π Mechanism |
Fechner fraction |
1 |
0.087 |
2 |
0.087? |
3 |
0.087 |
4 |
0.019 |
| 4' |
-- |
5 |
0.018 |
| 5' |
-- |
From Table 1 of Stiles (1959).
The Fechner fraction is defined as the ratio of the increment threshold to the field intensity when the conditioning field has the same color as the test field and the increment threshold is raised by it to 10 times the zero-field value (see Stiles, 1959, p. 107).
Stiles, W. S. (1959). Color vision: the approach through increment threshold sensitivity. Proceedings of the National Academy of Science U.S.A., 45, 100-114.