Absolute pitch and sound-color synesthesia provide for unique learning opportunities

The goal of this study was to investigate the impact of absolute pitch (AP) on statistical learning and on cross-modal associative learning. Previous studies have demonstrated that compared to non-musicians, musicians have an advantage in statistical learning and that musical expertise leads to a reorganization in the network supporting statistical learning. As the brains of AP possessors show stronger connectivity in this network, we hypothesized that they show a further advantage in statistical learning. We used a paradigm with fixed tone-color pairs presented to participants in a stream of adjacent three-element sequences. We assessed statistical learning by asking participants subsequently to give frequency judgements for presented and not presented sequences. We assessed cross-modal associative learning of tone-color pairs by probing memory for the colors that were presented with each tone. We compared musicians with AP (N = 24), musicians without AP (N = 22), and a non-musician control group without AP (N = 20). The results showed an advantage in statistical learning for both groups of musicians. AP musicians had a long-lasting advantage in the incidental learning of tone-color associations (indicated by follow-up assessments after one week and one month). One third of the musicians with AP also had sound-color synesthesia (N = 7), and additional analyses revealed that they had a unique statistical learning advantage. The results indicate that musical expertise, AP, and synesthesia provide specific learning advantages. We suggest that the results can be best explained in a framework that considers for each group of participants the different experiential consequences of the task requirements.