Differential neurophysiological correlates of retrieval of consolidated and reconsolidated memories in humans: An ERP and pupillometry study

Consolidated memories can return to a labile state if they are reactivated by unpredictable reminders. To persist, active memories must be re-stabilized through a process known as reconsolidation. Although there is consistent behavioral evidence about this process in humans, the retrieval process of reconsolidated memories remains poorly understood. In this context, one fundamental question is whether the same or different neurophysiological mechanisms are involved in retrieval of consolidated and reconsolidated memories. Because it has been demonstrated that the exposure to the reconsolidation process may restructure and strengthen memories, we hypothesized distinct neurophysiological patterns during retrieval of reconsolidated memories. In addition, we hypothesized that interfering with the reconsolidation process using a new learning can prevent these neurophysiological changes. To test it, consolidated, reconsolidated and declarative memories whose reconsolidation process was interfered (i.e., picture-word pairs) were evaluated in humans in an old/new associative recall task while the brain activity and the pupillary response were recorded using electroencephalography and eyetracking. Our results showed that retrieval of reconsolidated memories elicits specific patterns of brain activation, characterized by an earlier peak latency and a smaller magnitude of the left parietal ERP old/new effect compared to memories that were only consolidated or whose reconsolidation process was interfered by a new learning. Moreover, our results demonstrated that only retrieval of reconsolidated memories is associated with a late reversed mid-frontal effect in a 600–690 time window. Complementarily, memories that were reactivated showed an earlier peak latency of the pupil old/new effect compared to non-reactivated memories. These findings support the idea that reconsolidation has an important impact in how memories are retrieved in the future, showing that retrieval of reconsolidated memories is partially supported by specific brain mechanisms.Fil: Campos Arteaga, G.. Pontificia Universidad Católica de Chile; ChileFil: Forcato, Cecilia. Instituto Tecnológico de Buenos Aires; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Wainstein, G.. Pontificia Universidad Católica de Chile; Chile. The University of Sydney,; AustraliaFil: Lagos, R.. Universidad de Chile; ChileFil: Palacios García, I.. Pontificia Universidad Católica de Chile; Chile. Universidad Diego Portales; ChileFil: Artigas, C.. Pontificia Universidad Católica de Chile; ChileFil: Morales, R.. Pontificia Universidad Católica de Chile; ChileFil: Pedreira, Maria Eugenia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Fisiología, Biología Molecular y Neurociencias. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Fisiología, Biología Molecular y Neurociencias; ArgentinaFil: Rodríguez, E.. Pontificia Universidad Católica de Chile; Chil

Escenarios y modelo de usos-suelo dentro de una área natural protegida: ejido de san Antonio Acahualco

Prospective is an approach to planning that offers future alternatives of fact scenarios, taking into consideration aspects that influence the behavior of the phenomenon being studied. Therefore, it is useful for the design of strategies of actions based on proactivity and on theoretical models, to reverse socio-territorial costs. This study presents three future alternatives regarding land requirements for agricultural, housing and green area uses, sustained on territorial fragmentation, which has fostered a disproportionate growth of the three productive sectors, mostly in the decline of activities from the primary sector and the creation of gray spaces. The first scenario is the catastrophic, which evidences that the availability of land will be affected in 20 years. The second scenario is the trending and it projects that in 30 years there will be a land deficit for agricultural, housing and green area uses; and the third scenario is the desirable and feasible, which postpones the land deficit to 60 years. Faced with these prospective behaviors, traditional knowledge is reconsidered proactively for applying agro-forestry and conserving agro-biodiversity, to reverse the socio-territorial costs that social and economic welfare implies for peasant families.La prospectiva es un enfoque de la planeación que ofrece alternativas futuras de hechos a través de escenarios, considerando aspectos que influyen en el comportamiento del fenómeno estudiado. Por tanto, es útil para el diseño de estrategias de acciones fundamentadas en la proactividad y en modelos teóricos, para revertir costos socio-territoriales. El presente trabajo presenta tres alternativas de futuro sobre requerimientos de suelo para uso agrícola, vivienda y área verde, sustentados en la fragmentación territorial; la cual ha propiciado un crecimiento desproporcionado de los tres sectores productivos, principalmente en la declinación de las actividades del sector primario y la creación de espacios grises. El primer escenario es el catastrófico, que evidencia que la disponibilidad de tierra se verá afectada dentro de 20 años. El segundo escenario es el tendencial y proyecta que en 30 años habrá déficit de suelo para los usos agrícola, vivienda y área verde; y el tercer escenario es el deseable y factible, que pospone el déficit de suelo a 60 años. Ante estos comportamientos prospectivos, se reconsidera el conocimiento tradicional proactivamente para la práctica de la agroforestería y la conservación de la agrobiodiversidad, para revertir los costos socio-territoriales que implica el bienestar social y económico de las familias campesinas

Study of water Cherenkov detector designs for the SWGO experiment

The Southern Wide-field Gamma-ray Observatory (SWGO) is a next-generation ground-based gamma-ray detector under development to reach a full sky coverage together with the current HAWC and LHAASO experiments in the northern hemisphere. It will complement the observation of transient and variable multi-wavelength and multi-messenger phenomena, offering moreover the possibility to access the Galactic Centre. One of the possible SWGO configurations consists of an array of water Cherenkov tanks, with a high fill-factor inner array and a low-density outer array, covering an overall area of one order of magnitude larger than HAWC. To reach a high detection efficiency and discrimination capability between gamma-ray and hadronic air showers, various tank designs were studied. Double-layer tanks with several sizes, shapes and number of photomultiplier tubes have been considered. Single-particle simulations have been performed to study the tank response, using muons, electrons, and gamma-rays with energies typical of extensive air showers particles, entering the tanks with zenith angles from 0 to 60 degrees. The tank response was evaluated considering the particle detection efficiency, the number of photoelectrons produced by the photomultiplier tubes, and the time resolution of the measurement of the first photon. The study allowed to compare the performance of tanks with circular and square base, to understand which design optimizes the performance of the array. The method used in the study and the results will be discussed in this paper

Double-layered Water Cherenkov Detector for SWGO

The Southern Wide-field Gamma-ray Observatory (SWGO) will use the well-established and cost-effective technique of detecting Cherenkov light produced in water-filled detection units for TeV gamma-ray astronomy. Leveraging detector material reflectivity together with an optimised aspect ratio is an option to improve the performance of an array of such detector units. The double-layered Water Cherenkov Detector units comprise chambers with single photosensors in each. A reflective upper compartment enhances sensitivity to impinging secondary particles. A shallow lower compartment enables muon tagging and consequently improves the gamma hadron separation power of the observatory. Here we present detailed studies on the double-layered unit design

The Southern Wide-field Gamma-ray Observatory reach for Primordial Black Hole evaporation

The Southern Wide-field Gamma-ray Observatory (SWGO) is a proposed ground-based gamma-ray detector that will be located in the Southern Hemisphere and is currently in its design phase. In this contribution, we will outline the prospects for Galactic science with this Observatory. Particular focus will be given to the detectability of extended sources, such as gamma-ray halos around pulsars; optimisation of the angular resolution to mitigate source confusion between known TeV sources; and studies of the energy resolution and sensitivity required to study the spectral features of PeVatrons at the highest energies. Such a facility will ideally complement contemporaneous observatories in studies of high energy astrophysical processes in our Galaxy

Benchmarking the Science for the Southern Wide-Field Gamma-ray Observatory (SWGO)

The Southern Wide-field Gamma-ray Observatory (SWGO) is the project to build a new extensive air shower particle detector for the observation of very-high-energy gamma-rays in South America. SWGO is currently planned for installation in the Southern Hemisphere, which grants it a unique science potential among ground-based gamma-ray detectors. It will complement the capabilities of CTA, working as a wide-field instrument for the monitoring of transient and variable phenomena, and will expand the sky coverage of Northern Hemisphere facilities like HAWC and LHAASO, thus granting access to the entire Galactic Plane and the Galactic Center. SWGO aims to achieve excellent sensitivity over a very large target energy range from about 100 GeV to the PeV, and improve on the performance of current sampling array instruments in all observational parameters, including energy and angular resolution, background rejection, and single-muon detection capabilities. The directives for the final observatory design will be given by a number of key science goals which are being defined over the course of the Project’s R&D phase. In this contribution we will present the core science topics and target performance goals that serve as benchmarks to guide SWGO’s design configuration

Lake Deployment of Southern Wide-field Gamma-ray Observatory (SWGO) Detector Units

The Southern Wide-field Gamma-ray Observatory (SWGO) will be a next-generation high altitude gamma-ray survey observatory in the southern hemisphere consisting of an array of water cherenkov detectors. With its energy range, wide field of view, large duty cycle and location it will complement the other existing and planned gamma-ray observatories. In this contribution we describe the lake concept for SWGO, an alternative to a HAWC-like design with individual water tanks and a LHAASO-style design with artificial ponds. In the lake concept, bladders filled with clean water are deployed near the surface of a natural lake, where each bladder is a light-tight stand-alone unit containing one or more photosensors. We will give an overview of the advantages and challenges for this design concept and describe the first results obtained from prototyping

Technological options for the Southern Wide-field Gamma-ray Observatory (SWGO) and current design status

The SWGO Collaboration is in the process of designing and prototyping a wide field of view, high duty cycle complement to CTA and the existing ground-based particle detectors of the Northern Hemisphere (HAWC and LHAASO). In this contribution, we will compare the various technological options for designing the detector and present an overarching system design accommodating them. We will introduce a feasible reference configuration that is used for the first large-scale simulations and cost estimates, and show ongoing prototyping work focused on reaching a maintenance-free and cost-effective detector