Journal article

Publication year: 2015

Pages: 155-168

Journal: Vision Research

Volume number: 113B

ISSN: 0042-6989

eISSN: 1878-5646

Open access status: Green

DOI Link: https://doi.org/10.1016/j.visres.2015.05.004

Publisher: Elsevier

Abstract: 
When we search for visual targets in a cluttered background we systematically move our eyes around to bring different regions of the scene into foveal view. We explored how visual search behavior changes when the fovea is not functional, as is the case in scotopic vision. Scotopic contrast sensitivity is significantly lower overall, with a functional scotoma in the fovea. We found that in scotopic search, for a medium- and a low-spatial-frequency target, individuals made longer lasting fixations that were not broadly distributed across the entire search display but tended to peak in the upper center, especially for the medium-frequency target. The distributions of fixation locations are qualitatively similar to those of an ideal searcher that has human scotopic detectability across the visual field, and interestingly, these predicted distributions are different from those predicted by an ideal searcher with human photopic detectability. We conclude that although there are some qualitative differences between human and ideal search behavior, humans make principled adjustments in their search behavior as ambient light level decreases. (C) 2015 Elsevier Ltd. All rights reserved.

Harvard Citation style: Paulun, V., Schütz, A., Michel, M., Geisler, W. and Gegenfurtner, K. (2015) Visual search under scotopic lighting conditions, Vision Research, 113B, pp. 155-168. https://doi.org/10.1016/j.visres.2015.05.004

APA Citation style: Paulun, V., Schütz, A., Michel, M., Geisler, W., & Gegenfurtner, K. (2015). Visual search under scotopic lighting conditions. Vision Research. 113B, 155-168. https://doi.org/10.1016/j.visres.2015.05.004