Putting things into perspective: Which visual cues facilitate automatic extraretinal symmetry representation?use asterix (*) to get italics

Elena Karakashevska, Marco Bertamini and Alexis D.J. Makin Please use the format "First name initials family name" as in "Marie S. Curie, Niels H. D. Bohr, Albert Einstein, John R. R. Tolkien, Donna T. Strickland"

2023

<p>A challenge for the visual brain is to identify objects from a range of different viewpoints. This study will determine the conditions under which the brain spends computational resources to achieve view-invariance. We focus on view-invariant responses to planar visual symmetry. Visual symmetry generates an Event Related Potential (ERP) called Sustained Posterior Negativity (SPN). Amplitude is lower for symmetrical compared to asymmetrical stimuli at posterior electrodes. &nbsp;Symmetry in the retinal image is degraded by perspective slant. If the SPN is equivalent for flat and slanted presentations, the brain is generating an extraretinal representation. Previous studies have found extra-retinal symmetry representations are not constructed automatically when people attend to luminance. Our new study will use superior stimuli and systematically test three visual treatments that might reduce slant cost when attending to luminance. In Experiment 1, we will compare the Baseline condition where there are no cues supporting 3D interpretation. In the Monocular viewing condition, we will eliminate binocular disparity cue conflict by having participants view with one eye. In the Frame condition, a static frame will be presented during the baseline and stimulus intervals. Finally, in the Moving Frame condition, the frame will be presented during the pre-stimulus baseline and move about its center point. The four conditions will be presented in separate blocks. We predict slant cost will be reduced in all three treatment conditions. In Experiment 2 we will compare Baseline and All treatment conditions combined (moving frame with monocular viewing). We predict this will reduce slant cost further. If our predictions are confirmed, we will conclude automatic extra-retinal symmetry representation occurs during luminance-discrimination given adequate visual cues.</p>

vision, perception, symmetry, EEG, sustained posterior negativity

NonePlease indicate the methods that may require specialised expertise during the peer review process (use a comma to separate various required expertises).

Life Sciences

2023-04-17 21:52:26

Grace Edwards