Abstract
Visual search, the process of looking for targets amongst distractors, is an everyday activity executed in a variety of contexts. While searches are often mundane (e.g., looking for your keys) they can also be highly important (e.g., airport baggage screeners looking for contraband). Considerable research has examined the nature of visual search accuracy, but how well do the results generalize to real-world visual searches? For example, most cognitive psychology experiments present observers with a single search array and assess how quickly and accurately target(s) are found. However, airport baggage screeners often view displays that contain multiple search arrays (i.e., several bags on the same x-ray monitor), and these search arrays can be close together and/or appear physically connected (e.g., when passengers shove their bags into the x-ray machine). Here we investigated how accuracy is affected when multiple search arrays are simultaneously present, and whether spacing between arrays impacts performance. Experiment 1 presented 3 search arrays, either spaced close together (5-pixel separation) or far apart (100-pixel separation), and each array could contain 0, 1, or 2 targets. Trials progressed by having the arrays physically shift to the edge of the monitor as if on a conveyor belt, and participants were to only search the center array before advancing. Array spacing did not impact response time or accuracy on single- and no-target trials, but did affect dual-target trials: second target accuracy (after having found a first target in the same array) was significantly worse when the arrays were close together than far apart. Experiment 2 compared trials with 3 far-spaced arrays to trials with only a single array, and there were no response time or accuracy differences. Collectively, the results suggest that search array spacing can negatively impact accuracy for dual-target search, which is a particularly complex search process.
Meeting abstract presented at VSS 2013