State but not trait measures of vividness relate to memory accuracy.

Trait-level and averaged measures of vividness did not predict memory accuracy.

• Participants memorised objects within scenes and later identified whether specific changes had occurred.
• Trait vividness measures (such as questionnaire-based assessments) failed to predict subsequent memory performance.
• Averaged state vividness scores also did not significantly predict memory accuracy.
• This finding challenges the common assumption that vivid mental imagery relates to better memory accuracy when measured at the trait level.

Trial-by-trial state measures of vividness were significantly related to subsequent memory performance.

• State vividness was assessed on a trial-by-trial basis during the memorisation phase.
• Higher trial-level vividness ratings were associated with better subsequent memory accuracy on that trial.
• This finding was confirmed via re-analysis of an existing related dataset involving people with aphantasia.
• The authors conclude that future research must analyse vividness on a trial-by-trial basis to appropriately investigate the relationship between mental imagery vividness and memory accuracy.

Mental imagery vividness appeared to relate more to visual aspects of memory than to spatial aspects.

• The study used a scene-based paradigm in which participants memorised objects within scenes.
• Changes to be detected included both visual and spatial modifications to the scenes.
• Results provided evidence of a modality-specific effect, with vividness more strongly associated with visual memory than spatial memory.
• This is consistent with recent literature suggesting that the modality of the stimulus influences the vividness–memory association.

Older adults reported higher vividness ratings but performed worse on average than young adults.

• Both young and older participants were included in the experimental procedure.
• Older adults gave higher subjective vividness ratings for their mental imagery compared to young adults.
• Despite higher vividness ratings, older adults showed lower memory accuracy on average.
• This age-related dissociation suggests that vividness ratings may not accurately reflect memory fidelity in older populations, consistent with literature noting that vividness and confidence of memories may change over the lifespan.

Confidence and vividness were highly correlated but remained distinct subjective experiences.

• Both confidence and vividness ratings were collected from participants during the task.
• The two measures showed a high correlation with one another.
• Despite this correlation, statistical analyses indicated they were distinguishable as separate subjective constructs.
• The authors note this distinction is important for interpreting relationships between metacognitive measures and memory accuracy.

Re-analysis of an existing aphantasia dataset confirmed that state-level vividness relates to memory accuracy, highlighting limitations of prior research using averaged or trait-level measures.

• An existing related dataset involving people with aphantasia (absent or severely reduced mental imagery) was re-analysed.
• State-level trial-by-trial vividness findings from the main study were replicated in this aphantasia dataset.
• The re-analysis identified limitations of previous aphantasia research that relied on averaged or trait-level vividness measures.
• The authors suggest conflicting findings in the aphantasia and mental imagery literature may partly stem from reliance on non-trial-level measurement approaches.