Imperial College London

ProfessorMurrayShanahan

Faculty of EngineeringDepartment of Computing

Professor in Cognitive Robotics
 
 
 
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Contact

 

+44 (0)20 7594 8262m.shanahan Website

 
 
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Location

 

407BHuxley BuildingSouth Kensington Campus

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Summary

 

Publications

Citation

BibTex format

@unpublished{Fountas:2017:10.1101/197129,
author = {Fountas, Z and Shanahan, M},
doi = {10.1101/197129},
title = {Assessing Selectivity in the Basal Ganglia: The “Gearbox” Hypothesis},
url = {http://dx.doi.org/10.1101/197129},
year = {2017}
}

RIS format (EndNote, RefMan)

TY  - UNPB
AB - <jats:title>Abstract</jats:title><jats:p>Despite experimental evidence, the literature so far contains no systematic attempt to address the impact of cortical oscillations on the ability of the basal ganglia (BG) to select. In this study, we employed a state-of-the-art spiking neural model of the BG circuitry and investigated the effectiveness of this circuitry as an action selection device. We found that cortical frequency, phase, dopamine and the examined time scale, all have a very important impact on this process. Our simulations resulted in a canonical profile of selectivity, termed selectivity portraits, which suggests that the cortex is the structure that determines whether selection will be performed in the BG and what strategy will be utilized. Some frequency ranges promote the exploitation of highly salient actions, others promote the exploration of alternative options, while the remaining frequencies halt the selection process. Based on this behaviour, we propose that the BG circuitry can be viewed as the “gearbox” of action selection. Coalitions of rhythmic cortical areas are able to switch between a repertoire of available BG modes which, in turn, change the course of information flow within the cortico-BG-thalamo-cortical loop. Dopamine, akin to “control pedals”, either stops or initiates a decision, while cortical frequencies, as a “gear lever”, determine whether a decision can be triggered and what type of decision this will be. Finally, we identified a selection cycle with a period of around 200ms, which was used to assess the biological plausibility of the popular cognitive architectures.</jats:p><jats:sec><jats:title>Author summary</jats:title><jats:p>Our brains are continuously called to select the most appropriate action between alternative competing choices. A plethora of evidence and theoretical work indicates that a fundamental brain region called the basal ga
AU - Fountas,Z
AU - Shanahan,M
DO - 10.1101/197129
PY - 2017///
TI - Assessing Selectivity in the Basal Ganglia: The “Gearbox” Hypothesis
UR - http://dx.doi.org/10.1101/197129
ER -