THE ROLE OF THE CEREBELLUM AND VENTRAL TEGMENTAL AREA IN APPETITIVE AND AVERSIVE CONDITIONING: A 7 T FMRI STUDY

Extinction learning of learned fear responses is thought to be driven by reward-related prediction errors, with the unexpected omission of an aversive stimulus being a better outcome than expected. The cerebellum and ventral tegmental area (VTA) have been implicated in this process, showing increased activity during aversive stimulus omissions in human fear learning (Nio et al., 2025, eLife), while dopaminergic neurons in the VTA respond to similar signals in rodents (Salinas-Hernández et al., 2018, eLife). Reward-related prediction errors can be examined more directly in an appetitive learning context. This study compares unexpected delivery of reward with the unexpected omission of an aversive US, and investigate whether these events similarly activate the cerebellum and VTA and increase functional connectivity between these regions. Using a within-subjects design in a 7 T MRI scanner, 35 healthy participants (19F/16M; age: 25.06 ± 3.94 years) completed an appetitive paradigm using monetary reward and an aversive paradigm using electrical stimulation on two consecutive days. Each paradigm used an acquisition and reversal phase with 62.5% reinforcement. Behavioral results were consistent with prior work (Petrenko et al., 2025, Behavioural Brain Research), with stronger CS+/CS- differentiation in skin conductance responses during aversive compared with appetitive conditioning. Ratings nevertheless indicated successful learning in both paradigms, with comparable CS+/CS- differentiation for valence and US perception. Preliminary fMRI analyses show cerebellar activation during appetitive and aversive US presentations as well as during unexpected US omissions. Additional analyses, including model-based fMRI analyses and cerebellum–VTA connectivity analyses, are ongoing and will be presented.