Speed-accuracy decomposition yields a sudden insight into all-or-none information processing.

The existence of discrete all-or-none information processing has often been assumed as a basis for stage models and also as an important characteristic of nonlinear connectionist models; however, there has been little or no hard empirical evidence supporting the existence of this phenomenon. In search of such evidence, we applied speed-accuracy decomposition (Meyer et al., 1988), a technique for detecting partial response information, to the examination of the time-course of processing in a (Gestalt) insight-like task, namely, anagram solution. This task was chosen because the Gestalt psychologists conjectured that insight is a sudden, discrete phenomenon. Supporting this view, we found little or no evidence of partial information in two experiments, thereby providing what may be the strongest evidence to date for all-or-none processing.