Visual inspection alone produces a decrement in the horizontal-vertical illusion.
Subjects inspected either inverted-T or L figures for 5 min. and then shortened the extended vertical lines of inverted-T figures in an attempt to make the vertical line equal in length to the horizontal line. Those who inspected inverted-T figures were more accurate on initial trials than controls (who did not inspect figures), those who inspected L figures, or those who inspected inverted-T figures and made adjustments on the inspected figures. The results indicate that visual inspection alone can produce a decrease in the Horizontal-Vertical illusion and may account, in part, for changes in strategic factors which have been hypothesized to underlie illusion decrement.
Department of Psychology, American University, Washington, DC 20016, USA.
M L
ML
Glaser
B M
BM
Slotnick
D000328:Adult; D001288:Attention; D004193:Discrimination Learning; D005260:Female; D006801:Humans; D008297:Male; D009903:Optical Illusions; D009949:Orientation; D010364:Pattern Recognition, Visual; D011340:Problem Solving; D011597:Psychomotor Performance