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How does past experience influence visual search strategy (i.e., attentional set)? Recent reports have shown that, when given the option to use 1 of 2 attentional sets, observers persist with the set previously required in a training phase. Here, 2 related questions are addressed. First, does the training effect result only from perseveration with the currently active set or from long-term learning? Experiment 1 supported the latter alternative: When training and test were separated by up to 1 week, to prevent perseveration across the 2 sessions, the training effect was still obtained. Second, is the learning feature-specific (tuned to a precise set of colors) or more abstract? Experiments 2 and 3 supported the latter: When stimulus colors were switched between training and test to remove the possibility of feature-specific learning, the training effect again was obtained. These experiments indicate that attentional set is largely guided by long-term abstract learning. [ABSTRACT FROM AUTHOR]

When 2 targets are embedded in a rapid serial visual presentation stream of distractors, perception of the second target is impaired when the intertarget lag is relatively short (less than 500 ms). Stimuli concurrently presented with the stream can affect this phenomenon, which is called attentional blink (AB). Previous studies have yielded conflicting results concerning the direction of the effect of added distractors on the AB: Some studies report an increased AB, whereas others report a decreased AB. The present study explored the boundary conditions of the exaggeration-reduction effects of distractors on the AB and investigated underlying mechanisms by manipulating the spatial configuration, timing, and type of distractors. The results indicate that the magnitude of the AB deficit increased, regardless of the type of distractors, when spatial uncertainty of the target locations was involved. The reduction of the AB occurred at optimal presentation of distractors and disappeared when the second target was presented at a suprathreshold level. These results suggest that stochastic resonance or the center-surround attentional mechanism may contribute to the reduction effect of distractors on the AB deficit. [ABSTRACT FROM AUTHOR]

When observers try to identify successive targets in a visual stream at a rate of 100 ms per item, accuracy for the 2nd target is impaired for intertarget lags of 100-500 ms. Yet, when the same stream is presented more rapidly (e.g., 50 ms per item), this pattern reverses and a 1st-target deficit is obtained. M. C. Potter, A. Staub, and D. H. O'Connor (2002) accounted for these findings with a 2-stage competition theory (detection followed by identification) in which each stage is limited by its own pool of resources. In 5 experiments we varied the items that preceded the 1st target. The results show strong influences of these leading items on the 1st-target deficit, with almost no influence on 2nd-target accuracy. This is interpreted as strong support for multiple factors influencing target accuracy in rapid visual streams (J. Kawahara, J. T. Enns, & V. Di Lollo, 2006). [ABSTRACT FROM AUTHOR]