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Are redundant neurons redundant in categorical decision making? A robustness study of a network model

Biomedical Sciences Research Institute Computer Science Research Institute Environmental Sciences Research Institute Nanotechnology & Advanced Materials Research Institute

Wong-Lin, KongFatt (2009) Are redundant neurons redundant in categorical decision making? A robustness study of a network model. In: Society for Neuroscience meeting 2009, Washington D.C., USA. Society for Neuroscience. 1 pp. [Conference contribution]

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URL: http://www.abstractsonline.com/Plan/ViewAbstract.aspx?sKey=2ac59092-64e6-4e17-9df6-3c9bf86029c8&cKey=0aa4bac6-4994-48f1-80c7-fefa109d4811&mKey={081F7976-E4CD-4F3D-A0AF-E8387992A658}

Abstract

In two-alternative forced-choice task paradigms, subjects can be required to make a categorical choice regardless of the difficulty of the task. This can be represented in attractor neural network models with an unstable steady state that separates the alternative choices. The unstable steady state can exist within a range of afferent inputs from outside the local circuit, but can be limited by physiological factors such as saturation of synapses or neuronal input-output function. The wider this decision-making "bandwidth" is, the more possible additional stimuli or cognitive controls within the brain can modulate a decision while the latter is still forming. In this work, we investigate this robustness problem in the context of neuronal diversity in the local network. More specifically, we want to understand how the decision-making bandwidth is affected by the number of redundant excitatory neurons which have activities uncorrelated with any choice outcome. By using a mean-field approach to study the stability of a spiking neuronal network model for decision making, we show that having a larger proportion of redundant neurons can reduce the decision-making bandwidth, and thus its robustness. Thus, we argue that there is a cost in having such neurons when operating a specific forced-choice task (exploitation), as opposed to their more obvious benefits of handling or learning multiple tasks (exploration). Finally, we also study the effects of synaptic or cellular heterogeneity on robust decision making.

Item Type:Conference contribution (Poster)
Faculties and Schools:Faculty of Computing & Engineering
Faculty of Computing & Engineering > School of Computing and Intelligent Systems
Research Institutes and Groups:Computer Science Research Institute
Computer Science Research Institute > Intelligent Systems Research Centre
ID Code:21365
Deposited By:Dr Kongfatt Wong-Lin
Deposited On:14 Mar 2012 15:05
Last Modified:14 Mar 2012 15:05

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