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Building memories on prior knowledge: behavioral and fMRI evidence of impairment in early Alzheimer's disease.
Jonin, PY, Duché, Q, Bannier, E, Corouge, I, Ferré, JC, Belliard, S, Barillot, C, Barbeau, EJ
Neurobiology of aging. 2022;:1-12
Abstract
Impaired memory is a hallmark of prodromal Alzheimer's disease (AD). Prior knowledge associated with the memoranda improves memory in healthy individuals, but we ignore whether the same occurs in early AD. We used functional MRI to investigate whether prior knowledge enhances memory encoding in early AD, and whether the nature of this prior knowledge matters. Patients with early AD and Controls underwent a task-based fMRI experiment where they learned face-scene associations. Famous faces carried pre-experimental knowledge (PEK), while unknown faces with which participants were familiarized prior to learning carried experimental knowledge (EK). Surprisingly, PEK strongly enhanced subsequent memory in healthy controls, but importantly not in patients. Partly nonoverlapping brain networks supported PEK vs. EK associative encoding in healthy controls. No such networks were identified in patients. In addition, patients displayed impaired activation in a right sub hippocampal region where activity predicted successful associative memory formation for PEK stimuli. Despite the limited sample sizes of this study, these findings suggest that the role prior knowledge in new learning might have been so far overlooked and underestimated in AD patients. Prior knowledge may drive critical differences in the way healthy elderly and early AD patients learn novel associations.
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β-Lactolin Enhances Neural Activity, Indicated by Event-Related P300 Amplitude, in Healthy Adults: A Randomized Controlled Trial.
Kanatome, A, Ano, Y, Shinagawa, K, Ide, Y, Shibata, M, Umeda, S
Journal of Alzheimer's disease : JAD. 2021;(2):787-796
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Abstract
BACKGROUND Epidemiological studies have shown that dairy product consumption is beneficial for cognitive function in elderly individuals. β-lactolin is a Gly-Thr-Trp-Tyr lacto-tetrapeptide rich in fermented dairy products that improves memory retrieval, attention, and executive function in older adults with subjective cognitive decline and prevents the pathology of Alzheimer's disease in rodents. There has been no study on the effects of β-lactolin on neural activity in humans. OBJECTIVE We investigated the effects of β-lactolin on neural activity and cognitive function in healthy adults. METHODS In this randomized, double-blind, placebo-controlled study, 30 participants (45-64 years old) consumed β-lactolin or placebo for 6 weeks. Neural activity during auditory and language tasks was measured through 64-channel electroencephalography. Moreover, verbal fluency tests were performed at baseline and after 6 weeks. RESULTS The β-lactolin group had a significantly higher P300 amplitude at the Cp2 site (a part of the parietal lobe near the center of brain, p = 0.011), and C4 site (the area between the frontal and parietal lobe, p = 0.02) during the auditory tasks after 6 weeks than the placebo group. Thus, β-lactolin supplementation promoted neural activity in the parietal area, which increases concentration and attention during auditory cognitive tasks. Compared with the placebo group, the β-lactolin group also showed significant changes in the scores of verbal fluency test after 6 weeks (p = 0.033). CONCLUSION Our findings provide insight into the mechanisms underlying the effects of β-lactolin on attention in healthy adults.
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Neurocognitive Outcomes from Memantine: A Pilot, Double-Blind, Placebo-Controlled Trial in Children with Autism Spectrum Disorder.
Soorya, LV, Fogg, L, Ocampo, E, Printen, M, Youngkin, S, Halpern, D, Kolevzon, A, Lee, S, Grodberg, D, Anagnostou, E
Journal of child and adolescent psychopharmacology. 2021;(7):475-484
Abstract
Objective: Studies interrogating therapeutics which alter the excitation-inhibition balance in the treatment of autism spectrum disorder (ASD) have reported mixed results on social and behavioral outcomes. Methods: The aim of this randomized, double-blind placebo-controlled pilot trial was to evaluate neurocognitive effects of memantine over a 24-week trial. Twenty-three children ages 6-12 years old with ASD were randomized to memantine or placebo. Primary outcomes included measures of apraxia and expressive language with evaluations at midpoint (week 12) and endpoint (week 24). Secondary outcomes included memory and adaptive behavior measures. Exploratory outcomes included changes in overall cognitive functioning and behavior (e.g., Aberrant Behavior Checklist). Results: Results suggest that memantine was well-tolerated. Dropout rates were high across groups with only 14 participants completing the 6-month trial. Memantine was not associated with improvements in apraxia and expressive language. Treatment with memantine was associated with improvements in verbal recognition memory as measured by the Narrative Memory-Recognition (NEPSY-II) (F = 5.05, p = .03). In addition, exploratory analyses of changes in Intelligence quotient (IQ) suggest improvements on verbal IQ (d = 1.8). Conclusions: Results suggest future studies of memantine in ASD may benefit from shifting treatment targets from social and behavioral outcomes to exploration of effects of memantine on cognition, potentially as an adjunct to learning and educational interventions. ClinicalTrials.gov: NCT01372449.
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Efficacy and Safety of Sesame Oil Cake Extract on Memory Function Improvement: A 12-Week, Randomized, Double-Blind, Placebo-Controlled Pilot Study.
Jung, SJ, Jung, ES, Ha, KC, Baek, HI, Park, YK, Han, SK, Chae, SW, Lee, SO, Chung, YC
Nutrients. 2021;(8)
Abstract
The goal of treatment for mild cognitive impairment (MCI) is to reduce the existing clinical symptoms, delay the progression of cognitive impairment and prevent the progression to Alzheimer's disease (AD). At present, there is no effective drug therapy for AD treatment. However, early intake of dietary supplements may be effective in alleviating and delaying the MCI. This study aims to evaluate the effects of sesame oil cake extract (SOCE) supplementation on cognitive function in aged 60 years or older adults with memory impairment. A total of 70 subjects received either SOCE (n = 35) or placebo (n = 35) for 12 weeks based on random 1:1 assignment to these two groups. Cognitive function was evaluated by a computerized neurocognitive function test (CNT), and changes in the concentrations of plasma amyloid β (Aβ) proteins and urine 8-OHdG (8-hydroxy-2'-deoxyguanosine) were investigated before and after the experiment. Verbal learning test index items of the CNT improved markedly in the SOCE group compared to the placebo group (p < 0.05). Furthermore, plasma amyloid-β (1-40) and amyloid-β (1-42) levels in the SOCE group decreased significantly compared to that in the placebo group (p < 0.05). There was no statistically significant difference in urine 8-OHdG between the two groups (p > 0.05). Collectively, intake of SOCE for 12 weeks appears to have a beneficial effect on the verbal memory abilities and plasma β-amyloid levels of older adults with memory impairment.
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Dietary Lutein and Cognitive Function in Adults: A Meta-Analysis of Randomized Controlled Trials.
Li, J, Abdel-Aal, EM
Molecules (Basel, Switzerland). 2021;(19)
Abstract
Emerging literature suggests that dietary lutein may have important functions in cognitive health, but there is not enough data to substantiate its effects in human cognition. The current study was intended to determine the overall effect of lutein on the main domains of cognition in the adult population based on available placebo randomized-controlled trials. Literature searches were conducted in PubMed, AGRICOLA, Scopus, MEDLINE, and EMBASE on 14 November 2020. The effect of lutein on complex attention, executive function and memory domains of cognition were assessed by using an inverse-variance meta-analysis of standardized mean differences (SMD) (Hedge's g method). Dietary lutein was associated with slight improvements in cognitive performance in complex attention (SMD 0.02, 95% CI -0.27 to 0.31), executive function (SMD 0.13, 95% CI -0.26 to 0.51) and memory (SMD 0.03, 95% CI -0.26 to 0.32), but its effect was not significant. Change-from-baseline analysis revealed that lutein consumption could have a role in maintaining cognitive performance in memory and executive function. Although dietary lutein did not significantly improve cognitive performance, the evidence across multiple studies suggests that lutein may nonetheless prevent cognitive decline, especially executive function. More intervention studies are needed to validate the role of lutein in preventing cognitive decline and in promoting brain health.
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Effects of soy isoflavones on cognitive function: a systematic review and meta-analysis of randomized controlled trials.
Cui, C, Birru, RL, Snitz, BE, Ihara, M, Kakuta, C, Lopresti, BJ, Aizenstein, HJ, Lopez, OL, Mathis, CA, Miyamoto, Y, et al
Nutrition reviews. 2020;(2):134-144
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Abstract
CONTEXT The results of preclinical and observational studies support the beneficial effect of soy isoflavones on cognition. OBJECTIVE This review aimed to evaluate the effects of soy isoflavones on cognition in adults. DATA SOURCES The PUBMED, EMBASE, Ovid Medline, Cochrane Library, and clinicaltrials.gov databases were searched. STUDY SELECTION Two researchers independently screened 1955 records, using the PICOS criteria: participants were adults; intervention was dietary sources with soy isoflavones or isolated soy isoflavones; comparator was any comparator; outcome was cognitive function; study type was randomized controlled trials (RCTs). A third researcher was consulted to resolve any discrepancies. Sixteen RCTs were included and their quality assessed. DATA EXTRACTION Information on study design, characteristics of participants, and outcomes was extracted. PRISMA guidelines were followed. DATA ANALYSIS A random-effects meta-analysis was used to pool estimates across studies. In the 16 RCTs (1386 participants, mean age = 60 y), soy isoflavones were found to improve overall cognitive function (standardized mean difference [SMD], 0.19; 95% confidence interval [CI], 0.07-0.32) and memory (SMD, 0.15; 95%CI, 0.03-0.26). CONCLUSION The results showed that soy isoflavones may improve cognitive function in adults. SYSTEMATIC REVIEW REGISTRATION PROSPERO registration no. CRD42018082070.
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A Narrative Review of Handgrip Strength and Cognitive Functioning: Bringing a New Characteristic to Muscle Memory.
Shaughnessy, KA, Hackney, KJ, Clark, BC, Kraemer, WJ, Terbizan, DJ, Bailey, RR, McGrath, R
Journal of Alzheimer's disease : JAD. 2020;(4):1265-1278
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Abstract
BACKGROUND Measures of handgrip strength have not only emerged as a clinically viable screening tool for determining risk for morbidity, functional disability, and early mortality, but also for helping to identify cognitive deficits. However, the phenomena that links low handgrip strength with cognitive decline remains unclear. The role of the muscular and neural systems, and their adaptations to muscle strengthening activities over the life course, may provide important information for how age-related changes to muscle mass, strength, and neural capacity influence cognition. Moreover, disentangling how handgrip strength and cognitive function are associated may help to inform healthcare providers working with aging adults and guide targeted interventions aiming to preserve muscle and cognitive functioning. OBJECTIVE To 1) highlight and summarize evidence examining the associations of handgrip strength and cognitive functioning, and 2) provide directions for future research in this area. METHODS Articles from the PubMed database were searched from November 2018-May 2019. The search term algorithm, inclusion and exclusion criteria were pre-specified by investigators. RESULTS Several cross-sectional and longitudinal studies have revealed that measures of handgrip strength were associated with cognitive declines regardless of age demographics and the presence of comorbidities. CONCLUSION Handgrip strength can be used in clinical and epidemiological settings for helping to determine the onset and progression of cognitive impairment. Future research should continue to examine how handgrip strength and cognitive function are linked.
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Omega-3 and its domain-specific effects on cognitive test performance in youths: A meta-analysis.
Emery, S, Häberling, I, Berger, G, Walitza, S, Schmeck, K, Albert, T, Baumgartner, N, Strumberger, M, Albermann, M, Drechsler, R
Neuroscience and biobehavioral reviews. 2020;:420-436
Abstract
Omega-3 fatty acids are vital for brain development. The aim of this meta-analysis was to broaden current knowledge of the effects of omega-3 supplementation on cognitive test performance in youths. Randomized controlled trials (RCTs) meeting selection criteria were identified through two independent literature searches on PubMed, Cochrane Library, PsycARTICLES and PsycINFO (last search June 2019). Twenty-nine out of 1126 studies assessing 4247 participants met all selection criteria. A meta-analysis using random-effects model was performed for eight different cognitive domains. This first analysis revealed no main effect of omega-3 fatty acid supplementation on domain-specific cognitive test performance in youths. Subgroup analyses identified beneficial effects of eicosapentaenoic acid (EPA)-rich but not docosahexaenoic acid (DHA)-rich formulations in the domains of long-term memory, working memory and problem solving and a tendency towards beneficial effects in clinical rather than non-clinical populations. Future research should investigate differential effects of EPA and DHA and consider their baseline levels, other nutritional components and interactions with gene variations as potential predictors of response.
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Assessment of Factors Contributing to the Enhancement of Memory and Cognitive Abilities in the Context of Neurosciences.
Ktenas, S
Advances in experimental medicine and biology. 2020;:43-47
Abstract
The purpose of this paper is to present a brief on the evaluation of factors which contribute to cognitive ability enhancement under the spectrum of neuroscience, through the bibliographical research of scientific literature. The human brain has many possibilities, but it remains a largely uncharted area, which we just begin to understand in detail. One of its potentials, as concluded by the research, is its ability to adapt and improve its functioning by itself. Based on this physiological function, we can improve our ability to learn and remember, but we currently have limited resources to do so. After studying and evaluating relevant studies, it seems that the combination of physical exercise and nutrition has a more positive effect on molecular systems associated with synaptic plasticity, than more sophisticated methods, such as pharmaceutical drugs. Brain training using computer applications is also an area under heavy research but with mixed results at the moment. While brain training with scientific techniques can improve performance in specific areas, appropriate physical exercises, as well as proper nutrition, have additional benefits for the body. Supplementary studies will be useful in order to further specify the benefits and the ways of using both exercise and nutrition to design therapeutic interventions.
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The cognitive effects of an acute wild blueberry intervention on 7- to 10-year-olds using extended memory and executive function task batteries.
Whyte, AR, Lamport, DJ, Schafer, G, Williams, CM
Food & function. 2020;(5):4793-4801
Abstract
Evidence for the health benefits of blueberries is well documented. In particular, memory and executive function benefits have both been found for children aged 7-10 in the 6 hours period following acute blueberry consumption. Previous research has utilised a limited number of tasks when considering these domains. Therefore, in two separate experiments, we employed extended memory and executive function task batteries to further understand the extent of blueberry benefits. Following blueberry intervention, children aged 7-10 were tested on a memory battery at 75 minutes and an executive function battery at 3 hours. Shorter memory reaction times were observed on the visuo-spatial grid task and shorter executive function reaction times were observed on the congruent trials of the attention network task. Whilst providing further evidence for the cognitive benefits of blueberry consumption in school age children, these findings contrast with previous research where improved accuracy and reaction time benefits have most commonly been found on more cognitively demanding trials. Further research targeted to consider the areas of the brain related to each cognitive domain and how they coincide with mechanisms of action, such as increases in cerebral blood flow following blueberry intervention, is therefore recommended.