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1.
PLoS One ; 15(12): e0235179, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33296363

RESUMO

We aimed to replicate a published effect of transcranial direct-current stimulation (tDCS)-induced recognition enhancement over the human ventrolateral prefrontal cortex (VLPFC) and analyse the data with machine learning. We investigated effects over an adjacent region, the dorsolateral prefrontal cortex (DLPFC). In total, we analyzed data from 97 participants after exclusions. We found weak or absent effects over the VLPFC and DLPFC. We conducted machine learning studies to examine the effects of semantic and phonetic features on memorization, which revealed no effect of VLPFC tDCS on the original dataset or the current data. The highest contributing factor to memory performance was individual differences in memory not explained by word features, tDCS group, or sample size, while semantic, phonetic, and orthographic word characteristics did not contribute significantly. To our knowledge, this is the first tDCS study to investigate cognitive effects with machine learning, and future studies may benefit from studying physiological as well as cognitive effects with data-driven approaches and computational models.


Assuntos
Cognição/fisiologia , Memória/fisiologia , Estimulação Transcraniana por Corrente Contínua/métodos , Adolescente , Adulto , Encéfalo/fisiologia , Feminino , Humanos , Aprendizado de Máquina , Masculino , Memória Episódica , Memória de Curto Prazo/fisiologia , Testes Neuropsicológicos , Córtex Pré-Frontal/fisiologia , Reconhecimento Psicológico/fisiologia , Adulto Jovem
2.
Nat Commun ; 11(1): 6024, 2020 11 27.
Artigo em Inglês | MEDLINE | ID: mdl-33247134

RESUMO

The availability of blood-based assays detecting Alzheimer's disease (AD) pathology should greatly accelerate AD therapeutic development and improve clinical care. This is especially true for markers that capture the risk of decline in pre-symptomatic stages of AD, as this would allow one to focus interventions on participants maximally at risk and at a stage prior to widespread synapse loss and neurodegeneration. Here we quantify plasma concentrations of an N-terminal fragment of tau (NT1) in a large, well-characterized cohort of clinically normal elderly who were followed longitudinally. Plasma NT1 levels at study entry (when all participants were unimpaired) were highly predictive of future cognitive decline, pathological tau accumulation, neurodegeneration, and transition to a diagnosis of MCI/AD. These predictive effects were particularly strong in participants with even modestly elevated brain ß-amyloid burden at study entry, suggesting plasma NT1 levels capture very early cognitive, pathologic and neurodegenerative changes along the AD trajectory.


Assuntos
Disfunção Cognitiva/sangue , Disfunção Cognitiva/diagnóstico , Degeneração Neural/sangue , Degeneração Neural/complicações , Proteínas tau/sangue , Idoso , Doença de Alzheimer/sangue , Doença de Alzheimer/líquido cefalorraquidiano , Doença de Alzheimer/complicações , Peptídeos beta-Amiloides/sangue , Disfunção Cognitiva/complicações , Disfunção Cognitiva/fisiopatologia , Feminino , Substância Cinzenta/patologia , Humanos , Imagem por Ressonância Magnética , Masculino , Memória Episódica , Degeneração Neural/líquido cefalorraquidiano , Proteínas tau/líquido cefalorraquidiano
3.
BMC Geriatr ; 20(1): 452, 2020 11 05.
Artigo em Inglês | MEDLINE | ID: mdl-33153433

RESUMO

BACKGROUND: Older adults' cognitive abilities can be impaired through priming of negative age stereotypes. However, it is unclear whether the effects of negative priming can be extended to episodic memory, which is believed to be the most age-sensitive type among the long-term memory systems, in Asian populations. Social participation has recently emerged as a potential protective factor for maintaining the cognitive function of older adults. The purpose of this study was to examine the effects of negative age stereotype priming on episodic memory and the moderating role of social participation in the priming effect. METHODS: A total of 105 community-dwelling older adults residing in Hong Kong were randomly allocated to two experimental conditions. Participants were primed either with negative age stereotype words (n = 53) or neutral words (n = 52) using an implicit priming task. Episodic memory performance was assessed using the Hong Kong List Learning Task (HKLLT), which includes total learning, two delayed recalls and a recognition task. Analysis of covariance (ANCOVA) was used to assess group differences in the priming task and memory performance, while a series of moderation analyses were performed to examine the moderating effects of social participation. RESULTS: The group that received negative age stereotype priming performed significantly worse than the group that received neutral words in their episodic memory test. Additional analyses showed that socially active individuals might be less prone to the effects of negative age stereotypes for the recognition task only. CONCLUSIONS: Older adults who are more socially active might be more immune to the effects of negative age stereotype priming on episodic memory. These results provide initial support for the hypothesis that social participation might act as an effective strategy to ward against negative age stereotype priming. TRIAL REGISTRATION: ClinicalTrials.gov: NCT04202120 (first posted December 17, 2019), (Retrospectively registered).


Assuntos
Transtornos da Memória , Memória Episódica , Participação Social , Estereotipagem , Idoso , Envelhecimento , Hong Kong , Humanos , Transtornos da Memória/prevenção & controle
4.
Artigo em Inglês | MEDLINE | ID: mdl-33153203

RESUMO

The aim of this study was to investigate whether Timed Up-and-Go (TUG) dual-task (TUGdt) tests predict dementia incidence among patients with subjective or mild cognitive impairment (SCI; MCI). Other study objectives were to determine whether TUGdt improves dementia prediction compared to a) demographic characteristics and standard cognitive tests alone; and b) TUG and Verbal Fluency performed separately. Patients (n = 172, age range 39-91 years, 78 women) with SCI or MCI performed TUGdt tests, including 1) naming animals and 2) reciting months backwards, and clinical cognitive tests at baseline. Diagnoses were identified at follow-up after 2.5 years. Logistic regression was used to predict dementia incidence, receiver operating characteristic (ROC) curves and c-statistics for predictive capacity. Analyses were stratified by age and gender. At follow-up, 51 patients had developed dementia. The TUGdt result "animals/10 s" was associated with dementia incidence (standardized odds ratio (OR) = 4.06, 95% confidence interval (CI) 2.28-7.23, p < 0.001), more so among patients under the median age of 72 years (standardized OR = 19.4, 95% CI 3.53-106.17, p < 0.001). TUGdt "animals/10 s" improved dementia prediction compared to demographic characteristics and standard tests alone (c-statistics 0.88 to 0.94) and single-task tests (c-statistics 0.86 to 0.89), but only in the younger patient group. TUGdt has the potential to become a useful tool for dementia prediction.


Assuntos
Disfunção Cognitiva , Demência , Memória Episódica , Adulto , Idoso , Idoso de 80 Anos ou mais , Disfunção Cognitiva/diagnóstico , Disfunção Cognitiva/epidemiologia , Estudos de Coortes , Demência/diagnóstico , Demência/epidemiologia , Progressão da Doença , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Testes Neuropsicológicos
5.
Nat Commun ; 11(1): 6075, 2020 11 27.
Artigo em Inglês | MEDLINE | ID: mdl-33247100

RESUMO

Our memories enable us to form expectations for our future experiences, yet the precise neural mechanisms underlying how we compare any experience to our memory remain unknown. Here, using intracranial EEG recordings, we show that episodic memories formed after a single visual experience establish expectations for future experience within neocortical-medial temporal lobe circuits. When subsequent experiences violate these expectations, we find a 80-120 Hz prediction error signal that emerges in both visual association areas and the medial temporal lobe. Critically, this error signal emerges in visual association areas first and then propagates to the medial temporal lobe. This error signal is accompanied by alpha coherence between the two regions. Our data therefore suggest that internal models formed from episodic memories are generated throughout the visual hierarchy after just a single exposure, and that these internal models are then used for comparison with future experiences.


Assuntos
Memória Episódica , Rememoração Mental/fisiologia , Adulto , Ritmo alfa/fisiologia , Eletrodos , Feminino , Fixação Ocular/fisiologia , Humanos , Masculino , Modelos Neurológicos , Estimulação Luminosa , Percepção Espacial/fisiologia , Análise e Desempenho de Tarefas , Lobo Temporal/fisiologia , Fatores de Tempo , Córtex Visual/fisiologia , Percepção Visual/fisiologia
6.
Acta Psychol (Amst) ; 211: 103190, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33130488

RESUMO

BACKGROUND: Boundary extension (BE) is a phenomenon where participants report from memory that they have experienced more information of a scene than was initially presented. The goal of the current study was to investigate whether BE is fully based on episodic memory or also involves semantic scheme knowledge. METHODS: The study incorporated the remember/know paradigm into a BE task. Scenes were first learned incidentally, with participants later indicating whether they remembered or knew that they had seen the scene before. Next, they had to rate 3 views - zoomed in, zoomed out or unchanged - of the original picture on similarity in closeness in order to measure BE. RESULTS: The results showed a systematic BE pattern, but no difference in the amount of BE for episodic ('remember') and semantic ('know') memory. Additionally, the remember/know paradigm used in this study showed good sensitivity for both the remember and know responses. DISCUSSION: The results suggest that BE might not critically depend on the contextual information provided by episodic memory, but rather depends on schematic knowledge shared by episodic and semantic memory. Schematic knowledge might be involved in BE by providing an expectation of what likely lies beyond the boundaries of the scene based on semantic guidance. GEL CLASSIFICATION: 2343 learning & memory.


Assuntos
Memória Episódica , Semântica , Humanos , Conhecimento , Rememoração Mental
7.
Sci Rep ; 10(1): 16991, 2020 10 12.
Artigo em Inglês | MEDLINE | ID: mdl-33046753

RESUMO

Upon reactivation, consolidated memories can enter a temporary labile state and require restabilisation, known as reconsolidation. Interventions during this reconsolidation period can disrupt the reactivated memory. However, it is unclear whether different kinds of memory that depend on distinct brain regions all undergo reconsolidation. Evidence for reconsolidation originates from studies assessing amygdala-dependent memories using cue-conditioning paradigms in rodents, which were subsequently replicated in humans. Whilst studies providing evidence for reconsolidation of hippocampus-dependent memories in rodents have predominantly used context conditioning paradigms, studies in humans have used completely different paradigms such as tests for wordlists or stories. Here our objective was to bridge this paradigm gap between rodent and human studies probing reconsolidation of hippocampus-dependent memories. We modified a recently developed immersive Virtual Reality paradigm to test in humans whether contextual threat-conditioned memories can be disrupted by a reminder-extinction procedure that putatively targets reconsolidation. In contrast to our hypothesis, we found comparable recovery of contextual conditioned threat responses, and comparable retention of subjective measures of threat memory, episodic memory and exploration behaviour between the reminder-extinction and standard extinction groups. Our result provide no evidence that a reminder before extinction can prevent the return of context conditioned threat memories in humans.


Assuntos
Tonsila do Cerebelo/fisiologia , Condicionamento Clássico/fisiologia , Extinção Psicológica/fisiologia , Consolidação da Memória/fisiologia , Adolescente , Adulto , Aprendizagem da Esquiva , Medo , Feminino , Humanos , Masculino , Memória Episódica , Sistemas de Alerta , Realidade Virtual , Adulto Jovem
8.
Sci Rep ; 10(1): 16113, 2020 09 30.
Artigo em Inglês | MEDLINE | ID: mdl-32999309

RESUMO

Music listening is one of the most pleasurable activities in our life. As a rewarding stimulus, pleasant music could induce long-term memory improvements for the items encoded in close temporal proximity. In the present study, we behaviourally investigated (1) whether musical pleasure and musical hedonia enhance verbal episodic memory, and (2) whether such enhancement takes place even when the pleasant stimulus is not present during the encoding. Participants (N = 100) were asked to encode words presented in different auditory contexts (highly and lowly pleasant classical music, and control white noise), played before and during (N = 49), or only before (N = 51) the encoding. The Barcelona Music Reward Questionnaire was used to measure participants' sensitivity to musical reward. 24 h later, participants' verbal episodic memory was tested (old/new recognition and remember/know paradigm). Results revealed that participants with a high musical reward sensitivity present an increased recollection performance, especially for words encoded in a highly pleasant musical context. Furthermore, this effect persists even when the auditory stimulus is not concurrently present during the encoding of target items. Taken together, these findings suggest that musical pleasure might constitute a helpful encoding context able to drive memory improvements via reward mechanisms.


Assuntos
Percepção Auditiva/fisiologia , Rememoração Mental/fisiologia , Prazer/fisiologia , Adulto , Atenção/fisiologia , Emoções/fisiologia , Feminino , Humanos , Masculino , Memória Episódica , Música , Reconhecimento Psicológico/fisiologia , Recompensa , Adulto Jovem
9.
Proc Natl Acad Sci U S A ; 117(45): 28463-28474, 2020 11 10.
Artigo em Inglês | MEDLINE | ID: mdl-33109718

RESUMO

The organization of temporal information is critical for the encoding and retrieval of episodic memories. In the rodent hippocampus and entorhinal cortex, evidence accumulated over the last decade suggests that populations of "time cells" in the hippocampus encode temporal information. We identify time cells in humans using intracranial microelectrode recordings obtained from 27 human epilepsy patients who performed an episodic memory task. We show that time cell activity predicts the temporal organization of retrieved memory items. We also uncover evidence of ramping cell activity in humans, which represents a complementary type of temporal information. These findings establish a cellular mechanism for the representation of temporal information in the human brain needed to form episodic memories.


Assuntos
Córtex Entorrinal/fisiologia , Hipocampo/fisiologia , Memória Episódica , Escala de Avaliação Comportamental , Encéfalo , Epilepsia , Humanos , Lobo Temporal , Texas
10.
PLoS One ; 15(10): e0240858, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33095817

RESUMO

Individuals often choose between remembering information using their own memory ability versus using external resources to reduce cognitive demand (i.e. 'cognitive offloading'). For example, to remember a future appointment an individual could choose to set a smartphone reminder or depend on their unaided memory ability. Previous studies investigating strategic reminder setting found that participants set more reminders than would be optimal, and this bias towards reminder-setting was predicted by metacognitive underconfidence in unaided memory ability. Due to the link between underconfidence in memory ability and excessive reminder setting, the aim of the current study was to investigate whether metacognitive training is an effective intervention to a) improve metacognitive judgment accuracy, and b) reduce bias in strategic offloading behaviour. Participants either received metacognitive training which involved making performance predictions and receiving feedback on judgment accuracy, or were part of a control group. As predicted, metacognitive training increased judgment accuracy: participants in the control group were significantly underconfident in their memory ability, whereas the experimental group showed no significant metacognitive bias. However, contrary to predictions, both experimental and control groups were significantly biased toward reminder-setting, and did not differ significantly. Therefore, reducing metacognitive bias was not sufficient to eliminate the bias towards reminders. We suggest that the reminder bias likely results in part from erroneous metacognitive evaluations, but that other factors such as a preference to avoid cognitive effort may also be relevant. Finding interventions to mitigate these factors could improve the adaptive use of external resources.


Assuntos
Educação , Metacognição , Adulto , Idoso , Feminino , Humanos , Masculino , Memória Episódica , Rememoração Mental , Pessoa de Meia-Idade , Sistemas de Alerta , Autoavaliação , Adulto Jovem
11.
Annu Int Conf IEEE Eng Med Biol Soc ; 2020: 2540-2543, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-33018524

RESUMO

Clinical and biological changes during the prodromal stages of dementia are both complicated and expensive. A biomarker for cognitive reserve exposure would be highly useful as a dementia risk predictor, but has eluded researchers. Speech, which exhibits disfluencies due to dementia, is a good candidate as it is easy to collect and non-invasive. However, previous studies have only looked at the impact of dementia on speech after diagnosis. Here we extend our previous work that showed paralinguistic features extracted from audio recordings of older participants completing the LOGOS episodic memory test can be used to discriminate between high vs low cognitive reserve, hence low vs high risk of dementia. Specifically, we use the clinically validated Lifetime of Experiences Questionnaire (LEQ) to refine our ground truth estimate of cognitive reserve instead of an abridged version. Also, we improve the generalizability of our system by using feature warping to normalize across speakers. Our k-nearest neighbours (KNN) based classifier achieved an accuracy of 84% when trained with paralinguistic features alone and 91% with paralinguistic and episodic memory features.Clinical Relevance- This establishes efficacy of using speech from older participants completing the LOGOS episodic memory test to estimate risk of dementia.


Assuntos
Reserva Cognitiva , Demência , Memória Episódica , Demência/diagnóstico , Humanos , Sintomas Prodrômicos , Fala
12.
PLoS One ; 15(9): e0238434, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32877450

RESUMO

AIMS: This study is based on two experiments, the first, with an exploratory character. The aim of which is to assess the capacity of native vs international pop songs (NAT vs INT) from two consecutive life stages, Reminiscence bump (RB) and the immediately subsequent period (No reminiscence bump, NORB) to elicit positive emotions and autobiographical memories. METHOD: A total of 15 middle-aged adults and 15 older adults participated in Experiment 1 (E1). Emotionality, song familiarity and associated autobiographical memories were assessed. Each participant was exposed to 20 randomly selected age-specific songs. Pre-and post-test measures of mood state were also included. Experiment 2 (E2) focused on late adulthood, using a sample of 35 persons. The experimental design was similar to that used in E1. However, this second experiment also included an analysis of the types of autobiographical memories generated by the experimental task and a study of their relationship with the characteristics of the songs, their familiarity and the emotions they produced, and the number of trials. The aim was to delve into the effects that influence the effectiveness of the induction procedure, particularly as regards emotional positivity and memory specificity. RESULTS: Regarding age effect, E1 results varied: under some conditions, emotionality showed no difference between groups, others showed positive older adult bias. In E2, the analysis of the relationships between memory types and the selected variables suggests the latter are not useful predictors of differences between memory types. The study design yielded a relatively high level of memory specificity and emotional positivity. CONCLUSION: The findings question positivity bias in the elderly. RB music produces different effects depending on age. Enculturation can be an important mediating factor in emotionality and memory. Finally, experimental design improves specific memory and positivity.


Assuntos
Memória/fisiologia , Rememoração Mental/fisiologia , Música/psicologia , Adulto , Idoso , Sinais (Psicologia) , Emoções , Feminino , Humanos , Masculino , Memória Episódica , Pessoa de Meia-Idade , Reconhecimento Psicológico , Comportamento Social
13.
PLoS One ; 15(9): e0239077, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32960930

RESUMO

The Virtual Supermarket Task (VST) and Sea Hero Quest detect high-genetic-risk Alzheimer`s disease (AD). We aimed to determine their test-retest reliability in a preclinical AD population. Over two time points, separated by an 18-month period, 59 cognitively healthy individuals underwent a neuropsychological and spatial navigation assessment. At baseline, participants were classified as low-genetic-risk of AD or high-genetic-risk of AD. We calculated two-way mixed effects intraclass correlation coefficients (ICC) for task parameters and used repeated measures ANOVAS to determine whether genetic risk or sex contributed to test-retest variability. The egocentric parameter of the VST measure showed the highest test-retest reliability (ICC = .72), followed by the SHQ distance travelled parameter (ICC = .50). Post hoc longitudinal analysis showed that boundary-based navigation predicts worsening episodic memory concerns in high-risk (F = 5.01, P = 0.03), but in not low-risk, AD candidates. The VST and the Sea Hero Quest produced parameters with acceptable test-retest reliability. Further research in larger sample sizes is desirable.


Assuntos
Doença de Alzheimer/diagnóstico , Navegação Espacial , Idoso , Doença de Alzheimer/etiologia , Doença de Alzheimer/genética , Cognição , Feminino , Predisposição Genética para Doença , Humanos , Masculino , Memória Episódica , Pessoa de Meia-Idade , Testes Neuropsicológicos , Fatores de Risco , Fatores Sexuais
14.
PLoS One ; 15(9): e0239581, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32976533

RESUMO

Despite the prevalence of everyday memory failures, little is known about which specific types have the strongest impact on everyday life, and whether their impact changes across adulthood. An investigation of memory failures at different ages is particularly informative to disentangle the age paradox in prospective memory, which seems to suggest that remembering to perform intended actions in everyday life improves with age. Therefore, 58 young adults, 40 middle-aged adults, and 54 elderly adults recorded their memory failures as and when they occurred during a 7-day period, and described how serious and consequential they were. Failures were coded into several subcategories of retrospective memory, prospective memory, and absent-minded lapses. It was prospective memory lapses that were overall the most common, serious and consequential ones. Young adults had substantially more prospective memory failures than the elderly and middle-aged adults who did not differ from each other. A young adult disadvantage still held up when lifestyle differences between young adults and the elderly were taken into account. Our findings support the age-related benefit previously found in naturalistic prospective memory tasks, and suggest that it is robust across various types of prospective memory tasks. The results also suggest that the benefit may result from both young adults having poor everyday prospective memory, compared to any adults of a greater age, and everyday prospective memory being spared from age-related decline between the middle and late adulthood.


Assuntos
Envelhecimento/patologia , Transtornos da Memória/patologia , Rememoração Mental/fisiologia , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Intenção , Masculino , Memória Episódica , Pessoa de Meia-Idade , Testes Neuropsicológicos , Estudos Retrospectivos , Adulto Jovem
15.
Neurology ; 95(17): e2398-e2408, 2020 10 27.
Artigo em Inglês | MEDLINE | ID: mdl-32907958

RESUMO

OBJECTIVE: To understand how, biologically, the acute event of traumatic brain injury gives rise to a long-term disease, we address the relationship between evolving cortical and subcortical brain damage and measures of functional outcome and cognitive functioning at 6 months after injury. METHODS: For this longitudinal analysis, clinical and MRI data were collected in a tertiary neurointensive care setting in a continuous sample of 157 patients surviving moderate to severe traumatic brain injury between 2000 and 2018. For each patient, we collected T1- and T2-weighted MRI data acutely and at the 6-month follow-up, as well as acute measures of injury severity (Glasgow Coma Scale), follow-up measures of functional impairment (Glasgow Outcome Scale-extended), and, in a subset of patients, neuropsychological measures of attention, executive functions, and episodic memory. RESULTS: In the final cohort of 113 subcortical and 92 cortical datasets that survived (blind) quality control, extensive atrophy was observed over the first 6 months after injury across the brain. However, only atrophy within subcortical regions, particularly in the left thalamus, was associated with functional outcome and neuropsychological measures of attention, executive functions, and episodic memory. Furthermore, when brought together in an analytical model, longitudinal brain measurements could distinguish good from bad outcome with 90% accuracy, whereas acute brain and clinical measurements alone could achieve only 20% accuracy. CONCLUSION: Despite great injury heterogeneity, secondary thalamic pathology is a measurable minimum common denominator mechanism directly relating biology to clinical measures of outcome and cognitive functioning, potentially linking the acute event and the longer-term disease of traumatic brain injury.


Assuntos
Lesões Encefálicas Traumáticas/complicações , Encéfalo/diagnóstico por imagem , Disfunção Cognitiva/etiologia , Adulto , Idoso , Atenção , Lesões Encefálicas Traumáticas/diagnóstico por imagem , Lesões Encefálicas Traumáticas/psicologia , Disfunção Cognitiva/diagnóstico por imagem , Disfunção Cognitiva/psicologia , Estudos de Coortes , Função Executiva , Feminino , Seguimentos , Escala de Coma de Glasgow , Escala de Resultado de Glasgow , Humanos , Estudos Longitudinais , Imagem por Ressonância Magnética , Masculino , Memória Episódica , Pessoa de Meia-Idade , Testes Neuropsicológicos , Teste de Stroop , Adulto Jovem
16.
Sci Rep ; 10(1): 15276, 2020 09 17.
Artigo em Inglês | MEDLINE | ID: mdl-32943742

RESUMO

Brain training programs are currently one effective solution to prevent cognitive decline in healthy aging. We conducted a meta-analysis of randomized controlled trials assessing the use of commercially available computerised cognitive games to improve cognitive function in people aged above 60 years old without cognitive impairment. 1,543 participants from sixteen studies were included in the meta-analysis. Statistically significant improvements were observed for processing speed (SMD increased 0.40 [95% CI 0.20-0.60], p < 0.001), working memory (0.21 [95% CI 0.08-0.34], p = 0.001), executive function (0.21 [95% CI 0.06-0.35], p = 0.006), and for verbal memory (0.12 [95% CI 0.01-0.24, p = 0.031), but not for attention or visuospatial abilities. No relationship between the age of the participants and the amount of training was found. Commercially available computerised cognitive games are effective in improving cognitive function in participants without cognitive impairment aged over 60 years.


Assuntos
Cognição/fisiologia , Disfunção Cognitiva/prevenção & controle , Idoso , Idoso de 80 Anos ou mais , Encéfalo/fisiologia , Demência/prevenção & controle , Função Executiva , Feminino , Envelhecimento Saudável/fisiologia , Humanos , Masculino , Memória Episódica , Memória de Curto Prazo/fisiologia , Pessoa de Meia-Idade , Jogos de Vídeo
17.
BMC Womens Health ; 20(1): 177, 2020 08 14.
Artigo em Inglês | MEDLINE | ID: mdl-32795281

RESUMO

BACKGROUND: There may be changes in cognitive function in women going through the menopause. The current evidence remains unclear, however, whether these changes occur over and above those of general ageing. We aimed to evaluate the potential impact of the menopause (assessed by reproductive age and hormone levels) on cognitive function in women in mid-life accounting for the underlying effects of ageing. METHODS: The study was based on the follow up of women originally enrolled in pregnancy in a birth cohort when resident in the South West of England, UK between 1991 and 1992. Using up to three repeated measurements in 2411 women (mean age 51 at first assessment), we modelled changes in six cognitive function domains: immediate and delayed verbal episodic memory, working memory, processing speed, verbal intelligence and verbal fluency. The exposures of interest were reproductive age measured as years relative to the final menstrual period (FMP), chronological age and reproductive hormones (follicle-stimulating hormone (FSH), luteinizing hormone (LH) and anti-Müllerian hormone (AMH)). RESULTS: Processing speed (- 0.21 (95% CI - 0.36 to - 0.06) standard deviation (SD) difference per 10 years since FMP), immediate verbal episodic memory (- 0.15 (95% CI - 0.35 to 0.06)) and delayed verbal episodic memory (- 0.17 (95% CI - 0.37 to 0.03)) declined with reproductive age. Reproductive hormones were not robustly associated with processing speed, but FSH and LH were both negatively associated with immediate (- 0.08 (95% CI - 0.13 to - 0.02) SD difference per SD difference in hormone level) and delayed verbal episodic memory (- 0.08 (95% CI - 0.13 to - 0.03)). There was little consistent evidence of cognitive function declining with menopause in other cognitive domains. CONCLUSIONS: Of the cognitive domains tested only verbal episodic memory declined both in relation to age since the menopause and in conjunction with the reproductive hormones that reflect the menopause. This decline was independent of normal ageing and suggests that the menopause is associated with a mild impact on this specific domain of cognitive function.


Assuntos
Envelhecimento/fisiologia , Cognição/efeitos dos fármacos , Hormônios/fisiologia , Menopausa/efeitos dos fármacos , Inglaterra , Terapia de Reposição de Estrogênios , Feminino , Hormônio Foliculoestimulante/sangue , Hormônios Esteroides Gonadais/sangue , Humanos , Estudos Longitudinais , Memória/efeitos dos fármacos , Memória/fisiologia , Memória Episódica , Menopausa/fisiologia , Pessoa de Meia-Idade , Reino Unido
18.
Sci Rep ; 10(1): 14192, 2020 08 25.
Artigo em Inglês | MEDLINE | ID: mdl-32843700

RESUMO

Decline in episodic memory performance usually causes the first clinical symptoms of Alzheimer's disease. At present, Alzheimer's disease can only be diagnosed at a very late stage when neurodegeneration and cognitive impairment is already irreversible. New early disease markers are needed for earlier and more efficient Alzheimer's disease intervention. To identify early disease markers, we implemented a genome-wide bisulphite sequencing method for the analysis of plasma cell-free DNA methylation profiles and compared differences associated with episodic memory performance in Finnish twin pairs. A noticeable amount of cell-free DNA was present in plasma, however, the amounts as well as the genomic coverage of these fragments varied substantially between individuals. We found no significant markers associated with episodic memory performance in the twins' plasma cell-free DNA methylation profiles. Furthermore, our results indicate that due to the low genomic coverage of cell-free DNA fragments and the variety in these fragments between individuals, the implemented genome-wide bisulphite sequencing method is not optimal for comparing cell-free DNA methylation differences between large groups of individuals.


Assuntos
Doença de Alzheimer/diagnóstico , Ácidos Nucleicos Livres/metabolismo , Transtornos da Memória/genética , Idoso , Doença de Alzheimer/genética , Ácidos Nucleicos Livres/sangue , Cognição/fisiologia , Disfunção Cognitiva/genética , Metilação de DNA/fisiologia , Feminino , Finlândia , Estudo de Associação Genômica Ampla , Humanos , Masculino , Memória/fisiologia , Memória Episódica , Testes Neuropsicológicos , Plasma , Gêmeos/genética , Gêmeos Monozigóticos/genética
19.
J Neurosci ; 40(38): 7300-7310, 2020 09 16.
Artigo em Inglês | MEDLINE | ID: mdl-32817245

RESUMO

The human cerebellum is thought to interact with distributed brain networks to support cognitive abilities such as episodic memory and semantic prediction. Hippocampal and fronto-temporo-parietal networks that respectively support episodic memory versus semantic prediction have been associated with distinct endogenous oscillatory activity frequency bands: theta (∼3-8 Hz) versus beta (∼13-30 Hz) respectively. We sought to test whether it is possible to toggle cerebellar participation in episodic memory versus semantic prediction by noninvasively stimulating with theta versus beta rhythmic transcranial magnetic stimulation. In human subjects of both sexes, cerebellar theta stimulation improved episodic memory encoding but did not influence neural signals of semantic prediction, whereas beta stimulation of the same cerebellar location increased neural signals of semantic prediction but did not influence episodic memory encoding. This constitutes evidence for double dissociation of cerebellar contributions to semantic prediction versus episodic memory based on stimulation rhythm, supporting the hypothesis that the cerebellum can be biased to support these distinct cognitive abilities at the command of network-specific rhythmic activity.SIGNIFICANCE STATEMENT The cerebellum interacts with several distinct large-scale brain networks for cognitive function, but the factors governing selectivity of such interactions for particular functions are not fully understood. We tested the hypothesis that cerebellar contributions to cognition are guided by neural oscillations with function-specific frequency bands. We demonstrated that matching noninvasive stimulation to network-specific frequencies selectively enhanced episodic memory versus semantic prediction. These findings suggest that cerebellar contributions to cognitive networks are selected based on corresponding activity rhythms and could be used to develop cerebellar stimulation interventions for specific neurocognitive impairments.


Assuntos
Ritmo beta , Cerebelo/fisiologia , Memória Episódica , Semântica , Ritmo Teta , Adolescente , Adulto , Feminino , Humanos , Masculino , Estimulação Magnética Transcraniana/métodos
20.
Neurology ; 95(19): e2622-e2634, 2020 11 10.
Artigo em Inglês | MEDLINE | ID: mdl-32732300

RESUMO

OBJECTIVE: To determine whether vascular and neurodegenerative factors influence cognition before clinically relevant Alzheimer disease pathology, we analyzed MRI measures and amyloid imaging in an ethnoracially diverse cohort of cognitively normal individuals older than 60 years. METHODS: Participants (n = 154; mean age 74.15 ± 6.94; 50% female; 54% Caucasian, 22.1% Hispanic, 14.9% African American) were recruited from the University of California, Davis Alzheimer's Disease Research Center, who were cognitively normal at baseline, time of PET, and MRI, and received yearly cognitive assessment for 6.23 ± 4.16 years. Mixed model regression with random slope and intercept was calculated for episodic memory and executive function, adjusting for age, sex, education, and ethnicity. RESULTS: Vascular burden score was associated with total white matter hyperintensity (WMH) volume (ß, 0.171; 95% confidence interval [CI], 0.024-0.318). WMH volume was associated with low baseline executive function (-0.115; -0.226 to -0.003) and rate of change in memory (-0.029; -0.045 to -0.012). Hippocampal volume was associated with the rate of change in memory (0.040; 0.021-0.059) and executive function (0.024; 0.008-0.039). Continuous measures of amyloid status influenced change in memory (-0.026; -0.044 to -0.008) and executive function (-0.033; -0.046 to -0.021) independently of MRI measures. CONCLUSION: Vascular brain injury and neurodegeneration are associated with baseline cognitive performance and the rate of longitudinal change independent of amyloid status among community-dwelling, ethnicity diverse cognitively normal individuals, supporting the role of vascular diseases as risk factors for later-life dementia.


Assuntos
Peptídeos beta-Amiloides/metabolismo , Encéfalo/diagnóstico por imagem , Transtornos Cerebrovasculares/fisiopatologia , Disfunção Cognitiva/fisiopatologia , Hipocampo/diagnóstico por imagem , Placa Amiloide/diagnóstico por imagem , Substância Branca/diagnóstico por imagem , Idoso , Idoso de 80 Anos ou mais , Compostos de Anilina , Encéfalo/metabolismo , Cognição/fisiologia , Progressão da Doença , Função Executiva/fisiologia , Feminino , Hipocampo/patologia , Humanos , Vida Independente , Imagem por Ressonância Magnética , Masculino , Transtornos da Memória/fisiopatologia , Memória Episódica , Testes Neuropsicológicos , Tamanho do Órgão , Tomografia por Emissão de Pósitrons , Tiazóis , Substância Branca/patologia
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