scholarly journals Differential dopamine receptor-dependent sensitivity improves action selection in the basal ganglia

2020 ◽  
Author(s):  
Olivier Codol ◽  
Paul L Gribble ◽  
Kevin N Gurney
Keyword(s):  
Basal Ganglia ◽  
Computational Model ◽  
A Priori ◽  
Action Selection ◽  
Dopaminergic Receptors ◽  
Anatomy And Physiology ◽  
The Core ◽  
Sensitivity Ratio ◽  
New Feature ◽  
High Level

The problem of selecting one action from a set of different possible actions, simply referred to as the problem of action selection, is a ubiquitous challenge in the animal world. For vertebrates, the basal ganglia (BG) are widely thought to implement the core computation to solve this problem, as the anatomy and physiology of the BG are well-suited to this end. However, the BG still displays physiological features whose role in achieving efficient action selection remains unclear. In particular, it is known that the two types of dopaminergic receptors (D1 and D2) present in the BG give rise to mechanistically different responses. The overall effect will be a difference in sensitivity to dopamine which may have ramifications for action selection. However, which receptor type leads to a stronger response is, a priori, unclear, due to the complexity of the intracellular mechanisms involved. In this study, we use the action selection hypothesis to {\em predict} which of D1 or D2 has the greater sensitivity. Thus, we ask - what sensitivity ratio would result in enhanced action selection functionality in the basal ganglia? To do this, we incorporated differential D1 and D2 sensitivity in an existing, high level computational model of the macro-architecture of the basal ganglia, via a simple weighting variable. We then quantitatively assessed the model's capacity to perform action selection as we parametrically manipulated the new feature. We show that differential (rather than equal) D1 and D2 sensitivity to dopaminergic input improves action selection, and specifically, that greater D1 sensitivity (compared to that for D2) leads to these improvements.

scholarly journals Basal Ganglia Control of Reflexive Saccades: A Computational Model Integrating Physiology Anatomy and Behaviour

2017 ◽  
Author(s):  
Alex J. Cope ◽  
Jonathan M. Chambers ◽  
Tony J. Prescott ◽  
Kevin N. Gurney
Keyword(s):  
Basal Ganglia ◽  
Computational Model ◽  
Degrees Of Freedom ◽  
Model Comparison ◽  
Functional Anatomy ◽  
Computational Modelling ◽  
Action Selection ◽  
Oculomotor System ◽  
Model Dynamics ◽  
Reflexive Saccades

AbstractIt is hypothesised that the basal ganglia play a key role in solving the problem of action selection. Here we investigate this hypothesis through computational modelling of the primate saccadic oculomotor system. This system is an excellent target for computational modelling because it is supported by a reasonably well understood functional anatomy, has limited degrees of freedom, and there is a wealth of behavioural and electrophysiological data for model comparison. Here, we describe a computational model of the reflexive saccadic oculomotor system incorporating the basal ganglia, key structures in motor control and competition between possible actions. To restrict the likelihood of overfitting the model it is structured and parameterised by the known anatomy and neurophysiology along with data from a single experimental behavioural paradigm, then validated by testing against several additional behavioural experimental data without modification of the parameters. With this model we reproduce a range of fundamental reflexive saccadic results both qualitatively and quantitatively, comprising: the distribution of saccadic latencies; the effect of eccentricity, luminance and fixation-target interactions on saccadic latencies; and the effect of competing targets on saccadic endpoint. By investigating the model dynamics we are able to provide mechanistic explanations for the sources of these behaviours. Further, because of its accesibility, the oculomotor system has also been used to study general principle of sensorimotor control. We interpret the ability of the basal ganglia to successfully control saccade selection in our model as further evidence for the action selection hypothesis.

scholarly journals Roles for globus pallidus externa revealed in a computational model of action selection in the basal ganglia

2019 ◽  
Vol 109 ◽  
pp. 113-136 ◽  
Author(s):  
Shreyas M. Suryanarayana ◽  
Jeanette Hellgren Kotaleski ◽  
Sten Grillner ◽  
Kevin N. Gurney
Keyword(s):  
Basal Ganglia ◽  
Computational Model ◽  
Globus Pallidus ◽  
Action Selection

scholarly journals Integration of Navigation and Action Selection Functionalities in a Computational Model of Cortico-Basal-Ganglia–Thalamo-Cortical Loops

2005 ◽  
Vol 13 (2) ◽  
pp. 115-130 ◽  
Author(s):  
Benoît Girard ◽  
David Filliat ◽  
Jean-Arcady Meyer ◽  
Alain Berthoz ◽  
Agnès Guillot
Keyword(s):  
Basal Ganglia ◽  
Computational Model ◽  
Action Selection

scholarly journals A Computational Model of How the Basal Ganglia Produce Sequences

1998 ◽  
Vol 10 (1) ◽  
pp. 108-121 ◽  
Author(s):  
Gregory S. Berns ◽  
Terrence J. Sejnowski
Keyword(s):  
Basal Ganglia ◽  
Computational Model ◽  
Globus Pallidus ◽  
Contextual Information ◽  
Learning Rule ◽  
Learning Rate ◽  
Output Stage ◽  
Single Action ◽  
Anatomy And Physiology ◽  
Learning Rates

We propose a systems-level computational model of the basal ganglia based closely on known anatomy and physiology. First, we assume that the thalamic targets, which relay ascending information to cortical action and planning areas, are tonically inhibited by the basal ganglia. Second, we assume that the output stage of the basal ganglia, the internal segment of the globus pallidus (GPi), selects a single action from several competing actions via lateral interactions. Third, we propose that a form of local working memory exists in the form of reciprocal connections between the external globus pallidus (GPe) and the subthalamic nucleus (STN). As a test of the model, the system was trained to learn a sequence of states that required the context of previous actions. The striatum, which was assumed to represent a conjunction of cortical states, directly selected the action in the GP during training. The STN-to-GP connection strengths were modified by an associative learning rule and came to encode the sequence after 20 to 40 iterations through the sequence. Subsequently, the system automatically reproduced the sequence when cued to the first action. The behavior of the model was found to be sensitive to the ratio of the striatal-nigral learning rate to the STN-GP learning rate. Additionally, the degree of striatal inhibition of the globus pallidus had a significant influence on both learning and the ability to select an action. Low learning rates, which would be hypothesized to reflect low levels of dopamine, as in Parkinson's disease, led to slow acquisition of contextual information. However, this could be partially offset by modeling a lesion of the globus pallidus that resulted in an increase in the gain of the STN units. The parameter sensitivity of the model is discussed within the framework of existing behavioral and lesion data.

Consent

2018 ◽  
Author(s):  
Martin Krzywdzinski
Keyword(s):  
Production Systems ◽  
Employee Behavior ◽  
Labor Disputes ◽  
Performance Expectations ◽  
The Third ◽  
The Core ◽  
Core Requirements ◽  
High Level

This chapter deals with the dependent variable of the study: consent. It analyses workplace consent in Russia and China using three indicators that refer to the core requirements of the production systems in automotive companies regarding employee behavior: first, standardized work; and second, compliance with expectations in terms of flexibility, cooperation, and a commitment to improving processes. The third indicator of consent (or the lack of it) is the absence or presence of open criticism, resistance, and labor disputes. The chapter reveals significant and unexpected differences between the Chinese and Russian sites on all three indicators. While the Chinese factories exhibit (with some variance between the companies), a relatively high level of consent, the Russian plants have problems with standardized work, the acceptance of performance expectations, and to some extent with labor disputes.

The Logicism of Frege, Dedekind, and Russell

2009 ◽  
Author(s):  
William Demopoulos ◽  
Peter Clark
Keyword(s):  
A Priori ◽  
The Core ◽  
Common Thread ◽  
Synthetic A Priori ◽  
The Common

This article is organized around logicism's answers to the following questions: What is the basis for our knowledge of the infinity of the numbers? How is arithmetic applicable to reality? Why is reasoning by induction justified? Although there are, as is seen in this article, important differences, the common thread that runs through all three of the authors discussed in this article their opposition to the Kantian thesis that reflection on reasoning with mere concepts (i.e., without attention to intuitions formed a priori) can never succeed in providing satisfactory answers to these three questions. This description of the core of the view differs from more usual formulations which represent the opposition to Kant as an opposition to the contention that mathematics in general, and arithmetic in particular, are synthetic a priori rather than analytic.

scholarly journals Strategies for a Circular Economy in the Construction and Demolition Sector: Identifying the Factors Affecting the Recommendation of Recycled Concrete

2021 ◽  
Vol 13 (8) ◽  
pp. 4113
Author(s):  
Valeria Superti ◽  
Cynthia Houmani ◽  
Ralph Hansmann ◽  
Ivo Baur ◽  
Claudia R. Binder
Keyword(s):  
Circular Economy ◽  
A Priori ◽  
Recycled Concrete ◽  
Recycled Aggregates ◽  
Factors Affecting ◽  
Structural Applications ◽  
Adoption Of Innovation ◽  
Decision Making Processes ◽  
Behavioural Factors ◽  
High Level

With increasing urbanisation, new approaches such as the Circular Economy (CE) are needed to reduce resource consumption. In Switzerland, Construction & Demolition (C&D) waste accounts for the largest portion of waste (84%). Beyond limiting the depletion of primary resources, implementing recycling strategies for C&D waste (such as using recycled aggregates to produce recycled concrete (RC)), can also decrease the amount of landfilled C&D waste. The use of RC still faces adoption barriers. In this research, we examined the factors driving the adoption of recycled products for a CE in the C&D sector by focusing on RC for structural applications. We developed a behavioural framework to understand the determinants of architects’ decisions to recommend RC. We collected and analysed survey data from 727 respondents. The analyses focused on architects’ a priori beliefs about RC, behavioural factors affecting their recommendations of RC, and project-specific contextual factors that might play a role in the recommendation of RC. Our results show that the factors that mainly facilitate the recommendation of RC by architects are: a senior position, a high level of RC knowledge and of the Minergie label, beliefs about the reduced environmental impact of RC, as well as favourable prescriptive social norms expressed by clients and other architects. We emphasise the importance of a holistic theoretical framework in approaching decision-making processes related to the adoption of innovation, and the importance of the agency of each involved actor for a transition towards a circular construction sector.

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