Event-related BOLD responses distinguish aversive auditory second-order conditioning

Poster Session C - Sunday, April 14, 2024, 5:00 – 7:00 pm EDT, Sheraton Hall ABC

Prateek Dhamija^1,2 (prateek.dhamija@mail.utoronto.ca), Asaf Gilboa^1,2; ¹University of Toronto, ²Rotman Research Institute at Baycrest Academy for Research and Education

Background: Pavlov described second-order conditioning, where a stimulus that has acquired value (through classical conditioning) can be associated with other neutral stimuli. This paradigm is thought to model our motivations for much of our daily behaviour. Previous research in rodents and humans has suggested that second-order associations can be independently expressed. Our previous EEG research using aversive auditory stimuli has demonstrated that ERP responses can distinguish first-order and second-order stimuli, with activity localised to the prefrontal cortex for first-order stimuli and activity localized to the temporal cortex for second-order stimuli. Rodent research differs in that it finds that the hippocampus is critical for second order conditioning. Using fMRI, our goal was to explore the neuroanatomical structures involved in human second-order conditioning with greater spatial resolution. Method: In this experiment, we designed an event related fMRI study to explore the neural correlates of second-order aversive auditory conditioning. Young adults (18-35 years, n=27) underwent aversive auditory conditioning on day 1 and second-order conditioning in a 3T MRI scanner. White noise was used as an aversive unconditioned stimulus (US+). Initially neutral tones were used as first-order (CS+/CS-) and higher-order (HO+/HO-) associates. Results: We found that first-order stimuli could be differentiated by significant clusters in the right angular gyrus and cingulate cortex. We also found that second-order stimuli could be differentiated by significant clusters in right temporal areas. Conclusions: Prefrontal cortex and temporal cortex may play an important role in second-order conditioning in humans.

Topic Area: OTHER