The distance gradient in the after-effect of kinaesthetic width judgement

The combined effects of inspection-time and interfigural distance on a kinaesthetic figural after-effect were determined. The figural after-effect was defined as the degree to which a 2-in. width appeared to shrink following prolonged inspection of larger widths. The inspection-widths were 2.0, 2.5, 3.0, 3.5, 4.0, and 4.5 in. and the inspection-times were 10 and 50 sec. A control group which did not inspect any widths was also employed. 156 subjects were tested. The results indicated that the classical non-monotonic relationship between interfigural distance and figural after-effect was not present. Instead, the figural after-effect increased as a negatively accelerated function of interfigural distance. Increasing inspection-time increased the asymptotic level of the figural after-effect. These results were interpreted in terms of the effects of anchors on judgements of magnitude.