Incidental learning of secondary attentional cueing.

Subjects instructed to detect targets following moderately valid location cues started being presented at some point in the course of the experiment, without having been informed about it, with a color secondary cue on all invalidly cued trials. In Experiment 1 most subjects quickly learned to use the secondary cue, ending in latency cost being eliminated or even turned negative. The effect failed to manifest only when the secondary cue appeared outside the object serving as imperative cue. Experiment 2 showed that performance with a secondary cue differed significantly from the performance in two control conditions in which colors were not correlated with validity or were not presented at all. On the other hand, it resembled performance of subjects informed beforehand about the secondary cue. Awareness of the contingency as well as of its effect on behavior was probed by a post-test questionnaire. An effect of learning without awareness was not observed in Experiment 1, but was found in Experiment 3, where awareness was probed more shortly after the emergence of incidental learning. Conceivably, subjects first learn to use the contingencies implicitly, and only later do they become aware of the outcome of that learning. Apparently, the attentional system might incidentally learn contingencies detected while being engaged in another task and use them for orienting despite a partial conflict with the following as instructed endogenous cues.