Editorial: Metastable Dynamics of Neural Ensembles

A classical view of neural computation is that it can be characterized in terms of convergence to attractor states or sequential transitions among states in a noisy background. After over three decades, is this still a valid model of how brain dynamics implements cognition? This book provides a comprehensive collection of recent theoretical and experimental contributions addressing the question of stable versus transient neural population dynamics from complementary angles. These studies showcase recent efforts for designing a framework that encompasses the multiple facets of metastability in neural responses, one of the most exciting topics currently in systems and computational neuroscience

Risk-Based Approach for Life-Cycle Assessment and Management of Bridges and Ship Structures

Existing civil and marine structures and infrastructures have to maintain their serviceability and safety under the effects induced by normal events and to withstand the effects of extreme events . Although the quantification of the performance of a structural system is usually conducted considering only structural aspects, in this study consequences arising from the occurrence of potential disruption of service due to failure/malfunction of structural components are also considered, leading to risk assessment.Uncertainties are unavoidable in planning, design, and maintenance of structural systems. Advanced probabilistic methods, such as Monte Carlo simulations based on Latin Hypercube sampling, finite element and response surfaces analyses are used in this study in order to account for uncertainties and their propagation over time.The main focus of this study is to develop a risk-based approach for the life-cycle assessment and management of civil and marine structures with emphasis on single highway bridges, groups of bridges, and ship structures. Risk is assessed for highway bridges under the effects of multiple hazards, including traffic, environmental attacks, scour, and earthquakes, whereas the effects of traffic and earthquake are accounted for groups of bridges. Other performance indicators, including reliability, redundancy, and resilience to disasters, are also investigated. For ship structures, a novel approach is developed for the evaluation of time-variant reliability, redundancy, and risk accounting for different limit states of the ship hull, potential effects induced by corrosion, and considering different ship operational conditions over time.Risk is assessed based on reliability analysis by accounting several limit states and quantifying the associated potential monetary losses for a spectrum of consequences, including operating costs and accident costs.A novel approach for near real-time multi-criteria optimal ship routing, integrating risk and structural health monitoring data is developed considering different damage scenarios and generic operational conditions.The developed approaches are applied to several structures, including a highway bridge crossing the Wisconsin River in Wausau, WI, a highway bridge carrying a segment of the northbound I-15 crossing the Temescal Wash located close to the city of Corona, CA, a group of existing bridges located north of the San Diego metropolitan area, and a NAVY\u27s Joint High-Speed Sealift

La compaginación y el soporte del libro francés de vanguardia (1918-1924)

En este trabajo me he planteado analizar la forma del libro durante unos años clave en el desarrollo de las vanguardias históricas parisinas. He partido de la observación de 29 volúmenes, primeras ediciones de autores, en su mayoría pero no en exclusiva, de la órbita Dadá. He intentado describir las decisiones estéticas que determinaron estas publicaciones a partir del estudio de la compaginación (mise en page) y del soporte. En un segundo momento he propuesto algunas reflexiones sobre estas elecciones y comparado el libro francés de creación con la producción gráfica en otros ámbitos y países.Je me suis proposé ici d'analyser le livre du point de vue formel et matériel pendant une période clé de l'histoire des avant-gardes parisiennes. À partir de l'observation de 29 éditions originales d'auteurs appartenant en majorité - mais pas exclusivement - à la sphère Dada, j'ai tenté de décrire les choix esthétiques qui ont présidé à ces publications en étudiant leur mise en page et leur support. Dans un second temps, j'ai présenté quelques réflexions sur ces choix et comparé le livre littéraire en France à la production graphique dans d'autres domaines et d'autres pays. - In this paper I have considered the analysis of the shape of books during some critical years in the development of the historic Parisian avant-garde. I started from the observation of 29 volumes, first editions of authors, mostly but not exclusively, from Dada orbit. I tried to describe the aesthetic decisions that led to these publications from the study of the layout and the physical components (paper and binding). In a second stage I have proposed some thoughts on these choices and compared the French literary book with graphic production in other areas and countries

Edmond Jabès et Eduardo Chillida: "La Mémoire et la Main"

Several aspects of the work La Mémoire et la Main, fruit of the collaboration between Edmond Jabès and Eduardo Chillida are the object of our study. I aim to analyze the process of its editions, from the publication of the first poem in Orange Export Ltd. to the appearance of a second edition in 1987 published by Fata Morgana with a simplified reproduction of the etchings. Basing my findings primarily on the 1986 edition, I examine the format (paper, binding) and the mise en page (typography, page layout, etc.), with a particular analytical emphasis on the illustrations. I attempt to locate the connections between the domain of the etchings and the content of the text so as to consider the aesthetic functionality of the diverse elements of the book and their connections with one another.Se estudian aquí varios aspectos de la obra La mémoire et la main, fruto de la colaboración entre Edmond Jabès y Eduardo Chillida. Analizo el proceso de sus ediciones, desde la publicación del primer poema en Orange Export Ltd., hasta la aparición de una segunda edición en 1987 en la editorial Fata Morgana, con la reproducción simplificada de los aguafuertes. Basándome sobre todo en la edición de 1986, atiendo al soporte (papel, encuadernación) y a la mise en page (tipografía, disposición, etc.) y me detengo especialmente en el estudio de las ilustraciones. Intento poner en relación el ámbito de los aguafuertes y el contenido del texto y realizar una reflexión sobre la funcionalidad estética de los distintos elementos del libro en su interrelación.Il s’agit ici d’étudier plusieurs aspects de l’ouvrage La Mémoire et la Main, fruit de la collaboration entre Edmond Jabès et Eduardo Chillida. J’en analyse les différentes éditions depuis la publication du premier poème par Orange Export Ltd. jusqu’à la réédition de 1987 chez Fata Morgana, contenant une reproduction simplifiée des eaux-fortes de Chillida. En me fondant principalement sur l’édition de Lelong (1986), j’étudie le support –papier, reliure– et la mise en page, et je m’attache plus particulièrement aux illustrations. Je tente de mettre en relation l’univers des eaux-fortes et le contenu du texte et d’en tirer une réflexion sur la fonctionnalité esthétique des différents éléments du livre dans leur interaction

Prediction of Decisions from Noise in the Brain before the Evidence is Provided

Can decisions be predicted from brain activity? It is frequently difficult in neuroimaging studies to determine this, because it is not easy to establish when the decision has been taken. In a rigorous approach to this issue, we show that in a neurally plausible integrate-and-fire attractor-based model of decision-making, the noise generated by the randomness in the spiking times of neurons can be used to predict a decision for 0.5 s or more before the decision cues are applied. The ongoing noise at the time the decision cues are applied influences which decision will be taken. It is possible to predict on a single trial to more than 68% correct which of two decisions will be taken. The prediction is made from the spontaneous firing before the decision cues are applied in the two populations of neurons that represent the decisions. Thus decisions can be partly predicted even before the decision cues are applied, due to noise in the decision-making process. This analysis has interesting implications for decision-making and free will, for it shows that random neuronal firing times can influence a decision before the evidence for the decision has been provided

Modes of cognition: Evidence from metastable brain dynamics

Managing cognitive load depends on adequate resource allocation by the human brain through the engagement of metastable substates, which are large-scale functional networks that change over time. We employed a novel analysis method, deep autoencoder dynamical analysis (DADA), with 100 healthy adults selected from the Human Connectome Project (HCP) data set in rest and six cognitive tasks. The deep autoencoder of DADA described seven recurrent stochastic metastable substates from the functional connectome of BOLD phase coherence matrices. These substates were significantly differentiated in terms of their probability of appearance, time duration, and spatial attributes. We found that during different cognitive tasks, there was a higher probability of having more connected substates dominated by a high degree of connectivity in the thalamus. In addition, compared with those during tasks, resting brain dynamics have a lower level of predictability, indicating a more uniform distribution of metastability between substates, quantified by higher entropy. These novel findings provide empirical evidence for the philosophically motivated cognitive theory, suggesting on-line and off-line as two fundamentally distinct modes of cognition. On-line cognition refers to task-dependent engagement with the sensory input, while off-line cognition is a slower, environmentally detached mode engaged with decision and planning. Overall, the DADA framework provides a bridge between neuroscience and cognitive theory that can be further explored in the future