The Effects of Stimuli Type, Size, and Articulation on Estimating the Luminance Contrast of Real and CRT Targets

The goal of this thesis was to examine how luminance contrast estimates were affected by varying conditions of stimuli type, size, and articulation. Based on previous research, it was expected that lightness constancy would increase as stimuli moved from a spotlight, to paper, and finally to a CRT monitor. Lightness constancy was also expected to increase with articulation, and to vary as stimuli sized increased or decreased. Two separate experiments were conducted with a total of 80 college students from Wake Forest University. Observers were asked to make lightness and contrast matches of incremental and decremental spotlight, paper, and CRT targets, all of which were either small or large, and articulated or non-articulated. Results showed a strong effect of stimuli type in the predicted direction. Lightness constancy was lowest when matching spotlight targets, and highest when matching CRT targets. Effects of stimuli size were ambiguous. In experiment one, size affected lightness constancy only for decremental targets, not incremental targets; whereas in experiment two, size affected lightness constancy only for incremental targets, not decremental targets. Lastly, no effects of articulation were found.

Grantor dc:publisher

Wake Forest University

Year dc:date.issued

2011

Author dc:creator

• Riddle, Matthew Ryan

• Area Rule

Language dc:language.iso

en

Handle dc:identifier.uri

http://hdl.handle.net/10339/33448

OAI identifier oai:identifier

oai:wakespace.lib.wfu.edu:10339/33448