Searching Near and Far: The Attentional Template Incorporates Viewing Distance

• Published in: Journal of experimental psychology. Human perception and performance 2024-02, Vol.50 (2), p.216-231
• Main Authors: Gayet, Surya, Battistoni, Elisa, Thorat, Sushrut, Peelen, Marius V.
• Format: Article
• Language: English
• Subjects: Apparent Size; Attention; Female; Fixation; Human; Male; Object Recognition; Orientation behavior; Spatial attention; Stimulus; Stimulus Parameters; Visual Perception; Visual representation; Visual Search; Visual Stimulation
• ISSN: 0096-1523; 1939-1277; 1939-1277
• DOI: 10.1037/xhp0001172

According to theories of visual search, observers generate a visual representation of the search target (the "attentional template") that guides spatial attention toward target-like visual input. In real-world vision, however, objects produce vastly different visual input depending on their location: your car produces a retinal image that is 10 times smaller when it is parked 50 compared to 5 m away. Across four experiments, we investigated whether the attentional template incorporates viewing distance when observers search for familiar object categories. On each trial, participants were precued to search for a car or person in the near or far plane of an outdoor scene. In "search trials," the scene reappeared and participants had to indicate whether the search target was present or absent. In intermixed "catch-trials," two silhouettes were briefly presented on either side of fixation (matching the shape and/or predicted size of the search target), one of which was followed by a probe-stimulus. We found that participants were more accurate at reporting the location (Experiments 1 and 2) and orientation (Experiment 3) of probe stimuli when they were presented at the location of size-matching silhouettes. Thus, attentional templates incorporate the predicted size of an object based on the current viewing distance. This was only the case, however, when silhouettes also matched the shape of the search target (Experiment 2). We conclude that attentional templates for finding objects in scenes are shaped by a combination of category-specific attributes (shape) and context-dependent expectations about the likely appearance (size) of these objects at the current viewing location. Public Significance StatementWhen searching for an object in our surroundings, traditional theories of visual search posit that we generate a mental picture of the object we are looking for (the "attentional template"). Depending on where we look (e.g., further away), however, an object will produce a vastly different (i.e., smaller) image on the retina. Here we show that observers flexibly adjust their attentional template, based on their current search location, effectively accounting for viewing distance by searching for a smaller version of the object when searching further away. These findings reconcile traditional theories of visual search with the challenges imposed by naturalistic vision.