RESUMEN
Our cognition can be directed to external stimuli or to internal information. While there are many different forms of internal cognition (mind-wandering, recall, imagery etc.), their essential feature is independence from the immediate sensory input, conceptually referred to as perceptual decoupling. Perceptual decoupling is thought to be reflected in brain activity transitioning from a stimulus-processing to internally-processing mode, but a direct investigation of this remains outstanding. Here we present a conceptual and analysis framework that quantifies the extent to which brain networks reflect stimulus processing. We tested this framework by presenting subjects with an audiovisual stimulus and instructing them to either attend to the stimulus (external task) or engage in mental imagery, recall or arithmetic (internal tasks) while measuring the evoked brain activity using functional MRI. We found that stimulus responses were generally attenuated for the internal tasks, though they increased in a subset of tasks and brain networks. However, using our new framework, we showed that brain networks became less reflective of stimulus processing, even in the subset of tasks and brain networks in which stimulus responses increased. These results quantitatively demonstrate that during internal cognition brain networks become decoupled from the external stimuli, opening the door for a fundamental and quantitative understanding of internal cognition.
Asunto(s)
Atención , Cognición , Atención/fisiología , Encéfalo/fisiología , Mapeo Encefálico , Cognición/fisiología , Humanos , Imagen por Resonancia Magnética/métodosRESUMEN
BACKGROUND: To compare the underlying cause of death reported by the Israeli Central Bureau of Statistics (CBS) with diagnoses in the electronic health records (EHR) of a fully integrated payer/provider healthcare system. METHODS: Underlying cause of death was obtained from the CBS for deaths occurring during 2009-2012 of all Clalit Health Service members in Israel. The final cohort consisted of members who had complete medical records. The frequency of a supportive diagnosis in the EHR was reported for 10 leading causes of death (malignancies, heart disease, cerebrovascular disease, diabetes, kidney disease, septicemia, accidents, chronic lower respiratory disease, dementia and pneumonia and influenza). RESULTS: Of the 45 680 members included in the study, the majority of deaths had at least one diagnosis in the EHR that could support the cause of death. The lowest frequency of supportive diagnosis was for septicemia (52.2%) and the highest was for malignancies (94.3%). Sensitivity analysis did not suggest an alternative explanation for the missing documentation. CONCLUSIONS: The underlying cause of death coded by the CBS is often supported by diagnoses in Clalit's EHR. Exceptions are septicemia or accidents that cannot be anticipated from a patient's EHR, and dementia which may be under-reported.
Asunto(s)
Prestación Integrada de Atención de Salud , Diabetes Mellitus , Causas de Muerte , Registros Electrónicos de Salud , Humanos , IsraelRESUMEN
BACKGROUND: Skin appearance is badly affected when exposed to solar UV rays, which encourage physiological and structural cutaneous alterations that eventually lead to skin photo-damage. AIMS: To test the capability of two facial preparations, extreme day cream (EXD) and extreme night treatment (EXN), containing a unique complex of Dead Sea water and three Himalayan extracts, to antagonize biological effects induced by photo-damage. METHODS: Pieces of organ cultures of human skin were used as a model to assess the biological effects of UVB irradiation and the protective effect of topical application of two Extreme preparations. Skin pieces were analyzed for mitochondrial activity by MTT assay, for apoptosis by caspase 3 assay, and for cytokine secretion by solid phase ELISA. Human subjects were tested to evaluate the effect of Extreme preparations on skin wrinkle depth using PRIMOS and skin hydration by a corneometer. RESULTS: UVB irradiation induced cell apoptosis in the epidermis of skin organ cultures and increased their pro-inflammatory cytokine, tumor necrosis α (TNFα) secretion. Topical applications of both preparations significantly attenuated all these effects. Furthermore, in human subjects, a reduction in wrinkle depth and an elevation in the intense skin moisture were observed. CONCLUSIONS: The observations clearly show that EXD and EXN preparations have protective anti-apoptotic and anti-inflammatory properties that can attenuate biological effects of skin photo-damage. Topical application of the preparations improves skin appearance by reducing its wrinkles depth and increasing its moisturizing impact.