Two operations in character recognition: Some evidence from reaction-time measurements

ed so that, in session 2, the degradation of the test stimulus does not prolong the comparison operation. This conclusion follows from the virtual equality of the slopes of the two reaction-time functions in that session. The marked effect of degradation on reaction time is due, in both sessions, primarily to a change in some part of the process other than the comparison operation. It is plausible to assume that the affected part of the process occurs before the comparison stage and is, in fact, Operation 1. (The magnitude of the effect of degradation on the zerointercept, about 65 msec., then provides a lower bound for the duration of Operation 1 with degraded test