The Temporal Dynamics of Cortical Normalization Models of Decision-making

Thomas LoFaro, Kenway Louie, Ryan Webb, Paul Glimcher

Research output: Contribution to journalArticle

Abstract

Normalization is a widespread neural computation in both early sensory coding and higher-order processes such as attention and multisensory integration. It has been shown that during decision-making, normalization implements a context-dependent value code in parietal cortex. In this paper we develop a simple differential equations model based on presumed neural circuitry that implements normalization at equilibrium and predicts specific time-varying properties of value coding. Moreover, we show that when parameters representing value are changed, the solution curves change in a manner consistent with normalization theory and experiment. We show that these dynamic normalization models naturally implement a time-discounted normalization over past activity, implying an intrinsic reference-dependence in value coding of a kind seen experimentally. These results suggest that a single network mechanism can explain transient and sustained decision activity, reference dependence through time discounting, and hence emphasizes the importance of a dynamic rather than static view of divisive normalization in neural coding.

Original languageEnglish (US)
Pages (from-to)209-220
Number of pages12
JournalLetters in Biomathematics
Volume1
Issue number2
DOIs
StatePublished - Jan 1 2014

Fingerprint

Normalization
Dynamic models
Decision Making
Differential equations
Decision making
Coding
Parietal Lobe
Experiments
Model
Discounting
Cortex
Time-varying
Higher Order
Model-based
Differential equation
Predict
Curve
Dependent
Experiment

Keywords

  • cortical normalization
  • differential equations
  • neuroeconomics
  • neuroscience

ASJC Scopus subject areas

  • Applied Mathematics
  • Statistics and Probability
  • Biochemistry, Genetics and Molecular Biology (miscellaneous)

Cite this

The Temporal Dynamics of Cortical Normalization Models of Decision-making. / LoFaro, Thomas; Louie, Kenway; Webb, Ryan; Glimcher, Paul.

In: Letters in Biomathematics, Vol. 1, No. 2, 01.01.2014, p. 209-220.

Research output: Contribution to journalArticle

LoFaro, Thomas ; Louie, Kenway ; Webb, Ryan ; Glimcher, Paul. / The Temporal Dynamics of Cortical Normalization Models of Decision-making. In: Letters in Biomathematics. 2014 ; Vol. 1, No. 2. pp. 209-220.
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