Podcast with Encarni Marcos on prefrontal cortex and decision making

Why do some prefrontal neurons hold steady while others rapidly switch what they represent? Neuroscientist Encarni Marcos reveals that the prefrontal cortex operates through a continuum of neural stability and flexibility , where heterogeneous populations simultaneously maintain goals in memory and dynamically transform them into actions. Subscribe for more from the Convergent Science Network podcast series. Encarni Marcos joins Paul Verschure and Tony Prescott to discuss her research on how prefrontal cortex supports goal-directed behavior. Recording from dorsolateral prefrontal cortex in monkeys performing discrimination tasks, she finds that neurons do not simply encode one feature of a task. Instead, individual neurons represent multiple features, goals, cues, actions, often overlapping in time, with some neurons switching their representational allegiance as a decision unfolds while others remain locked to a single variable throughout the trial. The conversation explores what this heterogeneity means for decision-making. Marcos describes a model built from competing pools of neurons with different excitability levels: stable populations maintain task-relevant information as a kind of ground truth, while flexible populations reshape network dynamics to drive the transition from goal representation to action selection. This architecture, validated against physiological data including burst-pause patterns, offers a mechanistic account of how the brain can simultaneously remember what it needs to do and figure out how to do it , without requiring separate memory and decision systems. Key topics include why averaging across neural populations obscures the real dynamics of prefrontal cortex, how error signals in prefrontal neurons defy standard dopaminergic prediction error models, the limitations of drift-diffusion models for explaining individual neural dynamics, and why neural variability may carry more information about cognitive processing than firing rates alone. Part of the Convergent Science Network podcast series from the BCBT Summer School.