title: Aging, practice, and perceptual tasks: a diffusion model analysis.
abstract: Practice effects were examined in a masked letter discrimination task and a masked brightness discrimination task for college-age and 60- to 75-year-old subjects. The diffusion model (Ratcliff, 1978) was fit to the response time and accuracy data and used to extract estimates of components of processing from the data. Relative to young subjects, the older subjects began the experiments with slower and less accurate performance; however, across sessions their accuracy improved because the quality of the information on which their decisions were based improved, and this, along with reduced decision criteria, led to shorter response times. For the brightness, but not the letter, discrimination task, the older subjects' performance matched that of the younger group by the end of 4 sessions, except that their nondecision components of processing were slightly slower. These analyses illustrate how a well-specified model can provide a unified view of multiple aspects of data that are often interpreted separately.
authors.affiliation: Department of Psychology, Ohio State University, Columbus, OH 43210, USA.
authors.forename: Roger
authors.initials: R
authors.lastname: Ratcliff
authors.forename: Anjali
authors.initials: A
authors.lastname: Thapar
authors.forename: Gail
authors.initials: G
authors.lastname: McKoon
mesh_terms: D000328:Adult; D000368:Aged; D000375:Aging / Q000523:psychology*; D004193:Discrimination Learning; D004522:Educational Status; D005260:Female; D006801:Humans; D007858:Learning / Q000502:physiology*; D008297:Male; D010465:Perception; D011214:Practice, Psychological; D011930:Reaction Time; D011932:Reading; D021641:Recognition, Psychology; D013060:Speech; D014825:Vocabulary