Strategic value-directed learning and memory in Alzheimer's disease and behavioural-variant frontotemporal dementia

In healthy adults, the ability to prioritize learning of highly valued information is supported by executive functions and enhances subsequent memory retrieval for this information. In Alzheimer's disease (AD) and behavioural-variant frontotemporal dementia (bvFTD), marked deficits are evident in learning and memory, presenting in the context of executive dysfunction. It is unclear whether these patients show a typical memory bias for higher valued stimuli. We administered a value-directed word-list learning task to AD (n = 10) and bvFTD (n = 21) patients and age-matched healthy controls (n = 22). Each word was assigned a low, medium or high point value, and participants were instructed to maximize the number of points earned across three learning trials. Participants’ memory for the words was assessed on a delayed recall trial, followed by a recognition test for the words and corresponding point values. Relative to controls, both patient groups showed poorer overall learning, delayed recall and recognition. Despite these impairments, patients with AD preferentially recalled high-value words on learning trials and showed significant value-directed enhancement of recognition memory for the words and points. Conversely, bvFTD patients did not prioritize recall of high-value words during learning trials, and this reduced selectivity was related to inhibitory dysfunction. Nonetheless, bvFTD patients showed value-directed enhancement of recognition memory for the point values, suggesting a mismatch between memory of high-value information and the ability to apply this in a motivationally salient context. Our findings demonstrate that value-directed enhancement of memory may persist to some degree in patients with dementia, despite pronounced deficits in learning and memory.     

The attribute priming effect in patients with Alzheimer's disease

Experiments with semantic priming (SP) paradigms have documented early hypopriming in patients with AD when concepts are used as primes and attribute concept features as targets, suggesting that concept attributes are vulnerable to damage very early in the disease course. The aims of this study were to confirm early priming reduction in the attribute condition in patients with AD and to determine which of several semantic indexes (such as the level of distinctiveness, correlation or feature dominance of concept features) best predicts the priming effect size in AD. We administered an SP attribute condition paradigm to 20 mildly demented patients with AD and to 10 NCs. We used concept–attribute pairs for which normative data of semantic indexes relative to both concept primes (i.e., number, type, mean level of dominance, distinctiveness and correlation of features constituting the concepts) and target features (i.e., level of feature dominance, correlation and distinctiveness) were available. Results showed that compared to NCs, the AD group obtained very reduced priming facilitation. Furthermore, the item regression analyses showed that the priming decrement in the AD group was predicted by the feature dominance of the target in the related pairs; that is, the lower the target feature dominance, the lower the priming effect elicited. These results confirmed hypopriming in the attribute condition from the very early phase of AD and support the view that attributes which are more salient for the identification of a given concept are also those most resistant to semantic memory degradation in AD pathology.     

Assessing inhibitory control in early-stage Alzheimer's and Parkinson's disease using the Hayling Sentence Completion Test

The ability to inhibit irrelevant information is essential for coping with the demands of everyday life. Inhibitory deficits are present in all stages of dementia and commonly observed in people with Parkinson's disease (PwPD). Inhibition is frequently tested with the Stroop test, but this may lack ecological validity. This study investigates inhibitory control in people with Alzheimer's disease dementia (PwD) and PwPD using the Hayling Sentence Completion Test (HSCT), which aspires to be a more ecologically valid task. A total of 117 people completed the HSCT, a test where participants have to complete a sentence with an unrelated word. The sample comprised 30 PwD, 33 PwPD, and 54 healthy older controls. We compared response times and the number and type of errors across the three groups. Completion time in Part B (Inhibition) did not distinguish between PwD, PwPD, and controls when controlling for the initiation speed, but a higher proportion of Category A errors (producing a word that fits the sentence when instructed otherwise) was a unique characteristic of inferior performance in PwD and PwPD. While not part of the standard test scoring protocol, controlling for the initiation speed and distinguishing between speed and accuracy in test performance appear to be essential for accurate evaluation of the inhibitory control in HSCT in older people. The findings suggest that the HSCT may be sensitive to verbal suppression deficits and may provide insight into inhibitory control in PwD and PwPD.     

The Home-Based Occupational Therapy Intervention in the Alzheimer's Disease Multiple Intervention Trial (ADMIT)

There is no way to prevent functional declines related to Alzheimer's Disease (AD). The use of occupational therapy (OT) has been shown to be successful in managing some aspects of AD. We added home-based OT to evidence-based best practice for AD with the aim of delaying functional decline in people with AD. OT was delivered in the home to a caregiver dyad including the person with AD and her/his caregiver. This article describes the OT intervention for the AD Multiple Intervention Trial, a parallel randomized controlled trial. We include baseline data on the 180 caregiver dyads.     

No dual-task practice effect in Alzheimer's disease

Diagnosis of Alzheimer's disease (AD) requires evidence of progressive decline in cognitive function. However, many tests used to assess cognitive function suffer from considerable practice effects, reducing their reliability. Several studies have reported that the ability to do two things at once, or dual tasking, is impaired in AD, but unaffected by healthy ageing. The apparent specificity of this impairment suggests that this assessment may be particularly useful in the early diagnosis of AD, but the reliability of this assessment remains unknown. Therefore, this study investigated simultaneous performance of digit recall and tracking tasks across six testing sessions in eight people with AD, eight healthy older adults and eight healthy younger adults. The results found that dual-task performance was unaffected by healthy ageing, but significantly impaired in AD, with no effect of repeated exposure. The absence of any improvements in performance despite increased familiarity with the task's demands suggests that not only is the dual-task assessment well suited for monitoring progression over time, but also that dual tasking involves a specific cognitive function which is impaired in the AD brain.     

Modeling recall memory for emotional objects in Alzheimer's disease

ABSTRACT

Objective: To examine whether emotional memory (EM) of objects with self-reference in Alzheimer's disease (AD) can be modeled with binomial logistic regression in a free recall and an object recognition test to predict EM enhancement.?Method: Twenty patients with AD and twenty healthy controls were studied. Six objects (three presented as gifts) were shown to each participant. Ten minutes later, a free recall and a recognition test were applied. The recognition test had target–objects mixed with six similar distracter objects. Participants were asked to name any object in the recall test and identify each object in the recognition test as known or unknown.?Results: The total of gift objects recalled in AD patients (41.6%) was larger than neutral objects (13.3%) and a significant EM recall effect for gifts was found (Wilcoxon: p < .003). EM was not found for recognition in AD patients due to a ceiling effect. Healthy older adults scored overall higher in recall and recognition but showed no EM enhancement due to a ceiling effect. A logistic regression showed that likelihood of emotional recall memory can be modeled as a function of MMSE score (p < .014) and object status (p < .0001) as gift or non-gift.?Conclusion: Recall memory was enhanced in AD patients for emotional objects indicating that EM in mild to moderate AD although impaired can be provoked with strong emotional load. The logistic regression model suggests that EM declines with the progression of AD rather than disrupts and may be a useful tool for evaluating magnitude of emotional load.     

Directed forgetting of autobiographical memory in mild Alzheimer's disease

Using the autobiographical directed forgetting method (Barnier et al., 2007), the present paper addressed the intentional inhibitory processes of episodic and semantic autobiographical memory in Alzheimer's disease (AD). Mild AD patients and healthy elderly people were instructed to either forget or to continue remembering previously generated autobiographical events. In a later recall test they were asked to reconstruct the early-generated memories regardless of the forget/remember instruction. Autobiographical reconstruction was further distributed into episodic and semantic memories. Results showed no forget instruction effect on episodic or semantic autobiographical recall with AD patients, whereas healthy elderly people were able to inhibit only episodic autobiographical memories. The findings suggest an impairment of the intentional inhibitory processes in autobiographical memory with AD and a relative preservation of these mechanisms with normal ageing. They also demonstrate an earlier decline in the intentional inhibitory processes compared to the autobiographical deterioration in AD.     

Exercise Training for Persons with Alzheimer's Disease and Caregivers: A Review of Dyadic Exercise Interventions

Alzheimer's disease (AD) is the most common form of dementia and the prevalence will increase dramatically in the next decades. Although exercise has shown benefits for people with dementia due to AD as well as their caregivers, the impact of a dyadic exercise intervention including both groups as study participants remains to be determined. The authors review the current clinical evidence for dyadic exercise interventions, which are exercise regimens applied to both the person with dementia and the caregiver. A total of 4 controlled trials were reviewed. This review shows that dyadic exercise interventions are feasible and may produce a positive effect on functional independence and caregiver burden. However, there was insufficient evidence to support a benefit of dyadic exercise intervention on cognitive performance and on behavioral and neuropsychiatric symptoms in participants with dementia due to AD. A dyadic exercise intervention improves functional independence and caregiver burden. However, there is a need for well-designed randomized controlled clinical trials to confirm these benefits and to investigate several important points such as the effects of a dyadic exercise intervention on cognitive and noncognitive outcomes of AD, the optimal intensity of exercise training, and the cost effectiveness of such a program.     

Cognitive guidance and improvement of Alzheimer's disease patients based on human-computer interaction design

Cognitive dysfunction is a common problem in patients with Alzheimer's disease. This not only affects the comprehensive rehabilitation of motor function and activities of daily living, but also directly affects the social adaptability, and brings difficulties to the reintegration of Alzheimer's patients. Therefore, cognitive rehabilitation of Alzheimer's patients has become one of the important topics facing the medical community. Under the concept of human-computer interaction design, this study uses puzzle games as an entry point to observe the impact of puzzle games on cognitive function guidance and improvement in patients with Alzheimer's disease. Expecting to provide daily rehabilitation for patients with Alzheimer's disease. It is also hoped that it can promote the cognitive ability recovery of Alzheimer's patients, effectively delay the progress of dementia, improve the daily living ability and adaptability of patients, and improve the quality of life and life.     

Validation of a telephone screening test for Alzheimer's disease

ABSTRACT

Financial constraints, mobility issues, medical conditions, crime in local areas can make cognitive assessment difficult for elders and telephone interviews can be a good alternative. This study was carried out to evaluate the reliability, validity and clinical utility of a Brazilian telephone version of the Mini Mental State Examination (Braztel-MMSE) in a community sample of healthy elderly participants and AD patients. The MMSE and the Braztel-MMSE were applied to 66 AD patients and 67 healthy elderly participants. The test–retest reliability was strong and significant (r = .92, p = .01), and the correlation between the Braztel-MMSE and the MMSE were significant (p = .01) and strong (r = .92). The general screening ability of the Braztel-MMSE was high (AUC = 0.982; CI95% = 0.964–1.001). This telephone version can therefore be used as a screening measure for dementia in older adults that need neuropsychological screening and cannot present for an evaluation.     

The free and cued selective reminding test for predicting progression to Alzheimer's disease in patients with mild cognitive impairment: A prospective longitudinal study

Amnestic mild cognitive impairment (aMCI) patients carry a greater risk of conversion to Alzheimer's disease (AD). Therefore, the International Working Group (IWG) on AD aims to consider some cases of aMCI as symptomatic prodromal AD. The core diagnostic marker of AD is a significant and progressive memory deficit, and the Free and Cued Selective Reminding Test (FCSRT) was recommended by the IWG to test memory in cases of possible prodromal AD. This study aims to investigate whether the performance on the FCSRT would enhance the ability to predict conversion to AD in an aMCI group. A longitudinal study was conducted on 88 aMCI patients, and neuropsychological tests were analysed on the relative risk of conversion to AD. During follow‐up (23.82 months), 33% of the aMCI population converted to AD. An impaired FCSRT TR was significantly associated with the risk of conversion to dementia, with a mean time to conversion of 25 months. The FCSRT demonstrates utility for detecting AD at its prodromal stage, thus supporting its use as a valid clinical marker.     

Increasing the salience of fluency cues does not reduce the recognition memory impairment in Alzheimer's disease!

In Alzheimer's disease (AD), it is now well established that recollection is impaired from the beginning of the disease, whereas findings are less clear concerning familiarity. One of the most important mechanisms underlying familiarity is the sense of familiarity driven by processing fluency. In this study, we attempted to attenuate recognition memory deficits in AD by maximizing the salience of fluency cues in two conditions of a recognition memory task. In one condition, targets and foils have been created from the same pool of letters (Overlap condition). In a second condition, targets and foils have been derived from two separate pools of letters (No‐Overlap condition), promoting the use of letter‐driven visual and phonetic fluency. Targets and foils were low‐frequency words. The memory tasks were performed by 15 patients with AD and 16 healthy controls. Both groups improved their memory performance in the No‐Overlap condition compared to the Overlap condition. Patients with AD were able to use fluency cues during recognition memory as older adults did, but this did not allow to compensate for dysfunction of recognition memory processes.     

The free and cued selective reminding test: Validation for mild cognitive impairment and Alzheimer's disease

The International Working Group on Alzheimer's disease (AD) suggested the free and cued selective reminding test (FCSRT) to assess memory, as it showed high sensitivity and specificity in the differentiation of AD from healthy controls and other dementias. The FCSRT involves the use of selective reminding with semantic cueing in memory assessment. This study aims to validate the FCSRT for mild cognitive impairment (MCI) and AD through the analysis of the diagnostic accuracy and the suggestion of cut‐off scores. Patients were classified into two groups according to standard criteria: MCI (n = 100) and AD (n = 70). A matched control group (n = 101) of cognitively healthy subjects was included. The reliability and the validity of the FCSRT were analysed on the immediate (IR) and delayed (DR) recalls. The Cronbach's alpha was 0.915 for the IR and 0.879 for the DR. The total recall measures revealed good areas under the curve for MCI (IR: .818; DR: .828) and excellent for AD (IR: .987; DR: .991). Furthermore, the MCI group was subdivided with respect to a non‐similar/similar AD pattern of impairment, with almost half of the subjects showing an AD‐like decline. This analysis represents a novel contribution regarding the properties of the FCSRT in illustrating the heterogeneity of MCI at baseline. The FCSRT has proved to be a very useful tool in the characterization of the memory impairment of the AD spectrum.     

The use of a wearable camera improves autobiographical memory in patients with Alzheimer's disease

Despite the marked impairment of recent episodic memories in Alzheimer's disease, there have been few attempts to rehabilitate these deficits. We used a novel external memory aid to promote recall of episodic memories in patients with mild to moderate Alzheimer's disease. SenseCam, a small wearable camera, recorded significant events in the lives of six Alzheimer's disease patients. Every two days for two weeks each patient's memory for an event was assessed, followed by a structured review of the SenseCam images. Longer-term recall was tested one and three months later. A written diary control condition followed the same procedure. Across 40 events the SenseCam review method resulted in significantly more details of an event being recalled over two weeks than the written diary method in five out of the six patients. At three months post event, four out of five patients (one had dropped out) recalled significantly more details of events in the SenseCam condition while the other patient showed no significant difference. Viewing SenseCam images of personally experienced events may significantly improve autobiographical memory in patients with even moderate Alzheimer's disease.     

ASSESSMENT OF PREFERENCE FOR EDIBLE AND LEISURE ITEMS IN INDIVIDUALS WITH DEMENTIA

We conducted 2 studies on reinforcer preference in patients with dementia. Results of preference assessments yielded differential selections by 14 participants. Unlike prior studies with individuals with intellectual disabilities, all participants showed a noticeable preference for leisure items over edible items. Results of a subsequent analysis with 3 participants showed reinforcement effects when highly preferred items were delivered as consequences.     

Differential impacts of age of acquisition on letter and semantic fluency in Alzheimer's disease patients and healthy older adults

The degree to which the typical age of acquisition (AoA) of words and word frequency have separable influences on verbal production tasks has been strongly debated. To examine the overlap between these factors in verbal fluency tasks, the performance of Alzheimer's disease (AD) patients (N?=?34) and normal elderly controls (N?=?36) was compared on semantic (e.g., vegetables) and letter (e.g., words that begin with F) fluency tasks. These comparisons revealed that words generated for the semantic fluency task had an earlier AoA while words generated for the letter fluency task had a higher word frequency. Differences in AoA between AD patients and controls were larger for semantic than letter fluency. These results suggest that AoA has an effect on verbal production that is independent of word frequency and that AoA has a semantic locus.     

Episodic memory effects of gamma frequency precuneus transcranial magnetic stimulation in Alzheimer's disease: A randomized multiple baseline study

Episodic memory decline is the prominent neuropsychological feature of typical Alzheimer's Disease (AD), for which current treatments have a limited clinical response. Recently, gamma entrainment therapy has been used as a non-invasive treatment in AD, providing evidence that it may have the potential to alleviate brain pathology and improve cognitive function in AD patients. At the same time, the precuneus (PC) has been recognized as a key area involved in AD related memory deficits and as a key node of the Default Mode Network. This study aimed to investigate the effectiveness of a 40 Hz Transcranial Magnetic Stimulation (TMS) intervention, delivered bilaterally to the precuneus for 10 days, in improving the patients' episodic memory performance. Secondary outcome variables investigated included general cognitive function, semantic and spatial memory, as well as attention and executive function. A concurrent multiple baseline design across five cases was employed. Four patients completed the study. Visual analysis combined with effect size indices were used to evaluate changes across phases. An increase in the average level of immediate recalled words was observed in three out of four patients. Effect size indices indicated significant improvement of attention skills in two patients. No treatment effect was observed for semantic and visual memory, or for executive function. An immediate treatment effect was observed in all patients' general cognitive function as assessed with the Alzheimer's Disease Assessment Scale (mean reduction of 5 points), which was maintained and improved further three months post-treatment. The neuropsychological evaluations indicated improved performance three months post-treatment in immediate and delayed recall, attention, phonological verbal fluency, anxiety, and neuropsychiatric symptoms. This study provides preliminary evidence for the efficacy of a novel non-pharmacological treatment using gamma-band TMS in addressing cognitive dysfunction in AD.     

Preference for leisure items over edible items in individuals with dementia: A replication

We replicated previous research in which adults with dementia tended to show a preference for leisure items over edible items when presented in the same array. Additionally, we conducted engagement analyses with the highest, middle, and lowest preference leisure items to determine whether relative preference corresponded to engagement in the natural environment. The most highly preferred stimulus for 6 out of 7 participants was a leisure item, and for each of those six the top 3 preferred stimuli were leisure stimuli. For 4 participants, the most preferred stimulus also produced the longest duration of engagement. We discuss the issues we encountered when conducting preference assessments with adults with intact vocal verbal repertoires, and suggest potential explanations for the displacement of edibles by leisure stimuli in older adults with dementia.     

Word recognition in Alzheimer's disease: Effects of semantic degeneration

Impairments of word recognition in Alzheimer's disease (AD) have been less widely investigated than impairments affecting word retrieval and production. In particular, we know little about what makes individual words easier or harder for patients with AD to recognize. We used a lexical selection task in which participants were shown sets of four items, each set consisting of one word and three non‐words. The task was simply to point to the word on each trial. Forty patients with mild‐to‐moderate AD were significantly impaired on this task relative to matched controls who made very few errors. The number of patients with AD able to recognize each word correctly was predicted by the frequency, age of acquisition, and imageability of the words, but not by their length or number of orthographic neighbours. Patient Mini‐Mental State Examination and phonological fluency scores also predicted the number of words recognized. We propose that progressive degradation of central semantic representations in AD differentially affects the ability to recognize low‐imageability, low‐frequency, late‐acquired words, with the same factors affecting word recognition as affecting word retrieval.