A model for conceptual processing of naturalistic scenes.

Abstract Are there fundamental differences in the way in which a list of pictures and a list of words are processed? We report three experiments that examine serial position effects for rapidly - presented naturalistic scenes. The experiments provide a basis for comparison with the U - shaped serial position curve and list - length effect which typically result from verbal learning experiments. In contrast to the U - shaped verbal serial position function, our results show a flat function at the beginning serial positions and a recency effect which is small and limited to the last serial position. There is a set - size effect. Results suggest that the processing leading to a memory representation for visual stimuli such as pictures and linguistic stimuli such as words is qualitatively dissimilar. The findings can be accounted for by a serial processing model whose main parameter is the probability that the subject will switch attention from one picture to the next.Resume Y a - t - il des differences fondamentales dans la faeon dont sont traitees une liste d'images et une liste de mots? l'aide de trois experiences, nous avons examine les effets lies a la position serielle d'images illustrant des scenes naturelles, presentees rapidement. Ces experiences offrent une base de comparaison avec la courbe de positions serielles en forme de U et l'effet de la longueur de la liste, qui caracterisent les experiences sur l'apprentissage verbal. Contrairement a la courbe en U observee dans le cas des positions serielles verbales, nos resultats revelent une fonction stable au debut des positions serielles et un faible effet de recence limite a la derniere position serielle. La taille de la serie de stimuli visuels influe sur la performance. Les resultats obtenus nous portent a croire que le traitement de stimuli visuels tels les images et le traitement de stimuli linguistiques comme les mots, qui conduisent a une representation en memoire, different sur le plan qualitatif. Un modele de traitement seriel dont le principal parametre est la probabilite que le sujet prete attention aux images presentees tour a tour peut rendre compte des observations. When a person views a picture or a word, the result is a memory representation that depends on how the picture or word is processed. In this article, we seek to understand differences between processing of pictures and words. We present a model of picture - processing which is a simplified version of an earlier model (Loftus, Hanna, & Lester, 1988). The model's main parameter is the probability that the subject will switch attention from one serially - presented picture to the next. PERCEPTUAL AND CONCEPTUAL PROCESSINGTheorists (e.g., Intraub, 1984; Loftus & Ginn, 1984; Potter, 1976) have distinguished two kinds of encoding processes that operate on visual stimuli. Perceptual processes are defined as processes that operate on, and thus require the presence of, a stimulus or visible persistence of that stimulus. Conceptual processes are defined as those that do not require a stimulus or its visible persistence. Conceptual processes can operate while the stimulus is physically present, while there is visible persistence of the stimulus, and after any visible persistence has ceased. Perceptual and Conceptual MaskingA visual stimulus presented close in time to a target stimulus is called a mask and any target performance decrement that results is a masking effect. A distinction can be made between perceptual and conceptual masks. Perceptual masks interrupt or interference with perceptual processing. Conceptual masks interrupt or interfere with conceptual processing. A mask following target stimulus offset by 300 ms or more exerts only a conceptual masking effect whereas a mask following target stimulus onset by 50 ms or less exerts only a perceptual masking effect (Hines & Smith, 1977, Loftus & Ginn, 1984). In this paper we are interested in conceptual processing and conceptual masking; hence all our interstimulus intervals (ISIs) are at least 300 ms. …