Program

Understanding how the brain transforms often uncertain sensory evidence into a perceptual decision, and how confidence in that decision emerges, remains a core challenge in cognitive neuroscience. To fully explain how external inputs, prior expectations, and internal arousal shape perception and its subjective certainty across contexts and species, both local circuit mechanisms and global network states need to be considered.

This symposium brings together four complementary approaches that collectively disentangle bottom-up sensory and arousal influences from top-down expectation and learning factors. First, Stijn Nuiten demonstrates that humans and mice alternate between discrete and persistent behavioral states and that pupil-linked arousal and GABAergic activity in sensory regions jointly facilitate task-optimal state probability. Next, Alessandro Toso reveals distributed, competing accumulators in premotor and motor cortices that encode both decision speed and confidence, highlighting a link between the balance of competing neural signals and subjective certainty. Sarah Tune then explores how pharmacologically altering the cortical excitation-to-inhibition balance affects the integration of auditory signals and prior expectations in perceptual decision-making and metacognition. Finally, Monja Froböse focuses on how pharmacological inhibition of cholinergic transmission shapes learning and decision-making under uncertainty, demonstrating that processes of probabilistic inference and adaptive choice behavior depend on specific neuromodulatory mechanisms when the brain is challenged by volatile environments.

By combining diverse pharmacological, behavioral and analytic approaches, this symposium offers convergent insights into the neural algorithms that govern how evidence is acquired, weighted, and experienced in perceptual decision-making, metacognition, and learning.