Higher brain functions
Reward and Decision-Making
Block F (Module M.Neuro.16): Clinical Neurosciences and Higher Brain Functions
This lecture and accompanying tutorial covers the multifaceted nature of decision-making, examining how humans and animals choose actions across different contexts. We begin by categorizing decisions into perceptual, value-based, and “free” decisions and introducing Type 1 and Type 2 (metacognitive) decisions. Next, we explore how decisions are shaped by learning, focusing on reward mechanisms and conditioning. Topics include Pavlovian and instrumental conditioning, reinforcement learning (RL) models, prediction errors, and the role of dopamine. We also cover the Markov Decision Process (MDP) and the distinction between model-free and model-based RL. Building on this, we introduce decision theory and neuroeconomics, covering foundational concepts such as expected value, utility, and risk, along with deviations from rationality like Prospect Theory. We'll examine normalization and common currency models that guide valuation and choices. Finally, we discuss dynamic models of decision-making, emphasizing how decisions unfold over time and space. Topics include evidence accumulation models (e.g., diffusion to threshold), the affordance competition hypothesis, and the interplay between discrete and continuous decision processes. This lecture provides an integrative framework for understanding the cognitive and neural mechanisms of decision-making.