Neural Connectivity with Hidden Gaussian Graphical State-Model

The noninvasive procedures for neural connectivity are under questioning. Theoretical models sustain that the electromagnetic field registered at external sensors is elicited by currents at neural space. Nevertheless, what we observe at the sensor space is a superposition of projected fields, from the whole gray-matter. This is the reason for a major pitfall of noninvasive Electrophysiology methods: distorted reconstruction of neural activity and its connectivity or leakage. It has been proven that current methods produce incorrect connectomes. Somewhat related to the incorrect connectivity modelling, they disregard either Systems Theory and Bayesian Information Theory. We introduce a new formalism that attains for it, Hidden Gaussian Graphical State-Model (HIGGS). A neural Gaussian Graphical Model (GGM) hidden by the observation equation of Magneto-encephalographic (MEEG) signals. HIGGS is equivalent to a frequency domain Linear State Space Model (LSSM) but with sparse connectivity prior. The mathematical contribution here is the theory for high-dimensional and frequency-domain HIGGS solvers. We demonstrate that HIGGS can attenuate the leakage effect in the most critical case: the distortion EEG signal due to head volume conduction heterogeneities. Its application in EEG is illustrated with retrieved connectivity patterns from human Steady State Visual Evoked Potentials (SSVEP). We provide for the first time confirmatory evidence for noninvasive procedures of neural connectivity: concurrent EEG and Electrocorticography (ECoG) recordings on monkey. Open source packages are freely available online, to reproduce the results presented in this paper and to analyze external MEEG databases

Botão de ajuda para idosos através da plataforma Arduino

Se reporta el diseño e implementación de un sistema capaz de proveer a personas de la tercera edad de una vía rápida para pedir ayuda, de manera remota, al encargado de su cuidado, usando la red celular. Se implementó un sistema, cuya principal funcionalidad es un botón de ayuda, mediante el cual la persona encargada del cuidado del anciano recibirá un mensaje de texto cuando el anciano presione el botón. Reconociendo la poca vinculación de las personas de este grupo etario con la tecnología celular, definir el número al que se enviarán los mensajes (y escribirlos) es transparente para ellos. El sistema cuenta con otras prestaciones de gran valía, un grupo de alarmas automáticas, también vía SMS, definidas para un grupo de sensores incluidos en el sistema, que facilita la toma de decisiones de forma remota a través de un SMS.The design and implementation of a system capable of providing elderly people with a fast track to ask for help, remotely, to the person in charge of their care, using the cellular network is reported t. The main functionality is a help button, through which the person in charge of the elderly care will receive a text message when the elder presses the button. Recognizing the little connection between the people of this age group with cellular technology, defining the number to which the messages will be sent (and writing them) is not their task. The system has other features of great value, as a group of automatic alarms, also operating via SMS, generated by a group of sensors included in the system, which facilitates remote decision making from caregivers.É relatado o desenho e a implementação de um sistema capaz de fornecer aos idosos uma via rápida para pedir ajuda, remotamente, à pessoa responsável pelos cuidados, usando a rede celular. Foi implementado um sistema, cuja principal funcionalidade é um botão de ajuda, através do qual a pessoa encarregada de cuidar dos idosos receberá uma mensagem de texto quando o idoso pressionar o botão. Reconhecendo a pouca conexão das pessoas desta faixa etária com a tecnologia celular, definir o número para o qual as mensagens serão enviadas (e a sua redação) é transparente para eles. O sistema possui outros recursos de grande valor, um grupo de alarmes automáticos, também via SMS, definidos para um grupo de sensores incluídos no sistema, o que facilita a tomada de decisões de forma remota através de um SMS

Brain charts for the human lifespan

Over the past few decades, neuroimaging has become a ubiquitous tool in basic research and clinical studies of the human brain. However, no reference standards currently exist to quantify individual differences in neuroimaging metrics over time, in contrast to growth charts for anthropometric traits such as height and weight1. Here we assemble an interactive open resource to benchmark brain morphology derived from any current or future sample of MRI data (http://www.brainchart.io/). With the goal of basing these reference charts on the largest and most inclusive dataset available, acknowledging limitations due to known biases of MRI studies relative to the diversity of the global population, we aggregated 123,984 MRI scans, across more than 100 primary studies, from 101,457 human participants between 115 days post-conception to 100 years of age. MRI metrics were quantified by centile scores, relative to non-linear trajectories2 of brain structural changes, and rates of change, over the lifespan. Brain charts identified previously unreported neurodevelopmental milestones3, showed high stability of individuals across longitudinal assessments, and demonstrated robustness to technical and methodological differences between primary studies. Centile scores showed increased heritability compared with non-centiled MRI phenotypes, and provided a standardized measure of atypical brain structure that revealed patterns of neuroanatomical variation across neurological and psychiatric disorders. In summary, brain charts are an essential step towards robust quantification of individual variation benchmarked to normative trajectories in multiple, commonly used neuroimaging phenotypes

Harmonized-Multinational qEEG Norms (HarMNqEEG)

This paper extends the frequency domain quantitative electroencephalography (qEEG) methods pursuing higher sensitivity to detect Brain Developmental Disorders. Prior qEEG work lacked integration of cross-spectral information omitting important functional connectivity descriptors. Lack of geographical diversity precluded accounting for site-specific variance, increasing qEEG nuisance variance. We ameliorate these weaknesses. i) Create lifespan Riemannian multinational qEEG norms for cross-spectral tensors. These norms result from the HarMNqEEG project fostered by the Global Brain Consortium. We calculate the norms with data from 9 countries, 12 devices, and 14 studies, including 1564 subjects. Instead of raw data, only anonymized metadata and EEG cross-spectral tensors were shared. After visual and automatic quality control, developmental equations for the mean and standard deviation of qEEG traditional and Riemannian DPs were calculated using additive mixed-effects models. We demonstrate qEEG "batch effects" and provide methods to calculate harmonized z-scores. ii) We also show that the multinational harmonized Riemannian norms produce z-scores with increased diagnostic accuracy to predict brain dysfunction at school-age produced by malnutrition only in the first year of life. iii) We offer open code and data to calculate different individual z-scores from the HarMNqEEG dataset. These results contribute to developing bias-free, low-cost neuroimaging technologies applicable in various health settings

Semi-analytic Local Linearization Integration of high dimensional Neural Mass Models with distributed delays

Neuroscience has shown great progress in recent years. Several of the theoretical bases have arisen from the examination of dynamic systems, using Neural Mass Models (NMMs). Due to the largescale brain dynamics of NMMs and the difficulty of studying nonlinear systems, the local linearization approach to discretize the state equation was used via an algebraic formulation, as it intervenes favorably in the speed and efficiency of numerical integration. To study the spacetime organization of the brain and generate more complex dynamics, three structural levels (cortical unit, population and system) were defined and assumed, in which the new assumed representation for conduction delays and new ways of connecting were defined. This is a new time-delay NMM, which can simulate several types of EEG activities since kinetics information was considered at three levels of complexity. Results obtained in this analysis provide additional theoretical foundations and indicate specific characteristics for understanding neurodynamic.Comment: 12 pages, 6 figures, 2 table

Botão de ajuda para idosos através da plataforma Arduino

The design and implementation of a system capable of providing elderly people with a fast track to ask for help, remotely, to the person in charge of their care, using the cellular network is reported t. The main functionality is a help button, through which the person in charge of the elderly care will receive a text message when the elder presses the button. Recognizing the little connection between the people of this age group with cellular technology, defining the number to which the messages will be sent (and writing them) is not their task. The system has other features of great value, as a group of automatic alarms, also operating via SMS, generated by a group of sensors included in the system, which facilitates remote decision making from caregivers.Se reporta el diseño e implementación de un sistema capaz de proveer a personas de la tercera edad de una vía rápida para pedir ayuda, de manera remota, al encargado de su cuidado, usando la red celular. Se implementó un sistema, cuya principal funcionalidad es un botón de ayuda, mediante el cual la persona encargada del cuidado del anciano recibirá un mensaje de texto cuando el anciano presione el botón. Reconociendo la poca vinculación de las personas de este grupo etario con la tecnología celular, definir el número al que se enviarán los mensajes (y escribirlos) es transparente para ellos. El sistema cuenta con otras prestaciones de gran valía, un grupo de alarmas automáticas, también vía SMS, definidas para un grupo de sensores incluidos en el sistema, que facilita la toma de decisiones de forma remota a través de un SMS.É relatado o desenho e a implementação de um sistema capaz de fornecer aos idosos uma via rápida para pedir ajuda, remotamente, à pessoa responsável pelos cuidados, usando a rede celular. Foi implementado um sistema, cuja principal funcionalidade é um botão de ajuda, através do qual a pessoa encarregada de cuidar dos idosos receberá uma mensagem de texto quando o idoso pressionar o botão. Reconhecendo a pouca conexão das pessoas desta faixa etária com a tecnologia celular, definir o número para o qual as mensagens serão enviadas (e a sua redação) é transparente para eles. O sistema possui outros recursos de grande valor, um grupo de alarmes automáticos, também via SMS, definidos para um grupo de sensores incluídos no sistema, o que facilita a tomada de decisões de forma remota através de um SMS