Abstract
Information about coming events is of great importance for attentional performance. This has been demonstrated repeatedly by a speeding up of reaction times following spatial cueing of an upcoming target (e.g., Posner et al., 1980). In contrast, a significant benefit of cueing on recognition accuracy has only rarely been demonstrated (e.g., Van der Heijden et al., 1985), even though accuracy-based approaches provide more direct measures of cueing effects not confounded by motor preparation. Cueing paradigms usually assess performance at one specific target exposure, however, we argue that varying the exposure duration of the target allows for a more detailed characterization of cueing effects. Thus, we devised a spatially cued single-letter recognition paradigm with varied exposure durations (10–140 ms). In every trial the letter was presented in one of four boxes positioned at the corners of an imaginary square. The paradigm comprised four equally likely cueing conditions: 1) valid, 2) invalid, 3) neutral, and 4) no-cue. Cueing consisted in initiating one of the boxes 100 ms before the letter and the remaining boxes. In the neutral condition all four boxes were initiated 100 ms before the letter. Eye tracking was used to ensure that participants fixated centrally, and trials with eye movements were discarded and re-run online so all participants completed the same total number of trials. The results provide evidence to suggest that the observed effects of cueing involve at least two components influencing visual processing speed, i.e., a non-spatial alerting component induced by the appearance of the cue evident in Conditions 1–3, and a spatially specific expectation component evident in the valid and invalid conditions. We show how the contributions of these components can be described and modeled mathematically using the Theory of Visual Attention (Bundesen, 1990).