Sandali Liyanagoonawardena¹ (), Werner Schneider², Michael Herzog¹; ¹Laboratory of Psychophysics, Brain Mind Institute, École Polytechnique Fédérale de Lausanne (EPFL), Switzerland, ²Neuro-Cognitive Psychology & CITEC, Bielefeld University, Germany

Performances in basic visual tasks correlate very little with each other. For example, Landolt C acuity correlates very little with vernier and bisection acuity, despite high test–retest reliability on each test. Similar results were found for studies with visual illusions and in older participants. Here, we asked whether similar results hold true for visual search. We tested 32 healthy young adults with five conjunction visual search tasks with line and shape stimuli varying in shape, color, and orientation. In addition, we tested a letter search task (upright T among Ls). Each task was conducted under three distractor levels (2, 4, and 8 items), across two sessions, with two repetitions per session to assess test–retest reliability. Test-retest reliability was good in all but one condition, with ICCs ranging from 0.5 to 0.9. In contrast to visual acuity and illusion studies, moderate to very high correlations were observed between the different conjunction searches, varying across three of the primary dimensions: shape, color, and orientation. However, search efficiencies with these line and shape displays correlated only weakly with the letter search. We speculate that letter search is driven by integrated object representation rather than distinct target features, as in the first four tasks. Our results show how correlative studies can be used to unravel distinct mechanisms in visual search.