In the human brain, brief facial expression changes are quickly read from faces (Dzhelyova et al., 2017). In this study, faces were embedded in a natural context and varied in viewpoint, identity, gender, age, ethnic origin, and background context. We recorded 128-channel electroencephalography (EEG) in 17 participants while they viewed 50-s sequences with a neutral-expression face at a rate of 5.99 Hz (F) at two faces orientations (upright, inverted). Every five stimuli, the faces changed expression to one of the six basic expression (fear, disgust, happiness, anger, surprised, or sadness; Ekman, 1993), one emotion per sequence. EEG responses at 5.99 Hz reflect general visual processing, while the EEG responses at F/ 5¼1.1998 Hz and its harmonics (e.g., 2F/5¼2.3996, etc.) index detection of a brief change of natural facial expression. At the group-level, the categorization response was measured over occipito-temporal sites and was largely reduced when faces were inverted, indicating that it reflects high-level processes. Our observations with natural expressions highlight a stronger response for sadness, especially over the left hemisphere. Moreover, we observed a right hemisphere dominance for a shift from neutral to fearful faces and a left hemisphere dominance for a shift from neutral to happy faces.