Emotional faces interfere with saccadic inhibition and attention re-orientation: An fMRI study

Modulation of reflex responses is crucial to adapt our behavior and cognition, and this is especially difficult when biological relevant stimuli are present such as emotional faces. The aim of this study was to identify the effect of peripherally presented happy and angry facial expressions in reflexive saccades and saccadic inhibition/re-orientation of attention. Behavior through eye-tracking technique and fMRI event-related BOLD signals activations were evaluated in adult males during the performance of an antisaccade task. fMRI signals obtained during task performance were compared to a baseline. Results showed that antisaccades had a lower percentage of correct responses and higher latency onsets than prosaccades. At the activation brain level, differences between both emotions and the baseline were found during stimuli presentation. Prosaccades for happy and angry faces recruited larger clusters with higher Z values mainly in occipito-parietal and temporal regions related to visual basic and integration processing, as well as regions of the oculomotor network. Meanwhile, when compared to the baseline, antisaccades recruited similar areas but a lower number of clusters with lower Z values as expected for peripheral processing of faces. At antisaccades, happy faces recruited parieto-occipital, temporal and cerebellar regions, while the angry faces added activation of orbital and ventrolateral prefrontal cortex related to emotional regulation. These results suggest that emotional facial expressions are being processed outside of the focus of attention. Particularly, angry expressions recruit a wider brain network in order to inhibit automatic behavior and re-orientate voluntary attention efficiently that may be due to its biological relevance.