Annu Rev Psychol 1999 50 243 71 Copyright 1999 by Annual Reviews All rights reserved HIGH LEVEL SCENE PERCEPTION Annu Rev Psychol 1999 50 243 271 Downloaded from arjournals annualreviews org by University of Texas Austin on 10 23 07 For personal use only John M Henderson and Andrew Hollingworth Department of Psychology Michigan State University East Lansing Michigan 48824 e mail john eyelab msu edu andrew eyelab msu edu KEY WORDS eye movements vision scene identification object identification change blindness ABSTRACT Three areas of high level scene perception research are reviewed The first concerns the role of eye movements in scene perception focusing on the influence of ongoing cognitive processing on the position and duration of fixations in a scene The second concerns the nature of the scene representation that is retained across a saccade and other brief time intervals during ongoing scene perception Finally we review research on the relationship between scene and object identification focusing particularly on whether the meaning of a scene influences the identification of constituent objects CONTENTS INTRODUCTION EYE MOVEMENT CONTROL IN SCENE PERCEPTION Fixation Position During Scene Perception Fixation Time During Scene Perception Conclusions SCENE MEMORY ACROSS SACCADES Change Blindness Across Saccades During Scene Viewing Change Blindness and Simulated Saccades Conclusions SCENE CONTEXT AND OBJECT IDENTIFICATION Scene Identification Models of Object Identification in Scenes Studies of Object Identification in Scenes Conclusions CONCLUSION 0084 6570 99 0201 0243 08 00 244 245 245 251 252 253 254 255 258 258 258 260 262 267 268 243 244 HENDERSON HOLLINGWORTH Annu Rev Psychol 1999 50 243 271 Downloaded from arjournals annualreviews org by University of Texas Austin on 10 23 07 For personal use only INTRODUCTION To a first approximation research in human vision can be divided into three areas of investigation Low level or early vision is concerned with extraction of physical properties such as depth color and texture from an image as well as the generation of representations of surfaces and edges Marr 1982 Intermediate level vision concerns extraction of shape and spatial relations that can be determined without regard to meaning but that typically require a selective or serial process Ullman 1996 Finally high level vision concerns the mapping from visual representations to meaning and includes the study of processes and representations related to the interaction of cognition and perception including the active acquisition of information short term memory for visual information and the identification of objects and scenes In this chapter we review three important areas of investigation in the study of highlevel scene perception First we examine eye movements in scene perception focusing on the cognitive control of eye movements and the degree to which meaning and ongoing cognitive processes influence eye movement behavior Second we review recent work on the nature of the scene representation that is retained across a saccade and other similarly brief intervals during ongoing scene perception Finally we review work on the interaction of cognition and perception focusing on object and scene identification Although these topics have a long tradition of empirical investigation they each have received a flurry of new work in the past few years In research on high level scene perception the concept of scene is typically defined though often implicitly as a semantically coherent and often nameable view of a real world environment comprising background elements and multiple discrete objects arranged in a spatially licensed manner Background elements are taken to be larger scale immovable surfaces and structures such as ground walls floors and mountains whereas objects are smaller scale discrete entities that are manipulable e g can be moved within the scene Clearly these definitions are neither exact nor mutually exclusive For example the distinction between a scene and an object depends on spatial scale An office scene may contain a desk as one of its component objects But in a more focused view the desktop might become a scene with its surface forming the background and a stapler phone and pen serving as individuated objects It is difficult to determine precisely when the spatial scale becomes too small or too large to call the resulting view a scene Is the inside of a desk drawer a scene Is a box of paperclips a scene Most research on scene perception has avoided this problem of definition by using views of environments scaled to a human size So an encompassing view of a kitchen or a playground would be considered a good scene whereas a view of a box of paperclips or an aerial view of a city would not For the current purposes we adopt this imprecise intuitive and HIGH LEVEL SCENE PERCEPTION 245 not wholly satisfying definition holding to the belief that definitions are often best refined as a product of empirical investigation Annu Rev Psychol 1999 50 243 271 Downloaded from arjournals annualreviews org by University of Texas Austin on 10 23 07 For personal use only EYE MOVEMENT CONTROL IN SCENE PERCEPTION Because of the optical structure of the eyes the gradient in cone density in the retina and the preferential mapping of foveal photoreceptors onto visual cortical tissue acuity is highest at the point of fixation and drops off precipitously and continuously with increasing visual eccentricity Anstis 1974 Riggs 1965 The highest quality visual information is acquired from the region of the scene that projects to the fovea a region of the retina corresponding to about the central 2 of the viewed scene about the size of a thumbnail at arm s length The human visual cognitive system takes advantage of the high resolving power of the fovea by reorienting the fixation point around the viewed scene an average of three times each second via saccadic eye movements During a saccade the point of regard sweeps rapidly across the scene at velocities of up to 900 s as the eyes rotate in their sockets Carpenter 1988 During a fixation the point of regard is relatively though not perfectly still Pattern information is acquired during the fixations information useful for ongoing perceptual and cognitive analysis of the scene normally cannot be acquired during a saccade Matin 1974 Volkmann 1986 A complete understanding of scene perception requires understanding the processes that control where
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