Learning and forgetting new names and objects in MCI and AD

Could Accelerated Long-Term Forgetting Be a Feature of the Higher Rate of Memory Complaints Associated with Subjective Cognitive Decline? An Exploratory Study

Background

Recently, subjective cognitive decline (SCD) was proposed as an early risk factor for future Alzheimer's disease (AD).

Objective

In this study, we investigated whether accelerated long-term forgetting (ALF), assessed with extended testing intervals than those adopted in clinical practice, might be a cognitive feature of SCD. Using an explorative MRI analysis of the SCD sample, we attempted to investigate the areas most likely involved in the ALF pattern.

Methods

We recruited 31 individuals with SCD from our memory clinic and subdivided them based on their rate of memory complaints into mild SCDs (n = 18) and severe SCDs (n = 13). A long-term forgetting procedure, involving the recall of verbal and visuo-spatial material at four testing delays (i.e., immediate, 30 min, 24 h, and 7 days post-encoding) was used to compare the two sub-groups of SCDs with a healthy control group (HC; n = 16).

Results

No significant between-group difference was found on the standard neuropsychological tests, nor in the immediate and 30 min recall of the experimental procedure. By contrast, on the verbal test severe SCDs forgot significantly more than HCs in the prolonged intervals (i.e., 24 h and 7 days), with the greatest decline between 30 min and 24 h. Finally, in the whole SCD sample, we found significant associations between functional connectivity values within some cortical networks involved in memory (default mode network, salience network, and fronto-parietal network) and verbal long-term measures.

Conclusions

Our preliminary findings suggest that long-term forgetting procedures could be a sensitive neuropsychological tool for detecting memory concerns in SCDs, contributing to early AD detection.

Expressive recall and recognition as complementary measures to assess novel word learning ability in aphasia

Novel word learning ability has been associated with language treatment outcomes in people with aphasia (PWA), and its assessment could inform prognosis and rehabilitation. We used a brief experimental task to examine novel word learning in PWA, determine the value of phonological cueing in assessing learning outcomes, and identify factors that modulate learning ability. Twelve PWA and nineteen healthy controls completed the task, and recall and recognition tests of learning ability. Most PWA showed comparable learning outcomes to those of the healthy controls. Learning assessed via expressive recall was more clearly evidenced with phonological cues. Better single word processing abilities and phonological short-term memory and higher integrity of the left inferior frontal gyrus were related to better learning performance. Brief learning tasks like this one are clinically feasible and hold promise as screening tools of verbal learning in PWA once validated and evaluated for their capacity to predict treatment outcomes.

Accelerated long-term forgetting: A sensitive paradigm for detecting subtle cognitive impairment and evaluating BACE1 inhibitor efficacy in preclinical Alzheimer's disease

Given a long preclinical stage of Alzheimer's disease (AD) continuum before the onset of dementia, there is a growing demand for tools capable of detecting the earliest feature of subtle cognitive impairment and optimizing recruitment to clinical trials for potentially disease-modifying therapeutic interventions such as BACE1 inhibitors. Now that all BACE1 inhibitor programs in symptomatic and prodromal AD populations have ended in failure, trials need to shift to target the earlier preclinical stage. However, evaluating cognitive efficacy (if any) in asymptomatic AD individuals is a great challenge. In this context, accelerated long-term forgetting (ALF) is emerging as a sensitive cognitive measure that can discriminate between presymptomatic individuals with high risks for developing AD and healthy controls. ALF is characterized by increased forgetting rates over extended delays (e.g., days, weeks, months) despite normal learning and short-term retention on standard memory assessments that typically use around 30-min delays. This review provides an overview of recent progress in animal model and clinical studies on this topic, focusing on the utility and underlying mechanism of ALF that may be applicable to earlier diagnosis and BACE1 inhibitor efficacy evaluation at a preclinical stage of AD.

Categorical Perception of Lexical Tones in Mandarin-Speaking Seniors

PURPOSE

This study aims to investigate the different degeneration processes of categorical perception (CP) of Mandarin lexical tones in the normal aging population and the pathological aging population with mild cognitive impairment (MCI).

METHOD

In Experiment I, we compared the identification and discrimination of Tone 1 and Tone 2 across young adults, seniors aged 60-65 years, and older seniors aged 75-80 years with normal cognitive abilities. In Experiment II, we compared lexical tone identification and discrimination across young adults, healthy seniors, and age-matched seniors with MCI.

RESULTS

In Experiment I, tone perception was intact in seniors aged below 65 years. Those aged above 75 years could also maintain normal tone identification, whereas they showed poorer tone discrimination correlated with age-related poorer hearing level. In Experiment II, healthy seniors showed normal CP of Mandarin tones. Tone identification was also normal in those with MCI, whereas their tone discrimination had significantly degenerated.

CONCLUSIONS

In the normal aging population, age-related hearing loss decreased signal audibility, accounting for poorer discrimination of Mandarin lexical tones in seniors above 75 years. In the pathological aging population with MCI, the poorer discrimination of lexical tones may be attributed to the additive effect of age, hearing loss, and cognitive impairment (e.g., impaired working memory and long-term phonological memory). This study uncovered the roles of low-level sensory processing and high-level cognitive processing in lexical tone perception in the Chinese aging population.

Accelerated long-term forgetting in neurodegenerative disorders: A systematic review of the literature

Accelerated Long-term Forgetting (ALF) is a memory deficit characterised by normal retention up to relatively short intervals (e.g., minutes, hours) with increased forgetting over longer periods (e.g., days, weeks). ALF is often underestimated due to a lack of common memory assessments beyond 30-60 min. The purpose of this review was to provide an overview of ALF occurrence in neurodegenerative disorders, evaluating whether it can be considered a cognitive deficit useful for diagnosing and monitoring patients. We included 19 experimental studies that investigated ALF in neurodegenerative disorders. Most papers were focused on Alzheimer's disease (AD) dementia and related forms of cognitive decline (Mild Cognitive Impairment, Subjective Cognitive decline, Pre-symptomatic subjects at risk of AD dementia). The major finding of the present work concerns the presence of ALF in very early forms of cognitive decline related to AD. These findings, supporting the hypothesis that ALF is a subtle and undetected hallmark of pre-clinical AD, highlights the importance of investigating forgetting over a longer period and devising standardised measures to be included in clinical practice.

Are you more impulsive with age? Examining age, marital status, and gender on cognitive ageing

Understanding non-pathological cognitive aging processes remains a public health goal and research priority. Age-associated cognitive aging is a normal human process, however, individual differences may aid in the mitigation of cognitive aging. Assessing the role of certain protective factors (i.e., age, marital status, and gender) that influence age-related cognitive aging is imperative to slow down the progression of unwarranted cognitive aging. Participants aged over 18 (N = 123; 97 females and 26 males) recruited from Sydney, New South Wales, and Gold Coast, Queensland, completed an online neuropsychological test battery with computer-administered tasks, assessing impulsivity and working memory, which were entered as dependent variables. A 3(Age Group: 18-27 years; 28-61 years; 62+ years) x2(Marital Status: married; single) x2(Gender: male; female) Multivariate Analysis of Covariance (MANCOVA) design was used to examine the relationship between age, marital status, and gender (entered as independent variables) on cognitive aging. Participants' total scores from psychometrically sound measures assessing depressive symptomology, personal wellbeing, resilience, and social network engagement, were entered as covariates. No significant effects were found from the independent variables included in the MANCOVA. A significant covariate effect for resilience and depressive symptomology on impulsivity was found. A multiple regression analysis was performed on the significant covariates, and revealed increased resilience and depressive symptomology to significantly predict greater impulsivity.

Accelerated long-term forgetting in individuals with subjective cognitive decline and amyloid-β positivity

OBJECTIVES

We studied a sample of cognitively unimpaired individuals, with and without subjective cognitive decline (SCD), in order to investigate accelerated long-term forgetting (ALF) and to explore the relationships between objective and subjective cognitive performance and cerebrospinal fluid (CSF) Alzheimer's disease (AD) biomarkers.

METHODS

Fifty-two individuals were included and SCD was quantified through the Subjective Cognitive Decline Questionnaire (SCD-Q), using its validated cutoff to classify participants as Low SCD-Q (n = 21) or High SCD-Q (n = 31). These groups were further subdivided according to the presence or absence of abnormal levels of CSF Aβ₄₂ . Objective cognitive performance was assessed with the Ancient Farming Equipment Test (AFE-T), a new highly-demanding test that calls for acquisition and retention of novel object/name pairs and allows measuring ALF over a 6-month period.

RESULTS

The High SCD-Q group showed a significantly higher free forgetting rate at 3 months compared to the Low SCD-Q (F [1,44] = 4.72; p < 0.05). When stratifying by amyloid status, High SCD-Q/Aβ+ showed a significantly lower performance than High SCD-Q/Aβ-on the final free and cued learning scores (F [1,27] = 6.44, p < 0.05 and F [1,27] = 7.51, p < 0.05, respectively), the 1-week free and cued recall (F [1,24] = 4.49; p < 0.05 and F [1,24] = 7.10; p < 0.01, respectively), the 1-week cued forgetting rate (F [1,24] = 5.13; p < 0.05), and the 3-month cued recall (F [1,24] = 4.27; p < 0.05). Linear regression analyses showed that higher SCD-Q scores were associated with higher forgetting rates on the AFE-T (β = -0.212; p < 0.05).

CONCLUSIONS

It is possible to detect ALF in individuals with high SCD ratings, appearing especially in those with abnormal CSF Aβ₄₂ levels. Both in research and the clinical field, there is an increasing need of using more demanding cognitive measures, such as the AFE-T, for identifying and tracking the earliest cognitive changes in these populations.

Beta-synuclein in cerebrospinal fluid as an early diagnostic marker of Alzheimer's disease

OBJECTIVE

Synaptic loss plays a major role in Alzheimer's disease (AD). However so far no neurochemical marker for synaptic loss has been introduced into clinical routine. By mass spectrometry beta-synuclein was established as a candidate marker. We now aimed to set up a novel ELISA for beta-synuclein for evaluation of its potential as a diagnostic and predictive marker for AD.

METHODS

We analysed in total 393 patients from four specialised centres. The diagnostic groups comprised: AD (n=151), behavioural variant frontotemporal dementia (bvFTD, n=18), Parkinson syndrome (n=46), Creutzfeldt-Jakob disease (CJD, n=23), amyotrophic lateral sclerosis (ALS, n=29), disease control (n=66) and 60 non-neurodegenerative control patients. Results were compared with core AD biomarkers (total tau, phospho-tau and amyloid-β peptide 1-42). Additionally, coexistence of beta-synuclein with vesicular glutamate transporter 1 (VGLUT1) was determined and beta-synuclein levels were quantified in brain homogenates.

RESULTS

Beta-synuclein levels quantified with the newly established ELISA correlated strongly with antibody-free quantitative mass spectrometry data (r=0.92 (95% CI: 0.89 to 0.94), p<0.0001). Cerebrospinal fluid (CSF) beta-synuclein levels were increased in AD-mild cognitive impairment (p<0.0001), AD dementia (p<0.0001) and CJD (p<0.0001), but not in bvFTD, Parkinson syndrome or ALS. Furthermore, beta-synuclein was localised in VGLUT1-positive glutamatergic synapses, and its expression was significantly reduced in brain tissue from patients with AD (p<0.01).

CONCLUSION

We successfully established a sensitive and robust ELISA for the measurement of brain-enriched beta-synuclein, which we could show is localised in glutamatergic synapses. We confirmed previous, mass spectrometry-based observations of increased beta-synuclein levels in CSF of patients with AD and CJD supporting its potential use as a marker of synaptic degeneration.

EA, Busatto GF, Bottino CMC. Mnemonic strategy training modulates functional connectivity at rest in mild cognitive impairment: Results from a randomized controlled trial

INTRODUCTION

Mnemonic strategy training (MST) has been shown to improve cognitive performance and increase brain activation in those with mild cognitive impairment (MCI). However, little is known regarding the effects of MST on functional connectivity (FC) at rest. The aim of the present study was to investigate the MST focused on face-name associations effect on resting-state FC in those with MCI.

METHODS

Twenty-six amnestic MCI participants were randomized in MST (N = 14) and Education Program (active control; N = 12). Interventions occurred twice a week over two consecutive weeks (ie, four sessions). Resting-state functional magnetic resonance imaging was collected at pre- and post-intervention. Regions of interest (ROIs) were selected based on areas that previously showed task-related activation changes after MST. Changes were examined through ROI-to-ROI analysis and significant results were corrected for multiple comparisons.

RESULTS

At post-intervention, only the MST group showed increased FC, whereas the control group showed decreased or no change in FC. After MST, there was an increased FC between the left middle temporal gyrus and right orbitofrontal cortex. In addition, a time-by-group interaction indicated that the MST group showed greater increased FC between the right inferior frontal gyrus and left brain regions, such as fusiform gyrus, temporal pole, and orbitofrontal cortex relative to controls.

DISCUSSION

MST enhanced FC in regions that are functionally relevant for the training; however, not in all ROIs investigated. Our findings suggest that MST-induced changes are reflected in task-specific conditions, as previously reported, but also in general innate connectivity. Our results both enhance knowledge about the mechanisms underlying MST effects and may provide neurophysiological evidence of training transfer.

Diagnostic Value of Time-Constrained Naming Test in Mild Cognitive Impairment

BACKGROUND

Naming difficulties have recently garnered more interest in elderly individuals with mild cognitive impairment (MCI). We anticipate that naming tests with the consideration of response time can provide more informative and distinct neuropsychological profiles of individuals with MCI.

METHODS

Naming tests were administered to 76 elderly individuals with MCI and 149 healthy elderly (HE). We analyzed the impact of MCI on naming performance and occurrence of "delayed" response. We also validated the predictive power of naming tests with a time-constrained scoring system.

RESULTS

MCI participants performed poorer on the noun naming test than HE participants (p = 0.014). MCI was significantly associated with the occurrence of "delayed" response on the noun (odds ratio [OR] = 3.57; 95% confidence interval [CI] = 1.78-7.17) and verb naming tests (OR = 4.66; 95% CI = 2.07-10.46). The time-constrained naming scores were significantly better able to distinguish the MCI from the HE group than the conventional spontaneous naming score on both the noun (p < 0.001) and verb (p = 0.002) naming tests.

CONCLUSIONS

Our findings broaden the knowledge related to the naming ability in individuals with MCI, with respect to the response time. We also confirmed the validity of the naming tests by applying the "delayed" responses as supplementary assessments in the diagnosis of MCI.

Does Severity of Alzheimer's Disease Contribute to Its Responsiveness to Modifying Gut Microbiota? A Double Blind Clinical Trial

Alzheimer's disease (AD) is associated with cognitive dysfunction. Evidence indicates that gut microbiota is altered in the AD and, hence, modifying the gut flora may affect the disease. In the previous clinical research we evaluated the effect of a probiotic combination on the cognitive abilities of AD patients. Since, in addition to pathological disorders, the AD is associated with changes in oxidant/antioxidant and inflammatory/anti-inflammatory biomarkers, the present work was designed to evaluate responsiveness of the inflammatory and oxidative biomarkers to the probiotic treatment. The control (CON) and probiotic (PRO) AD patients were treated for 12 weeks by the placebo and probiotic supplementation, respectively. The patients were cognitively assessed by Test Your Memory (TYM = 50 scores). Also serum concentrations of nitric oxide (NO), glutathione (GSH), total antioxidant capacity (TAC), malondialdehyde (MDA), 8-hydroxy-2′ -deoxyguanosine (8-OHdG) and cytokines (TNF-a, IL-6, and IL-10) were measured. The cognitive test and the serum biomarkers were assessed pre- and post-treatment. According to TYM test 83.5% of the patients showed severe AD. The CON (12.86% ± 8.33) and PRO (−9.35% ± 16.83) groups not differently scored the cognitive test. Not pronounced change percent was found in the serum level of TNF-α (1.67% ± 1.33 vs. −0.15% ± 0.27), IL-6 (0.35% ± 0.17 vs. 2.18% ± 0.15), IL-10 (0.05% ± 0.10 vs. −0.70% ± 0.73), TAC (0.07% ± 0.07 and −0.06% ± 0.03), GSH (0.08% ± 0.05 and 0.04% ± 0.03) NO (0.11% ± 0.06 and 0.05% ± 0.09), MDA (−0.11% ± 0.03 and −0.17% ± 0.03), 8-OHdG (43.25% ± 3.01 and 42.70% ± 3.27) in the CON and PRO groups, respectively. We concluded that the cognitive and biochemical indications in the patients with severe AD are insensitive to the probiotic supplementation. Therefore, in addition to formulation and dosage of probiotic bacteria, severity of disease and time of administration deeply affects results of treatment.

Normative Data of the Story and Six-Object Memory Recall Tests in Older Spanish Adults: NEDICES Population-Based Cohort

Objective

We provide normative data for the story and six-object recall tasks, stratified by age and education in a large population-based cohort of older Spanish adults.

Method

The sample consisted of 2,581 participants without dementia (age range: 67-98 years) from different socioeconomic areas of central Spain. Normative data are presented in percentile ranks and divided into four overlapping age tables with different midpoints.

Results

Spearman correlations and shared variances were calculated to evaluate the effects of sociodemographic variables on both tasks. Our findings showed that age and education influence the scores in the story and six-object recall tasks, whereas sex had null effect on story recall and an almost negligible on object recall, respectively.

Conclusion

The norms presented herein are important for the correct interpretation of scores in the story and six-object recall tasks when assessing older adults in Spain.

Understanding the world of dementia. How do people with dementia experience the world?

BACKGROUND

There is growing awareness that the subjective experience of people with dementia is important for understanding behavior and improving quality of life. This paper reviews and reflects on the currently available theories on subjective experience in dementia and it explores the possibility of a knowledge gap on the influence of neurological deficits on experience in late stage dementia.

METHODS

A literature review on current commonly used theories on experience in dementia was supplemented with a systematic review in PubMed and Psychinfo. For the systematic review, the terms used were Perception and Dementia and Behavior; and Awareness and Dementia and Long term care.

RESULTS

Current models emphasize the psychosocial factors that influence subjective experience, but the consequences of neurological deficits are not elaborated upon. The systematic literature search on the neuropsychological functioning in dementia resulted in 631 papers, of which 94 were selected for review. The current knowledge is limited to the early stages of Alzheimer's disease. Next to memory impairments, perception of the direct environment, interpretation of the environment, and inhibition of own responses to the environment seem to be altered in people with dementia.

CONCLUSIONS

Without knowledge on how perception, interpretation and the ability for response control are altered, the behavior of people with dementia can easily be misinterpreted. Research into neuropsychological functioning of people in more severe stages and different forms of dementia is needed to be able to develop a model that is truly biopsychosocial. The proposed model can be used in such research as a starting point for developing tests and theories.

Cognitive Training in a Large Group of Patients Affected by Early-Stage Alzheimer's Disease can have Long-Lasting Effects: A Case-Control Study

Introduction: Cognitive training in Alzheimer's disease (AD) has recently started to demonstrate its efficacy. We used our ‘puzzle-like’ task (GEO) as training for a large group of early-stage AD patients, to detect its effects over time.

Method: AD patients (N = 40) and healthy controls (N = 40) were involved. Participants were administered the Geographical Exercises for cognitive Optimization (GEO) task. Participants underwent individual sessions with GEO three times a week for 2 months, and then their performance was recorded again. Lastly, at the 12-month follow-up the GEO task was administered for the last time.

Results: Patients’ scores were significantly worse than controls’ scores only on a few neuropsychological tests. We ran a repeated measures GLM by considering groups’ performance on the GEO task at the assessment points. Results showed a significant main effect of group, and a significant effect of the interaction between group and time: patients’ performances both at the end of the training and at the follow-up were virtually identical to controls’ performances.

Conclusions: Patients effectively acquired new procedural abilities, and their achievements were stable at follow-up. This study suggests the GEO is a useful strategy for cognitive training in AD, and should prompt further investigations about the degree of generalisability of patients’ acquired skills.

Contributions of the Computer-Administered Neuropsychological Screen for Mild Cognitive Impairment (CANS-MCI) for the diagnosis of MCI in Brazil

ABSTRACT Background: The Computer-Administered Neuropsychological Screen for Mild Cognitive Impairment (CANS-MCI) is a computer-based cognitive screening instrument that involves automated administration and scoring and immediate analyses of test sessions. The objective of this study was to translate and culturally adapt the Brazilian Portuguese version of the CANS-MCI (CANS-MCI-BR) and to evaluate its reliability and validity for the diagnostic screening of MCI and dementia due to Alzheimer's disease. Methods: The test was administered to 97 older adults (mean age 73.41 ± 5.27 years) with at least four years of formal education (mean education 12.23 ± 4.48 years). Participants were classified into three diagnostic groups according to global cognitive status (normal controls, n = 41; MCI, n = 35; AD, n = 21) based on clinical data and formal neuropsychological assessments. Results: The results indicated high internal consistency (Cronbach's α = 0.77) in the total sample. Three-month test-retest reliability correlations were significant and robust (0.875; p < 0.001). A moderate level of concurrent validity was attained relative to the screening test for MCI (MoCA test, r = 0.76, p < 0.001). Confirmatory factor analysis supported the three-factor model of the original test, i.e., memory, language/spatial fluency, and executive function/mental control. Goodness of fit indicators were strong (Bentler Comparative Fit Index = 0.96, Root Mean Square Error of Approximation = 0.09). Receiver operating characteristic curve analyses suggested high sensitivity and specificity (81% and 73% respectively) to screen for possible MCI cases. Conclusions: The CANS-MCI-BR maintains adequate psychometric characteristics that render it suitable to identify elderly adults with probable cognitive impairment to whom a more extensive evaluation by formal neuropsychological tests may be required.

Dose-dependent improvements in learning and memory deficits in APPPS1-21 transgenic mice treated with the orally active Aβ toxicity inhibitor SEN1500

In the Alzheimer's disease (AD) brain, accumulation of Aβ1-42 peptides is suggested to initiate a cascade of pathological events. To date, no treatments are available that can reverse or delay AD-related symptoms in patients. In the current study, we introduce a new Aβ toxicity inhibitor, SEN1500, which in addition to its block effect on Aβ1-42 toxicity in synaptophysin assays, can be administered orally and cross the blood-brain barrier without adverse effects in mice. In a different set of animals, APPPS1-21 mice were fed with three different doses of SEN1500 (1 mg/kg, 5 mg/kg and 20 mg/kg) for a period of 5 months. Cognition was assessed in a variety of behavioral tests (Morris water maze, social recognition, conditioned taste aversion and passive avoidance). Results suggest a positive effect on cognition with 20 mg/kg SEN1500 compared to control APPPS1-21 mice. However, no changes in soluble or insoluble Aβ1-40 and Aβ1-42 were detected in the brains of SEN1500-fed mice. SEN1500 also attenuated the effect of Aβ1-42 on synaptophysin levels in mouse cortical neurons, which indicated that the compound blocked the synaptic toxicity of Aβ1-42. In vitro and in vivo effects presented here suggest that SEN1500 could be an interesting AD therapeutic.

Medial temporal lobe function during emotional memory in early Alzheimer's disease, mild cognitive impairment and healthy ageing: an fMRI study

BACKGROUND

Relative to intentional memory encoding, which quickly declines in Mild Cognitive Impairment (MCI) and Alzheimer's disease (AD), incidental memory for emotional stimuli appears to deteriorate more slowly. We hypothesised that tests of incidental emotional memory may inform on different aspects of cognitive decline in MCI and AD.

METHODS

Patients with MCI, AD and Healthy Controls (HC) were asked to attend to emotional pictures (i.e., positive and neutral) sequentially presented during an fMRI session. Attention was monitored behaviourally. A surprise post-scan recognition test was then administered.

RESULTS

The groups remained attentive within the scanner. The post-scan recognition pattern was in the form of (HC = MCI) > AD, with only the former group showing a clear benefit from emotional pictures. fMRI analysis of incidental encoding demonstrated clusters of activation in para-hippocampal regions and in the hippocampus in HC and MCI patients but not in AD patients. The pattern of activation observed in MCI patients tended to be greater than that found in HC.

CONCLUSIONS

The results suggest that incidental emotional memory might offer a suitable platform to investigate, using behavioural and fMRI measures, subtle changes in the process of developing AD. These changes seem to differ from those found using standard episodic memory tests. The underpinnings of such differences and the potential clinical use of this methodology are discussed in depth.

"Keep up the good work"! A case study of the effects of a specific cognitive training in Alzheimer's disease

Alzheimer's disease (AD) is a neurodegenerative condition characterized by significant impairment in multiple cognitive domains. In recent years, the development of cognitive trainings in AD has received significant attention. In the present case study we designed a cognitive training program (GEO, Geographical Exercises for cognitive Optimization) based on an errorless paradigm and tailored to the patient's cultural interests. The aim of this training was to investigate the potential for acquiring and possibly retaining both procedural and verbal knowledge in early-stage AD. This study involved an 80-year-old female patient diagnosed with early-stage AD, and 10 matched healthy subjects. Participants were asked to perform the two GEO training tasks: a "puzzle-like" task for procedural memory, and an "association" task for verbal memory. Both the patient and the healthy controls were subsequently trained with GEO using the same two tasks for 2 months. Although the patient's performance before training in both tasks was poor compared to healthy controls, after the training these differences disappeared. Our results showed that the patient was able to acquire new procedural abilities and verbal knowledge, and that her achievements were stable at the follow-up testing scheduled 3 months after the end of the intervention. This case study suggests a potentially useful strategy for cognitive training in AD.

Behavioural and cellular effects of exogenous amyloid-β peptides in rodents

A better understanding of Alzheimer's disease (AD) and the development of disease modifying therapies are some of the biggest challenges of the 21st century. One of the core features of AD are amyloid plaques composed of amyloid-beta (Aβ) peptides. The first hypothesis proposed that cognitive deficits are linked to plaque-development and transgenic mice have been generated to study this link, thereby providing a good model to develop new therapeutic approaches. Since later it was recognised that in AD patients the cognitive deficit is rather correlated to soluble amyloid levels, consequently, a new hypothesis appeared associating the earliest amyloid toxicity to these soluble species. The purpose of this review is to give a summary of behavioural and cellular data obtained after soluble Aβ peptide administration into rodents' brain, thereby showing that this model is a valid tool to investigate AD pathology when no plaques are present. Additionally, this method offers an excellent, efficient model to test compounds which could act at such early stages of the disease.

Everyday episodic memory in amnestic mild cognitive impairment: a preliminary investigation

BACKGROUND

Decline in episodic memory is one of the hallmark features of Alzheimer's disease (AD) and is also a defining feature of amnestic Mild Cognitive Impairment (MCI), which is posited as a potential prodrome of AD. While deficits in episodic memory are well documented in MCI, the nature of this impairment remains relatively under-researched, particularly for those domains with direct relevance and meaning for the patient's daily life. In order to fully explore the impact of disruption to the episodic memory system on everyday memory in MCI, we examined participants' episodic memory capacity using a battery of experimental tasks with real-world relevance. We investigated episodic acquisition and delayed recall (story-memory), associative memory (face-name pairings), spatial memory (route learning and recall), and memory for everyday mundane events in 16 amnestic MCI and 18 control participants. Furthermore, we followed MCI participants longitudinally to gain preliminary evidence regarding the possible predictive efficacy of these real-world episodic memory tasks for subsequent conversion to AD.

RESULTS

The most discriminating tests at baseline were measures of acquisition, delayed recall, and associative memory, followed by everyday memory, and spatial memory tasks, with MCI patients scoring significantly lower than controls. At follow-up (mean time elapsed: 22.4 months), 6 MCI cases had progressed to clinically probable AD. Exploratory logistic regression analyses revealed that delayed associative memory performance at baseline was a potential predictor of subsequent conversion to AD.

CONCLUSIONS

As a preliminary study, our findings suggest that simple associative memory paradigms with real-world relevance represent an important line of enquiry in future longitudinal studies charting MCI progression over time.

Effectiveness of a multistimulant home-based program on cognitive function of older adults

The purpose of this study was to test the effects of a multistimulant home-based program on cognitive function among older adults. This study was conducted in northeastern Turkey between March and June 2010. It was planned as an experimental versus control two-group design and carried out on 96 (intervention group = 48, control group = 48) participants. The intervention and control groups were similar regarding sex, education, partner status, and continuous drug use. Data were collected with a Standardized Mini Mental Test, the Geriatric Depression Scale (GDS), and the Beck Anxiety Scale. Each senior received a total of 10 home visits on a once-per-week basis. Results for the intervention group showed that the Mini Mental State Test scores of the participants had statistically increased, and the Beck Anxiety and the GDS scores showed a decrease. The study found an association between the multistimulant home-based intervention program and cognitive function.

Pretraining affects Morris water maze performance with different patterns between control and ovariectomized plus D-galactose-injected mice

There is little literature addressing the influences of the repeated Morris water maze (MWM) test on behavioral performance under physiological and neurodegenerative conditions. The results revealed that pretraining had distinctively different effects on MWM performances of vehicle control mice and Alzheimer's disease model mice induced by ovariectomy plus injection of D-galactose after an 8-w interval. This interference effect should be considered during analyzing behavioral outcomes using repeated MWM tests.