Indici psicofisiologici (potenziali corticali evento-correlati) nel decoding dell'espressione facciale delle emozioni. Effetto della stimolazione sovraliminale e subliminale sull'indice N200

[Autom. eng. transl.] The research aims to analyze the presence of a specific cognitive process for the "decoding" of facial expressions of emotions through the related ERPs (event-related potentials). In Experiment 1 (supraiminal condition) 20 subjects were subjected to five different emotional expressions (anger, fear, surprise, joy and sadness) and a neutral face (baseline configuration). Emotional recognition led to the elicitation of a negative deflection of around 230 ms post-stimulus (N2 effect, temporal window 180-300), following the ERP N1 variation, more localized in the posterior cortical areas (Pz). This effect appears to be specific for emotional mimicry, distinct from the structural index elicited by N1. The N2 also presents variations in relation to the evaluation expressed on individual emotions, in terms of hedonic value and "arousal" of the configuration. Furthermore, a cortical asymmetry was observed for some of the emotions, with right lateralization for negative expressions (anger, fear and sadness). In Experiment 2 (20 subjects) a condition of subliminal stimulation was set (10 ms exposure times), which prevented the conscious processing of emotional stimuli, in order to analyze their impact on the cognitive level. The ERP profile for subliminal stimulation appears morphologically similar to that detected in a supraiminal condition, but with longer latency times (240 ms). This suggests a partial similarity of the cognitive processes underlying the supraiminal and subliminal processing, albeit with temporal variations due to the experimental condition.