Assessing the time course and magnitude of different forms of attentional priming

Priming of attentional selection involves speeded selection of task-relevant visual search items when search stimuli remain constant between trials. Various paradigms involving different features have been used to study the nature of this priming. The tasks differ greatly in difficulty and the neural mechanisms involved, raising the question of how easily priming on one feature dimension can be used to draw conclusions about priming on another. Here, this was addressed by contrasting time courses and relative sizes of priming effects for the repetition of a lower-level and higher-level feature (color vs. facial expression). Priming was tested in two odd-one-out search tasks, one involving discrimination (experiments 1A and 1B), the other a present/absent judgment (experiments 2A and 2B). The main question was how similar the size and temporal profiles of priming are for the two features. The sizes of the priming effects were very different for color and expression and color priming effects lasted for much longer than expression priming (measured with memory kernel analyses), suggesting that the mechanisms behind the effects differ in their operational principles. Different forms of priming should only be compared with great caution and priming seems to occur at many levels of processing. Priming should be thought of as a general principle of perceptual processing.

Automated summary

By contrasting the repetition effects of lower-level and higher-level feature dimensions (color and facial expression), it was found that there were significant differences in the size and temporal profiles of priming effects for color and expression. This suggests that the underlying mechanisms behind these effects operate differently. Thus, different forms of priming should be compared with caution, and priming seems to occur at various levels of processing, indicating that it should be considered a general principle of perceptual processing.