EFFECTS OF RETRIEVAL PRACTICE ON COGNITIVE EFFORT AS MEASURED BY PUPILLOMETRY

The principle of desirable difficulties suggests that long-term learning is enhanced by engaging study strategies that require additional cognitive effort directed toward learning. We directly tested this hypothesis for one well-established strategy, retrieval practice, using pupil dilation as a measure of cognitive effort. While pupil size was measured by an eye-tracker, Middle Georgia State University student volunteers engaged in a standard retrieval practice paradigm intended to yield learning benefits on an immediate test. They initially studied a word list and then engaged in retrieval practice by attempting cued recall on 1/2 of the words out loud from memory. The other 1/2 of the words were restudied and read aloud as a control. Word lists and task orders were fully counterbalanced. Finally, participants took a free recall test on all words after a short delay. Consistent with our hypotheses, retrieval practice was significantly more effortful than restudying, as measured by changes in pupil size from baseline. However, participants did not benefit from retrieval practice on the free recall task, instead recalling more words from the restudy condition. Previous research suggests these patterns may change using a delayed final test, with the more effortful retrieval practice condition reducing forgetting rates over time. This study demonstrates that pupillometry can effectively measure cognitive effort in the context of study strategies like retrieval practice, which may help to differentiate theories regarding cognitive load, performance, and learning