Book ChapterDOI
The Basal Ganglia System as an Engine for Exploration
V. Srinivasa Chakravarthy,Pragathi Priyadharsini Balasubramani +1 more
- pp 59-96
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TLDR
This chapter argues that describing the two BG pathways as having mutually opponent actions has limitations and argues that the BG indirect pathway also plays a role in exploration, which is used to simulate various processes of the basal ganglia.Abstract:
One of the earliest attempts at building a theory of the basal ganglia (BG) is based on the clinical findings that lesions to the direct and indirect pathways of the BG produce quite opposite motor manifestations (Albin et al., in Trends Neurosci 12(10):366–375, 1989). While lesions of the direct pathway (DP), affecting particularly the projections from the striatum to GPi, are associated with hypokinetic disorders (distinguished by a paucity of movement), lesions of the indirect pathway (IP) produce hyperkinetic disorders, such as chorea and tremor. In this chapter, we argue that describing the two BG pathways as having mutually opponent actions has limitations. We argue that the BG indirect pathway also plays a role in exploration. We should evidence from various motor learning and decision-making tasks that exploration is a necessary process in various behavioral processes. Importantly, we use the exploration mechanism explained here to simulate various processes of the basal ganglia which we discuss in the following chapters.read more
Citations
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Journal ArticleDOI
Roles for globus pallidus externa revealed in a computational model of action selection in the basal ganglia.
Shreyas M. Suryanarayana,Jeanette Hellgren Kotaleski,Jeanette Hellgren Kotaleski,Sten Grillner,Kevin Gurney +4 more
TL;DR: The role of the GPe is highlighted as a major control hub of the basal ganglia, and the so-called 'prototypical' GPe neurons are shown to be the principal subpopulation influencing action selection.
Journal ArticleDOI
A network model of basal ganglia for understanding the roles of dopamine and serotonin in reward-punishment-risk based decision making.
Pragathi Priyadharsini Balasubramani,V. Srinivasa Chakravarthy,Balaraman Ravindran,Ahmed A. Moustafa,Ahmed A. Moustafa +4 more
TL;DR: The model predicts that optimizing 5HT levels along with DA medications might be essential for improving the patients' reward-punishment learning deficits, and describes how DA and 5HT mediate activity in these classes of neurons (D1R, D2R-, D1R-D2R- MSNs).
Journal ArticleDOI
Identifying the basal ganglia network model markers for medication-induced impulsivity in Parkinson's Disease patients
Pragathi Priyadharsini Balasubramani,V. Srinivasa Chakravarthy,Manal Ali,Balaraman Ravindran,Ahmed A. Moustafa +4 more
TL;DR: Computational modeling has the potential to become an invaluable tool to predict the onset of behavioral changes during disease progression and a significant decrease in sensitivity to punishment and risk was crucial for explaining behavioral changes observed in PD-ON ICD patients.
Journal ArticleDOI
Prefrontal Dynamics Associated with Efficient Detours and Shortcuts: A Combined Functional Magnetic Resonance Imaging and Magnetoencenphalography Study
Amir-Homayoun Javadi,Amir-Homayoun Javadi,Eva Zita Patai,Eugenia Marin-Garcia,Aaron Margolis,Heng-Ru May Tan,Dharshan Kumaran,Dharshan Kumaran,Marko Nardini,William D. Penny,Emrah Düzel,Peter Dayan,Hugo J. Spiers +12 more
TL;DR: Activity in the right dorsolateral PFC specifically increased when participants encountered tempting false shortcuts that led along suboptimal paths that needed to be differentiated from real shortcuts, providing insight to the temporal evolution of response to encountering detours and shortcuts.
Journal ArticleDOI
A Neurocomputational Model of the Effect of Cognitive Load on Freezing of Gait in Parkinson's Disease.
Vignesh Muralidharan,Pragathi Priyadharsini Balasubramani,V. Srinivasa Chakravarthy,Moran Gilat,Simon J.G. Lewis,Ahmed A. Moustafa +5 more
TL;DR: A computational model of the cognitive and motor cortico-basal ganglia loops that explains the effects of sensory and cognitive processes on FOG is presented, providing a plausible framework for understanding the influence of cognition on automatic motor actions in controls and Parkinson's Disease.
References
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Journal ArticleDOI
A spiking Basal Ganglia model of synchrony, exploration and decision making
TL;DR: A spiking network model to relate exploration to synchrony levels in the BG (which are a neural marker for tremor in Parkinson's disease) is built and shows that exploration levels could be controlled by STN's lateral connection strength which also influenced the synchrony Levels in the STN-GPe circuit.
Journal ArticleDOI
The role of the basal ganglia in exploration in a neural model based on reinforcement learning.
TL;DR: Invoking the property of chaotic systems to explore state-space, it is suggested that the complex exploratory dynamics of STN-GPe system in conjunction with dopamine-based reward signaling from the Substantia Nigra pars compacta (SNc) present the two key ingredients of a reinforcement learning system.
Journal ArticleDOI
Modeling basal ganglia for understanding parkinsonian reaching movements
Kulam Najmudeen Magdoom,Deepak Subramanian,V. S. Chakravarthy,Balaraman Ravindran,Shun-ichi Amari,N. Meenakshisundaram +5 more
TL;DR: In this article, a computational model that highlights the role of basal ganglia (BG) in generating simple reaching movements was presented, and the model was cast within the reinforcement learning (RL) framework with correspondence between RL components and neuroanatomy.
Journal ArticleDOI
Modeling Basal Ganglia for understanding Parkinsonian Reaching Movements
Kulam Najmudeen Magdoom,Deepak Subramanian,V. S. Chakravarthy,Balaraman Ravindran,Shun-ichi Amari,N. Meenakshisundaram +5 more
TL;DR: A computational model that highlights the role of basal ganglia (BG) in generating simple reaching movements associated with Parkinson's disease (PD) is presented, echoing the notion that PD is a dynamical disease.
Journal ArticleDOI
Effects of parkinsonism on motor control
TL;DR: Evidence that the wide spectrum of motor impairments observed in Parkinsonism may be due to a reduced capability of neurochemical modulation of pallido-thalamocortical activities that impairs movement implementation and execution is reviewed.