Efficiency of visual selective attention is related to the type of target.

Lavie and Cox (1997, Psychological Science, 8, 395) suggested that stimuli outside the focus of attention can have more distracting effects when the task requires less attention than when it requires more. This idea provides an explanation for the proposed dissociation found between two forms of attentional control (Folk & Remington, 1998, Journal of Experimental Psychology: Human Perception and Performance, 24, 847). This proposal was based on a red (green) distractor that captured attention when a red (green) target was used, but not when a green (red) target was used, and the further result that, if there were no distractor, reaction times were faster than with either type of distractor. We tested whether a target that requires serial search would eliminate the dissociation. With the same targets used by Folk and Remington (ones that can be found with parallel search), we also obtained a dissociation. However, with the serial-search targets, dissociation was not found. Our interpretation is that the dissociation represents two forms of the same attentional process.

Time Course of Location-Cuing Effects With a Probability Manipulation.

A location-cuing paradigm was used to study the effects of cue probability on the allocation of visual attention. A cue was used to indicate the likely location of a target (out of 4 possible target locations), with 8 cue-target onset intervals, ranging from 0 to 233 ms. There were 3 blocked proportions of correctly cued trials, 100%, 75%, and 50%. The observers had higher target discrimination accuracy at highly probable locations than at less probable locations, and these differences were maintained across all cue-target onset intervals. Thus, it appeared that the observers were allocating attention as a function of cue probability, with a consistent pattern throughout the time course of the development of attention. The consistent pattern across stimulus onset asynchronies (SOAs) suggests that the effects of time after cue and the effects of probability may rely on independent processes.

Attention Operating Characteristics in a Location-Cuing Task.

The authors studied the allocation of visual attention in the location-cuing paradigm in order to differentiate between 2 general classes of mechanisms: (a) switching attention across locations on different trials and (b) sharing attention across multiple locations within a trial. In Experiment 1, attention was directed by the use of central cues of 4 different cue validities: 100%, 80%, 50%, or 20% (in separate blocks). In Experiment 2, the percentage of correctly cued trials was fixed at 50%, but instructions and feedback were manipulated. The attention operating characteristic (AOC) curves provided evidence of sharing or hybrid (2-process) mechanisms. Thus, it appears that visual attention is characterized by a flexible allocation in response to task demands.

Theme Issue on Visual Attention: Guest Editor's Introduction.

WHEN GARVIN CHASTAIN ASKED ME to be guest editor for a theme issue of The Journal of General Psychology, I thought it might be worthwhile if I could improve on the very lengthy time lag between submission and acceptance that most of us have seen from other journals. Unfortunately, most journals still request multiple printed copies (4 or 5). In all my years of writing for publications, I have never been able to simply e-mail the manuscript or have the manuscript reviewed entirely by e-mail and the decision made in a short time. Therefore, I suggested that we do all of that by e-mail. I was not certain that the publisher would be willing to do that because of very uniform practices of submission and review. However, they welcomed the experiment, and I was launched on this project.