Pictures and anaphora: evidence for independent processes

Pictures enhance our comprehension of written texts, but the perceptual and cognitive processes that underlie this effect have not been identified. Because integrating the information contained in a text places demands on working memory, the effect of a picture may be to expand the functional capacity of working memory and thereby to facilitate comprehension. Reasoning thus, we predicted that the availability of a diagram would interact with the difficulty of resolving anaphoric references in texts. The resolution of an anaphor distant from its antecedent (which should stress working memory) should benefit greatly from the presentation of a picture, whereas the resolution of an anaphor near to its antecedent should benefit less from the presentation of a picture. Picture availability and distance separating the anaphor from its antecedent were manipulated in experiments involving both cumulative and moving window presentations of texts. Although picture presence and ease of anaphor resolution significantly improved comprehension of the material, no evidence was found for an interaction of these factors. The results are interpreted as consistent both with dual code theory and with aspects of working memory management that do not involve anaphor resolution.