Incidental learning of rewarded associations bolsters learning on an associative task

Reward has been shown to change behavior as a result of incentive learning (by motivating the individual to increase their effort) and instrumental learning (by increasing the frequency of a particular behavior). However, Palminteri et al. (2011) demonstrated that reward can also improve the incidental learning of a motor skill even when participants are unaware of the relationship between the reward and the motor act. Nonetheless, it remains unknown whether these effects of reward are the indirect results of manipulations of top-down factors. To identify the locus of the benefit associated with rewarded incidental learning, we used a chord-learning task (Seibel, 1963) in which the correct performance of some chords was consistently rewarded with points necessary to complete the block whereas the correct performance of other chords was not rewarded. Following training, participants performed a transfer phase without reward and then answered a questionnaire to assess explicit awareness about the rewards. Experiment 1 revealed that rewarded chords were performed more quickly than unrewarded chords, and there was little awareness about the relationship between chords and reward. Experiment 2 obtained similar findings with simplified responses to show that the advantage for rewarded stimulus combinations reflected more efficient binding of stimulus-response (S-R) associations, rather than a response bias for rewarded associations or improved motor learning. These results indicate that rewards can be used to significantly improve the learning of S-R associations without directly manipulating top-down factors. (PsycINFO Database Record