Working with Episodic Memory: The N-back Task

We present a model of how working memory (WM) and episodic memory (EM) interact in the n-back task. Contrary to previous models in which information is actively maintained in WM, our model posits that information about previous stimuli is retained exclusively in EM. Unlike WM-based active maintenance, which has limited maintenance capacity, EM-based storage has unlimited storage capacity but is subject to proactive interference. Using the model we show that benchmark phenomena ordinarily attributed to use of a limited-capacity WM system (the set size effect and the lure interference effect) can also arise in a model with no such maintenance constraints.