The power of many: The role of global matching in the episodic flanker compatibility effect

The episodic flanker task is a memory analog of the classic perceptual flanker task. It was designed to test the conjecture that memory retrieval is perceptual attention turned inward. It measures the sharpness of the focus of attention on memory and produces episodic compatibility effects from flanking items analogous to the perceptual flanker task. Here we ask whether the episodic flanker compatibility effect results from a local match between the probe item and the cued item in the memory list, a global match between the entire (multiletter) probe and the memory list, or a combination of the two. We report two episodic flanker experiments that manipulate the compatibility of near (adjacent to the target) and far (nonadjacent) flankers independently. Local matching predicts no effect of remote targets. Global matching predicts that remote flankers will modulate the compatibility effect, reducing it when one is compatible and the other is incompatible. The results of both experiments confirmed the global matching prediction. A third experiment manipulated near and far flankers in a classic perceptual flanker task and found that far flankers modulated the compatibility effect in the same way, strengthening the parallels between episodic and perceptual flanker tasks. We conclude that the episodic flanker compatibility effect, like the perceptual effect, depends on both local and global matching. Our results provide converging evidence for the idea that memory retrieval is perceptual attention turned inward.