Threat modulates neural responses to looming visual stimuli
Vagnoni, Eleonora and Lourenco, S.F. and Longo, Matthew R. (2015) Threat modulates neural responses to looming visual stimuli. European Journal of Neuroscience 42 (5), pp. 2190-2202. ISSN 0953-816X.
Objects on a collision course with an observer produce a specific pattern of optical expansion on the retina known as looming, which in theory exactly specifies the time-to-collision (TTC) of approaching objects. We recently demonstrated that the affective content of looming stimuli influences perceived TTC, with threatening objects judged as approaching sooner than non-threatening objects. Here, we investigated the neural mechanisms by which perceived threat modulates spatiotemporal perception. Participants judged the TTC of threatening (snakes, spiders) or non-threatening (butterflies, rabbits) stimuli, which expanded in size at a rate indicating one of five TTCs. We analysed visual-evoked potentials (VEPs) and oscillatory neural responses measured with electroencephalography (EEG). The arrival time of threatening stimuli was underestimated compared to non-threatening stimuli, though an interaction suggested that this underestimation was not constant across TTCs. Further, both speed of approach and threat modulated both VEPs and oscillatory responses. Speed of approach modulated the N1 parietal and oscillations in the beta band. Threat modulated several VEP components (P1, N1 frontal, N1 occipital, EPN and LPP) and oscillations in the alpha and high gamma band. The results for the high gamma band suggest an interaction between these two factors. Previous evidence suggests that looming stimuli activate sensorimotor areas, even in absence of an intended action. Our results show that threat disrupts the synchronization over the sensorimotor areas that are likely activated by the presentation of a looming stimulus.
|Additional Information:||"This is the peer reviewed version of the article, which has been published in final form at http://dx.doi.org/10.1111/ejn.12998 - This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving.|
|Keyword(s) / Subject(s):||time-to-collision, visual evoked potential, oscillatory responses, emotion|
|School:||Birkbeck Schools and Departments > School of Science > Psychological Sciences|
|Research Centre:||Brain and Cognitive Development, Centre for (CBCD)|
|Depositing User:||Matthew Longo|
|Date Deposited:||01 Jul 2015 13:13|
|Last Modified:||02 Dec 2016 11:52|
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