Separate Capacities for Storing Different Features in Visual Working Memory

Recent empirical and theoretical work suggests that visual features such as color and orientation can be stored or retrieved independently in visual working memory (VWM), even in cases when they belong to the same object. Yet it remains unclear whether different feature dimensions have their own capacity limits, or whether they compete for shared but limited resources in VWM. In 3 experiments, participants memorized arrays of dual-feature objects, for which the number of feature values was fixed on one feature dimension and was varied on the other feature dimension. The results show that memory performance on the fixed dimension was not affected by the number of to-be-stored feature values on the other. These findings provide converging evidence that visual features can be encoded and stored separately in VWM if the task requires it, with each having its own capacity limit and little cross-dimensional interference.