In chapter 8 of Ace on the River, Barry Greenstein examines how brain chemistry influences gambling behavior, arguing that understanding—and protecting—the brain is essential for long-term poker success.
Why Brain Health Matters in Poker
Greenstein opens by warning that poker players often operate near psychological limits. Because poker rewards risk-taking, focus, and emotional intensity, players who neglect their mental health are more likely to lose control, judgment, and stability.
A Layered View of How the Brain Works
He walks through increasingly sophisticated explanations of brain function:
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At a basic level, the brain sends electrical signals that control behavior.
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At a biological level, neurons transmit impulses through networks insulated by myelin, allowing fast and efficient signaling.
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At a biochemical level, these electrical signals rely on chemical messengers—neurotransmitters—to pass information across synapses.
This progression sets up his main argument: behavior is not just psychological, but also chemical.
Neurotransmitters and Gambling Behavior
Greenstein highlights several key neurotransmitters, focusing especially on serotonin. Research shows that lower serotonin levels are linked to compulsive behavior. Since gambling attracts and rewards compulsive tendencies, poker players as a group are more likely than average to have serotonin imbalances.
This helps explain why many gamblers struggle with impulse control even when they understand the risks intellectually.
Medication, Nutrition, and Compulsion
Certain prescription medications are known to increase serotonin activity and are often used to treat compulsive or depressive disorders. Greenstein suggests that if compulsive urges were broadly reduced, gambling environments themselves would suffer—underscoring how central compulsion is to casino economics.
He also notes that diet and overall health influence brain chemistry, implying that lifestyle choices directly affect poker performance and self-control.
The Risks of Drugs and Alcohol
Greenstein strongly cautions against recreational drug use and excessive alcohol consumption. These substances can damage nerves and disrupt brain chemistry, leading to anxiety, depression, paranoia, memory loss, and impaired judgment. Because gamblers already tend toward compulsive behavior, they are especially vulnerable to addiction—and the negative effects can be amplified if their brain chemistry is already borderline.
Long-Term Consequences for Decision-Making
Altered brain chemistry does more than affect mood. It undermines memory, discipline, and logical reasoning—skills essential for poker. A player may believe substances help them relax or focus, but over time the damage erodes their edge and increases the likelihood of destructive behavior.
Core Message of the Chapter
Greenstein’s central point is that poker success depends not only on strategy and psychology, but also on biology. Maintaining healthy brain chemistry through responsible habits is a form of bankroll protection. Players who ignore this reality risk crossing from competitive gambling into loss of control—often without realizing it until serious damage has already been done.