Altered upright face recognition and presence of face inversion effect in temporal lobe epilepsy: An event-related potential study

Abstract

Aim: Facial recognition can be assessed by examining an event-related potential component, namely the N170. The amplitude of the N170 is larger in response to inverted faces than to upright faces. To examine facial processing in patients with temporal lobe epilepsy (TLE), we investigated the amplitude of the N170, the face inversion effect, and the association between social functioning and face-specific configuration processing. Methods: Sixteen patients with TLE and 17 normal controls (NC) participated in this study. Event-related potentials in response to upright or inverted neutral faces and bicycles were recorded. Social functioning was assessed by the socioeconomic status of the participants using the 5-point Hollingshead–Redlich Scale. Results: Compared with NC, patients with TLE had decreased N170 amplitudes. The inversion effect was observed for face stimuli in both groups; however, no inversion effect was observed for bicycle stimuli. Additionally, in TLE patients, but not in NC, socioeconomic status was significantly correlated with the N170 amplitudes in response to upright faces. Conclusion: In a social context, upright faces are processed as a whole. This process is impaired in TLE. Conversely, inverted faces are processed analytically. This function is normal in TLE. Abnormal face-specific configuration processing may contribute to lower social functioning in TLE.