Masking Effects of Irrelevant Visual Information under Conditions of Basic and Superordinate Categorization of Complex Images

Abstract

We analyzed the accuracy and reaction time (RT) of basic and superordinate image categorization under forward masking conditions in 41 healthy subjects. Images of man-made objects and animals were used as target stimuli, while images of man-made objects, animals, faces, and buildings were used as masks. The comparison of the psychometric characteristics of the basic and superordinate categorization showed the influence of mask and stimulus semantic similarity on the forward masking effectiveness, which depended on the type of experimental task performed by the subject (the level of categorization of the target stimulus). The masking effect at the basic-level categorization was more pronounced at a greater semantic similarity between the mask and the target stimulus. In contrast, a greater masking effect at the superordinate-level categorization was observed when the mask and the stimulus belonged to different categories. The images of faces and buildings had a less pronounced masking effect compared to the images of animals and man-made objects, regardless of the type of task. For basic-level categorization, the increase in RT under semantically related conditions was caused by distributional skewing. In contrast, for superordinate categorization, semantically unrelated conditions led to distributional shifting towards greater values. The results of this study suggest a hypothesis of temporal and spatial division of cognitive processes of the basic and superordinate categorization.