Neuronal assembly dynamics in supervised and unsupervised learning scenarios

The dynamic formation of groups of neurons—neuronal assemblies—is believed to mediate cognitive phenomena at many levels, but their detailed operation and mechanisms of interaction are still to be uncovered. One hypothesis suggests that synchronized oscillations underpin their formation and functioning, with a focus on the temporal structure of neuronal signals. In this context, we investigate neuronal assembly dynamics in two complementary scenarios: the first, a supervised spike pattern classification task, in which noisy variations of a collection of spikes have to be correctly labeled; the second, an unsupervised, minimally cognitive evolutionary robotics tasks, in which an evolved agent has to cope with multiple, possibly conflicting, objectives. In both cases, the more traditional dynamical analysis of the system’s variables is paired with information-theoretic techniques in order to get a broader picture of the ongoing interactions with and within the network. The neural network model is inspired by the Kuramoto model of coupled phase oscillators and allows one to fine-tune the network synchronization dynamics and assembly configuration. The experiments explore the computational power, redundancy, and generalization capability of neuronal circuits, demonstrating that performance depends nonlinearly on the number of assemblies and neurons in the network and showing that the framework can be exploited to generate minimally cognitive behaviors, with dynamic assembly formation accounting for varying degrees of stimuli modulation of the sensorimotor interactions

The spatiotemporal representation of dance and music gestures using topological gesture analysis (TGA)

SPATIOTEMPORAL GESTURES IN MUSIC AND DANCE HAVE been approached using both qualitative and quantitative research methods. Applying quantitative methods has offered new perspectives but imposed several constraints such as artificial metric systems, weak links with qualitative information, and incomplete accounts of variability. In this study, we tackle these problems using concepts from topology to analyze gestural relationships in space. The Topological Gesture Analysis (TGA) relies on the projection of musical cues onto gesture trajectories, which generates point clouds in a three-dimensional space. Point clouds can be interpreted as topologies equipped with musical qualities, which gives us an idea about the relationships between gesture, space, and music. Using this method, we investigate the relationships between musical meter, dance style, and expertise in two popular dances (samba and Charleston). The results show how musical meter is encoded in the dancer's space and how relevant information about styles and expertise can be revealed by means of simple topological relationships

Time- and depth-wise trophic niche shifts in Antarctic benthos

Climate change is expected to affect resource-consumer interactions underlying stability in polar food webs. Polar benthic organisms have adapted to the marked seasonality characterising their habitats by concentrating foraging and reproductive activity in summer months, when inputs from sympagic and pelagic producers increase. While this enables the persistence of biodiverse food webs, the mechanisms underlying changes in resource use and nutrient transfer are poorly understood. Thus, our understanding of how temporal and spatial variations in the supply of resources may affect food web structure and functioning is limited. By means of C and N isotopic analyses of two key Antarctic benthic consumers (Adamussium colbecki, Bivalvia, and Sterechinus neumayeri, Echinoidea) and Bayesian mixing models, we describe changes in trophic niche and nutrient transfer across trophic levels associated with the long- and short-term diet and body size of specimens sampled in midsummer in both shallow and deep waters. Samplings occurred soon after the sea-ice broke up at Tethys Bay, an area characterised by extreme seasonality in sea-ice coverage and productivity in the Ross Sea. In the long term, the trophic niche was broader and variation between specimens was greater, with intermediate-size specimens generally consuming a higher number of resources than small and large specimens. The coupling of energy channels in the food web was consequently more direct than in the short term. Sediment and benthic algae were more frequently consumed in the long term, before the sea-ice broke up, while consumers specialised on sympagic algae and plankton in the short term. Regardless of the time scale, sympagic algae were more frequently consumed in shallow waters, while plankton was more frequently consumed in deep waters. Our results suggest a strong temporal relationship between resource availability and the trophic niche of benthic consumers in Antarctica. Potential climate-driven changes in the timing and quality of nutrient inputs may have profound implications for the structure of polar food webs and the persistence of their constituent species, which have adapted their trophic niches to a highly predictable schedule of resource inputs

Predicting Skin Permeability by means of Computational Approaches : Reliability and Caveats in Pharmaceutical Studies

© 2019 American Chemical Society.The skin is the main barrier between the internal body environment and the external one. The characteristics of this barrier and its properties are able to modify and affect drug delivery and chemical toxicity parameters. Therefore, it is not surprising that permeability of many different compounds has been measured through several in vitro and in vivo techniques. Moreover, many different in silico approaches have been used to identify the correlation between the structure of the permeants and their permeability, to reproduce the skin behavior, and to predict the ability of specific chemicals to permeate this barrier. A significant number of issues, like interlaboratory variability, experimental conditions, data set building rationales, and skin site of origin and hydration, still prevent us from obtaining a definitive predictive skin permeability model. This review wants to show the main advances and the principal approaches in computational methods used to predict this property, to enlighten the main issues that have arisen, and to address the challenges to develop in future research.Peer reviewedFinal Accepted Versio

The autism spectrum as a source of cognitive and cultural diversity

Individual differences in perception and in social cognition are products of both biology and cultural experience. Many of the same differences that typify autism when they occur in extremes also underlie normal human cognitive variation when they occur to more subtle degrees. In particular, autism spectrum conditions are characterised by low degrees of two linked capacities: level of construal, meaning the tendency to represent percepts as individual details rather than as whole contexts; and psychological distance, meaning the tendencies to perceive objects and events in distant rather than peri-personal space, to recall or to anticipate past or future time rather than the here-and-now, to approach social interactions in the allocentric frame of other people rather than one's own egocentric frame, and to represent hypothetical, counterfactual, or fictional beliefs that are at odds with actual facts. Significantly, culture also exerts linked effects on level of construal and psychological distance, which are relatively increased in more contextual, socially focussed cultures and decreased in more individualistic, self-focussed cultures

El impacto de la formación en línea en la transferencia de comportamiento y en el desempeño laboral en una gran organización

Este estudio analiza la efectividad de la formación en línea en una gran organización. Se ha probado la influencia de diferentes procesos de la formación, como las estrategias de aprendizaje, las reacciones, el apoyo a la transferencia y las barreras, en la transferencia del comportamiento y el desempeño laboral. Los participantes fueron 3,600 empleados de un banco público brasileño que participaron en una formación en línea en el trabajo. Seis meses después, sus supervisores evaluaron las influencias de la formación en el comportamiento laboral de sus subordinados. Los hallazgos indicaron que en la autoevaluación la transferencia del comportamiento se predijo mediante estrategias de aprendizaje de elaboración/aplicación práctica, reacciones a la formación, apoyo organizacional y de pares; las estrategias de control de la motivación, cognitivas/búsqueda de ayuda y elaboración/aplicación práctica, junto con las reacciones a la formación, se relacionaron significativamente con el desempeño laboral. En la heteroevaluación, el apoyo del supervisor contribuyó a explicar la transferencia del comportamiento y las estrategias cognitivas/búsqueda de ayuda explicaron el desempeño laboral. Se identificó el papel mediador de las reacciones a la formación y el apoyo a la transferencia mostró efectos moderadores marginales.This study analyzes the effectiveness of online training in a large organization. We tested the influence of different training processes, such as learning strategies, reactions, support of transfer, and barriers, on behavioral transfer and job performance. The participants were 3,600 employees of a Brazilian public bank after taking part in online training at work. Six months later, their supervisors evaluated the influences of the training on their subordinates’ work behaviors. Findings indicated that in self-evaluation behavioral transfer was predicted by elaboration/practical application learning strategies, trainees’ reactions to training, organizational, and peer support; motivation control, cognitive/help-seeking, and elaboration/practical application learning strategies, along with trainees’ reactions to training, were significantly related to job performance. In hetero-evaluation, supervisor support contributed to explaining behavioral transfer, and cognitive/help-seeking strategies explained job performance. The mediating role of reactions to training was identified, and support of transfer showed marginal moderating effects.Ministerio de Economía y Competitividad PSI2015-64894-

A multi-scale method to assess pesticide contamination risks in agricultural watersheds

The protection of water is now a major priority for environmental managers, especially around drinkingpumping stations. In view of the new challenges facing water agencies, we developed a method designedto support their public policy decision-making, at a variety of different spatial scales. In this paper, wepresent this new spatial method, using remote sensing and a GIS, designed to determine the contami-nation risk due to agricultural inputs, such as pesticides. The originality of this method lies in the useof a very detailed spatial object, the RSO (Reference Spatial Object), which can be aggregated to manyworking and managing scales. This has been achieved thanks to the pixel size of the remote sensing, witha grid resolution of 30 m × 30 m in our application.The method – called PHYTOPIXAL – is based on a combination of indicators relating to the environmen-tal vulnerability of the surface water environment (slope, soil type and distance to the stream) and theagricultural pressure (land use and practices of the farmers). The combination of these indicators for eachpixel provides the contamination risk. The scoring of variables was implemented according knowledgein literature and of experts.This method is used to target specific agricultural input transfer risks. The risk values are first calculatedfor each pixel. After this initial calculation, the data are then aggregated for decision makers, accordingto the most suitable levels of organisation. These data are based on an average value for the watershedareas.In this paper we detail an application of the method to an area in the hills of Southwest France. Weshow the pesticide contamination risk by in areas with different sized watersheds, ranging from 2 km2to 7000 km2, in which stream water is collected for consumption by humans and animals. The resultswere recently used by the regional water agency to determine the protection zoning for a large pumpingstation. Measures were then proposed to farmers with a view to improving their practices.The method can be extrapolated to different other areas to preserve or restore the surface water