Manipulation of contextual stimuli and response allocation in a slot-machine experiment

Previous studies on the effect of contextual control on slot-machine gambling has shown that several participants allocate the majority of their responses to the slot machine sharing formal properties of color with the contextual cue for “more than”. It has however, been some diverging results regarding number of participants that actually altered their responding. Most of these studies have arranged equal payout probabilities for the two different machines in test for response allocation. The present study aimed to shed light on the effects of arranging programmed consequences during posttest. Thirty participants were quasi-randomly assigned to three different payout probabilities for the two machines; 50-50, 80-20, and 80-80 for the “more than” and “less than” machine respectively. The results showed that more participants in the 80-20 group altered response allocation than did participants in the 50-50. Furthermore, only three out of ten participants experiencing 80-80 percent payout probabilities for the two machines increased gambling on the “more than” machine following the first training phase.