Deliberate control of facial expressions in a go/no-go task: An ERP study

In two studies we investigate the role of affective factors and top-down processes underlying production and deliberate control of emotional facial expressions and its neural underpinnings. In Study 1 we examine facial expressions of joy, fear and disgust depending on the emotional content of the visual stimuli (upright faces, inverted faces, emotion inducing pictures without faces). In Study 2 we focus on expressions of joy and disgust depending on gaze direction (with and without eye contact) in a more natural setting with a real person as stimulus. We hypothesized that the more automatic processes are induced by stimuli (e.g., arousal, mimicry or social cues like eye contact) the harder it is to control facial expressions; particularly expressions of joy compared to fear and disgust. In both studies we used go/no-go tasks and showed faster RTs for conditions with upright faces or eye contact, respectively. We also found faster RTs for expressions of joy than of fear and disgust. In Study 1 participants showed more errors in no-go trials for expressions of joy than for expressions of fear and disgust, indicating worse top-down control for expressions of joy than of fear or disgust. An ERP analysis of the no-go P3 in Study 1 revealed larger amplitudes for upright faces compared with both inverted faces and emotion inducing pictures and larger amplitudes for expressions of joy than for disgust. This indicates greater demand of top-down control when automatic mimicry processes are activated and some degree of specificity to particular facial expressions. In Study 2 more errors in no-go trials in conditions with eye contact only for expressions of joy indicate mimicry could be larger for expressions with high affiliative intent like expressions of joy, and reduced mimicry for negative expressions. All results indicate that facial expressions buffered by automatic processes (e.g., mimicry) have a greater need for top-down control, especially expressions of joy compared to expressions of fear and disgust.