@entity935 modulates reward expectancy during performance of a slot machine task in XXXX : evidence for a 'near-miss' effect.

@entity11640 @entity10432 @entity935 @entity11532 @entity11170 @entity35 @entity4944
Cognitive accounts of gambling suggest that the experience of almost winning-so-called 'near-misses'-encourage continued play and accelerate the development of @entity11532 ( @entity11532 ) in vulnerable individuals. One explanation for this effect is that near-misses signal imminent winning outcomes and heighten reward expectancy, galvanizing further play. Determining the neurochemical processes underlying the drive to gamble could facilitate the development of more effective treatments for @entity11532 . With this aim in mind, we evaluated @entity35 ' performance on a novel model of slot machine play, a form of gambling in which near-miss events are particularly salient. Subjects responded to a series of three @entity11170 lights, loosely analogous to the wheels of a slot machine, causing the lights to set to 'on' or 'off'. A winning outcome was signaled if all three lights were illuminated. At the end of each trial, @entity35 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. @entity35 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. Erroneous collect responses were increased by @entity4944 and the D(2) receptor agonist @entity11640 , but not by the D(1) receptor agonist @entity10432 or receptor subtype selective antagonists. These data suggest that @entity935 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.
