Digital pictures can be type-identical in respect of colours, shapes and sizes (allographic), but they are not tokens of notational systems, because the types under which they are identical have vague limits and do not meet the requirements for notational characters. Digital display devices are designed to instantiate only limited ranges of objective properties (light intensities, sizes and shapes). Those ranges keep differences in objective magnitudes below sensory discrimination thresholds, and thus define objective conditions sufficient, but not necessary, for the (...) phenomenal type-identity of pictures. The fact that digital pictures are types shows that pictures are not necessarily autographic. Moreover, the reasons why digital pictures are allographic (essentially, the consistent manipulation of sub-phenomenal information) could in principle also be made to apply to non-digital pictures. (shrink)

Several psychological experiments have suggested that concepts can influence perceived color (e.g., Delk and Fillenbaum in Am J Psychol 78(2):290–293, 1965, Hansen et al. in Nat Neurosci 9(11):1367–1368, 2006, Olkkonen et al. in J Vis 8(5):1–16, 2008). Observers tend to assign typical colors to objects even when the objects do not have those colors. Recently, these findings were used to argue that perceptual experience is cognitively penetrable (Macpherson 2012). This interpretation of the experiments has far-reaching consequences: it implies that the (...) way we think of objects determines how we see them, thus threatening the role of perception in justifying beliefs. In this paper, I show that the psychological findings can be accounted for without admitting cognitive penetrability. An underestimated but key feature of the experiments is that observers had to judge colors in borderline cases, in conditions of reduced acuity, or on the basis of color-concepts instead of matching. Such judgments are sensitive to the form of bias that Tversky and Kahneman (Science 185:1124–1131, 1974) have termed ‘anchoring’. Adopting a suggestion from Raffman (Philos Rev 103(1):41–74, 1994), I argue that the way subjects in the experiments think of the objects could affect their color judgments without altering their color experiences. (shrink)