Abstract
Behavioral responses to threat are critical to survival. Several cortical and subcortical brain regions respond selectively to threat. However, the relation of these neural responses and their underlying representations to behavior is unclear. We examined the contribution of lower-order subcortical representations to behavioral responses to threat in adult humans. In Experiments 1 and 2, participants viewed pairs of images presented to the same eye or to different eyes. We observed a monocular advantage, which indicates subcortical facilitation, for ancestral threats (snakes, spiders), but not for modern threats, positive images, or neutral images. In Experiment 3, we presented pairs of snakes or neutral images into the temporal or nasal hemifield. For snakes only, we observed a temporal hemifield advantage, which indicates facilitation by the retino-tectal subcortical pathway. These results advance the current understanding of processing of threat by adult humans by revealing the characteristics of behaviors driven by a lower-order neural mechanism that is specialized for the processing of ancestral threats. The results also contribute to ongoing debates concerning the biological generality of neural mechanisms for processing of complex, emotionally-relevant stimuli by providing evidence for conservation of lower-order neural mechanisms for processing of ancestral threats across both ontogeny and phylogeny.
Highlights
Adult humans detect and respond more rapidly to threatening images than to non-threatening images, whether the images depict ancestral threats[1,2,3,4,5,6,7] or modern threats[8,9]
With respect to the question of conservation over phylogeny, it is of interest whether there is subcortical facilitation of behavioral responses to threat in adult humans, which would suggest that the lower-order neural mechanism proposed to facilitate threat processing in both human and non-human primates is active in humans[15]
With respect to the question of conservation over ontogeny, it is of interest whether the subcortical visual pathway contributes to facilitation of behavioral responses to threat in adult humans, which would suggest that the subcortical mechanism proposed to guide threat processing early in development continues to function in adulthood
Summary
Adult humans detect and respond more rapidly to threatening images than to non-threatening images, whether the images depict ancestral threats[1,2,3,4,5,6,7] (e.g., snakes, spiders) or modern threats[8,9] (e.g., guns). In Experiment 1, we investigated whether the subcortical visual pathway facilitates behavioral responses to ancestral threats (snakes and spiders), and to neutral images.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
