The Thalamus and Language

The role of the thalamus in language remains a matter of debate. Multiple thalamic nuclei (e.g., pulvinar, intralaminar nuclei, and the ventral tier nuclei) are implicated in language, as indicated by their connectivity with the cortex and lesion data. Lesions of the dominant thalamus may produce difficulties in naming with relative preservation of other functions such as repetition. In addition, dominant thalamic lesions are associated with fluctuations in language performance based on overall level of arousal, perseverations, and relatively rapid recovery. Bilateral thalamic activations (with left greater than right responses), along with activation of traditional cortical areas associated with language, are seen in functional imaging studies of human subjects during covert naming and sentence generation tasks. Potential thalamic mechanisms underlying language behavior are multiple and are discussed within this chapter.