title: Perceptual learning improves efficiency by re-tuning the decision 'template' for position discrimination.
abstract: Visual position discrimination improves with practice; however, the mechanism(s) underlying this improvement are not yet known. We used positional noise to explore the underlying neural mechanisms and found that position discrimination improved with practice over a range of noise levels. This improvement can be largely explained by an increasing efficiency with which observers used positional information in the stimulus. In a second experiment, we tested the hypothesis that the improved efficiency reflects a re-tuning of the observers' perceptual 'template'--the weightings of inputs from basic visual mechanisms--to more closely match the ideal template required to perform the perceptual task. Using a new technique to measure which parts of the stimulus influenced the observer's performance, we were able to record the re-tuning of the decision template across training sessions; we found a robust and steady increase in template efficiency during learning.
authors.affiliation: School of Optometry and Helen Wills Neuroscience Institute, University of California, Berkeley, Berkeley, California 94720-2020, USA.
authors.forename: Roger W
authors.initials: RW
authors.lastname: Li
authors.forename: Dennis M
authors.initials: DM
authors.lastname: Levi
authors.forename: Stanley A
authors.initials: SA
authors.lastname: Klein
mesh_terms: D004192:Discrimination, Psychological / Q000502:physiology; D006801:Humans; D007858:Learning / Q000502:physiology*; D010775:Photic Stimulation; D017603:Signal Detection, Psychological; D013028:Space Perception / Q000502:physiology*; D014796:Visual Perception / Q000502:physiology*