Multisensory Connections of Novel Linguistic Stimuli in Japanese as a Native Language and Referential Tastes.

Previous findings have shown essential connections between linguistic and gustatory stimuli for people with autism or lexical gustatory synesthesia. We examined the associative learning of novel linguistic forms in Japanese as a native language and tastes (candies and chocolates) for healthy people. Healthy subjects performed four phases: (a) evaluation phase of gustatory features; (b) learning phases of novel linguistic form and gustatory stimulus pairs (G) or novel word forms (W); (c) recognition memory phases linked with G and W; and (d) free recall phase for G and W. In the recognition memory phases, the performance scores of W were higher than those of G, while there was no significant difference between response times of G and W. Additionally, no difference between recall performances in G and W was also shown. A subjective evaluation of gustatory features (sweetness) negatively correlated with the recall score for linguistic forms connected to the gustatory feature, whereas the accuracy rates of the recognition memory phase in G positively correlated with those of the free recall phase in G. Although learning of novel linguistic forms is more efficient than learning of the relationships between novel linguistic forms and tastes, gustatory features influence the free recall performances of linguistic forms linked with the tastes. These results may contribute to future applications to word learning not just for patients, but also healthy people.