Can nonconceptual content be stored in visual memory?

Dartnall claims that visual short-term memory (VSTM) stores nonconceptual content (NCC), in the form of compressed images. In this paper I argue against the claim that NCC can be stored in VSTM. I offer four reasons why NCC cannot be stored in visual memory and why only conceptual information can: (1) NCC lasts for a very short time and does not reach either visual short-term memory or visual long-term memory; (2) the content of visual states is stored in memory only if and when object-centered attention modulates visual processing and this modulation signifies the onset of the conceptualization of that content; (3) only categorical high-level information that characterizes conceptual content and not metric and precise iconic information that characterizes NCC can be stored in visual memory for long periods; and (4) if NCC were stored in visual memory then this would allow recognitional judgments pertaining to NCCone could recognize the precise shade of a color that one had seen before. However NCC does not allow such recognitional judgments.