Gambling rewires brain in a negative way

LAS VEGAS - The excitement and risk-taking of betting can change the brain's chemistry and create compulsive gamblers, a Harvard professor told casino executives Thursday during an American Gaming Association seminar.

"Addictive behaviors rewire the brain," Dr. Howard Shaffer, director of Harvard Medical School's Division on Addictions, told a group of about 100 hotel-casino officials at the Golden Nugget.

Shaffer recently completed a study on gambling behavior in the United States and Canada and focused much of his talk on explaining how a person develops a gambling addiction. He noted that when people gamble, they feel excitement, control, power and stimulation. …

From gamblers playing blackjack to investors picking stocks, humans make a wide range of decisions that require gauging risk versus reward. However, laboratory studies have not been able to unequivocally determine how the very basic information-processing "subcortical" regions of the brain function in processing risk and reward.

Now, Steven Quartz and colleagues at the California Institute of Technology have created a simple gambling task that, when performed by humans undergoing functional magnetic resonance imaging (fMRI) of their brains, distinguishes the "gambling" structures in the brain. Importantly, their findings tease apart the gambling function of these brain structures from their functions in learning, motivation, and assessment of the salience of a stimulus.

In their research article published in the August, 2006, issue of Neuron, published by Cell Press, the researchers said their findings and experimental method could help in understanding and perhaps treating aberrant risk-taking in disorders including gambling addiction, bipolar disorders, and schizophrenia.

In their experiments, the researchers asked subjects to choose two cards from a deck numbered one to ten. Before their choice, however, the subjects were asked to bet $1 on whether the first or second card would be higher. The fMRI imaging of the subjects' brains during the gambling task could show the researchers which areas of the brain activated during different parts of the task. In fMRI, harmless radio signals and magnetic fields are used to measure blood flow in brain regions, which reflects activity in those regions...

Quartz and colleagues found they could distinguish brain regions that specifically responded to either reward expectation or risk. Importantly, these areas showed activity that increased with the level of expected reward and perceived risk. The researchers found that the activation related to expected reward was immediate, while the activation related to risk was delayed.

These regions were part of the brain circuitry governed by the neurotransmitter dopamine that is also involved in learning, motivation, and salience. However, emphasized the researchers, the design of their gambling task and analysis of their data ruled out involvement of these functions, meaning that they had, indeed, isolated the "gambling" function of these regions.

Until now, most researchers thought that gambling mania is mainly caused by the high expectations of some people to win large amounts of money and also by their inability to realize the cost of their loss. But a recent study showed that gambling is closely linked to a brain center and this unhealthy passion can be associated with key neurological areas.

Scientists at the California Institute of Technology in Pasadena carried out a study in which they asked volunteers to choose two cards from a deck which they cannot see. Then subjects were supposed to place a 1 dollar bill on the card they thought to be higher of the two they have previously opted out for...

"They had to first place the bet without seeing the cards. Then, the expectation changes when they see the first card," explained team members.

While this action took place, researchers scanned participants' brains with Magnetic Resonance Imaging (MRI). The experts' team aimed at detecting if a certain key area of the brain is stimulated when the volunteers take risks and also when they expect a reward....

Researchers pointed out, in today's issue of Neuron Journal, that such pathological behaviors "ranging from addiction to gambling, as well as a variety of mental illnesses such as bipolar disorder and schizophrenia, are partially characterized by risk-taking. For example, a bipolar subject during a manic episode may invest in a risky business proposition either because they misperceive the risk to be lower than it actually is, or because they accurately perceive the risk to be high but may have impaired learning, attentional, working memory, or choice processes."

Tracing key regions in the brain that are tightly connected with gambling and risk-reward decisions is extremely useful in further developing new treatment methods to cure this kind of behavioral disorders and addictions. "If we can understand the pathway, maybe we can help develop methods to fix it," Preuschoff concluded.

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