What information survives saccades in the real world?

Abstract

Recent change detection research demonstrates impressively that we do not retain and fuse the pictorial content of successive fixations. This raises two distinct issues: (1) when and how is point-by-point information lost or replaced? and (2) might more abstract information be extracted and retained from fixations? In this chapter I explore both of these issues. I consider the evidence for a very short-term richly detailed visual representation of the current target of fixation that survives the saccade but is overwritten by the content of each new fixation shortly after it begins. The possibility of abstract representations of the visual surroundings is then discussed. Under conditions of competitive, parallel processing, as are present in real life situations, multiple types of information are extracted and retained from complex natural scenes. Time courses for extraction vary between different types of information. The inclusion of eye movement data reveals a crucial role for fixations in information extraction. The data suggest that information assimilation into the representations tested here is dominated by the fovea and is integrated and accumulated from multiple foveations. From these studies we are able to construct a rudimentary framework, in which representational faithfulness and richness depend upon fixation history of that part of the visual scene, thus producing an efficient and potentially task-specific representation.