# A decision-space model explains context-specific decision-making

## TL;DR

This paper introduces a model explaining how the brain's striosomes create a flexible decision-making space influenced by context and internal state, shedding light on individual differences and neuropsychiatric disorders.

## Contribution

The paper introduces a novel computational model of striosome and matrix interactions in context-dependent decision-making.

## Key findings

- Striosomes construct a context-dependent mathematical space for decision-making.
- Striosome and matrix neurons increase synchrony during difficult tasks due to higher space dimensionality.
- The model unifies theories on reward prediction error and striatal pathways under one framework.

## Abstract

Optimal decision-making requires consideration of internal and external contexts. Biased decision-making is a transdiagnostic symptom of neuropsychiatric disorders. We created a computational model demonstrating how the striosome compartment of the striatum constructs a context-dependent mathematical space for decision-making computations, and how the matrix compartment uses this space to define action value. The model explains multiple experimental results and unifies other theories like reward prediction error, roles of the direct versus indirect pathways, and roles of the striosome versus matrix, under one framework. We also found, through new analyses, that striosome and matrix neurons increase their synchrony during difficult tasks, caused by a necessary increase in dimensionality of the space. The model makes testable predictions about individual differences in disorder susceptibility, decision-making symptoms shared among neuropsychiatric disorders, and differences in neuropsychiatric disorder symptom presentation. The model provides evidence for the central role that striosomes play in neuroeconomic and disorder-affected decision-making.

Beck et al. develop a model where striosomes create a flexible “decision-space” that adapts to environmental context and internal state. It explains how we make choices and why decision-making varies between people, and in neuropsychiatric disorders.