Eye movement analyses of strong and weak memories and goal-driven forgetting.

Research indicates that eye movements can reveal expressions of memory for previously studied relationships. Specifically, eye movements are disproportionately drawn to test items that were originally studied with the test scene, compared to other equally familiar items in the test display - an effect known as preferential viewing (e.g., Hannula, Ryan, Tranel, & Cohen, 2007). Across four studies we assessed how strength-based differences in memory are reflected in preferential viewing. Participants studied objects superimposed on background scenes and were tested with three-object displays superimposed on the scenes viewed previously. Eye movements were monitored at test. In Experiment 1 we employed an item-method directed forgetting (DF) procedure to manipulate memory strength. In Experiment 2, viewing patterns were examined across differences in memory strength assessed through subjective confidence ratings. In Experiment 3, we used spaced repetitions to objectively strengthen items, and Experiment 4 involved a list-method DF manipulation. Across all experiments, eye movements consistently differentiated the effect of DF from other strength-based differences in memory, producing different viewing patterns. They also differentiated between incidental and successful intentional forgetting. Finally, despite a null effect in recognition accuracy in list-method DF, viewing patterns revealed both common as well as critical differences between list-method DF and item-method DF. We discuss the eye movement findings from the perspective of theoretical accounts of DF and other strength-based differences in memory.