The Effect of Exposure Duration on Visual Character Identification in Single, Whole, and Partial Report

• Published in: Journal of experimental psychology. Human perception and performance Vol. 38; no. 2; pp. 498 - 514
• Main Authors: Petersen, Anders, Andersen, Tobias S
• Format: Journal Article
• Language: English
• Published: United States American Psychological Association 01-04-2012
• Subjects: Adult; Alphabets; Attention; Comparative Analysis; Contrast Sensitivity; Denmark; Discrimination Learning; Foreign Countries; Humans; Identification; Male; Memory, Short-Term; Pattern Recognition, Visual; Perceptual Masking; Psychometrics; Reaction Time; Short Term Memory; Time; Visual Fields; Visual Perception; Young Adult; Denmark
• ISSN: 0096-1523; 1939-1277
• DOI: 10.1037/a0026728

The psychometric function of single-letter identification is typically described as a function of stimulus intensity. However, the effect of stimulus exposure duration on letter identification remains poorly described. This is surprising because the effect of exposure duration has played a central role in modeling performance in whole and partial report (Shibuya & Bundesen, 1988). Therefore, we experimentally investigated visual letter identification as a function of exposure duration. We compared the exponential, the gamma, and the Weibull psychometric functions, all with a temporal offset included, as well as the ex-Gaussian, the log-logistic, and finally the squared-logistic, which is a psychometric function that to our knowledge has not been described before. The log-logistic and the squared-logistic psychometric function fit well to experimental data. Also, we conducted an experiment to test the ability of the psychometric functions to fit single-letter identification data, at different stimulus contrast levels; also here the same psychometric functions prevailed. Finally, after insertion into Bundesen's Theory of Visual Attention (Bundesen, 1990), the same psychometric functions enable closer fits to data from a previous whole and partial report experiment. (Contains 8 figures.)