality, and such overestimation was more pronounced in men relative to women. Individual variations in self-awareness of handwriting quality were positively correlated with gray matter volume in the left fusiform gyrus, right middle frontal gyrus and right precuneus. The left fusiform gyrus and right middle frontal gyrus are thought to represent domain-specific brain mechanisms for handwriting self-awareness, while the right precuneus that has been reported in other domains likely represents a domain-general brain mechanism for metacognition. Furthermore, the activity of these structurally related regions in a handwriting task was not correlated with self-awareness of handwriting, suggesting the correlation with metacognition was independent of task performance. Together, this study reveals that metacognition for practiced motor skills relies on both domain-general and domain-specific brain systems, extending our understanding about the neural basis of human metacognition.

Cross-sectional association between objective cognitive performance and perceived age-related gains and losses in cognition

OBJECTIVES

Evidence linking subjective concerns about cognition with poorer objective cognitive performance is limited by reliance on unidimensional measures of self-perceptions of aging (SPA). We used the awareness of age-related change (AARC) construct to assess self-perception of both positive and negative age-related changes (AARC gains and losses). We tested whether AARC has greater utility in linking self-perceptions to objective cognition compared to well-established measures of self-perceptions of cognition and aging. We examined the associations of AARC with objective cognition, several psychological variables, and engagement in cognitive training.

DESIGN

Cross-sectional observational study.

PARTICIPANTS

The sample comprised 6056 cognitively healthy participants (mean [SD] age = 66.0 [7.0] years); divided into subgroups representing middle, early old, and advanced old age.

MEASUREMENTS

We used an online cognitive battery and measures of global AARC, AARC specific to the cognitive domain, subjective cognitive change, attitudes toward own aging (ATOA), subjective age (SA), depression, anxiety, self-rated health (SRH).

RESULTS

Scores on the AARC measures showed stronger associations with objective cognition compared to other measures of self-perceptions of cognition and aging. Higher AARC gains were associated with poorer cognition in middle and early old age. Higher AARC losses and poorer cognition were associated across all subgroups. Higher AARC losses were associated with greater depression and anxiety, more negative SPA, poorer SRH, but not with engagement in cognitive training.

CONCLUSIONS

Assessing both positive and negative self-perceptions of cognition and aging is important when linking self-perceptions to cognitive functioning. Objective cognition is one of the many variables - alongside psychological variables - related to perceived cognitive losses.

Associations of subjective cognitive and memory decline with depression, anxiety, and two-year change in objectively-assessed global cognition and memory

Research studies exploring the association of cognitive complaints with objectively assessed cognitive decline report inconsistent results. However, many of these have methodological limitations. We investigated whether 1) more severe subjective cognitive decline (SCD) and subjective memory decline (SMD) predict change in objectively assessed global cognition, remote memory, recent memory, learning; 2) the predictive value of more severe SMD over change in objectively assessed remote memory, recent memory, and learning is stronger for individuals that report an SMD that started within the past five years than for those that report an SMD that started five or more years previously and/or stronger for those that experienced SMD within the past two years than for those who had not; and 3) greater depression and anxiety are associated with more severe SCD and SMD. We used two-year longitudinal data from the CFAS-Wales study (N = 1,531; mean (SD) age = 73.0 (6.0) years). We fitted linear regression models. More severe SCD and SMD did not predict change in objectively assessed global cognition, remote memory, and recent memory but predicted lower scores in learning. The prediction of SMD over change in learning was not stronger when individuals reported an SMD that started within the past five years compared to when they reported an SMD that started five or more years previously nor when individuals reported an SMD that started within the past two years than those who did not. Greater depression and anxiety were associated with more severe SCD and SMD. More severe SMD may be useful for predicting lower learning ability and for identifying individuals experiencing depression and anxiety.

Anosognosia in Mild Cognitive Impairment: Lack of Awareness of Memory Difficulties Characterizes Prodromal Alzheimer's Disease

While anosognosia is often present in Alzheimer's disease, the degree of awareness of cognitive difficulties in the earlier stages, such as Mild Cognitive Impairment (MCI), is less clear. Using a questionnaire and Feeling-of-Knowing tasks, the aims of this study were (1) to test the hypothesis that anosognosia is present specifically in prodromal AD stage in patients that, owing to a more severe AD neuropathology, will rapidly progress to overt dementia and (2) to assess the neural bases of self-awareness for memory functioning. A group of 44 patients with amnestic MCI and a group of 29 healthy older participants (CTRL) performed two Feeling-of-Knowing tasks (episodic and semantic FOK) and responded to the Functional Memory Scale (MARS), also completed by one of their relatives. They underwent FDG-PET and structural MRI. The participants were followed clinically for 4 years. At the end of follow-up, 23 patients with MCI developed Alzheimer's disease (converters) and 21 patients still presented symptoms of MCI without progression (non-converters). The analyses focused on the data from inclusion stratified according to clinical status 4 years later (converters, non-converters, CTRL). On the episodic FOK task, converters patients overestimated their ability to later recognize unrecalled words and they showed prediction accuracy (Hamann coefficient) at the level of chance. No difficulty was observed in any group with the semantic FOK task. On the MARS, converters patients had a higher anosognosia score than non-converters patients and CTRL, which did not differ from each other. Correlations between self-awareness scores and neuroimaging data using small volume correction analyses in a priori regions of interest in converters indicated that inaccurate episodic FOK judgments was related to changes in brain areas that might support interpretation of retrieved content for judging the likelihood of recognition. For the MARS, the association between anosognosia and decreased gray matter density of the left inferior prefrontal cortex in converters might indicate poor inhibition over outdated personal knowledge. In amnestic MCI, anosognosia could be an early sign of neurodegeneration in brain areas that would support control mechanisms over memory representations.

International relevance of two measures of awareness of age-related change (AARC)

BACKGROUND

A questionnaire assessing awareness of positive and negative age-related changes (AARC gains and losses) was developed in the US and Germany. We validated the short form of the measure (AARC-10 SF) and the cognitive functioning subscale from the 50-item version of the AARC (AARC-50) questionnaire in the UK population aged 50 and over.

METHODS

Data from 9410 participants (Mean (SD) age = 65.9 (7.1)) in the PROTECT cohort were used to explore and confirm the psychometric properties of the AARC measures including: validity of the factor structure; reliability; measurement invariance across men and women, individuals with and without a university degree, and in middle age, early old age, and advanced old age; and convergent validity with measures of self-perception of aging and mental, physical, and cognitive health. We explored the relationship between demographic variables (age, sex, marital status, employment, and university education) and AARC.

RESULTS

We confirmed the two-factor structure (gains and losses) of the AARC-10 SF and the AARC-50 cognitive functioning subscale. Both scales showed good reliability and good convergent validity for AARC losses, but weak convergent validity for AARC gains. For both scales metric invariance was held for the two subgroups defined by education level and age. For the AARC-50 subscale, but not for the AARC-10 SF, strong invariance was also held for the two subgroups defined by sex. Age, sex, marital status, employment, and university education predicted AARC gains and losses.

CONCLUSIONS

The AARC-10 SF and AARC-50 cognitive functioning subscale identify UK individuals who perceive age-related changes in their mental, physical, and cognitive health.

Anosognosia and default mode subnetwork dysfunction in Alzheimer's disease

Research on the neural correlates of anosognosia in Alzheimer's disease varied according to methods and objectives: they compared different measures, used diverse neuroimaging modalities, explored connectivity between brain networks, addressed the role of specific brain regions or tried to give support to theoretical models of unawareness. We used resting‐state fMRI connectivity with two different seed regions and two measures of anosognosia in different patient samples to investigate consistent modifications of default mode subnetworks and we aligned the results with the Cognitive Awareness Model. In a first study, patients and their relatives were presented with the Memory Awareness Rating Scale. Anosognosia was measured as a patient‐relative discrepancy score and connectivity was investigated with a parahippocampal seed. In a second study, anosognosia was measured in patients with brain amyloid (taken as a disease biomarker) by comparing self‐reported rating with memory performance, and connectivity was examined with a hippocampal seed. In both studies, anosognosia was consistently related to disconnection within the medial temporal subsystem of the default mode network, subserving episodic memory processes. Importantly, scores were also related to disconnection between the medial temporal and both the core subsystem (participating to self‐reflection) and the dorsomedial subsystem of the default mode network (the middle temporal gyrus that might subserve a personal database in the second study). We suggest that disparity in connectivity within and between subsystems of the default mode network may reflect impaired functioning of pathways in cognitive models of awareness.

Subjective working and declarative memory in dementia and normal aging

OBJECTIVE

Subjective memory complaints are common in both elderly individuals and patients with dementia. This study investigated the power of subjective memory, divided into declarative and working memory, to differentiate between patients with dementia and normal elderly individuals.

METHOD

Two groups of participants, patients with dementia (n = 117) and normal elderly individuals (n = 117), individually matched with regard to age, gender, and education. All subjects had participated in the third wave of the HUNT population health survey in Nord-Trøndelag County in Norway and completed the Meta-Memory Questionnaire (MMQ) in the HUNT study. The MMQ was subdivided into two components, one associated with declarative memory (episodic and semantic) and the other with working memory.

RESULTS

Patients with dementia reported significantly more subjective memory concerns than normal elderly individuals. The difference between working and declarative memory components was significantly greater in patients with dementia than in normal elderly individuals. This finding made it possible to differentiate patients with dementia from the normal elderly individuals. Mental and somatic health conditions did not significantly add power to differentiating the two groups.

CONCLUSION

In clinical and research applications, subjective memory components could contribute to differentiation of patients with dementia and normal elderly individuals by using self-reported impairment in working memory, rather than declarative memory.

Metacognitive functioning in bipolar disorder versus controls and its correlations with neurocognitive functioning in a cross-sectional design

INTRODUCTION

Metacognition is an important factor in the development and persistence of bipolar disorder. One of the most striking examples of impairment in metacognitive functioning in bipolar disorder is the lack of insight these patients have in their disorder. Despite its importance, research regarding metacognition in bipolar disorder is scarce. Furthermore, the neurocognitive basis of metacognitive functioning is unknown.

METHODS

The current study included 29 patients with bipolar disorder and 29 age, educational level and gender matched healthy controls. All the participants filled in a metacognition questionnaire that examined their metacognitive beliefs. In addition, it was tested how well they estimated their performance on a neurocognitive test-battery beforehand (metacognitive knowledge) and afterwards (metacognitive experience).

RESULTS

Bipolar disorder patients showed maladaptive metacognitive beliefs in comparison with the healthy controls. They also showed impaired metacognitive knowledge and experience. That is, they overestimated their own cognitive performance. However, the latter result was also true for the healthy controls. In addition, metacognition had neurocognitive correlates. However, for the bipolar patients, depressive symptomatology had an important effect on this relationship and on metacognition in general.

CONCLUSION

Maladaptive metacognitive skills are related to depression in bipolar disorder. A more healthy metacognitive thinking should be promoted. An effective training for this could be a therapy that includes various elements, from basic cognitive- to higher order metacognitive training.

Depressed mood and cognitive deficits as distinct mechanisms of subjective memory and executive complaints

Background

Subjective cognitive decline (SCD) is the sense of deterioration in cognitive functioning in terms of memory, executive function, attention, etc. SCD is reported by nearly 70% of the population. Very intensive research on the predictive role of SCD in the development of dementia and determinants SCD did not bring common solutions. For exploration of the phenomenon, studies were undertaken in order to identify: a) on the basis of which factors a high level of SCD can be predicted, and b) whether these factors have similar prognostic value for two types of SCD, i.e. concerning executive function (SED) and memory (SMD).

Participants and procedure

The study involved 274 Polish people aged 18 to 84 years (M = 53.23, SD = 16.8). For the evaluation of SCD three methods were used: memory self-assessment scales (ProCog and MARS), and an executive functions self-assessment scale (DEX-S). Subtests of the WAIS-PL to assess cognitive function were used, and GDS-15 or BECK II to assess the severity of depressive mood. In the first stage, two separate cluster analyses (k-means method) were performed: the first related to the results of the memory self-assessment scale (ProCog and MARS), the second to the subjective difficulty of executive functions (DEX-S). In step II a logistic regression analysis of the forward selection with the likelihood ratio and interaction effects was performed – separately for the two types of self-reports.

Results

The results indicate that higher depressed mood increases the likelihood of both the SMD and SED. Higher efficiency attention-al processes reduce the possibility of formulating the SED, and higher efficiency of the delayed memory, abstract thinking, or certain aspects of language functions reduces the possibility of SMD.

Conclusions

There are two independent mechanisms of SCD – emotional and cognitive.

Metamemory monitoring in Alzheimer's disease A systematic review

Metamemory is the awareness of one’s own knowledge and control of memory, and refers to the online ability to gather information about the current state of the memory system.

An evaluation of community-based cognitive stimulation therapy: a pilot study with an Irish population of people with dementia

OBJECTIVES

Research shows that cognitive stimulation therapy (CST) improves cognitive function, quality of life, and well-being of people with mild-moderate dementia. Despite consistent evidence and recommendations, CST is not routinely available in Ireland post-diagnosis. The aim of the current research was to develop and evaluate community-based CST for people with mild-moderate dementia, run by the Alzheimer Society of Ireland across four pilot sites in Ireland.

METHODS

Participants with mild-moderate dementia attended once weekly CST sessions for 14 weeks. Baseline and post-intervention assessments were completed by CST participants, carers, and CST facilitators. Primary outcomes of interest for CST participants included quality of life (Quality of Life in Alzheimer Disease Scale), cognitive function (Montreal Cognitive Assessment), and subjective cognitive function (Memory Awareness Rating Scale-Functioning Subscale). Secondary outcomes included well-being, cognitive ability, satisfaction with cognitive performance, and engagement and confidence of CST participants; well-being of carers; and job satisfaction of facilitators. Post-intervention interviews supplemented quantitative analyses.

RESULTS

In total, 20 CST participants, 17 carers, and six CST facilitators completed evaluation assessments. Results showed that CST improved participants' satisfaction with cognitive performance (p=0.002), level of engagement (p=0.046), level of confidence (p=0.026). Improvements on subjective cognitive function just fell short of significance (p=0.055). Qualitative analysis of interview data identified consistent themes of cognitive and overall benefits of CST; and provided support for quantitative data.

CONCLUSIONS

Community-based CST positively impacted the lives of people with dementia and their families. This study supports prior recommendations that CST should be made routinely available to people with mild-moderate dementia, particularly in light of the lack of post-diagnostic interventions currently offered in Ireland.

The Impact of Awareness of and Concern About Memory Performance on the Prediction of Progression From Mild Cognitive Impairment to Alzheimer Disease Dementia

OBJECTIVE

To investigate the relationship of awareness of and concern about memory performance to progression from mild cognitive impairment (MCI) to Alzheimer disease (AD) dementia.

METHODS

Participants (n = 33) had a diagnosis of MCI at baseline and a diagnosis of MCI or AD dementia at follow-up. Participants were categorized as "Stable-MCI" if they retained an MCI diagnosis at follow-up (mean follow-up = 18.0 months) or "Progressor-MCI" if they were diagnosed with AD dementia at follow-up (mean follow-up = 21.6 months). Awareness was measured using the residual from regressing a participant's objective memory score onto their subjective complaint score (i.e., residual<0 indicates overestimation of performance). Concern was assessed using a questionnaire examining the degree of concern when forgetting. Logistic regression was used to determine whether the presence of these syndromes could predict future diagnosis of AD dementia, and repeated measures analysis of covariance tests were used to examine longitudinal patterns of these syndromes.

RESULTS

Baseline anosognosia was apparent in the Progressor-MCI group, whereas participants in the Stable-MCI group demonstrated relative awareness of their memory performance. Baseline awareness scores successfully predicted whether an individual would progress to AD-dementia. Neither group showed change in awareness of performance over time. Neither group showed differences in concern about memory performance at baseline or change in concern about performance over time.

CONCLUSION

These data suggest that anosognosia may appear prior to the onset of AD dementia, while anosodiaphoria likely does not appear until later in the AD continuum. Additionally, neither group showed significant changes in awareness or concern over time, suggesting that change in these variables may happen over longer periods.

Multiple Types of Memory and Everyday Functional Assessment in Older Adults

Objective

Current proxy measures for assessing everyday functioning (e.g., questionnaires, performance-based measures, and direct observation) show discrepancies in their rating of functional status. The present study investigated the relationship between multiple proxy measures of functional status and content memory (i.e., memory for information), temporal order memory, and prospective memory in an older adult sample.

Method

A total of 197 community-dwelling older adults who did (n = 45) or did not meet (n = 152) criteria for mild cognitive impairment (MCI), completed six different assessments of functional status (two questionnaires, two performance-based tasks, and two direct observation tasks) as well as experimental measures of content memory, prospective memory, and temporal order memory.

Results

After controlling for demographics and content memory, the temporal order and prospective memory measures explained a significant amount of variance in all proxy functional status measures. When all variables were entered into the regression analyses, content memory and prospective memory were found to be significant predictors of all measures of functional status, whereas temporal order memory was a significant predictor for the questionnaire and direct observation measures, but not performance-based measures.

Conclusion

The results suggest that direct observation and questionnaire measures may be able to capture components of everyday functioning that require context and temporal sequencing abilities, such as multi-tasking, that are not as well captured in many current laboratory performance-based measures of functional status. Future research should aim to inform the development and use of maximally effective and valid proxy measures of functional ability.

Awareness of functional ability in people with early-stage dementia

OBJECTIVES

Assessment of functional ability in people with early-stage dementia (PwD) is an important area of study because it forms part of the diagnostic process and may help in monitoring disease progression. Most researchers and clinicians rely on informant ratings rather than observing actual functional performance or employing self-ratings. There has however been little research to verify whether informant ratings of functioning are accurate, and there has been even less research investigating the accuracy of self-ratings of functional ability in PwD. No study has used the performance-monitoring metacognitive approach to investigate awareness of functional ability.

METHODS

Thirty-seven people with early-stage dementia completed an objective functional assessment and provided self-ratings before and after completing each section of the objective test. Informants provided ratings of functioning and burden. Scores were converted to percentages to allow for direct comparison.

RESULTS

Objectively assessed functional ability significantly correlated with self-ratings and informant ratings. Self-ratings did not correlate with informant ratings. For converted scores, self-ratings were more similar than informant ratings to the objectively assessed mean scores. Burden was unrelated to functional assessments after correcting for multiple comparisons.

CONCLUSIONS

Self-rated functional ability was more accurate than informant ratings when compared with objectively assessed ability, with informants tending to significantly underestimate the functional ability of PwD. The findings call into question the likelihood that informants will provide accurate ratings of functional ability and suggests that self-ratings may offer a more accurate estimate of functional ability. Self-ratings made by PwD should be more widely employed in clinical and research settings. Copyright © 2017 John Wiley & Sons, Ltd.

Integrating the Constructs of Anosognosia and Metacognition: a Review of Recent Findings in Dementia

The current review integrates recent findings regarding the construct of self-awareness in dementia from both clinical and cognitive perspectives. We present the predominant theoretical models of awareness and summarize both traditional and emerging approaches to assessing awareness from clinical and meta-cognitive perspectives. In this review, we focus primarily on findings from recent studies in anosognosia and meta-cognition in the context of neurodegenerative disease with special emphasis on Alzheimer's disease and frontotemporal dementia. Emerging trends in the study of awareness, including examination of the longitudinal course of anosognosia, and investigation of the neural substrates underlying meta-cognitive abilities are addressed. Finally, the practical importance of studying and assessing awareness from both theoretical and clinical angles is emphasized.

Memory self-awareness in the preclinical and prodromal stages of Alzheimer's disease

While loss of insight of cognitive deficits, anosognosia, is a common symptom in Alzheimer's disease dementia, there is a lack of consensus regarding the presence of altered awareness of memory function in the preclinical and prodromal stages of the disease. Paradoxically, very early in the Alzheimer's disease process, individuals may experience heightened awareness of memory changes before any objective cognitive deficits can be detected, here referred to as hypernosognosia. In contrast, awareness of memory dysfunction shown by individuals with mild cognitive impairment (MCI) is very variable, ranging from marked concern to severe lack of insight. This study aims at improving our mechanistic understanding of how alterations in memory self-awareness are related to pathological changes in clinically normal (CN) adults and MCI patients. 297 CN and MCI patients underwent PiB-PET (Positron Emission Tomography using Pittsburgh Compound B) in vivo amyloid imaging. Amyloid burden was estimated from Alzheimer's disease vulnerable regions, including the frontal, lateral parietal and lateral temporal, and retrosplenial cortex. Memory self-awareness was assessed using discrepancy scores between subjective and objective measures of memory function. A set of univariate analysis of variance were performed to assess the relationship between self-awareness of memory and amyloid pathology. Whereas CN individuals harboring amyloid pathology demonstrated hypernosognosia, MCI patients with increased amyloid pathology demonstrated anosognosia. In contrast, MCI patients with low amounts of amyloid were observed to have normal insight into their memory functions. Altered self-awareness of memory tracks with amyloid pathology. The findings of variability of awareness may have important implications for the reliability of self-report of dysfunction across the spectrum of preclinical and prodromal Alzheimer's disease.

Therapeutically relevant structural and functional mechanisms triggered by physical and cognitive exercise

Physical and cognitive exercise may prevent or delay dementia in later life but the neural mechanisms underlying these therapeutic benefits are largely unknown. We examined structural and functional magnetic resonance imaging (MRI) brain changes after 6 months of progressive resistance training (PRT), computerized cognitive training (CCT) or combined intervention. A total of 100 older individuals (68 females, average age=70.1, s.d.±6.7, 55-87 years) with dementia prodrome mild cognitive impairment were recruited in the SMART (Study of Mental Activity and Resistance Training) Trial. Participants were randomly assigned into four intervention groups: PRT+CCT, PRT+SHAM CCT, CCT+SHAM PRT and double SHAM. Multimodal MRI was conducted at baseline and at 6 months of follow-up (immediately after training) to measure structural and spontaneous functional changes in the brain, with a focus on the hippocampus and posterior cingulate regions. Participants' cognitive changes were also assessed before and after training. We found that PRT but not CCT significantly improved global cognition (F(90)=4.1, P<0.05) as well as expanded gray matter in the posterior cingulate (P_corrected <0.05), and these changes were related to each other (r=0.25, P=0.03). PRT also reversed progression of white matter hyperintensities, a biomarker of cerebrovascular disease, in several brain areas. In contrast, CCT but not PRT attenuated decline in overall memory performance (F(90)=5.7, P<0.02), mediated by enhanced functional connectivity between the hippocampus and superior frontal cortex. Our findings indicate that physical and cognitive training depend on discrete neuronal mechanisms for their therapeutic efficacy, information that may help develop targeted lifestyle-based preventative strategies.

Relating pessimistic memory predictions to Alzheimer's disease brain structure

Patients with Alzheimer's disease (AD) show impairment of episodic memory and related metacognitive processes. The present study examined subjective metacognitive judgments preceding objective memory retrieval and investigated the neural correlates of pessimistic predictions for successfully retrieved memories in AD patients. AD patients and healthy older (HO) participants provided predictive judgments on their recognition performance before retrieval of famous (semantic) and recently learned (episodic) names. Correlations between gray matter volume (GMV) in T1 images and behavioral scores were examined with multivariate (partial least square - PLS) and univariate (general linear model - GLM) analyses in AD patients. AD patients showed a significant proportion of successful name recognition preceded by pessimistic prediction in episodic memory. PLS revealed that the behavioral pattern in AD patients was related with a mainly right lateralized pattern of GMV decrease including medial temporal lobe and posterior cingulate cortex (PCC), but also right ventrolateral prefrontal cortex (VLPFC). GLM further confirmed that pessimistic prediction negatively correlated with GMV in VLPFC. Thus, impaired monitoring processes (possibly influenced by inaccurate beliefs) allowing inferences about one's own memory performance are primarily related to decrease GMV in VLPFC in AD patients.

A Conceptualization of the Utility of Subjective Cognitive Decline in Clinical Trials of Preclinical Alzheimer's Disease

This commentary outlines a conceptual model for subjective cognitive decline (SCD) in relation to Alzheimer's disease (AD) biomarkers in the preclinical stages of disease and a framework for effectively utilizing SCD in secondary prevention clinical trials. Mounting evidence supports the notion that SCD is sensitive to encroaching Aβ-amyloid and neurodegeneration. SCD has also been shown to provide additive information of AD-dementia risk beyond what is known about the biomarker status of the individual. Thus, we provide recommendations for the implementing SCD measurement in clinical trials. We argue that SCD can be measured at three catch points within the course of the clinical trial: firstly, at the initial recruitment and screening phase; secondly, to create more robust estimates of rates of AD-dementia progression; and finally, to measure subjective experiences of cognitive change and quality of life over the course of the trial as a proxy of clinically meaningful functional improvement. We provide recommendations of how SCD can be approached at each of these points. SCD is an important component of the preclinical AD-dementia trajectory. Future studies need to elucidate the interactive influence of Aβ-amyloid and tau on SCD from a spatiotemporal perspective. Even as this evidence accrues, it is clear that SCD can provide unique and additive information about rates of progression and subjectively experienced cognitive change within clinical trials.

Metacognitive knowledge and experience in recently diagnosed patients with bipolar disorder

INTRODUCTION

Metacognition, which refers to an individual's ability to assess their own cognitive ability or performance, is poorly understood in bipolar disorder. This study was conducted to evaluate two aspects of metacognitive ability in recently diagnosed patients with bipolar disorder: (a) metacognitive knowledge, pertaining to awareness of one's own general cognitive functioning; and (b) metacognitive experience, referring to awareness of one's cognitive performance on a specific, online cognitive task.

METHOD

Participants consisted of 50 clinically euthymic patients recently diagnosed with Diagnostic and Statistical Manual of Mental Disorders-Fourth Edition (DSM-IV) bipolar I disorder who were within three months of resolution of their first manic episode, and a comparison group of 38 demographically similar healthy volunteers. To assess metacognitive knowledge, participants provided a general rating of their estimated cognitive ability prior to completing a neuropsychological battery, and self-ratings were compared to actual ability based on a composite score of overall cognitive functioning. To assess metacognitive experience, subjects provided a postdiction rating of their perceived memory performance after completing a list learning verbal memory test, and self-ratings were compared to actual memory performance. Measures of both relative and absolute accuracy of ratings were obtained.

RESULTS

Results indicated that patients showed diminished accuracy in rating their general cognitive ability, implying deficits in metacognitive knowledge. In contrast, patients were accurate in rating their online memory performance, suggesting intact metacognitive experience.

CONCLUSIONS

Findings suggest that in patients with bipolar disorder, intact task-specific cognitive self-appraisals may fail to generalize to or to modify inaccurate global cognitive self-appraisals. Further research using more comprehensive metacognitive tasks is warranted in bipolar disorder.

Connecting Self-Awareness and Error-Awareness in Patients with Traumatic Brain Injury

Impaired self-awareness after traumatic brain injury (TBI) is often seen in stark contrast to the observations of significant-others, who are acutely aware of the difficulties experienced by patients. Our objective was to investigate the relationship between metacognitive knowledge in daily life and emergent awareness of errors during laboratory tasks, since the breakdown of error detection mechanisms may impose limitations on the recovery of metacognitive knowledge after TBI. We also examined the extent to which these measures of awareness can predict dysexecutive behaviors. A sample of TBI patients (n=62) and their significant-others, provided reports of daily functioning post injury. In addition, patients underwent a neuropsychological assessment and were instructed to signal their errors during go/no-go tests. Interrelationships between metacognitive and emergent levels of awareness were examined, after controlling for the influence of secondary cognitive variables. Significant-other ratings correlated with errors made by the patients on neuropsychological tests but not with their premorbid function. Patients who under-reported daily life difficulties or over-reported their competency, compared to significant-other reports, were less likely to show awareness of laboratory errors. Emergent awareness was also identified as the sole predictor of performance on the modified six-element test, an ecologically valid test of multitasking. The online breakdown of error awareness after brain injury is related to difficulties with metacognitive awareness as reported in daily life, and is also predictive of dysexecutive behaviors. These findings are discussed in the context of multidimensional and neural models of awareness and error monitoring.

Awareness of memory deficits in subjective cognitive decline, mild cognitive impairment, Alzheimer's disease and Parkinson's disease

BACKGROUND

Impaired awareness of memory deficits has been recognized as a common phenomenon in Alzheimer's disease (AD) and research is now increasingly focusing on awareness in groups at risk for future dementia. This study aimed to determine whether levels of awareness differ among healthy elderly people and patients with subjective cognitive decline (SCD), amnestic and non-amnestic subtypes of mild cognitive impairment (aMCI, naMCI), Alzheimer's disease (AD) and Parkinson's disease (PD), to explore correlates of awareness and to establish frequencies of memory over- and underestimation within each diagnostic group.

METHODS

756 consecutive outpatients of a memory clinic and 211 healthy controls underwent thorough neuropsychological testing. Impairment of awareness was measured as the difference between subjective memory appraisals (16-item questionnaire on current memory-related problems in everyday life) and objective memory performance (15-item delayed recall task). Subgroups of over- and underestimators were classified using percentile ranks of controls.

RESULTS

At group level, awareness significantly decreased along the naMCI→aMCI→AD continuum, with naMCI patients showing a tendency towards overestimation of memory dysfunction. PD patients showed accurate self-appraisals as long as memory function was largely unaffected. However, there was a considerable between-group overlap in awareness scores. Furthermore, different correlates of awareness were observed depending on the diagnostic group. In general, unawareness seems to be associated with decreased cognitive performance in various domains (especially memory), higher age and lower levels of depression and self-reported functional impairment.

CONCLUSION

Impaired awareness is an important symptom in aMCI. Yet, given the considerable variability in awareness scores, longitudinal studies are required to evaluate their predictive power.

Predictors of perceived functional ability in early-stage dementia: self-ratings, informant ratings and discrepancy scores

OBJECTIVE

Assessing functional ability is an important element in diagnosing and monitoring the progression of dementia, with research suggesting a link between functional ability and cognition. We investigated the predictors of total score and individual item functional ratings made by people with dementia (PwD), carers of PwD and the resulting discrepancy score.

METHODS

People with early-stage Alzheimer's disease, vascular or mixed dementia (n = 100) and their carers completed the Functional Activities Questionnaire. PwD also completed tests of memory, verbal executive function, language and cognitive screening, and provided ratings of mood. Carers provided a rating of stress.

RESULTS

Immediate memory predicted self-rated functioning, whereas carer stress predicted informant-rated functioning. Letter fluency predicted the discrepancy between self-rated and informant-rated functioning. For self-rated functioning, the direction and pattern of the individual item predictors suggested a degree of functional awareness. Informant ratings were dominated by carer stress and, to a lesser extent, everyday memory. The discrepancy scores were also predicted by carer stress and everyday memory, but also letter fluency.

CONCLUSIONS

Self-rated functioning showed evidence of awareness based on the direction and pattern of significant individual item predictors. Informant ratings, however, were found to be significantly influenced by carer stress. The findings have implications for the use of perceived functional ratings in clinical and research settings.

What contributes to a good quality of life in early dementia? Awareness and the QoL-AD: a cross-sectional study

Background

Self-report quality of life (QoL) measures for people with dementia are widely used as outcome measures in trials of dementia care interventions. Depressed mood, relationship quality and neuropsychiatric symptoms predict scores on these measures, whereas cognitive impairment and functional abilities typically do not. This study examines whether these self-reports are influenced by personality and by the person’s awareness of his/her impairments. A strong negative association between QoL and awareness of deficits would have implications for the validity of self-report in this context and for therapeutic interventions aiming to increase adjustment and coping.

Methods

Participants were 101 individuals with early‒stage dementia and their family carers participating in the Memory Impairment and Dementia Awareness (MIDAS) Study. QoL was assessed using the QoL-AD scale, and awareness was assessed in relation to memory, activities of daily living and social functioning. Self-concept, conscientiousness, quality of relationship and mood were assessed and a brief neuropsychological battery administered. Carers rated their own stress and well-being and reported on neuropsychiatric symptoms. A series of regression analyses predicting QoL-AD were carried out, identifying key variables in each domain of assessment to take forward to an overall model.

Results

Cognitive impairment was not related to QoL. The final model accounted for 57% of the variance in QoL-AD scores, with significant contributions from depressed mood, severity of irritability shown by the person with dementia, self-concept, quality of relationship (rated by the person with dementia) and male gender. The bivariate relationships of QoL-AD with awareness of memory function, awareness of functional abilities and conscientiousness were mediated by both depressed mood and self-concept.

Conclusions

This study reports the most comprehensive approach to evaluation of awareness to date. Most of the indices of awareness used are not related to self-reported QoL. Discrepancies in evaluative judgements of memory function and functional abilities between people with dementia and carers are related to QoL, but this relationship is mediated by both depressed mood and self-concept, which have a much stronger relationship with QoL. The validity of self-report measures of QoL in people with early stage dementia is supported by these results.

Memory awareness profiles differentiate mild cognitive impairment from early-stage dementia: evidence from assessments of performance monitoring and evaluative judgement

BACKGROUND

Measures of memory awareness based on evaluative judgement and performance monitoring are often regarded as equivalent, but the Levels of Awareness Framework suggests they reflect different awareness phenomena. Examination of memory awareness among groups with differing degrees of impairment provides a test of this proposition.

METHOD

Ninety-nine people with dementia (PwD), 30 people with mild cognitive impairment (PwMCI), and their relatives completed isomorphic performance monitoring and evaluative judgement measures of memory awareness and were followed up at 12 and (PwD only) 20 months. In addition to the resulting awareness indices, comparative accuracy scores were calculated using the relatives' data to establish whether any inaccuracy was specific to self-ratings.

RESULTS

When making evaluative judgements about their memory in general, both PwD and PwMCI tended to overestimate their own functioning relative to informant ratings made by relatives. When monitoring performance on memory tests, PwD again overestimated performance relative to test scores, but PwMCI were much more accurate. Comparative accuracy scores indicated that, unlike PwD, PwMCI do not show a specific inaccuracy in self-related appraisals.

CONCLUSIONS

The results support the proposition that awareness indices at the levels of evaluative judgement and performance monitoring should be regarded as reflecting distinct awareness phenomena.

Is expressed emotion related to estimates of ability made by older people with cognitive impairments and their partners?

OBJECTIVES

Discrepancies in ratings of ability are used to assess awareness in people with cognitive impairments, and previously have been found to be associated with comorbid depression and carer distress. This study explored how the degree of discrepancy between self-ratings of ability made by older people with a cognitive impairment and informant ratings made by their partners relates to aspects of their relationship quality. It was hypothesised that discrepancies between self- and partner ratings would be associated with partner's expressed emotion (EE), and replicate previous findings for associations with depression and carer distress.

METHOD

Forty-six people aged over 65 with mild cognitive impairment or early-stage dementia were recruited through NHS mental health services for older people. In a semi-structured interview, they and their partners gave separate ratings of cognitive abilities and instrumental activities of daily living (IADL). Partners also completed a 5-minute speech sample task to assess the type of EE. Depression in cognitively impaired participants and partner distress were also measured.

RESULTS

High EE, depression and carer distress were associated with larger discrepancies in ratings of ability on the cognitive measure. EE was not associated with self-ratings or partner ratings of cognitive or IADL ability.

CONCLUSION

The findings suggest that where disagreement about the abilities of an older person with cognitive impairments is greater, the affective environment around that person is more likely to be characterised by criticism and/or emotional over-involvement. The implications of this for assessment, diagnosis, and helping couples adjust to cognitive deterioration are discussed.

Self-concept in early stage dementia: profile, course, correlates, predictors and implications for quality of life

OBJECTIVE

Although it is increasingly accepted that people with dementia retain a sense of self, there is a need for empirical evidence regarding the nature of the self-concept in early stage dementia, how this changes over time and how it relates to quality of life.

METHODS

Self-concept was assessed using the short form of the Tennessee Self-concept Scale in 95 individuals with early stage dementia; 63 were reassessed after 12 months, and 45 were seen again at 20 months. Participants also completed measures of mood, cognitive functioning and quality of life. Caregivers provided proxy ratings of self-concept, completed measures of symptoms and distress at symptoms and rated their own levels of stress and well-being.

RESULTS

Self-ratings of self-concept were close to the average range for the standardization sample, and the distribution did not differ significantly from expected values. Although caregiver ratings were slightly lower, discrepancies were small. There were no significant changes over time in self-ratings or informant ratings or discrepancies. At Time 1, self-ratings were predicted by anxiety, depression and memory, caregiver ratings were predicted by caregiver distress and by depression in the person with dementia and discrepancies were predicted by caregiver distress. These models remained predictive at later time points. Self-rated self-concept predicted quality of life, with the relationship only partially mediated by depression and anxiety.

CONCLUSIONS

Self-concept appears largely intact in early stage dementia, but in view of the association between self-concept and quality of life, a preventive approach focused on supporting self-concept may offer benefits as dementia progresses.

Awareness of executive deficits in people with Parkinson's disease

Executive functioning is frequently impaired among people with Parkinson's disease (PD). Little is known about awareness of executive functioning, in the sense of being able to accurately appraise functioning or performance, in people with PD, or about whether awareness is particularly affected in those who have impaired executive functioning. This study explored awareness of executive functioning at the levels of evaluative judgment (comparison of self- and informant ratings of executive functioning), and performance monitoring (comparison of performance on cognitive tests and self-ratings of that performance). Awareness levels were assessed in people with PD with and without executive deficits, and in healthy controls. When the level of agreement between self- and informant ratings was considered, people with PD in both groups appeared as accurate in evaluating their overall executive functioning as healthy controls. When appraising their performance as the specific tasks were completed, people with PD who had impairments in executive functioning appeared less accurate than controls and people with PD without executive impairments. People with PD who have executive deficits may lack the ability to recognize their limitations while performing specific tasks, which may have implications for their functional abilities.

Verbal fluency and awareness of functional deficits in early-stage dementia

Assessment of activities of daily living is an important element in the diagnosis of dementia, with research suggesting a link between functional ability and cognition. We investigated the relationship between self- and informant ratings of instrumental activities of daily living (iADL) and verbal executive functioning in early-stage dementia. A total of 96 people with early-stage Alzheimer's disease or vascular or mixed dementia and their carers completed the Functional Activities Questionnaire; people with dementia also completed a test of letter fluency. Letter fluency was associated with self-ratings of iADL, while informant ratings of iADL were associated with the age and Mini-Mental State Examination score of the person with dementia. Self-ratings of perceived functioning suggested significantly less impairment than informant ratings. Those with impaired letter fluency rated themselves as having greater difficulties in iADLs than those who performed better. People with early-stage dementia vary in their subjective level of awareness of their iADL functioning, and difficulties with language production may contribute to better awareness of iADL impairments.

Medial prefrontal functional connectivity--relation to memory self-appraisal accuracy in older adults with and without memory disorders

It is tentatively estimated that 25% of people with early Alzheimer's disease (AD) show impaired awareness of disease-related changes in their own cognition. Research examining both normative self-awareness and altered awareness resulting from brain disease or injury points to the central role of the medial prefrontal cortex (MPFC) in generating accurate self-appraisals. The current project builds on this work - examining changes in MPFC functional connectivity that correspond to impaired self-appraisal accuracy early in the AD time course. Our behavioral focus was self-appraisal accuracy for everyday memory function, and this was measured using the Memory Function Scale of the Memory Awareness Rating Scale - an instrument psychometrically validated for this purpose. Using regression analysis of data from people with healthy memory (n=12) and people with impaired memory due to amnestic mild cognitive impairment or early AD (n=12), we tested the hypothesis that altered MPFC functional connectivity - particularly with other cortical midline structures and dorsolateral prefrontal cortex - explains variation in memory self-appraisal accuracy. We spatially constrained (i.e., explicitly masked) our regression analyses to those regions that work in conjunction with the MPFC to evoke self-appraisals in a normative group. This empirically derived explicit mask was generated from the result of a psychophysiological interaction analysis of fMRI self-appraisal task data in a separate, large group of cognitively healthy individuals. Results of our primary analysis (i.e., the regression of memory self-appraisal accuracy on MPFC functional connectivity) were generally consistent with our hypothesis: people who were less accurate in making memory self-appraisals showed attenuated functional connectivity between the MPFC seed region and proximal areas within the MPFC (including subgenual anterior cingulate cortex), bilateral dorsolateral prefrontal cortex, bilateral caudate, and left posterior hippocampus. Contrary to our expectations, MPFC functional connectivity with the posterior cingulate was not significantly related to accuracy of memory self-appraisals. Results reported here corroborate findings of variable memory self-appraisal accuracy during the earliest emergence of AD symptoms and reveal alterations in MPFC functional connectivity that correspond to impaired memory self-appraisal.

Multidimensional assessment of awareness in early-stage dementia: a cluster analytic approach

BACKGROUND/AIMS

Research on awareness in dementia has yielded variable and inconsistent associations between awareness and other factors. This study examined awareness using a multidimensional approach and applied cluster analytic techniques to identify associations between the level of awareness and other variables.

METHODS

Participants were 101 individuals with early-stage dementia (PwD) and their carers. Explicit awareness was assessed at 3 levels: performance monitoring in relation to memory, evaluative judgement in relation to memory, everyday activities and socio-emotional functioning, and metacognitive reflection in relation to the experience and impact of the condition. Implicit awareness was assessed with an emotional Stroop task.

RESULTS

Different measures of explicit awareness scores were related only to a limited extent. Cluster analysis yielded 3 groups with differing degrees of explicit awareness. These groups showed no differences in implicit awareness. Lower explicit awareness was associated with greater age, lower MMSE scores, poorer recall and naming scores, lower anxiety and greater carer stress.

CONCLUSION

Multidimensional assessment offers a more robust approach to classifying PwD according to level of awareness and hence to examining correlates and predictors of awareness.

Awareness of social and emotional functioning in people with early-stage dementia and implications for carers

OBJECTIVES

This study explores the extent to which awareness of social and emotional function is reduced in early-stage dementia and whether this relates to the quality of life of the person with dementia (PwD), the quality of the relationship between the PwD and carer and carer stress.

METHOD

Ninety-seven participants with a diagnosis of Alzheimer's, vascular or mixed dementia rated their social functioning using the Socio-Emotional Questionnaire (SEQ). Carers provided parallel ratings, allowing calculation of discrepancy scores used to index awareness. Neuropsychiatric symptoms, PwD quality of life, the perceived quality of the relationship for both partners and carer stress were also measured.

RESULTS

Factor analysis of the SEQ indicated three domains of social functioning: emotional recognition and empathy (ERE), social relationships (SR) and prosocial behaviour (PB). For PwD unawareness was related to cognitive dysfunction and psychiatric disturbance, but not to quality of life or quality of relationship. Lower awareness was associated with greater carer stress and poorer perceived quality of relationship.

CONCLUSION

Lack of awareness of social functioning had important implications for relationship quality and levels of carer stress.