Effects of perceptual load in visual search in immersive virtual reality
53.4079, Tuesday, 19-May, 8:30 am - 12:30 pm, Pavilion
Bettina Olk1, David Zielinski2, Regis Kopper2; 1Jacobs University Bremen, 2Duke University
Research using computerized displays of simple stimuli has identified perceptual load as a critical factor for modulating distraction. Distraction is stronger when perceptual load is low than when it is high. Typically, participants determine which of two targets, e.g., letters, is present in a search array composed of other letters and perceptual load of the displays is varied. In the present experiment we made contact with the literature but increased ecological validity by assessing distraction in immersive Virtual Reality (VR), in which life-sized stimuli can be displayed in realistic settings, without losing the advantage of controlling conditions. Participants searched for a target (soda or yoghurt) among other daily objects on the countertop in a virtual kitchen. The search array was accompanied by a congruent or incongruent flanker. Perceptual load was manipulated. As expected, participants responded slower with incongruent flankers (flanker effect) and with high load (load effect), confirming that our materials and set up in the VR environment were suitable to elicit the basic effects. Contrary to our expectations based on the load theory of attention the flanker effect was not modulated by load. This finding may suggest that perceptual load may play a smaller role in attention and search in everyday situations than one would assume based on previous work. Obviously, virtual scenarios are more complex than the stimuli used and the conditions run in previous studies. Further, it is possible that daily, very familiar objects may be harder to ignore or be prioritized for processing also under high perceptual load. We discuss factors that may dilute or negate effects of perceptual load in a more ecologically valid situation and outline suggestions for further research. We suggest that VR offers an exciting interdisciplinary approach that may challenge our beliefs based on traditional laboratory research.