scholarly journals Identifying control ensembles for decision-making within the cortico-basal ganglia-thalamic circuit

2021 ◽  
Author(s):  
Catalina Vich ◽  
Matthew Clapp ◽  
Timothy Verstynen ◽  
Jonathan Rubin
Keyword(s):  
Decision Making ◽  
Basal Ganglia ◽  
Environmental Changes ◽  
Latin Hypercube Sampling ◽  
Indirect Pathway ◽  
Policy Responsiveness ◽  
Network Properties ◽  
Low Dimensional ◽  
Decision Policies ◽  
High Degree

During action selection, mammals exhibit a high degree of flexibility in adapting their decisions in response to environmental changes. Although the cortico-basal ganglia-thalamic (CBGT) network is implicated in this adaptation, it features a synaptic architecture comprising multiple feed-forward, reciprocal, and feedback pathways, complicating efforts to elucidate the roles of specific CBGT populations in the process of evidence accumulation during decision-making. In this paper we apply a strategic sampling approach, based on Latin hypercube sampling, to explore how CBGT network properties, including subpopulation firing rates and synaptic weights, map to parameters of a normative drift diffusion model (DDM) representing algorithmic aspects of information accumulation during decision-making. Through the application of canonical correlation analysis, we find that this relationship can be characterized in terms of three low-dimensional control ensembles impacting specific qualities of the emergent decision policy: responsiveness (associated with overall activity in corticothalamic and direct pathways), pliancy (associated largely with overall activity in components of the indirect pathway of the basal ganglia), and choice (associated with differences in direct and indirect pathways across action channels). These analyses provide key mechanistic predictions about the roles of specific CBGT network elements in shifting different aspects of decision policies.

scholarly journals Reward-driven changes in striatal pathway competition shape evidence evaluation in decision-making

2018 ◽  
Author(s):  
Kyle Dunovan ◽  
Catalina Vich ◽  
Matthew Clapp ◽  
Timothy Verstynen ◽  
Jonathan Rubin
Keyword(s):  
Decision Making ◽  
Basal Ganglia ◽  
Diffusion Model ◽  
Process Models ◽  
Decision Task ◽  
Drift Diffusion Model ◽  
Indirect Pathway ◽  
Drift Diffusion ◽  
Pathway Activity ◽  
Evidence Accumulation

AbstractCortico-basal-ganglia-thalamic (CBGT) networks are critical for adaptive decision-making, yet how changes to circuit-level properties impact cognitive algorithms remains unclear. Here we explore how dopaminergic plasticity at corticostriatal synapses alters competition between striatal pathways, impacting the evidence accumulation process during decision-making. Spike-timing dependent plasticity simulations showed that dopaminergic feedback based on rewards modified the ratio of direct and indirect corticostriatal weights within opposing action channels. Using the learned weight ratios in a full spiking CBGT network model, we simulated neural dynamics and decision outcomes in a reward-driven decision task and fit them with a drift diffusion model. Fits revealed that the rate of evidence accumulation varied with inter-channel differences in direct pathway activity while boundary height varied with overall indirect pathway activity. This multi-level modeling approach demonstrates how complementary learning and decision computations can emerge from corticostriatal plasticity.Author summaryCognitive process models such as reinforcement learning (RL) and the drift diffusion model (DDM) have helped to elucidate the basic algorithms underlying error-corrective learning and the evaluation of accumulating decision evidence leading up to a choice. While these relatively abstract models help to guide experimental and theoretical probes into associated phenomena, they remain uninformative about the actual physical mechanics by which learning and decision algorithms are carried out in a neurobiological substrate during adaptive choice behavior. Here we present an “upwards mapping” approach to bridging neural and cognitive models of value-based decision-making, showing how dopaminergic feedback alters the network-level dynamics of cortico-basal-ganglia-thalamic (CBGT) pathways during learning to bias behavioral choice towards more rewarding actions. By mapping “up” the levels of analysis, this approach yields specific predictions about aspects of neuronal activity that map to the quantities appearing in the cognitive decision-making framework.

scholarly journals Believer-Skeptic meets Actor-Critic: Rethinking the role basal ganglia pathways in decision-making and reinforcement learning

2016 ◽  
Author(s):  
Kyle Dunovan ◽  
Timothy Verstynen
Keyword(s):  
Decision Making ◽  
Reinforcement Learning ◽  
Basal Ganglia ◽  
Empirical Evidence ◽  
Behavioral Control ◽  
Traditional View ◽  
Indirect Pathway ◽  
Dynamic Competition ◽  
Immediate Feedback ◽  
Growing Body

AbstractThe flexibility of behavioral control is a testament to the brain’s capacity for dynamically resolving uncertainty during goal-directed actions. This ability to select actions and learn from immediate feedback is driven by the dynamics of basal ganglia (BG) pathways. A growing body of empirical evidence conflicts with the traditional view that these pathways act as independent levers for facilitating (i.e., direct pathway) or suppressing (i.e., indirect pathway) motor output, suggesting instead that they engage in a dynamic competition during action decisions that computationally captures action uncertainty. Here we discuss the utility of encoding action uncertainty as a dynamic competition between opposing control pathways and provide evidence that this simple mechanism may have powerful implications for bridging neurocomputational theories of decision making and reinforcement learning.

Perancangan aplikasi multi criteria decision making dalam penerimaan beasiswa kepada dosen studi lanjut STMIK Balikpapan menggunakan metode SAW

2018 ◽  
Vol 1 (1) ◽  
pp. 35-42
Author(s):  
Muslimin B ◽  
Sumardi Sumardi
Keyword(s):  
Decision Making ◽  
Learning Process ◽  
Teaching And Learning ◽  
Teaching Assistants ◽  
Multi Criteria Decision Making ◽  
Scholarship Recipients ◽  
The Matrix ◽  
Application Decision ◽  
High Degree ◽  
New Student

 Interests and number of STMIK Balikpapan new student enrollments are increasing every year. The balance of the ratio of lecturers to students is one of the most important components in improving the quality and teaching and learning process of a university. Avoiding shortages in the number of lecturers can be realized by providing scholarship programs to alumni and teaching assistants. This study aims to build a multi criteria decision making application that can assist the Head of HRD in the process of receiving scholarships to advanced and effective study lecturers. The multi criteria decision making application developed in this study uses the SAW method. The implementation of the SAW method includes the process of evaluating the weighting of criteria, evaluating alternative weights, the matrix process, the results of decision making preferences, resulting in the weighting and ranking of each alternative candidate for the scholarship recipient. The results of the evaluation of multi-criteria application decision making in the study are expected to produce modeling with a high degree of accuracy. The results of the analysis carried out can provide alternative recommendations for prospective scholarship recipients to advanced study lecturers in STMIK Balikpapan.

Network Embedding on Hierarchical Community Structure Network

2021 ◽  
Vol 15 (4) ◽  
pp. 1-23
Author(s):  
Guojie Song ◽  
Yun Wang ◽  
Lun Du ◽  
Yi Li ◽  
Junshan Wang
Keyword(s):  
Community Structure ◽  
Structural Information ◽  
Spherical Surface ◽  
Network Embedding ◽  
The Galaxy ◽  
Community Information ◽  
The Hierarchical Structure ◽  
Network Properties ◽  
Multi Class Classification ◽  
Low Dimensional

Network embedding is a method of learning a low-dimensional vector representation of network vertices under the condition of preserving different types of network properties. Previous studies mainly focus on preserving structural information of vertices at a particular scale, like neighbor information or community information, but cannot preserve the hierarchical community structure, which would enable the network to be easily analyzed at various scales. Inspired by the hierarchical structure of galaxies, we propose the Galaxy Network Embedding (GNE) model, which formulates an optimization problem with spherical constraints to describe the hierarchical community structure preserving network embedding. More specifically, we present an approach of embedding communities into a low-dimensional spherical surface, the center of which represents the parent community they belong to. Our experiments reveal that the representations from GNE preserve the hierarchical community structure and show advantages in several applications such as vertex multi-class classification, network visualization, and link prediction. The source code of GNE is available online.

scholarly journals 18F-fluorodeoxyglucose positron emission tomography and magnetic resonance imaging evaluation of chorea

2018 ◽  
Vol 10 (3) ◽  
Author(s):  
Nobuyuki Ishii ◽  
Hitoshi Mochizuki ◽  
Miyuki Miyamoto ◽  
Yuka Ebihara ◽  
Kazutaka Shiomi ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Positron Emission Tomography ◽  
Basal Ganglia ◽  
Magnetic Resonance ◽  
Emission Tomography ◽  
Fluorodeoxyglucose Positron Emission Tomography ◽  
Resonance Imaging ◽  
Indirect Pathway ◽  
Positron Emission ◽  
Fluorodeoxyglucose Positron Emission

Chorea is thought to be caused by deactivation of the indirect pathway in the basal ganglia circuit. However, few imaging studies have evaluated the basal ganglia circuit in actual patients with chorea. We investigated the lesions and mechanisms underlying chorea using brain magnetic resonance imaging (MRI) and 18F-fluorodeoxyglucose positron emission tomography (FDG-PET). This retrospective case series included three patients with chorea caused by different diseases: hyperglycemic chorea, Huntington’s disease, and subarachnoid hemorrhage. All the patients showed dysfunction in the striatum detected by both MRI and FDG-PET. These neuroimaging findings confirm the theory that chorea is related to an impairment of the indirect pathway of basal ganglia circuit.

Impactul activităților umane asupra stării peisajelor geografice din bazinul hidografic Cogâlnic în anii 2004-2014

2020 ◽  
Author(s):  
Nicolae Boboc ◽  
◽  
Valentina Munteanu ◽  
Keyword(s):  
Statistical Data ◽  
Environmental Changes ◽  
Spatial Dynamics ◽  
Anthropogenic Pressure ◽  
Human Pressure ◽  
Republic Of Moldova ◽  
Temporal And Spatial ◽  
The Republic ◽  
High Degree

The high degree of land use in the Republic of Moldova as a whole, and the Cogâlnic river basin in particular, imposes the need to assess the quality of the environment and the characteristics of the anthropogenic pressure on the landscapes in temporal and spatial dynamics and to identifying an adequate of measure system for the purpose to maintain/restore the optimal structure and functioning of landscape systems. Based from the Land Cadastre on data, statistical data of population censuses, bibliographic and cartographic sources, a system, was appraised a system of indicators(of naturalness, of artificialization of landscapes, environmental changes) and quantified human pressure on the environment through agriculture and anthropogenic pressure on forest landscapes from the Cogâlnic catchment area. The values of the indices and the human pressure on the landscapes were processed using GIS techniques and elaborated cartographic models.

Dynamic Changes in the Cortex-Basal Ganglia Network After Dopamine Depletion in the Rat

2008 ◽  
Vol 100 (1) ◽  
pp. 385-396 ◽  
Author(s):  
Cyril Dejean ◽  
Christian E. Gross ◽  
Bernard Bioulac ◽  
Thomas Boraud
Keyword(s):  
Basal Ganglia ◽  
Local Field ◽  
Signal Transmission ◽  
Local Field Potentials ◽  
Cellular Level ◽  
Cortical Activation ◽  
Field Potentials ◽  
Dopamine Depletion ◽  
Indirect Pathway ◽  
Before And After

It is well established that parkinsonian syndrome is associated with alterations in the temporal pattern of neuronal activity and local field potentials in the basal ganglia (BG). An increase in synchronized oscillations has been observed in different BG nuclei in parkinsonian patients and animal models of this disease. However, the mechanisms underlying this phenomenon remain unclear. This study investigates the functional connectivity in the cortex-BG network of a rodent model of Parkinson's disease. Single neurons and local field potentials were simultaneously recorded in the motor cortex, the striatum, and the substantia nigra pars reticulata (SNr) of freely moving rats, and high-voltage spindles (HVSs) were used to compare signal transmission before and after dopaminergic depletion. It is shown that dopaminergic lesion results in a significant enhancement of oscillatory synchronization in the BG: the coherence between pairs of structures increased significantly and the percentage of oscillatory auto- and cross-correlograms. HVS episodes were also more numerous and longer. These changes were associated with a shortening of the latency of SNr response to cortical activation, from 40.5 ± 4.8 to 10.2 ± 1.07 ms. This result suggests that, in normal conditions, SNr neurons are likely to be driven by late inputs from the indirect pathway; however, after the lesion, their shorter latency also indicates an overactivation of the hyperdirect pathway. This study confirms that neuronal signal transmission is altered in the BG after dopamine depletion but also provides qualitative evidence for these changes at the cellular level.

scholarly journals Pediatric Deep Brain Stimulation Using Awake Recording and Stimulation for Target Selection in an Inpatient Neuromodulation Monitoring Unit

2018 ◽  
Vol 8 (7) ◽  
pp. 135 ◽  
Author(s):  
Terence D. Sanger ◽  
Mark Liker ◽  
Enrique Arguelles ◽  
Ruta Deshpande ◽  
Arash Maskooki ◽  
...  
Keyword(s):  
Deep Brain Stimulation ◽  
Basal Ganglia ◽  
Brain Stimulation ◽  
Rating Scale ◽  
Target Selection ◽  
Test Stimulation ◽  
Depth Electrodes ◽  
A New Technique ◽  
High Degree ◽  
Deep Brain

Deep brain stimulation (DBS) for secondary (acquired, combined) dystonia does not reach the high degree of efficacy achieved in primary (genetic, isolated) dystonia. We hypothesize that this may be due to variability in the underlying injury, so that different children may require placement of electrodes in different regions of basal ganglia and thalamus. We describe a new targeting procedure in which temporary depth electrodes are placed at multiple possible targets in basal ganglia and thalamus, and probing for efficacy is performed using test stimulation and recording while children remain for one week in an inpatient Neuromodulation Monitoring Unit (NMU). Nine Children with severe secondary dystonia underwent the NMU targeting procedure. In all cases, 4 electrodes were implanted. We compared the results to 6 children who had previously had 4 electrodes implanted using standard intraoperative microelectrode targeting techniques. Results showed a significant benefit, with 80% of children with NMU targeting achieving greater than 5-point improvement on the Burke–Fahn–Marsden Dystonia Rating Scale (BFMDRS), compared with 50% of children using intraoperative targeting. NMU targeting improved BFMDRS by an average of 17.1 whereas intraoperative targeting improved by an average of 10.3. These preliminary results support the use of test stimulation and recording in a Neuromodulation Monitoring Unit (NMU) as a new technique with the potential to improve outcomes following DBS in children with secondary (acquired) dystonia. A larger sample size will be needed to confirm these results.

Modeling Cyclic Variability in Spark-Assisted HCCI

2008 ◽  
Vol 130 (5) ◽  
Author(s):  
C. Stuart Daw ◽  
K. Dean Edwards ◽  
Robert M. Wagner ◽  
Johney B. Green
Keyword(s):  
Control Strategies ◽  
Experimental Studies ◽  
Mode Switching ◽  
Load Range ◽  
Gasoline Engines ◽  
Cyclic Variability ◽  
Hcci Combustion ◽  
Quantitative Understanding ◽  
Low Dimensional ◽  
High Degree

Spark assist appears to offer considerable potential for increasing the speed and load range over which homogeneous charge compression ignition (HCCI) is possible in gasoline engines. Numerous experimental studies of the transition between conventional spark-ignited (SI) propagating-flame combustion and HCCI combustion in gasoline engines with spark assist have demonstrated a high degree of deterministic coupling between successive combustion events. Analysis of this coupling suggests that the transition between SI and HCCI can be described as a sequence of bifurcations in a low-dimensional dynamic map. In this paper, we describe methods for utilizing the deterministic relationship between cycles to extract global kinetic rate parameters that can be used to discriminate multiple distinct combustion states and develop a more quantitative understanding of the SI-HCCI transition. We demonstrate the application of these methods for indolene-containing fuels and point out an apparent HCCI mode switching not previously reported. Our results have specific implications for developing dynamic combustion models and feedback control strategies that utilize spark assist to expand the operating range of HCCI combustion.

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