Consistent implementation of decisions in the brainJames Marshall, Rafal Bogacz, Iain Gilchrist, Consistent implementation of decisions in the brain. PLOS One, 7, pp. e43443–. September 2012. No electronic version available. External information
Despite the complexity and variability of decision processes, motor responses are often stereotypical and independent of decision difficulty. How is this consistency achieved? Through an engineering analogy we consider how and why a system should be designed to realise both flexible decision-making and, consistent decision implementation. We specifically consider accumulator models of decision-making, in which decisions are made when a decision threshold is reached. To trade-off between the speed and accuracy of the decision in these models, one can either adjust the thresholds themselves or, equivalently, fix the thresholds and adjust baseline activation. Here we argue that manipulating baseline activation is preferable as it realises consistent decision implementation by ensuring consistency of motor inputs, summarise empirical evidence in support of this hypothesis, and suggest that it could be a general principle of decision making and implementation.