Read about the latest research on vision published in Psychological Science.
A Bayesian Optimal Foraging Model of Human Visual Search
Matthew S. Cain, Edward Vul, Kait Clark, and Stephen R. Mitroff
When searching displays containing an unknown number of targets, it can be difficult to know when to stop searching. In this study, researchers quantified visual-search strategies by having participants look for targets among distractors. In the first condition, only 25% of the trials had one or more targets; in the second condition, 50% of the trials had one or more targets; and in the third condition, 75% of the trials had one or more targets. Researchers found that participants searched longer if more targets were likely to be in the display. Once a target had been found, whether participants continued to search depended on the likelihood that more targets were present. These findings suggest that searchers can adapt to complex statistics within their search environment in sophisticated ways.
Published in the September 2012 issue of Psychological Science
Distinct Attention Networks for Feature Enhancement and Suppression in Vision
David A. Bridwell and Ramesh Srinivasan
How do enhancement and suppression shape our visual processes? Electroencephalogram was recorded while participants performed a feature detection task that encouraged enhancement of the neurons coding the spatial frequency and orientation spectrum of attended background textures — one of which encouraged suppressing of those features and one of which was neutral. The researchers found that suppression primarily modulated parietal networks and had a preferred frequency in the lower alpha band, while enhancement primarily influenced parietal and occipital networks and had a preferred frequency in the upper alpha bands. This suggests that although suppression and enhancement work together to shape visual perception, they are two distinct processes.
Published online August 23, 2012 in Psychological Science