No contribution of object category information in perceptual thresholds : evidence from Candy Crush

An emerging view in visual learning is that the rewards associated with particular visual stimuli lead to enhanced early sensory representations. However, it is unclear whether object category information is required for reward-related facilitation of early sensory representations, or whether any facilitation occurs at a more fundamental level. Video games which rely on in-game icons of rewarding or neutral value offer an excellent arena in which to investigate the development of any changes in representation. To test these alternative explanations, we compared the ability of 33 Candy-Crush players against 32 non-players to detect icons which had rewarding or neutral roles within the game. Using diffeomorphic scrambling to preserve the basic visual properties, the threshold for detection of a rewarding icon, a neutral icon and a control pair of non-game icons within a 7x7 grid of distractor icons was measured. Each participant's thresholds were measured in a 2AFC staircase procedure. Both players and non-players were significantly better at detecting the rewarding in-game icon than the neutral icon and all participants showed similar reductions in threshold for the reward-associated control icon compared to the neutral control icon. Even though our most practiced players had accumulated years of experience, there was no association between playing time and perceptual thresholds. Our results suggest that there is a strong contribution of the basic visual features to performance levels both with the Candy-Crush and control targets, and provide no evidence that even long experience with reward-association heightens perceptual sensitivity independent of object category information.