| 0.050 | 0.047 | 0.079 |
When four signals were used, a red and a green light being added to the others, it became, for the same observers,
| 0.157 | 0.073 | 0.132 |
Prof. Cattell found he could get no results by this method, and reverted to one used by observers previous to Wundt and which Wundt had rejected. This is the einfache Wahlmethode, as Wundt calls it. The reacter awaits the signal and reacts if it is of one sort, but omits to act if it is of another sort. The reaction thus occurs after discrimination; the motor impulse cannot be sent to the hand until the subject knows what the signal is. Reacting in this way, Prof. Cattell found the increment of time required for distinguishing a white signal from no signal to be, in two observers,
| 0.030 | and | 0.050; |
that for distinguishing one color from another was similarly
| 0.100 | and | 0.110; |
that for distinguishing a certain color from ten other colors,
| 0.105 | and | 0.117; |
that for distinguishing the letter A in ordinary print from the letter Z,