Visual MMN elicited by orientation changes of faces.

Faces are socially very important visual objects and the detection of a change in faces is an essential evolutionary skill. To investigate whether configural computation of faces automatically occurs under non-attentional condition, visual mismatch negativity (vMMN) elicited by deviant orientation (90° vs. 0°) of faces was analyzed using the equi-probable paradigm which eliminated the low-level refractory effects. Fourteen participants were tested and schematic face stimuli were used. In comparison with control face stimuli, the deviant orientation of faces elicited larger N170 and smaller P2. During the time range between 100-300 ms post stimulus onset, face orientation changes elicited occipital-temporal distributed vMMN. The source analysis of face-MMN showed that it was generated in both temporal and frontal lobes. These data supported the hypotheses that the disruption of facial configuration processing caused by inverted faces is relatively independent of attentional resources.