Do You Know Him? Gaze Dynamics Toward Familiar Faces on a Concealed Information Test

Can gaze position reveal concealed knowledge? During visual processing, gaze allocation is influenced not only by features of the visual input, but also by previous exposure to objects. However, the dynamics of gaze allocation toward personally familiar items remains unclear, especially in the context of revealing concealed familiarity. When memorizing four pictures of faces on a short term memory task, participants' gaze was initially directed toward a personally familiar face, followed by a strong avoidance from it. This avoidance was evident even when participants were instructed to conceal their familiarity and direct their gaze equally to all faces. On the other hand, participants were partially able to control the initial preference to fixate on the familiar face. By exploiting these patterns, a machine learning classification algorithm and signal detection analysis revealed impressive detection efficiency estimates, suggesting practical applications of recent theoretical insights from the domains of eye tracking and memory.