Comparetti, C. M. 1, 2 , Pichon, S. . 2 , Ricciardelli, P. 1 & Vuilleumier, P. 2
1 Department of Psychology, University of Milano-Bicocca - Italy
2 Laboratory for Behavioral Neurology and Imaging of Cognition, Medical School, University of Geneva - Switzerland
Others’ gaze direction and body position are powerful social cues indicating the presence of relevant information in the environment. We investigated how the processing of gaze direction (averted, directed) and head position (deviated, frontal) diminishes AB for subsequent visual events. AB refers to the reduced detection of a stimulus-T2 during a brief time-window (~250ms) following the detection of another first target stimulus-T1. Subjects had to report the gender of a face(T1) with different gaze and head orientation, and then categorize an indoor or outdoor scene(T2). Behavioral data showed that, outside the AB refractory-period, faces with congruent gaze and head position facilitated the identification of T2_scenes. During the AB-period, recognition for T2_scenes was diminished, except after T1_faces with direct gaze and frontal head. Comparison of trials where T1_faces or T2_scenes were correctly detected showed increased activity in FFA and PPA respectively. Activity in bilateral IPS decreased during AB in parallel to the decrease in T2 performance. Outside AB-period the interaction between head and gaze showed activity within ACC; face network activity increased for gaze contact but drastically diminished during AB. These results show that body and gaze position modulate the AB effect and influence the observer's attention for subsequent visual stimuli.