Abstract
Although people seek to avoid expenditure of cognitive effort, reward incentives can increase investment of processing resources in challenging situations that require cognitive control, resulting in improved performance. At the same time, subjective value is relative, rather than absolute: The value of a reward is increased if the local context is reward-poor versus reward-rich. Although this notion is supported by work in economics and psychology, we propose that reward relativity should also play a critical role in the cost–benefit computations that inform cognitive effort allocation. Here we demonstrate that reward-induced cognitive effort allocation in a task-switching paradigm is sensitive to reward context, consistent with the notion of relative value. Informed by predictions of a computational model of divisive reward normalization, we demonstrate that reward-induced switch cost reductions depend critically upon reward context, such that the same reward amount engenders greater control allocation in impoverished versus rich reward context. Succinctly, these results confirm that reward relativity factors into the value computation driving effort allocation, revealing that motivated cognitive control, like choice, is all relative.
