Neurodiversity in mental simulation: conceptual but not visual imagery priming modulates perception across the imagery vividness spectrum.

Mental simulation-the ability to internally model sensory, conceptual, or future events-may include mental imagery as a component, with considerable individual variability in its vividness and dependence on sensory detail. While self-reports have been widely used to assess imagery, they are subjective and prone to bias. Among more objective methods, imagery priming in binocular rivalry has been employed to investigate the influence of mental imagery on perception, but findings have been ambiguous. Here, we introduce a no-report version of the task, using eye-tracking-based optokinetic nystagmus assessment to provide a more reliable measure of perceptual shifts. In addition to visual imagery priming, we introduce conceptual priming, which does not rely on sensory imagery but engages abstract representations. In visual imagery priming, perceptual modulation correlated with self-reported vividness, and participants with low vividness did not show modulatory effects. However, in conceptual priming, effects were observed across the entire vividness spectrum, demonstrating that both concrete sensory-based and abstract conceptual representations can influence perception. These findings challenge purely sensory accounts of mental imagery. We propose avoiding deficit-based terms such as "aphantasia" and advocate for a neuroaffirmative perspective on mental simulation diversity.