Language dysfunctions are a key feature in schizophrenia, which clinically manifests as formal thought disorder (FTD). Dysfunctions within the semantic system are expressed in aberrant activation, inhibition, or selection processes within the semantic network. On the neurobiological level, the results of functional neuroimaging and electrophysiological studies imply a dysfunction of the fronto-temporal language network and disturbances in hemispheric interaction in patients with FTD. This chapter presents morphological analyses, earlier metabolic investigations with positron emission tomography (PET) and functional imaging studies during language tasks, which strengthen the role of the superior temporal gyrus (STG) in the pathogenesis of FTD. It explores the anatomical and functional deficits of this structure into the framework of lateralization anomalies in patients with FTD. Finally, the chapter discusses approaches which integrate structure (i.e. reduced STG volume), function (i.e. aberrant temporal activation patterns), and symptom (i.e. FTD) relations.