Visual competition attenuates emotion effects during overt attention shifts.

Numerous different objects are simultaneously visible in a person's visual field, competing for attention. This competition has been shown to affect eye-movements and early neural responses toward stimuli, while the role of a stimulus' emotional meaning for mechanisms of overt attention shifts under competition is unclear. The current study combined EEG and eye-tracking to investigate effects of competition and emotional content on overt shifts of attention to human face stimuli. Competition prolonged the latency of the P1 component and of saccades, while faces showing emotional expressions elicited an early posterior negativity (EPN). Remarkably, the emotion-related modulation of the EPN was attenuated when two stimuli were competing for attention compared to non-competition. In contrast, no interaction effects of emotional expression and competition were observed on other event-related potentials. This finding indicates that competition can decelerate attention shifts in general and also diminish the emotion-driven attention capture, measured through the smaller effects of emotional expression on EPN amplitude. Reduction of the brain's responsiveness to emotional content in the presence of distractors contradicts models that postulate fully automatic processing of emotions.

Overt and covert attention shifts to emotional faces: Combining EEG, eye tracking, and a go/no-go paradigm.

In everyday life, faces with emotional expressions quickly attract attention and eye movements. To study the neural mechanisms of such emotion-driven attention by means of event-related brain potentials (ERPs), tasks that employ covert shifts of attention are commonly used, in which participants need to inhibit natural eye movements towards stimuli. It remains, however, unclear how shifts of attention to emotional faces with and without eye movements differ from each other. The current preregistered study aimed to investigate neural differences between covert and overt emotion-driven attention. We combined eye tracking with measurements of ERPs to compare shifts of attention to faces with happy, angry, or neutral expressions when eye movements were either executed (go conditions) or withheld (no-go conditions). Happy and angry faces led to larger EPN amplitudes, shorter latencies of the P1 component, and faster saccades, suggesting that emotional expressions significantly affected shifts of attention. Several ERPs (N170, EPN, LPC) were augmented in amplitude when attention was shifted with an eye movement, indicating an enhanced neural processing of faces if eye movements had to be executed together with a reallocation of attention. However, the modulation of ERPs by facial expressions did not differ between the go and no-go conditions, suggesting that emotional content enhances both covert and overt shifts of attention. In summary, our results indicate that overt and covert attention shifts differ but are comparably affected by emotional content.