Transcranial magnetic stimulation (TMS) in the neuroscience of language

We all know the beautiful pictures of the brain “lighting up” during a certain cognitive task that are produced by functional neuroimaging methods like fMRI. Unfortunately, neuroimaging methods are merely correlative; they cannot determine whether a brain region is causally involved in (i.e. necessary for) a particular task. Transcranial magnetic stimulation (TMS)—a non-invasive method to stimulate the brain—provides a means to determine the causal relevance of a certain brain region for a task. In this talk, I will present how we can leverage TMS in neurolinguistics to investigate the brain networks causally supporting language. TMS is mainly used in two ways: (1) after fMRI—to test the causal relevance of functional activation, and (2) before fMRI—to investigate the adaptive plasticity of the brain, i.e. changes in functional activation and connectivity after TMS is applied over a critical brain region. Both types of studies also have clinical relevance as they can be used to predict which cognitive functions will be impaired when a certain region is damaged, and to what extent (and how) the brain can compensate for such damage