Abstract
Visual stimuli are not created equal; some are consistently remembered across observers while others are consistently forgotten. This stimulus memorability phenomena highlights the existence of intrinsic stimulus properties that can outweigh individual differences in visual cognition and predict subsequent memory performance. While several contributing factors have been identified, much about stimulus memorability remains unknown, including whether observers are aware of these intrinsic stimulus properties (e.g., Bainbridge et al., 2013; Isola et al., 2013). Here, we assessed participants’ conscious access to stimulus memorability as they encoded 150 real-world objects (Experiment 1) or human faces (Experiment 2) into visual long-term memory. For each stimulus, participants provided a subjective judgment of learning (JOL) that indicated how likely they were to remember that stimulus during later recognition testing. If participants have conscious access to stimulus memorability during encoding, we should expect that (1) JOLs made for a given stimulus would be consistent across participants and that (2) group consistency in JOLs would be predictive of group consistency in memory performance (i.e., stimulus memorability). For a given studied image, we found group consistency in JOLs (mean split-half correlation = 0.811, Experiment 1, 0.458, Experiment 2) that predicted stimulus memorability (r = 0.682, Experiment 1, 0.596, Experiment 2), suggesting that participants’ subjective JOLs were influenced by intrinsic stimulus properties that predicted parallel patterns in objective encoding success. Interestingly, however, participants’ access to stimulus memorability was not comprehensive. Residual memory performance for a given stimulus was still consistent across participants after regressing out JOLs (mean split-half correlation = 0.487, Experiment 1, 0.352, Experiment 2), revealing group consistency in unanticipated remembering and forgetting, when JOLs underestimated and overestimated stimulus memorability, respectively. Together, these findings demonstrate that some—but not all—aspects of stimulus memorability are consciously accessible to observers while encoding visual information into visual long-term memory.