A patient has damage to their ventromedial prefrontal cortex (vmPFC). They score normally on tests of logical reasoning and can articulate decision rules perfectly. What would you predict about their real-world behavior?
AThey would struggle to follow instructions because working memory for rules is impaired
BThey would make poor real-world decisions despite intact reasoning ability
CThey would be unable to detect when they have made a mistake
DThey would respond impulsively because they can no longer inhibit habitual responses
The Somatic Marker Hypothesis captures this dissociation: vmPFC damage removes the bodily value signals that normally guide real-world choice, leaving intact reasoning but devastated practical judgment. This is the key insight — value representation and logical reasoning are neurally separable. Option A describes a dlPFC working-memory deficit; option C describes an ACC dysfunction; option D describes a failure of dlPFC-mediated inhibition.
Question 2 Multiple Choice
A skilled driver completes a familiar commute while mentally planning their workday, barely attending to the mechanics of driving. What does this illustrate about neural decision-making systems?
AThe vmPFC has replaced the dlPFC as the dominant value-computing region for driving
BThe ACC has suppressed conflict detection to allow automatic processing
CDriving has shifted from model-based (deliberate, goal-directed) to model-free (habitual, cached) processing
DRepeated practice has eliminated the need for prediction error signaling
Well-practiced behaviors transition from model-based (using a cognitive map to simulate action sequences) to model-free (retrieving cached stimulus-response associations from the striatum). This is efficient — model-free systems produce fast, accurate responses in familiar contexts without burdening working memory. The shift is not permanent: introduce an unexpected obstacle and model-based deliberation re-engages.
Question 3 True / False
Loss aversion — weighting losses more heavily than equivalent gains — reflects a fundamental flaw in the brain's decision-making architecture.
TTrue
FFalse
Answer: False
Loss aversion correlates with amygdala reactivity and reflects a bias that was adaptive in ancestral environments where survival-relevant losses (injury, starvation, social exclusion) had catastrophic consequences that outweighed equivalent gains. It is a mismatch to some modern contexts (e.g., long-term investing) but not a 'flaw' — it is a heuristic tuned to a different environment. Neural decision-making research shows that systematic deviations from rational choice theory are largely explainable as evolved heuristics, not arbitrary errors.
Question 4 True / False
The anterior cingulate cortex (ACC) is involved in monitoring both unexpected outcomes and conflicts between competing options of similar value.
TTrue
FFalse
Answer: True
ACC plays a dual role: it signals prediction errors when outcomes are worse than expected (driving value updating for future choices) and it detects decisional conflict when two options have similar expected values (recruiting additional cognitive resources). This dual function links the brain's outcome-monitoring and conflict-resolution systems in a single region — it is a neural implementation of the feedback mechanisms that normative choice theory predicts should exist.
Question 5 Short Answer
Why does addiction persist even when the person knows cognitively that the addictive behavior is destructive?
Think about your answer, then reveal below.
Model answer: Addiction reflects a pathological dominance of model-free habit systems (striatum) over model-based goal-directed control (prefrontal cortex and hippocampus). Model-free systems store cached action values from repeated reward, producing automatic responses that bypass deliberative evaluation. The person's cognitive knowledge — a model-based representation — exists but loses the competition with the deeply reinforced habit system. This is why knowing the behavior is harmful does not automatically produce behavior change: the two systems can hold conflicting 'beliefs' simultaneously.
This illustrates the broader point that rationality is an achievement requiring model-based systems to override model-free ones — which demands cognitive resources and is vulnerable to stress, time pressure, and depletion. Treatment approaches that recognize this architecture (habit substitution, environmental restructuring, reducing cue exposure) are more effective than those relying purely on insight.