The Effect of Different Encoding Strategies on Memory Formation between Typical Imagers and Individuals with Aphantasia

Visual mental imagery is widely theorized to support memory encoding by enhancing the richness and distinctiveness of encoded representations. However, how imagery ability interacts with different encoding strategies to shape both true and false memory remains poorly understood. The present study examined how encoding modality (imagery vs. verbal) and processing depth (shallow vs. deep) interact with imagery ability to influence true recall, critical lure recall, and intrusion errors in the Deese-Roediger-McDermott (DRM) paradigm. Using a 2 × 2 × 2 between-subjects design, 171 participants (69 aphantasics, 89 typical imagers) were assigned to one of four encoding conditions and completed ten DRM lists. Both categorical group comparisons and continuous Vividness of Visual Imagery Questionnaire (VVIQ) score analyses were conducted. True recall did not differ between groups or as a function of VVIQ score, consistent with evidence that imagery vividness does not straightforwardly predict memory performance. For critical lure recall, imagery encoding was associated with significantly lower false memory rates than verbal encoding across the imagery ability spectrum. Aphantasic participants, who showed higher rates of inability to perform imagery-based encoding than typical imagers, still benefited from imagery encoding instructions. This suggests that aphantasic individuals either lack metacognitive awareness of their imagery ability or employ alternative non-verbal, non-visual strategies that confer comparable false memory protection. A marginal VVIQ score × depth interaction for intrusion errors tentatively suggested that imagery vividness and encoding depth interact in shaping intrusion susceptibility, consistent with the possibility that imagery-based distinctiveness supports source monitoring under deep encoding conditions. These findings challenge the assumption that imagery vividness predicts memory performance and open new avenues for understanding compensatory encoding mechanisms in aphantasia.