Abstract
This study examined whether graded reductions in high spatial frequency (HSF) information impair visual short-term memory (VSTM) for naturalistic scenes and whether patterns of confusion between blur levels reveal changes in memory precision. Thirty young adults completed a delayed match-to-sample task using naturalistic scene images presented at three blur levels (low, medium, high) and three delay intervals (0, 2, and 7s). On each trial, participants viewed a target scene and then selected the matching blur level from three response options. Mean accuracy, median reaction time for correct trials, and delay-based confusion matrices were analyzed. Results showed significant main effects of blur level and delay on accuracy, as well as a significant interaction of blur and delay, indicating that memory performance declined as blur increased and that this effect changed across retention intervals. A parallel analysis of reaction time also revealed significant main effects of blur and delay and a significant blur and delay interaction: responses were fastest in the lowest-blur condition at all delays, and the medium and highest-blur conditions became more similar at the longest delay. Confusion matrices showed that errors were not random: as delay increased, the highest blur level was increasingly confused with the moderate blur level, while confusion with the lowest blur level remained relatively low. Together, these findings suggest that reducing HSF detail weakens both the accuracy and precision of scene representation in VSTM and that these effects become more pronounced as memory demands increase.