Spontaneous attention to primed and nonprimed inputs

The literature is ambiguous with respect to whether attention is drawn spontaneously to expected or unexpected items in mixed arrays. Several studies from our own laboratory indicate that even though expected words are more localizable than unexpected words in unmixed four-word arrays, showing a baseline advantage for expected words, unexpected words are sometimes more localizable than their expected companions in mixed arrays, suggesting that unexpected words attract attention (see, e.g., Johnston & Schwarting, 1996). By contrast, Dark, Vochatzer, and VanVoorhis (1996) observed that expected words were more reportable than their unexpected companions in mixed, two-word arrays. However, because the Dark et al. research did not include arrays in which both words were expected, it is not clear whether their findings reflect an attentional effect over and above a baseline advantage of expected words. The present study added some additional controls in order to assess this possibility. The superior reportability of expected words was even greater in mixed arrays than in unmixed arrays, suggesting that expected words in mixed arrays attract attention. Following Johnston and Hawley (1994), the conflicting effects of expectancy on spontaneous attention are taken as further evidence that the mind/brain system is biased simultaneously toward both what it most expects and what it least expects to perceive.