Fast auditory and pupillary responses to high temporally modulated sounds suggest the existence of a human magnocellular auditory pathway for threat

Poster Session B - Sunday, April 14, 2024, 8:00 – 10:00 am EDT, Sheraton Hall ABC

Martina Trisia Cinca-Tomás^1,2 (cinca-tomas_t@ub.edu), Emmanouela Kosteletou Kassotaki^1,2, Jordi Costa-Faidella^1,2,3, Nadia Paraskevoudi^1,2, Carles Escera^1,2,3, Judith Domínguez-Borràs^1,2; ¹Brainlab – Grup de Recerca en Neurociència Cognitiva, Universitat de Barcelona, ²Institut de Neurociències, Universitat de Barcelona, ³Institut de Recerca Sant Joan de Déu (IRSJD), Esplugues de Llobregat, Spain

Neural models for emotional processing in vision suggest the existence of an ultrafast magnocellular route to the amygdala, which allows for efficient detection of threat and subsequent adaptive behavior in humans. This route is known to mediate coarse visual processing, eliciting differential responses to threat than other more fine-grained pathways. In the auditory domain, animal evidence suggests the existence of a similar route for threat detection, but it remains unknown in humans. We investigated, with fear conditioning, a procedure that depends on amygdala response, whether a magnocellular pathway to the amygdala, particularly sensitive to high temporal modulations, mediates auditory and pupillary responses to threat that may differ from a parvocellular pathway, sensitive to low temporal modulations. We recorded electroencephalography and pupillometry of 28 healthy participants while they detected voices. Voices were either paired (conditioned) or unpaired (not conditioned) with an unpleasant white noise, which determined their threatening significance. Results suggest that fear conditioning was effective, and threatening stimuli at high temporal modulations elicited earlier auditory and pupillary responses than those presented at low temporal modulations. In turn, early auditory threat responses to high amplitude modulated sounds correlated with response time in higher anxiety participants. These results are compatible with faster cortical responses to threat when encoded through magnocellular inputs to the amygdala, and suggest the existence of an auditory route for threat detection in humans, similar to that in vision.

Topic Area: EMOTION & SOCIAL: Emotional responding