Abstract. Pachinko is a popular form of recreation in Japan. However, in recent years, along with Pachinko's popularity, "Pachinko dependence" has become topical news. The purpose of this study was to investigate beta-endorphin, catecholamines, immune system responses and heart rate during the playing of Pachinko. The following significant results were observed. (1) Plasma concentration of beta-endorphin increased before playing Pachinko and while in the Pachinko-center (p<0.05). (2) Beta-endorphin and norepinephrine increased when the player began to win (i.e. at "Feverstart") compared to baseline (p<0.05).(3) Beta-endorphin, norepinephrine and dopamine increased when the winning streak finished (i.e. at "Fever-end") compared to baseline (p<0.05-0.01). (4) Norepinephrine increased past 30 minutes after "Fever-end" compared to baseline(p<0.05). (5) Heart rate increased before "Fever-start" compared to baseline, peaked at "Feverstart" and rapidly decreased to match rates measured at rest. But the increase was observed from 200 seconds after "Fever-start" (p<0.05-0.001). (6) There was a positive correlation between the number of hours subjects played Pachinko in a week and the differences between beta-endorphin levels at "Fever-start" and those at rest (p<0.05). (7) The number of T-cells decreased while the number of NK cells increased at "Fever-start" compared to baseline (p<.05). These results suggest that intracerebral substances such as beta-endorphin and dopamine are involved in the habit-forming behavior associated with Pachinko.

This research, conducted in 1998 and 2008, uses go/no-go data to investigate the fundamentals of cognitive functioning in the inhibitory control ability of Japanese children. 844 subjects from kindergarten to junior high school participated in go/no-go task experiments. Performance of go/no-go tasks, which are frequently used to investigate response inhibition, measures a variety of cognitive components besides response inhibition. With normal brain development, the ability to inhibit responses improves substantially in adolescence. An increase over time in the error rate during the go/no-go tasks of subjects of the same age indicates that these processes are not functioning properly. Comparisons between the 1998 and 2008 data revealed several differences in error rates. In 2008, there were increases in the number of errors in groups from each age range. The comparison also revealed that overall error rates peaked at later ages in the 2008 subjects. Taken together, these results show changing conditions in the inhibitory function of the prefrontal cortex. However, the reason for these changing conditions remains unclear. While a lifestyle questionnaire revealed several differences in factors such as bedtimes and hours spent watching TV, analysis did not reveal a significant correlation.

The purpose of this study was to compare the hemodynamic changes that occur during Mahjong game play in virtual and real-life settings. Fourteen healthy right-handed men (average age ± standard deviation; 36.7 ± 14.9 years) played: 1) a Mahjong solitaire game on a video console against virtual rivals; 2) a Mahjong game against human opponents without conversation; and 3) a Mahjong game against human opponents with conversation. We measured oxygenated hemoglobin concentration at 44 locations over both hemispheres during Mahjong game play in each setting using near-infrared spectroscopy. The increase in oxygenated hemoglobin concentration at several locations, including Broca's area, the somatosensory cortex, the somatosensory association cortex, the supramarginal gyrus part of Wernicke's area, the primary and auditory association cortex, the angular gyrus part of Wernicke's area, and the associative visual cortex was greater during game play in the real-life settings than during game play in the video game setting. There were no significant differences during game play in real-life settings without and with conversation. Each cortical area correlated with broad or specific areas. The common correlation areas were found at Angular gyrus part of Wernicke's area of left hemisphere during real-life settings without and with conversation, but not during game play in a video game setting. These results suggest that the brain responds differently to game play in real world and virtual world settings, and indicate that comparison of games played in the virtual world and the real world may be an effective model to enhance understanding of the effects of video game on the brain.