Effects of a multivitamin, mineral and herbal supplement on cognition and blood biomarkers in older men: a randomised, placebo-controlled trial

OBJECTIVE: Nutritional and vitamin status may be related to cognitive function and decline in older adults. The aim of this study was to investigate the effects of nutritional supplementation on cognition in older men. METHOD: The current study was an 8-week, placebo-controlled, double-blind investigation into the effects of a multivitamin, mineral and herbal supplement (Swisse Men's Ultivite®, Swisse Vitamins Pty Ltd, Melbourne, Australia) on cognitive performance in older men. Participants were 51 male individuals aged between 50 and 74 years, with a sedentary lifestyle. Cognitive performance was assessed at baseline and post-treatment using a computerised battery of cognitive tasks, enabling the measurement of a range of attentional and memory processes. Blood measures of vitamin B(12) , folate and homocysteine were collected prior to and after supplementation. RESULTS: The results of this study revealed that contextual recognition memory performance was significantly improved following multivitamin supplementation (p < 0.05). Performance on other cognitive tasks did not change. Levels of vitamin B(12) and folate were significantly increased with a concomitant decrease in homocysteine, indicating that relatively short-term supplementation with a multivitamin can benefit these risk factors for cognitive decline. CONCLUSION: Findings from this study indicate that daily multivitamin supplementation may improve episodic memory in older men at risk of cognitive decline.

Diferenças funcionais das regiões hipocampais na formação da memória do tipo o quê", "quando" e "onde" em ratos

Episodic memory refers to the recollection of what, where and when a specific event occurred. Hippocampus is a key structure in this type of memory. Computational models suggest that the dentate gyrus (DG) and the CA3 hippocampal subregions are involved in pattern separation and the rapid acquisition of episodic memories, while CA1 is involved in memory consolidation. However there are few studies with animal models that access simultaneously the aspects ‗what-where-when . Recently, an object recognition episodic-like memory task in rodents was proposed. This task consists of two sample trials and a test phase. In sample trial one, the rat is exposed to four copies of an object. In sample trial two, one hour later, the rat is exposed to four copies of a different object. In the test phase, 1 h later, two copies of each of the objects previously used are presented. One copy of the object used in sample trial one is located in a different place, and therefore it is expected to be the most explored object.However, the short retention delay of the task narrows its applications. This study verifies if this task can be evoked after 24h and whether the pharmacological inactivation of the DG/CA3 and CA1 subregions could differentially impair the acquisition of the task described. Validation of the task with a longer interval (24h) was accomplished (animals showed spatiotemporal object discrimination and scopolamine (1 mg/kg, ip) injected pos-training impaired performance). Afterwards, the GABA agonist muscimol, (0,250 μg/μl; volume = 0,5 μl) or saline were injected in the hippocampal subregions fifteen minutes before training. Pre-training inactivation of the DG/CA3 subregions impaired the spatial discrimination of the objects (‗where ), while the temporal discrimination (‗when ) was preserved. Rats treated with muscimol in the CA1 subregion explored all the objects equally well, irrespective of place or presentation time. Our results corroborate the computational models that postulate a role for DG/CA3 in spatial pattern separation, and a role for CA1 in the consolidation process of different mnemonic episodes

Efeito do alerta e valência emocional nos componentes de lembrança e familiaridade da memória episódica

The episodic memory system allows us to retrieve information about events, including its contextual aspects. It has been suggested that episodic memory is composed by two independent components: recollection and familiarity. Recollection is related to the vivid e detailed retrieval of item and contextual information, while familiarity is the capability to recognize items previously seen as familiars. Despite the fact that emotion is one of the most influent process on memory, only a few studies have investigated its effect on recollection and familiarity. Another limitation of studies about the effect of emotion on memory is that the majority of them have not adequately considered the differential effects of arousal and positive/negative valence. The main purpose of the current work is to investigate the independent effect of emotional valence and arousal on recollection and familiarity, as well as to test some hypothesis that have been suggested about the effect of emotion on episodic memory. The participants of the research performed a recognition task for three lists of emotional pictures: high arousal negative, high arousal positive and low arousal positive. At the test session, participants also rated the confidence level of their responses. The confidence ratings were used to plot ROC curves and estimate the contributions of recollection and familiarity of recognition performance. As the main results, we found that negative valence enhanced the component of recollection without any effect on familiarity or recognition accuracy. Arousal did not affect recognition performance or their components, but high arousal was associated with a higher proportion of false memories. This work highlight the importance of to consider both the emotional dimensions and episodic memory components in the study of emotion effect on episodic memory, since they interact in complex and independent way

White matter abnormalities associated with Alzheimer's disease and mild cognitive impairment: A critical review of MRI studies

In this article, the authors aim to present a critical review of recent MRI studies addressing white matter (WM) abnormalities in Alzheimer's disease (AD) and mild cognitive impairment (MCI), by searching PubMed and reviewing MRI studies evaluating subjects with AD or MCI using WM volumetric methods, diffusion tensor imaging and assessment of WM hyperintensities. Studies have found that, compared with healthy controls, AD and MCI samples display WM volumetric reductions and diffusion tensor imaging findings suggestive of reduced WM integrity. These changes affect complex networks relevant to episodic memory and other cognitive processes, including fiber connections that directly link medial temporal structures and the corpus callosum. Abnormalities in cortico-cortical and cortico-subcortical WM interconnections are associated with an increased risk of progression from MCI to dementia. It can be concluded that WM abnormalities are detectable in early stages of AD and MCI. Degeneration of WM networks causes disconnection among neural cells and the degree of such changes is related to cognitive decline. © 2013 2013 Expert Reviews Ltd.

Rate of cognitive decline in relation to sex after 60 years-of-age: A systematic review

Some studies have shown differences in specific cognitive ability domains between the sexes at 60 years-of-age. However is important to analyze whether the rate of cognitive decline is also similar between the sexes after this age. The present study examined previously published literature to investigate whether cognitive decline is distinct between men and women after the age of 60 years. A systematic review was carried out with the PubMed, LILACS and PsycINFO databases (2001-2011) using the following search terms: aging, aged, cognitive function, mild cognitive impairment, mental health and cognition. We analyzed longitudinal research that used neuropsychological tests for evaluating cognitive function, showed results separated by sex and that excluded participants with dementia. Elderly women showed better performance in tests of episodic memory, whereas elderly men had a better visuospatial ability. Only one study detected distinct rates of cognitive decline in specific tests between the sexes. Despite differences observed in some domains, most of the studies showed that this rate is similar between the sexes until the age of 80 years. It is unclear whether sex influences the rate of cognitive decline after the age of 80 years. The present review observed that sex does not determine the rate of cognitive decline between 60 and 80 years-of-age. The contextual and cultural factors that involve men and women might determine a distinct decline between them, rather than sex alone. © 2013 Japan Geriatrics Society.

Influência do exercício físico em memória e funções executivas de pessoas com doença de Parkinson

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Exercise and cognitive functions in Parkinson's disease: Gender differences and disease severity

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Longitudinal effects of physical activity on self-efficacy and cognitive processing of active and sedentary elderly women

Previous studies support that regular physical activity in aging contributes as a protective factor against cognitive decline and improves mood states. However, there is a lack of longitudinal studies in this area. Objective: To observe possible changes in cognition related with physical activity. METHODS: This study reassessed, after one-year period, 31 elderly women divided into two groups, sedentary versus active, using behavioral scales and cognitive tests. RESULTS: The active group exhibited significantly enhanced performance in general cognitive function, particularly on tasks of episodic memory and praxis, and also on the mood states scale compared to the sedentary group. The active women also reported higher self-efficacy. CONCLUSION: Long-term physical activity promoted improvement on quality of life in the elderly women.

Seeing with the eyes shut: Neural basis of enhanced imagery following ayahuasca ingestion

The hallucinogenic brew Ayahuasca, a rich source of serotonergic agonists and reuptake inhibitors, has been used for ages by Amazonian populations during religious ceremonies. Among all perceptual changes induced by Ayahuasca, the most remarkable are vivid seeings. During such seeings, users report potent imagery. Using functional magnetic resonance imaging during a closed-eyes imagery task, we found that Ayahuasca produces a robust increase in the activation of several occipital, temporal, and frontal areas. In the primary visual area, the effect was comparable in magnitude to the activation levels of natural image with the eyes open. Importantly, this effect was specifically correlated with the occurrence of individual perceptual changes measured by psychiatric scales. The activity of cortical areas BA30 and BA37, known to be involved with episodic memory and the processing of contextual associations, was also potentiated by Ayahuasca intake during imagery. Finally, we detected a positive modulation by Ayahuasca of BA 10, a frontal area involved with intentional prospective imagination, working memory and the processing of information from internal sources. Therefore, our results indicate that Ayahuasca seeings stem from the activation of an extensive network generally involved with vision, memory, and intention. By boosting the intensity of recalled images to the same level of natural image, Ayahuasca lends a status of reality to inner experiences. It is therefore understandable why Ayahuasca was culturally selected over many centuries by rain forest shamans to facilitate mystical revelations of visual nature. Hum Brain Mapp, 2012. (c) 2011 Wiley Periodicals, Inc.

Determinants of cognitive performance among community dwelling older adults in an impoverished sub-district of Sao Paulo in Brazil

Determinants of cognitive performance in old age have received limited attention in Latin America. We investigated the association of socio-demographic and health-related variables with cognitive performance in a sample of older adults with limited educational experience living in a poor subdistrict of the city of Sao Paulo. This was a cross-sectional population-based study which included a sample of 384 seniors 65 years and older. Cognition was assessed by the Mini-Mental State Examination (MMSE) and the Brief Cognitive Screening Battery (BCSB) (episodic memory test with 10 pictures, verbal fluency (VF), Clock Drawing Test (CDT)). Results indicated that age, sex, schooling, depressive symptoms, and systolic blood pressure (SBP) level had a significant impact on the cognitive performance of the sample. Therefore, pharmacological and psychosocial interventions with a focus on improving mood and controlling hypertension may have beneficial effects on cognition among seniors with similar socio-demographic characteristics. (C) 2011 Elsevier Ireland Ltd. All rights reserved.

Correlation between topographic N400 anomalies and reduced cerebral blood flow in the anterior temporal lobes of patients with dementia

In Alzheimer's disease (AD) patients, episodic memory impairments are apparent, yet semantic memory difficulties are also observed. While the episodic pathology has been thoroughly studied, the neurophysiological mechanisms of the semantic impairments remain obscure. Semantic dementia (SD) is characterized by isolated semantic memory deficits. The present study aimed to find an early marker of mild AD and SD by employing a semantic priming paradigm during electroencephalogram recordings. Event-related potentials (ERP) of early (P1, N1) and late (N400) word processing stages were obtained to measure semantic memory functions. Separately, baseline cerebral blood flow (CBF) was acquired with arterial spin labeling. Thus, the analysis focused on linear regressions of CBF with ERP topographical similarity indices in order to find the brain structures that showed altered baseline functionality associated with deviant ERPs. All participant groups showed semantic priming in their reaction times. Furthermore, decreased CBF in the temporal lobes was associated with abnormal N400 topography. No significant CBF clusters were found for the early ERPs. Taken together, the neurophysiological results suggested that the automatic spread of activation during semantic word processing was preserved in mild dementia, while controlled access to the words was impaired. These findings suggested that N400-topography alterations might be a potential marker for the detection of early dementia. Such a marker could be beneficial for differential diagnosis due to its low cost and non-invasive application as well as its relationship with semantic memory dysfunctions that are closely associated to the cortical deterioration in regions crucial for semantic word processing.

Orthostatic hypotension in Parkinson's disease: association with cognitive decline?

BACKGROUND Orthostatic hypotension is common in Lewy body disorders and may be related to disease progression and the spread of Lewy body pathology. We therefore hypothesize that PD patients with orthostatic hypotension (OH) have a different cognitive profile compared to PD patients without OH. METHODS This cross-sectional study included 175 PD patients. Blood pressure (BP) was measured with a validated digital blood pressure monitor and patients with a systolic BP drop of > or =20 mmHg or a systolic pressure of <90 mm Hg after standing were considered to have OH. Cognition was assessed using MMSE extended by a selection of computerized cognitive tests focusing on reaction time, sustained attention, working memory and episodic verbal and visual memory. RESULTS Eighty-seven (49.7%) of the PD patients had OH. These patients were significantly more impaired in sustained attention and visual episodic memory compared to PD patients without OH. CONCLUSION We conclude that there are differences in the neuropsychological performance of patients with PD and OH, supporting the hypothesis that OH might be a marker for disease progression and cognitive decline in PD.

Event-relating to potential dementia. Semantic processing in the course of healthy and pathological aging

While most healthy elderly are able to manage their everyday activities, studies showed that there are both stable and declining abilities during healthy aging. For example, there is evidence that semantic memory processes which involve controlled retrieval mechanism decrease, whereas the automatic functioning of the semantic network remains intact. In contrast, patients with Alzheimer’s disease (AD) suffer from episodic and semantic memory impairments aggravating their daily functioning. In AD, severe episodic as well as semantic memory deficits are observable. While the hallmark symptom of episodic memory decline in AD is well investigated, the underlying mechanisms of semantic memory deterioration remain unclear. By disentangling the semantic memory impairments in AD, the present thesis aimed to improve early diagnosis and to find a biomarker for dementia. To this end, a study on healthy aging and a study with dementia patients were conducted investigating automatic and controlled semantic word retrieval. Besides the inclusion of AD patients, a group of participants diagnosed with semantic dementia (SD) – showing isolated semantic memory loss – was assessed. Automatic and controlled semantic word retrieval was measured with standard neuropsychological tests and by means of event-related potentials (ERP) recorded during the performance of a semantic priming (SP) paradigm. Special focus was directed to the N400 or N400-LPC (late positive component) complex, an ERP that is sensitive to the semantic word retrieval. In both studies, data driven topographical analyses were applied. Furthermore, in the patient study, the combination of the individual baseline cerebral blood flow (CBF) with the N400 topography of each participant was employed in order to relate altered functional electrophysiology to the pathophysiology of dementia. Results of the aging study revealed that the automatic semantic word retrieval remains stable during healthy aging, the N400-LPC complex showed a comparable topography in contrast to the young participants. Both patient groups showed automatic SP to some extent, but strikingly the ERP topographies were altered compared to healthy controls. Most importantly, the N400 was identified as a putative marker for dementia. In particular, the degree of the topographical N400 similarity was demonstrated to separate healthy elderly from demented patients. Furthermore, the marker was significantly related to baseline CBF reduction in brain areas relevant for semantic word retrieval. Summing up, the first major finding of the present thesis was that all groups showed semantic priming, but that the N400 topography differed significantly between healthy and demented elderly. The second major contribution was the identification of the N400 similarity as a putative marker for dementia. To conclude, the present thesis added evidence of preserved automatic processing during healthy aging. Moreover, a possible marker which might contribute to an improved diagnosis and lead consequently to a more effective treatment of dementia was presented and has to be further developed.

Detecting Analogies Unconsciously

Analogies may arise from the conscious detection of similarities between a present and a past situation. In this functional magnetic resonance imaging study, we tested whether young volunteers would detect analogies unconsciously between a current supraliminal (visible) and a past subliminal (invisible) situation. The subliminal encoding of the past situation precludes awareness of analogy detection in the current situation. First, participants encoded subliminal pairs of unrelated words in either one or nine encoding trials. Later, they judged the semantic fit of supraliminally presented new words that either retained a previously encoded semantic relation (“analog”) or not (“broken analog”). Words in analogs versus broken analogs were judged closer semantically, which indicates unconscious analogy detection. Hippocampal activity associated with subliminal encoding correlated with the behavioral measure of unconscious analogy detection. Analogs versus broken analogs were processed with reduced prefrontal but enhanced medial temporal activity. We conclude that analogous episodes can be detected even unconsciously drawing on the episodic memory network.

Hippocampus is place of interaction between unconscious and conscious memories retrieval

Recent experiments suggest that humans can form and later retrieve new semantic relations unconsciously by way of hippocampus - the key structure thought to support conscious relational (episodic) memory. Given that the hippocampus subserves both conscious and unconscious relational encoding/retrieval, we expected the hippocampus to be place of unconscious-conscious interactions. This hypothesis was tested in an fMRI experiment on the interaction between the unconscious retrieval of face-associated occupations and the subsequent conscious retrieval of celebrities’ occupations. For subliminal encoding, masked combinations of an unfamiliar face and a written occupation (“actor” or “politician”) were subliminally presented. At test, we presented the former subliminal faces again, without occupations and masks, as conscious retrieval cues. We hypothesized that faces would trigger the unconscious reactivation of the associated occupation - actor or politician -, which in turn would facilitate or inhibit the subsequent conscious recollection of a celebrity’s occupation. Following the presentation of a former subliminal face, we presented the portrait of a celebrity that participants were required to sort according to “actor” or “politician”. Depending on whether the triggered unconscious occupation was congruent or incongruent with the celebrity’s occupation, we expected an expedited or retarded conscious retrieval process as reflected in reaction times. Conscious retrieval was expedited in the congruent condition, but there was no effect in the incongruent condition. fMRI data collected during subliminal relational encoding confirmed that the hippocampus was interacting with neocortical semantic storage sites. fMRI data collected at test indicated that the facilitated conscious retrieval of celebrity-associated occupations was related to deactivations in this same network spanning hippocampus and neocortical semantic storage sites. Hence, unconscious retrieval likely preactivated this network, which allowed for a sparing recruitment of additional neural resources to assist conscious retrieval. This finding supports the notion that consciously and unconsciously acquired relational memories are stored in a single, cohesive hippocampal-neocortical memory space.