People have the power. Even when the mind is busy. Priority differences among socially relevant and irrelevant targets in a change detection task

The priority afforded to social information has been demonstrated in several perceptual tasks, from change detection to visual search. In this study we adopted a change detection paradigm in which twenty subjects were randomly assigned to two conditions: single and dual task. The secondary task was a simplified version of PASOT, which requires a verbal effort. Subjects were administered a set of 46 pictures in which the change consisted either in the removal of a person or an object. The target elements were comparable in position and dimension, keeping as a within-factor only their social meaning. Since the change detection performance is enhanced with highly informative targets, we hypothesized a lower detection time for persons with respect to objects, with the PASOT performance remaining stable across the person vs object trials. Results from a two-way mixed ANOVA supported this prediction, given the significant main effects of condition and kind of target. This findings suggest that the processing of social stimuli requires less cognitive resources than other equally salient elements.