Seeing objects as face modulates visual search performance

Some products are explicitly or implicitly designed so that objects can be seen as a face; this will possibly support a fluent human-environment communication. The present study investigated the effects of seeing objects as face on human's visual search performance by means of psychological experiments. The participants were asked to search a target among distractors on a computer display as quickly as possible. The target and distractors differed in the vertical direction. The participants were randomly assigned to a face task or a triangle task. In the face task, the visual stimulus was either a cartoon face or three dots arranged in triangle that could be seen as a face, and the participants were instructed to search a upright or inverted face among distractors. In the triangle task, the visual stimulus was either the three dots same as the face task or a line-drawing triangle, and the participants were instructed to search a triangle. In both tasks, two types of stimuli were randomly presented during the trial sequence. We found that visual search for the three-dot target was slower in the face task than in the triangle task. However, when the target stimulus was informed immediately before each trial, the results were reversed; visual search for the three-dot target in the face task was faster than in the triangle task. These results suggest that, even if the target stimulus par se is identical, seeing the target as face modulates visual search performance, and the effects interact with expectation or preparation of the subsequent target.