![]() ![]() In support of this general hypothesis, drugs that alter dopaminergic activity have been shown to modify slot-machine play, a form of gambling in which near-misses are particularly salient. These observations suggest that near-misses convey a positive reward signal encoded by the dopaminergic circuits that support reward expectancy and reinforcement learning ( Schultz et al, 1997 Schultz, 1998 Fiorillo et al, 2003). In line with this theory, near-misses have been shown to increase the desire to continue gambling ( Kassinove and Schare, 2001 Cote et al, 2003 MacLin et al, 2007) and to enhance neural activity within the mid-brain and the ventral striatum ( Clark et al, 2009 Habib and Dixon, 2010). Near-misses may therefore heighten reward expectancy due to their similarity to wins, making continued play more likely ( Reid, 1986). Near-miss events can produce similar psychological and physiological changes as winning outcomes ( Griffiths, 1991). One prominent hypothesis is that the experience of almost-winning-a so-called ‘near-miss’-can invigorate gambling activity, and may accelerate the development of PG in vulnerable individuals ( Reid, 1986 Griffiths, 1991 Clark, 2010). Determining why people gamble could therefore provide valuable insight into addictive behaviors, as well as furthering our knowledge of non-normative or ‘irrational’ decision making.Ĭognitive accounts of PG propose that gambling is sustained because of the erroneous or distorted beliefs about the independence of gambling outcomes, the intervention of luck, and the ability of personal skills to confer success when gambling ( Ladouceur et al, 1988 Toneatto et al, 1997). However, for a significant minority, gambling develops into a compulsive and pathological behavior that strongly resembles substance abuse ( Potenza, 2008), and current estimates as to the lifetime prevalence of such pathological gambling (PG) vary between 0.2–2% ( Shaffer et al, 1999 Petry et al, 2005). ![]() The majority of people enjoy recreational gambling with no adverse effects. As gambling becomes more prevalent and socially acceptable, public debate is growing as to its potentially harmful consequences ( Shaffer and Korn, 2002). This behavior has resulted in a highly profitable gambling industry that continues to grow even in times of recession. People gamble despite being aware that the odds are stacked in the house's favor. These data suggest that dopamine modulates reward expectancy following the experience of almost winning during slot machine play, via activity at D 2 receptors, and this may result in an enhancement of the near-miss effect and facilitate further gambling. Erroneous collect responses were increased by amphetamine and the D 2 receptor agonist quinpirole, but not by the D 1 receptor agonist SKF 81297 or receptor subtype selective antagonists. Rats showed a marked preference for the collect lever when both two and three lights were illuminated, indicating heightened reward expectancy following near-misses similar to wins. At the end of each trial, rats chose between responding on the ‘collect’ lever, resulting in reward on win trials, but a time penalty on loss trials, or starting a new trial. A winning outcome was signaled if all three lights were illuminated. #The east side gamblers the big machine seriesSubjects responded to a series of three flashing lights, loosely analogous to the wheels of a slot machine, causing the lights to set to ‘on’ or ‘off’. With this aim in mind, we evaluated rats' performance on a novel model of slot machine play, a form of gambling in which near-miss events are particularly salient. Determining the neurochemical processes underlying the drive to gamble could facilitate the development of more effective treatments for PG. One explanation for this effect is that near-misses signal imminent winning outcomes and heighten reward expectancy, galvanizing further play. Cognitive accounts of gambling suggest that the experience of almost winning-so-called ‘near-misses’-encourage continued play and accelerate the development of pathological gambling (PG) in vulnerable individuals. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |