EXCESSIVE COMPUTER GAME PLAYING, GAMBLING, EVEN MAKING RISKY FINANCIAL DECISIONS SHARE CHARACTERISTICS WITH DRUG ADDICTION, ACCORDING TO NEW RESEARCH
For immediate release.
NR-11-05 (11/14/05). For more information, please contact Sara Harris at (202) 462-6688 or sharris@sfn.org.
EXCESSIVE COMPUTER GAME PLAYING, GAMBLING, EVEN MAKING RISKY FINANCIAL DECISIONS SHARE CHARACTERISTICS WITH DRUG ADDICTION, ACCORDING TO NEW RESEARCH
WASHINGTON, DC, November 14, 2005 — Researchers have long studied the neurological manifestations of drug and alcohol addiction. Now, new research is helping scientists get closer to understanding how these mechanisms may relate to excessive computer game playing, gambling, and even making risky financial investment decisions.
Recent perspectives on addictive behavior have integrated psychological and neurobiological correlates to focus on the key role of the brain’s reward system. “We believe that conditioned drug-associated and behavior-associated cues can activate an ‘addiction memory’ and craving and therefore maintain the addiction,” says Sabine M. Grüsser-Sinopoli, PhD, of the Charité-University Medicine in Berlin, Germany.
Grüsser-Sinopoli found that, in contrast to healthy subjects, excessive computer gamers reported significantly higher scores of computer game-stimulus-induced arousal, and craving, as well as feelings of being controlled by the cues. Psychophysiological data indicate that the excessive computer gamers perceived the computer game-associated stimuli as significantly more pleasant, as well as significantly more arousing, than did non-excessive computer gamers, who viewed these stimuli as neutral. “These reactions are similar to what we found in drug users,” says Grüsser-Sinopoli.
Participants in the experimental group, who were selected from registered male users of a large German gaming network, had to meet several criteria that relate to excessive behavior in terms of a behavioral addiction. The experiment also included age-matched controls who played computer games (in part occupationally), but did not play excessively. The controls did not regularly neglect any other interests, such as education or work. “This is the first psychophysiological study to investigate the learning mechanisms of a behavioral addiction that does not involve monetary reward,” says Grusser-Sinopoli. “The study is important for therapeutic intervention because the differences between both groups support the assumption of a ‘drug memory’ in subjects who meet criteria for a behavioral addiction.”
Further studies by Jakob Linnet, PhD, of Aarhus University in Denmark, found a significant increase in the release of dopamine—a brain chemical associated with so-called reward mechanisms in drug addiction—in the brains of high sensation-seeking healthy men during gambling.
“Our data are interesting for two reasons,” says Linnet. “First, they support the hypothesis that dopamine levels can be altered behaviorally through rewarding (or punishing) activities such as gambling, suggesting that dopamine may function as the body’s own drug, independent of external drug intake.”
Although it is unclear whether individuals become addicted to a “dopamine rush” in itself, dopamine may contribute to certain types of addictive behavior. “In the case of gambling,” says Linnet, “pathological gamblers may feel a kick or rush from gambling, despite the negative consequences of losing money.”
Second, Linnet and his colleagues’ data support the hypothesis that characteristics of the dopaminergic reward mechanisms differ with personality traits such as sensation seeking. “Although we currently have no basis for assuming that high sensation seekers are more at risk for developing addictive disorders,” says Linnet, “the data may suggest that high and low sensation seekers are affected differently by addictive behavior due to differences in dopaminergic reward.”
High sensation seekers may be more likely to become addicted to excitement-inducing skill games like poker or black jack, reflecting the characteristics of their dopaminergic system. In contrast, low sensation seekers may be more likely to become addicted to chance games like slot machines. “Such differences in dopaminergic response may have implications for the onset, treatment, and course of gambling disorders,” says Linnet.
Other researchers examined the field of financial investments. “Investors typically make mistaken financial decisions, yet the mechanisms responsible for these mistakes are unknown,” according to Brian D. Knutson, PhD, of Stanford University.
Researchers used fMRI technology on two groups of PhD students—one in finance and the other in the humanities. The participants in the study were asked to repeatedly choose between two risky stocks and one riskless bond. A “good” stock had a 50 percent chance of paying $10 and a 25 percent chance of deducting $10. A “bad” stock had a 25 percent chance of paying $10 and a 50 percent chance of deducting $10. The bond always paid $1. After 10 trials, the good and bad stocks were randomly switched. Mistakes were determined by comparing subjects’ choices to those of a player who chose according to what had happened in the past. Differences in two critical areas were observed in the study. One involved the nucleus accumbens, a brain area that is a primary target of dopamine innervation. Another involved the anterior insula, a brain area commonly associated with negative emotional responses.
“We found that nucleus accumbens activation not only preceded risky choices, but also risk-seeking mistakes, for example, choosing a stock when the bond was best,” says Knutson. “Additionally, anterior insula activation not only preceded riskless choices, but also risk-aversion mistakes, for example, choosing the bond when one of the stocks was best.”
Research from Knutson’s lab and others indicates that activation of the nucleus accumbens brain area is correlated with how much positive feeling people report feeling while anticipating financial gains. Other studies have shown increased nucleus accumbens activation when people receive injections of stimulants like amphetamine and cocaine.
On the other hand, activation of the anterior insula brain area has been associated with anticipation of physical pain as well as the experience of chronic anxiety, according to Knutson. “These findings are new and interesting,” he says, “because they support the notion that two distinct neural systems associated with anticipatory emotions might influence financial decision making in opposite ways.” The findings also suggest that excessive activation in either system might bias a person toward certain types of mistakes.
“This is one of the first studies to use brain activation to predict financial choices—both rational and irrational,” says Knutson. On average, the subjects in Knutson’s study made mistakes on about a quarter of their choices, and the two groups did not differ significantly in the number of mistakes they made.
