Prevalence Effects in Visual Search: Theoretical and Practical Implications

What this Trial Is About

Researchers are investigating how visual search behavior differs when performing the same search repeatedly in a row compared to doing multiple different search tasks mixed together. The study focuses on four search tasks where the target remains the same but distractors vary. This helps understand whether findings from lab studies using repeated blocked tasks apply to more mixed, real-world search situations. The research is linked to a larger grant supported by the National Cancer Institute and is part of a bundle of related experiments. Participants are trained on four different visual search tasks. In the Blocked condition, each task is completed in a block of 100 trials, while in the Mixed condition, all four tasks are randomly mixed in a single block of 400 trials. Stimuli are displayed in a jiggled 5x5 grid on a computer screen with items varying in number and type. Participants respond to whether the target is present or absent by pressing designated keys, and accuracy feedback is provided after each trial. Throughout the study, participants complete 400 trials under each condition over about one year. Researchers measure response time and accuracy as primary and secondary outcomes. The study includes color vision screening and excludes those with certain vision impairments or neuromuscular disorders. Participants will be monitored for their performance during the tasks, helping scientists understand how visual search varies with task structure in healthy adults.

Experiment 2: One Target in Many Situations