Attention and Perceptual Learning

For a number of years, the author's research research is been concerned with the problem of the determinants of tachistoscopic word recognition thresholds and with visual illusions, particularly the Muller-Lyer illusion. More recently, he has become interested in the practice effect in these two tasks. In both the word recognition and the Muller-Lyer illusion task situations, subjects show a very marked improvement in performance with practice and the author takes this improvement as evidence of perceptual learning. In this address he discusses perceptual learning in somewhat general terms and points out what seems to be an as yet unresolved theoretical issue; He also describes some experimental work by himself and his students that is relevant to the theoretical issue and briefly discusses the experimental results in terms of perceptual learning theory.