Effects of preliminary information in a Go versus No-go task.

A series of studies using a Go versus No-go task examined the question of whether preliminary information available early in the recognition of a stimulus is made available to later processes before stimulus recognition is finished, a question relevant to the controversy between discrete and continuous models. Experiment 1 showed that a Go response is faster following a cue indicating that the response probably would be required than following a cue indicating it probably would not be required. Experiments 2-7 were conducted to find out whether analogous preparation occurred when probability of the Go response was signalled by easily discriminable features of a single stimulus rather than a separate cue. The effect was observed when the easily discriminable features uniquely determined the name of the stimulus letter, but not when they merely indicated that the stimulus name was one of two visually similar letters. These results are consistent with the Asynchronous Discrete Coding model, in which the perceptual system makes available to later processes only preliminary information corresponding to discretely activated stimulus attributes.