This chapter illustrates how transcranial magnetic stimulation (TMS) can be used to investigate the functional relevance and temporal characteristics of language-related brain networks for various aspects of language processing. In contrast to neuroimaging methods establishing mainly correlative relationships between patterns of neural activity and cognitive functions, TMS enables a direct manipulation of neural network activity with respective functional consequences on behavior and cognition. Examples of whether and how TMS has been demonstrated to unravel such functional brain-behavior relationships in the domain of language processing, which is unarguably one of the most complex human abilities one could aim to investigate from a neuroscience perspective, are presented. This chapter therefore first introduces the basic principles and mechanisms of action underlying TMS, including the many possible application protocols. Based on the understanding that TMS can investigate both the spatial as well as temporal characteristics of the neural correlates of language, the suitability and limitations of TMS in language research are discussed. Next, examples of TMS language studies that have successfully employed the different advantages of TMS are presented. Finally, the applicability of TMS for clinical populations in the context of language-related deficits such as aphasia are reviewed briefly, followed by a short outlook on future perspectives of TMS in the study of language.
Myelin Water Imaging and Transcranial Magnetic Stimulation Suggest Structure-Function Relationships in Multiple Sclerosis
