Dissociating Intensity and Specificity: A Multidimensional Framework for Visual Imagery Vividness

A significant portion of human conscious experience, such as recalling the past or imagining the future, occurs in the absence of direct sensory stimulation. The "vividness" of these mental images is a key factor in cognition, yet its measurement has historically been challenging. This project aims to address this gap through a new psychophysical tool, the **Visual Imagery Vividness Matching (ViVIM)** task. The primary objective is to test a theoretical model proposing that vividness is not a single quality, but a construct composed of at least two main dimensions: *Subjective Intensity* (e.g., brightness, contrast) and *Subjective Specificity* (e.g., detail level, sharpness). Participants (N=70) will perform a 40-minute computer task where they generate mental images (recalling photos, personal memories, or imagining scenes) and adjust an on-screen image to match the qualities of their internal experience. We predict that Perceptual Recall will elicit higher specificity than Episodic Recall and Scene Imagination (the "Vividness Hierarchy"). Furthermore, we hypothesize a dissociation between Intensity and Specificity, validating the multidimensional framework. This Registered Report outlines the methodology and pre-registered analysis plan for characterizing these distinct forms of offline perception.