title: The effect of exposure duration on visual character identification in single, whole, and partial report.
abstract: 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.
authors.affiliation: Department of Informatics and Mathematical Modeling, Technical University of Denmark, Kgs. Lyngby, Denmark. apn@dti.dk
authors.forename: Anders
authors.initials: A
authors.lastname: Petersen
authors.forename: Tobias S
authors.initials: TS
authors.lastname: Andersen
mesh_terms: D000328:Adult; D001288:Attention; D015350:Contrast Sensitivity; D004193:Discrimination Learning; D006801:Humans; D008297:Male; D008570:Memory, Short-Term; D010364:Pattern Recognition, Visual; D010470:Perceptual Masking; D011930:Reaction Time; D014794:Visual Fields; D055815:Young Adult