Mental Imagery and Visual Working Memory

Visual working memory provides an essential link between past and future events. Despite recent efforts, capacity limits, their genesis and the underlying neural structures of visual working memory remain unclear. Here we show that performance in visual working memory - but not iconic visual memory - can be predicted by the strength of mental imagery as assessed with binocular rivalry in a given individual. In addition, for individuals with strong imagery, modulating the background luminance diminished performance on visual working memory and imagery tasks, but not working memory for number strings. This suggests that luminance signals were disrupting sensory-based imagery mechanisms and not a general working memory system. Individuals with poor imagery still performed above chance in the visual working memory task, but their performance was not affected by the background luminance, suggesting a dichotomy in strategies for visual working memory: individuals with strong mental imagery rely on sensory-based imagery to support mnemonic performance, while those with poor imagery rely on different strategies. These findings could help reconcile current controversy regarding the mechanism and location of visual mnemonic storage

Impacto em cuidadores de idosos com demência atendidos em um serviço psicogeriátrico Impact on caregivers of elderly patients with dementia treated at a psychogeriatric service

OBJETIVO: O número de idosos com demência no Brasil está crescendo rapidamente, e há carência de dados empíricos sobre o impacto em cuidadores informais. O objetivo do estudo foi avaliar o impacto sobre cuidadores informais de pacientes com síndrome demencial. MÉTODOS: Estudo de corte transversal foi conduzido em um serviço psicogeriátrico da cidade de São Paulo, Brasil. Entrevistas estruturadas e semi-estruturadas foram aplicadas em 49 idosos com demência e em seus cuidadores informais. O impacto em cuidadores foi avaliado com a Zarit Burden Interview. RESULTADOS: Os pacientes eram em sua maioria do sexo feminino, apresentavam escore médio no mini exame do estado mental de 12,2 e alta freqüência de transtornos de comportamento. Os cuidadores eram predominantemente mulheres, filhas ou esposas, e co-residiam com seus pacientes. A média de impacto foi de 32,4 (dp: 16,7). As variáveis estatisticamente associadas a níveis de impacto foram o grau de parentesco do cuidador com o paciente (p=0,011), sintomas psiquiátricos do cuidador (p<0,001) e tempo em que o cuidador exercia o papel de cuidar (p=0,001). CONCLUSÕES: Observou-se alta média de impacto em cuidadores de idosos, com demência, que necessitam de atendimento psicogeriátrico. É necessário que os profissionais de saúde estejam aptos a prover suporte adequado a esses cuidadores, com o objetivo de minimizar problemas tanto para pacientes, quanto para cuidadores.<br>OBJECTIVE: There is an increasingly number of demented elderly in Brazil but empirical data on the resulting impact on their informal caregivers is still poorly documented. The purpose of this study was to evaluate the impact on informal caregivers of elderly with dementia. METHODS: A cross-sectional study was conducted at a psychogeriatric unit in the city of São Paulo, Brazil. Structured and semi-structured interviews were administered to 49 elderly patients with dementia and their caregivers. The impact on the caregiver was measured using the Zarit Burden Interview. RESULTS: Most patients were females, had an average score of 12.2 in the Mini Mental State Examination and high incidence of disruptive behavior. Caregivers were predominantly females, generally wives or daughters who lived with their patients. The mean impact score was 32.4 (SD 16.7). Variables statistically associated with the level of impact were: degree of kinship between patient and caregiver (p=0.011); caregiver's psychiatric symptoms (p<0.001), and duration of caregiving role (p=0.001). CONCLUSIONS: A high impact on caregivers of demented elderly who required psychogeriatric intervention was detected. Healthcare providers should be able to provide the needed support to caregivers in order to minimize problems to both patients and their caregivers

Voluntary control and the dynamics of perceptual bi-stability

van Ee R, van Dam L, Brouwer GJ. Voluntary control and the dynamics of perceptual bi-stability. VISION RESEARCH. 2005;45(1):41-55

910 metagenome-assembled genomes from the phytobiomes of three urban-farmed leafy Asian greens

10.1038/s41597-020-00617-9Scientific Data7127

Metabolic footprint of epiphytic bacteria on Arabidopsis thaliana leaves

The phyllosphere, which is defined as the parts of terrestrial plants above the ground, is a large habitat for different microorganisms that show a high extent of adaption to their environment. A number of hypotheses were generated by culture-independent functional genomics studies to explain the competitiveness of specialized bacteria in the phyllosphere. In contrast, in situ data at the metabolome level as a function of bacterial colonization are lacking. Here, we aimed to obtain new insights into the metabolic interplay between host and epiphytes upon colonization of Arabidopsis thaliana leaves in a controlled laboratory setting using environmental metabolomics approaches. Quantitative nuclear magnetic resonance (NMR) and imaging high-resolution mass spectrometry (IMS) methods were used to identify Arabidopsis leaf surface compounds and their possible involvement in the epiphytic lifestyle by relative changes in compound pools. The dominant carbohydrates on the leaf surfaces were sucrose, fructose and glucose. These sugars were significantly and specifically altered after epiphytic leaf colonization by the organoheterotroph Sphingomonas melonis or the phytopathogen Pseudomonas syringae pv. tomato, but only to a minor extent by the methylotroph Methylobacterium extorquens. In addition to carbohydrates, IMS revealed surprising alterations in arginine metabolism and phytoalexin biosynthesis that were dependent on the presence of bacteria, which might reflect the consequences of bacterial activity and the recognition of not only pathogens but also commensals by the plant. These results highlight the power of environmental metabolomics to aid in elucidating the molecular basis underlying plant-epiphyte interactions in situ