scholarly journals Control of entropy in neural models of environmental state

eLife ◽  
2019 ◽  
Vol 8 ◽  
Author(s):  
Timothy H Muller ◽  
Rogier B Mars ◽  
Timothy E Behrens ◽  
Jill X O'Reilly

Humans and animals construct internal models of their environment in order to select appropriate courses of action. The representation of uncertainty about the current state of the environment is a key feature of these models that controls the rate of learning as well as directly affecting choice behaviour. To maintain flexibility, given that uncertainty naturally decreases over time, most theoretical inference models include a dedicated mechanism to drive up model uncertainty. Here we probe the long-standing hypothesis that noradrenaline is involved in determining the uncertainty, or entropy, and thus flexibility, of neural models. Pupil diameter, which indexes neuromodulatory state including noradrenaline release, predicted increases (but not decreases) in entropy in a neural state model encoded in human medial orbitofrontal cortex, as measured using multivariate functional MRI. Activity in anterior cingulate cortex predicted pupil diameter. These results provide evidence for top-down, neuromodulatory control of entropy in neural state models.

2020 ◽  
Vol 19 (1) ◽  
pp. 85-88
Author(s):  
A. S. J. Cervera ◽  
F. J. Alonso ◽  
F. S. García ◽  
A. D. Alvarez

Roundabouts provide safe and fast circulation as well as many environmental advantages, but drivers adopting unsafe behaviours while circulating through them may cause safety issues, provoking accidents. In this paper we propose a way of training an autonomous vehicle in order to behave in a human and safe way when entering a roundabout. By placing a number of cameras in our vehicle and processing their video feeds through a series of algorithms, including Machine Learning, we can build a representation of the state of the surrounding environment. Then, we use another set of Deep Learning algorithms to analyze the data and determine the safest way of circulating through a roundabout given the current state of the environment, including nearby vehicles with their estimated positions, speeds and accelerations. By watching multiple attempts of a human entering a roundabout with both safe and unsafe behaviours, our second set of algorithms can learn to mimic the human’s good attempts and act in the same way as him, which is key to a safe implementation of autonomous vehicles. This work details the series of steps that we took, from building the representation of our environment to acting according to it in order to attain safe entry into single lane roundabouts.


2018 ◽  
Author(s):  
O. Colizoli ◽  
J.W. de Gee ◽  
A.E. Urai ◽  
T.H. Donner

AbstractPerceptual decisions about the state of the environment are often made in the face of uncertain evidence. Internal uncertainty signals are considered important regulators of learning and decision-making. A growing body of work has implicated the brain’s arousal systems in uncertainty signaling. Here, we found that two specific computational variables, postulated by recent theoretical work, evoke boosts of arousal at different times during a perceptual decision: decision confidence (the observer’s internally estimated probability that a choice was correct given the evidence) before feedback, and prediction errors (deviations from expected reward) after feedback. We monitored pupil diameter, a peripheral marker of central arousal state, while subjects performed a challenging perceptual choice task with a delayed monetary reward. We quantified evoked pupil responses during decision formation and after reward-linked feedback. During both intervals, decision difficulty and accuracy had interacting effects on pupil responses. Pupil responses negatively scaled with decision confidence prior to feedback and scaled with uncertainty-dependent prediction errors after feedback. This pattern of pupil responses during both intervals was in line with a model using the observer’s graded belief about choice accuracy to anticipate rewards and compute prediction errors. We conclude that pupil-linked arousal systems are modulated by internal belief states.


2010 ◽  
pp. 310-328
Author(s):  
Zakaria Maamar ◽  
Djamal Benslimane

Web services are nowadays attracting the attention of both academia and industry. However, a very little has so far been accomplished in terms of design and development methods that assist those who are responsible for specifying and running applications based on Web services. For this purpose, we developed CP4WS that stands for Context and Policy for Web Services. CP4WS is a context-based and policy-driven method for designing and developing composite Web services. Policies manage various aspects related to Web services like participation in composition and adjustment due to changes in the environment, and context provides the necessary information that enables for instance to trigger the appropriate policies and to regulate the interactions between Web services according to the current state of the environment. CP4WS consists of several steps such as user needs identification and Web services behavior specification. Each step has a specific graphical notation that facilitates the representation, description, and validation of the composition operations of Web services. A running scenario that illustrates the use of CP4WS is presented in the article as well.


2016 ◽  
Vol 81 (2) ◽  
pp. 44-60
Author(s):  
Cheryl Le Roux ◽  

It is not uncommon to find that Christians are blamed for contributing to the destruction of the environment – a view that derives from the Biblical precept that ‘man was given dominion over the earth’ (cf. Gen. 1:28). The current state of the environment indicates that humankind has indeed ravaged the earth, but it could be argued that this has occurred through greed, covetousness, materialism, competitiveness and short-sightedness which are specific human traits in conflict with God and Christianity. Furthermore, the true significance of the ‘dominion over the earth’ tenet is invariably overlooked. Having dominion over the earth means that man has the responsibility of representing God on earth; of ruling as His co-regents or, put differently, acting as His stewards or custodians of His creation. It is argued that environmental stewardship is a dimension of the Christian stewardship ethic that is inherent in the Christian faith. This article reports on research undertaken with ministers, lecturers and students of the United Reformed Church in Southern Africa who were asked to provide their views on Christian stewardship as a requisite component of their role as leaders and aspirant leaders in the Church. Perspectives on environmental stewardship as a dimension of the Christian stewardship ethic were also probed. The research showed that respondents were unanimous in their understanding that Christian stewardship is Biblically founded and mandated and that environmental stewardship is part of that ethic. However, environmental stewardship is inadequately provided for in Church teaching and seminary training programmes. This article examines respondents’ views on the above and puts forward ways in which environmental stewardship could be enhanced and promoted. Dit is nie ongewoon dat Christene daarvoor geblameer word dat hulle bydra tot die vernietiging van die omgewing nie – ʼn beskouing wat afkomstig is van die Bybelse voorskrif dat “die mens heerskappy oor die aarde gegee is” (vgl. Gen. 1:28). Die huidige toestand waarin die omgewing verkeer dui daarop dat die mens inderdaad die aarde verniel het. Daar kan egter aangevoer word dat hebsug, gierigheid, materialisme, mededingendheid en kortsigtigheid, wat spesifieke menslike eienskappe is wat in konflik met God en met Christenskap is, hiertoe aanleiding gegee het. Die ware betekenis van die beginsel van “heerskappy oor die aarde” word boonop keer op keer misgekyk. Om heerskappy oor die aarde te hê beteken dat die mens die verantwoordelikheid het om God se verteenwoordigers op aarde te wees; om as Sy medeheersers te regeer of, anders gestel, as Sy toesighouers of bewaarders van Sy skepping op te tree. Daar word aangevoer dat rentmeesterskap van die omgewing ʼn dimensie van die Christelike rentmeesterskapsetos is wat eie aan die Christelike geloof is. Hierdie artikel doen verslag oor navorsing wat onder predikante, dosente en studente van die Verenigende Gereformeerde Kerk in Suider-Afrika gedoen is. Die deelnemers is gevra om hul menings te gee oor Christelike rentmeesterskap as ʼn noodsaaklike komponent van hul rol as leiers en aspirantleiers in die kerk. Perspektiewe oor omgewingsrentmeesterskap as ʼn dimensie van die Christelike rentmeesterskapsetos is ook ondersoek. Die navorsing het getoon dat respondente eensgesind was ten opsigte van hul siening dat Christelike rentmeesterskap op die Bybel gegrond is en Bybelse mandaat het, en dat omgewingsrentmeesterskap deel is van daardie etos. Daar word egter nie na behore vir omgewingsrentmeesterskap voorsiening gemaak in die kerk se onderrig- en seminariese opleidingsprogramme nie. Hierdie artikel bestudeer respondente se sienings oor die bogenoemde en stel maniere voor waarop omgewingsrentmeesterskap versterk en bevorder kan word.


2020 ◽  
Vol 11 (3) ◽  
Author(s):  
Khomiachenko Svitlana ◽  
◽  
Korniakova Tetiana ◽  
Yuzikova Nataliia ◽  
◽  
...  

The article provides a criminological analysis of the current state and trends of environmental crime in Ukraine as well as identifies the structure of environmental crime. The article identifies the most common types of environmental crime, including those that have global and local effect. According to the results of the research, a system of combating environmental crime is proposed supplementing it with the description and characterization of its components. An execution of systematic targeted control over the state of the environment combined with a prevention of environmental crimes by the state, society and individual citizens will become a counterbalance to the destructive attitude towards the environment and, accordingly, the basis for life safety in the ecosystem. Keywords: determinants of crime, crimes against the environment, ecology, environmental policy, judicial statistics


eLife ◽  
2018 ◽  
Vol 7 ◽  
Author(s):  
Ali Mashhoori ◽  
Saeedeh Hashemnia ◽  
Bruce L McNaughton ◽  
David R Euston ◽  
Aaron J Gruber

The anterior cingulate cortex (ACC) encodes information supporting mnemonic and cognitive processes. We show here that a rat’s position can be decoded with high spatiotemporal resolution from ACC activity. ACC neurons encoded the current state of the animal and task, except for brief excursions that sometimes occurred at target feeders. During excursions, the decoded position became more similar to a remote target feeder than the rat’s physical position. Excursions recruited activation of neurons encoding choice and reward, and the likelihood of excursions at a feeder was inversely correlated with feeder preference. These data suggest that the excursion phenomenon was related to evaluating real or fictive choice outcomes, particularly after disfavoured reinforcements. We propose that the multiplexing of position with choice-related information forms a mental model isomorphic with the task space, which can be mentally navigated via excursions to recall multimodal information about the utility of remote locations.


2020 ◽  
Vol 180 ◽  
pp. 03018
Author(s):  
Ancuta Alexandra Petre ◽  
Florin Nenciu ◽  
Nicoleta Alexandra Vanghele ◽  
Mariana Mădălina Stanciu ◽  
Dumitru Bogdan Mihalache ◽  
...  

The use of antibiotics in large quantities against the combat of pests in soils, indicates an increased remanence of them, which leads to major environmental risks. After entering in the soil, antibiotics are subjected to a succession of biogeochemical processes under the action of multiple environmental factors: absorption, migration, transformation, degradation or nutritional prosperity of plants. In order to know the current state of the environment and the effects of antibiotics it is essential to discover procedures for improving the degradation and combating the dissemination of antibiotic resistance. Research in recent years on the extraction of antibiotics from the soil is based on complex processes, such as: Soxhlet extraction, ultrasonic extraction or accelerated solvent extraction. Soil residue was determined using liquid chromatography coupled with mass spectrometry, being the equipment that provides the highest accuracy in the analysis of polar compounds in very low concentrations. The purpose of the paper is to find an efficient and ecological solution for the elimination of antibiotics from soils and to highlight the evaluation of the contaminated land regarding the antibiotic residues and the impact on the composition of the bacterial community. Information about the effects of antibiotics accumulated in soil, persistence, resistance and sensitivity to chemical and microbiological substances, degradation and results related to soil fertility and crop production are highlighted.


Games ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 2 ◽  
Author(s):  
Igor V. Erovenko

I investigate how different dispersal patterns affect the evolution of cooperation in a spatially-structured population. I consider a finite fixed-size population of cooperators and free-riders residing on a one-dimensional lattice with periodic boundaries. Individuals interact via a multiplayer game, which is a version of a public goods game, and the population evolves via a Moran process. Individuals try to improve their interactions by evaluating the current state of the environment and moving to locations with better payoffs. I ran stochastic simulations of the evolution of this Markov process and found that if individuals disperse deterministically to locations with the best payoffs, then cooperation can still be maintained even in the worst-case scenarios, albeit at reduced levels compared to the better-case scenarios. This contrasts with an earlier investigation of probabilistic dispersal patterns, which resulted in the breakdown of cooperation in sparse populations with small interaction neighborhoods, a high mobility rate, and a large dispersal range.


2018 ◽  
Vol 8 (8) ◽  
pp. 158 ◽  
Author(s):  
Sarah Farrell ◽  
Alexander Green ◽  
Tipu Aziz

Chronic intractable pain is debilitating for those touched, affecting 5% of the population. Deep brain stimulation (DBS) has fallen out of favour as the centrally implantable neurostimulation of choice for chronic pain since the 1970–1980s, with some neurosurgeons favouring motor cortex stimulation as the ‘last chance saloon’. This article reviews the available data and professional opinion of the current state of DBS as a treatment for chronic pain, placing it in the context of other neuromodulation therapies. We suggest DBS, with its newer target, namely anterior cingulate cortex (ACC), should not be blacklisted on the basis of a lack of good quality study data, which often fails to capture the merits of the treatment.


2015 ◽  
Vol 14 (2) ◽  
pp. 605 ◽  
Author(s):  
Pablo Páramo ◽  
Marithza Sandoval-Escobar ◽  
Adriana Jakovcevic ◽  
Julian Ferreiro ◽  
Alba Mustaca ◽  
...  

This study explores the assessments made by the inhabitants of eight Latin American countries regarding the current state of the environment, at a local, national and global scale, and how it is perceived looking ahead to the future. It also examines the assignment of responsibility in the future management of the environment. A total of 944 people took part in the study from the eight participating countries, men and women over the age of 18 with different levels of education. The study uses the Environmental Futures Scale to which two relevant items have been added to assess the environment in the region, as well as the Assignment of Environmental Responsibility Scale. The results show differences between the countries, although in general they are pessimistic regarding the current and future state of the environment at the local, national and global level, with the exception of Brazil. In general, and with the exception of Brazil, in the countries surveyed, people assign a high level of responsibility to external social agents at the different levels, increasing their judgement of external responsibility at the national and global levels of analysis. The implications of these findings for environmental policy and education in the countries of this region are also discussed.


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