Visual memory for natural scenes: Evidence from change detection and visual search

Abstract

This paper reviews research examining the role of visual memory in scene perception and visual search. Recent theories in these literatures have held that coherent object representations in visual memory are fleeting, disintegrating upon the withdrawal of attention from an object. I discuss evidence demonstrating that, far from being transient, visual memory supports the accumulation of information from scores of individual objects in scenes, utilizing both visual short-term memory and visual long-term memory. In addition, I review evidence that memory for the spatial layout of a scene and memory for specific object positions can efficiently guide search within natural scenes.

Acknowledgments

This research was supported by National Institute of Health Grant R03 MH65456.

Notes

¹The coherence theory view of VSTM differs from standard models in that coherence theory claims low-level sensory representations (proto-objects) constitute a component of VSTM; attention allows the continued maintenance of proto-objects for the attended object in VSTM (Rensink, 2000). However, a great deal of evidence demonstrates that even for attended objects, VSTM is abstracted away from precise sensory information (Henderson, 1997; Henderson & Hollingworth, 2003b; Irwin, 1991; Phillips, 1974). For example, Phillips (1974) presented single, checkerboard objects at fixation in a change detection task. The checkerboard object was clearly attended, since it was the only stimulus on display. Yet, Phillips found that high-capacity sensory persistence was fleeting, and that VSTM maintained representations abstracted away from sensory persistence, even for an attended object.

²Memory for object orientation was also tested in a two-alternative forced-choice task and produced the same serial position effects as token change detection.

³This estimate is consistent with independent estimates of VSTM capacity for complex objects (Alvarez & Cavanagh, 2004).

⁴See Henderson and Hollingworth (2003b) for one of the few cases in which change blindness is apparently absolute.

⁵If visible object representations were to accumulate as attention shifts from object to object in a scene, then the following should occur. When first gazing upon a new environment, perceptual experience should be quite impoverished, since few objects would yet have been attended. However, visual experience should get progressively richer as more objects are attended and visible representations are accumulated. The fact that this does not happen—the world looks equivalently rich whether one has been looking at a scene for a few hundred ms or a few minutes—provides further, intuitive evidence that visible information does not accumulate during viewing, whether across shifts of attention or shifts of the eyes.