Neural and cognitive underpinnings of trustworthiness in the prefrontal cortex via optical brain imaging

Human face has been considered to be an indicator of various attributes including attractiveness, calmness, and trustworthiness. Even a single look for a short duration might have an influence on one's attitude. This empirical study aimed to understand the neural correlates of trustworthiness judgments on face photos via an optic brain imaging (fNIRS) method. The experimental design has been developed to categorize the presented photos after watching them for 4000 milliseconds. The responses were collected within a 3-point Likert scale. The obtained findings indicate that there is a significant level of neural activation difference between positive and negative responses among a specific optode (Optode-3). Moreover, there are also significant levels of neural activation differences for the neutral responses versus others among 3 optodes (Optodes 12, 14, and 16). The results were also controlled regarding the saliency levels of the photos as well as the emotional states of the individuals in the photos via facial activation coding analysis. Overall results imply that trustworthiness level might be understood at a certain level.