The influence of emotional stimuli on the oculomotor system: A review of the literature

In the past decade, more and more research has been investigating oculomotor behavior in relation to attentional selection of emotional stimuli. Whereas previous research on covert emotional attention demonstrates contradictory results, research on overt attention clearly shows the influence of emotional stimuli on attentional selection. The current review highlights studies that have used eye-movement behavior as the primary outcome measure in healthy populations and focusses on the evidence that emotional stimuli-in particular, threatening stimuli-affect temporal and spatial dynamics of oculomotor programming. The most prominent results from these studies indicate that attentional selection of threatening stimuli is under bottom-up control. Moreover, threatening stimuli seem to have the greatest impact on oculomotor behavior through biased processing via the magnocellular pathway. This is consistent with an evolutionary account of threat processing, which claims a pivotal role for a subcortical network including pulvinar, superior colliculus, and amygdala. Additionally, I suggest a neurobiological model that considers possible mechanisms by which emotional stimuli could affect oculomotor behavior. The present review confirms the relevance of eye-movement measurements in relation to researching emotion in order to elucidate processes involved in emotional modulation of visual and attentional selection.