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Category: Project

Description: The prevalence effect refers to a cognitive bias towards detecting more quickly and efficiently, targets which appear more frequent (high prevalence) in your visual field versus less frequent targets (low prevalence). Participants will be asked to complete one testing session online, which lasts approximately 1 hour. The experiment consists of 10 practise trials and 400 experimental trials. Participants will have to complete a Multiple Target Search (MTS) task, where they will be presented with 8 different items of real-life stimuli and they will have to detect targets amongst distractors as quickly as possible (i.e. reaction time task). Out of the 400 trials, 200 will be target-present and 200 will be target-absent trials. For the duration of the whole experiment, participants will have to mentally hold representations of three different possible targets with three different levels of prevalence: high, middle and low prevalent targets. In target-present trials, only 1 target (out of the three possible target templates) will be present amongst 7 distractors and participants will have to give a target present response. The high prevalent target will be present on 70% of trials, the middle prevalent target will be present on 20% of trials and the low prevalent target will be present on 10% of trials. In target-absent trials, only distractors will be present with no target, and participants will have to give a target-absent response. The primary investigation of interest is the RT difference in participants’ target-present responses across the three different levels of prevalence. It is expected that, participants will be better and quicker at detecting high versus low prevalent targets.