Perceptual failures in the selection and identification of low-prevalence targets in relative prevalence visual search
- 552 Downloads
Previous research has shown that during visual search tasks target prevalence (the proportion of trials in which a target appears) influences both the probability that a target will be detected, and the speed at which participants will quit searching and provide an ‘absent’ response. When prevalence is low (e.g., target presented on 2 % of trials), participants are less likely to detect the target than when prevalence is higher (e.g., 50 % of trials). In the present set of experiments, we examined perceptual failures to detect low prevalence targets in visual search. We used a relative prevalence search task in order to be able to present an overall 50 % target prevalence and thereby prevent the results being accounted for by early quitting behavior. Participants searched for two targets, one of which appeared on 45 % of trials and another that appeared on 5 % of trials, leaving overall target prevalence at 50 %. In the first experiment, participants searched for two dissimilar targets; in the second experiment, participants searched for two similar targets. Overall, the results supported the notion that a reduction in prevalence primarily influenced perceptual failures of identification, rather than of selection. Together, these experiments add to a growing body of research exploring how and why observers fail to detect low prevalence targets, especially in real-world tasks in which some targets are more likely to appear than others.
KeywordsVisual search Relative prevalence Eye movements
This work was supported by funding from the Economic and Social Sciences Research Council (grant ref. ES/I032398/1).
- Davies, D. R., & Parasuraman, R. (1982). The psychology of vigilance. London: Academic Press.Google Scholar
- Godwin, H. J., Menneer, T., Cave, K. R., Thaibsyah, M., & Donnelly, N. (in press). The effects of increasing target prevalence on information processing during visual search. Psychonomic Bulletin & Review. doi: 10.3758/s13423-014-0686-2
- Godwin, H. J., Reichle, E. D., & Menneer, T. (in press). Coarse-to-fine eye movement behavior during visual search. Psychonomic Bulletin and Review. doi: 10.3758/s13423-014-0613-6
- Wolfe, J. M. (2007). Guided Search 4.0: Current Progress with a model of visual search. In W. Gray (Ed.), Integrated Models of Cognitive Systems (pp. 99–119). New York: Oxford.Google Scholar