The perception of natural visual scenes that contain many objects poses computational problems that are absent when objects are perceived in isolation1. Vision researchers have captured this attribute of real-world perception in the laboratory by using visual search tasks, in which subjects search for a target object in arrays containing varying numbers of non-target distractor objects. Under many conditions, the amount of time required to detect a visual search target increases as the number of objects in the stimulus array increases, and some investigators have proposed that this reflects the serial application of attention to the individual objects in the array2,3. However, other investigators have argued that this pattern of results may instead be due to limitations in the processing capacity of a parallel processing system that identifies multiple objects concurrently4,5. Here we attempt to address this longstanding controversy by using an electrophysiological marker of the moment-by-moment direction of attention — the N2pc component of the event-related potential waveform — to show that attention shifts rapidly among objects during visual search.
Subscribe to Journal
Get full journal access for 1 year
only $3.90 per issue
All prices are NET prices.
VAT will be added later in the checkout.
Tax calculation will be finalised during checkout.
Rent or Buy article
Get time limited or full article access on ReadCube.
All prices are NET prices.
Mozer, M. C. The Perception of Multiple Objects (MIT Press, Cambridge, Massachusetts, 1991).
Treisman, A. Features and objects: The fourteenth Bartlett memorial lecture. Q. J. Exp. Psychol. 40, 201–237 (1988).
Wolfe, J. M. Guided search 2.0: A revised model of visual search. Psychonomic Bull. Rev. 1, 202–238 (1994).
Bundesen, C. Atheory of visual attention. Psychol. Rev. 97, 523–547 (1990).
Duncan, J., Ward, R. & Shapiro, K. Direct measurement of attentional dwell time in human vision. Nature 369, 313–315 (1994).
Luck, S. J. & Hillyard, S. A. Electrophysiological correlates of feature analysis during visual search. Psychophysiology 31, 291–308 (1994).
Luck, S. J. & Hillyard, S. A. Spatial filtering during visual search: Evidence from human electrophysiology. J. Exp. Psychol. Hum. Percept. Perform. 20, 1000–1014 (1994).
Luck, S. J., Girelli, M., McDermott, M. T. & Ford, M. A. Bridging the gap between monkey neurophysiology and human perception: An ambiguity resolution theory of visual selective attention. Cogn. Psychol. 33, 64–87 (1997).
Wolfe, J. M. What can 1 million trials tell us about visual search? Psychol. Sci. 9, 33–39 (1998).
McCarthy, G. & Wood, C. C. Scalp distributions of event-related potentials: An ambiguity associated with analysis of variance models. Electroencephalogr. Clin. Neurophysiol. 62, 203–208 (1985).
Carrasco, M., Evert, D. L., Change, I. & Katz, S. M. The eccentricity effect: Target eccentricity affects performance on conjunction searches. Percept. Psychophys. 57, 1241–1261 (1995).
Wolfe, J. M., O'Neill, P. & Bennett, S. C. Why are there eccentricity effects in visual search? Visual and attentional hypotheses. Percept. Psychophys. 60, 140–156 (1998).
Townsend, J. T. Serial vs. parallel processing. Sometimes they look like Tweedledum and Tweedledee but they can (and should) be distinguished. Psychol. Sci. 1, 46–54 (1990).
This work was supported by grants from the National Institute of Mental Health, the National Science Foundation and the Human Frontier Science Program.
About this article
Cite this article
Woodman, G., Luck, S. Electrophysiological measurement of rapid shifts of attention during visual search. Nature 400, 867–869 (1999). https://doi.org/10.1038/23698
Neural Evidence Suggests Both Interference and Facilitation from Embedding Regularity into Visual Search
Journal of Cognitive Neuroscience (2021)
Attention, Perception, & Psychophysics (2021)
Behavioral and electrophysiological evidence for a dissociation between working memory capacity and feature-based attention