The pupillometric production effect: Evidence for enhanced processing preceding, during, and following production

The production effect refers to superior memory performance for words read aloud than for those read silently. This finding has usually been attributed to the incorporation of distinctive sensorimotor information into the memory record of items read aloud, facilitating their successful retrieval during the memory test. Less research has explored other cognitive or motivational differences between the aloud and silent conditions. Here we used pupillometry to explore the time course of attention allocated during aloud, silent, and control (say "check") study trials. Across four experiments, instructions were presented either concurrently with or preceding the word. To permit evaluation of preparatory processing independent of a verbal response, we explored the case where responses had to be withheld until a "Go" signal appeared. In addition to the typical behavioral production effect in memory, each experiment also revealed a pupillometric production effect (greater pupil dilation for aloud than for silent words) that-while separable from the act of speaking itself-was correlated with the size of the memory benefit. Critically, this pupillometric-behavioral correlation did not occur for control (say "check") trials. We interpret these findings as support for an initial attention-focusing effect that comes from preparing for and executing vocalization during both aloud and control trials, followed by a phase of distinctive processing of target word features that is unique to aloud trials.