The effect of unconscious priming on emotional facial expression processing

According to recent theories of consciousness, there is an unconscious automatic perceptual process when there is no directed attention and perceptual inputs are low. It is known that these processes show autonomous responses to emotional stimuli. It has also been demonstrated that facial expressions are one stimulus that is processed at an unconscious level. This study examined the effects of priming with conscious and unconscious facial and nonfacial emotional stimuli on the recognition process in facial expression recognition processes. Accordingly, it is thought that unconscious perception processes related to facial expressions arise because of a bias in facial expressions, not emotional stimulation, which is thought to trigger automatic responses. The study was carried out by measuring behavioral and physiological responses, as a result of presenting emotional stimuli with the same emotional content, both face and non-face categories and in conscious and unconscious conditions, before recognizing positive (happiness) and negative (fear) emotional expressions. Behavioral responses consist of reaction times and correct response rates related to the recognition task. During the task, electroencephalogram (EEG) recordings were taken to examine the brain signals of the participants, and event-related potentials (ERP, Event-Related Potentials) were examined. The investigated ERP components comprised N170, N200, and P100 components, which are thought to be specific to the facial stimuli. ERP analyzes were examined in terms of amplitude levels, according to the conditions of the priming-test stimulus. As a result of the study, shorter response times and increased correct response rates were determined after conscious and unconscious facial priming compared to non-face priming stimuli. The P100 ERP components showed increased amplitudes in face presentation. In priming with the face, the N170 and N200 ERP components showed higher amplitudes in the frontal areas compared to other stimulus categories. In the posterior regions, no face-specific bias was detected in terms of N170 and N200 signals. A face-specific perceptual bias is seen when the activity spreading to the frontal areas is considered face-specific. That N170 and N200 components show higher amplitudes in neutral preparation compared to congruent indicate the existence of a perceptual process related to the basic structural features of the face such as eyes, mouth, and nose rather than facial expressions in early processing. Contrary to the findings in the literature, this effect occurs at different levels in different temporal windows and brain regions, which shows it is important to examine the perceptual processes of facial expressions in detail. Keywords: Unconscious Facial Expressions, EEG, Priming Effect, N170, N200, P100, Emotional Facial Expressions