Can visual objects be identified without spatial attention? For example, could a driver attending to another car interpret a passing road sign? This question has generated a large literature, in large part because it is central to how we characterize human visual attention (e.g., whether visual information processing is serial or parallel). The present study examined how spatial attention affects the semantic activation of words. In particular, we examined whether increasing the expectation for specific words within a given context, by repeating a small set of target words, would enable word processing in the absence of spatial attention. The computations involved in word recognition could potentially become much simpler when the set of possible words is greatly reduced, so it is plausible that word recognition would become more automatic and not require spatial attention.
Spatial Attention in Word ProcessingThe role of spatial attention in word processing has long been a contentious issue (see Neely & Kahan, 2001, for a review). Most studies have used some variant of a priming paradigm. In a typical paradigm, a word (which we will refer to as the prime) that requires no response is presented simultaneously with, or immediately preceding, a target word to which a speeded response is made. In such studies it is well documented that, when the prime is attended, participants respond faster to related targets than to unrelated targets. In the lexical decision task (word vs. nonword), for instance, participants are faster to indicate that the target is a word (e.g., butter) when an attended prime is a related word (e.g., bread ) rather than an unrelated word (e.g., nurse; e.g., Meyer & Schvaneveldt, 1971; see Neely, 1991, for a review of associative priming effects). Similarly, people are slower to name the color of a bar if the name of a different color is printed nearby (the Stroop effect; e.g., Stroop, 1935; see MacLeod, 1991, for a review).In most of the studies described above, the prime was presented in an attended location, even though the prime itself did not require a response. Priming effects have proven to be less consistent when attention is not directed to the prime. Some studies have suggested that spatial attention plays little or no role in semantic activation during word processing (e.g., Brown, Gore, & Carr,
973© 2010 The Psychonomic Society, Inc. Previous studies have disagreed about the extent to which people extract meaning from words presented outside the focus of spatial attention. The present study examined a possible explanation for such discrepancies inspired by attenuation theory: Unattended words can be read more automatically when they are expected within a given context (e.g., due to frequent repetition). We presented a brief prime word in lowercase, followed by a target word in uppercase. Participants indicated whether the target word belonged to a particular category (e.g., "sports"). When we used a visual cue to draw attention to the location of the prime word, it produced substantia...