The implementation of verbal instructions: an fMRI study.

In everyday life, our actions are often guided by verbal instructions. Usually, we can implement such instructions immediately without trial and error learning. This raises the fundamental question how verbal instructions are transformed into efficient motor behavior. The aim of this study was to gain deeper insights into the implementation of verbal instructions both on a neural and a cognitive level. To this end, we devised an fMRI experiment in which participants were required to permanently implement new stimulus-response (S-R) mappings and object-color (O-C) mappings. This enabled us to test whether there are brain areas that are specific to the implementation of newly instructed S-R mappings or whether newly instructed rules are represented independently from the specific content. Furthermore, we could test which brain areas are involved in the processing of S-R mappings when compared with O-C mappings. Our results suggest that only one brain area, the left inferior frontal junction (IFJ), was sensitive to the novelty of instructions regardless of whether these instructions conveyed S-R or O-C mappings. Furthermore, our results show that instructions conveying S-R mapping involve a network of brain areas, including pre-PMd, M1, and IPS that was not sensitive to the novelty of the instructions. Therefore, we conclude that the implementation of verbal instructions results from an interplay of a brain areas that represent novel rulelike information in domain general terms and brain areas that are specific to S-R rules.