Abstract

Transcranial magnetic stimulation is a neuromodulatory technique that allows investigation of the necessity of brain cortical areas in cognitive processes to be assessed in both non-clinical and clinical populations, and offers great utility for the clarification of the underlying mechanisms of cognitive functions and disorders. In the case of synaesthesia, in which one sensory input leads to unusual sensory experiences in either the same or a different modality, to date TMS has been used in relatively few studies. While these studies have been undoubtedly informative, there is significant potential for future studies using this technique. Following an overview of current predominant theories of the origin of synaesthetic experiences, we discuss the different approaches that can be used when employing TMS in neurocognitive investigations. These are then related to either studies of synaesthesia, where they exist, or to potential investigations in which they might be readily applied.