The sensitivity of face specific ERP components to the nature of stimulus noise

Abstract The processing of any noisy stimuli requires extra means from the nervous system. Several electrophysiological studies have proved that the processing of noise starts approximately 150–200 milliseconds after stimulus onset. This is suggested by the fact that the amplitude of the face-selective N170 component has been reduced and its latency prolonged by adding Gaussian noise to a face stimulus while the earlier P100 component is not influenced by added noise. While previous studies tested the electrophysiological correlates of noisy face perception in humans, the nature of added noise has not been studied yet in relation to face processing. Our goal was to distinguish the effects of added phase-noise from that of another irrelevant, overlapping non-face object (a car) on the electrophysiological correlates of human face processing. Subjects performed a two-alternative gender discrimination task with seven levels of difficulty, equalised between the phase-noise and overlapping object conditions. W...