The involvement of subcortical grey matter in verbal semantic comprehension: A systematic review and meta-analysis of fMRI and PET studies

Abstract

Abstract Semantic processing is a fundamental aspect in human communication. The cortical organization of semantic processing has been exhaustively described, in contrast to inconsistent results on the function of subcortical grey matter structures. Hence, this manuscript reports a systematic review and meta-analysis on the subcortical involvement in verbal semantic comprehension in healthy individuals. The 50 included studies indicate specific contributions by the cerebellum, thalamus and caudate nucleus respectively. In particular, the right posterior cerebellum is proposed to be involved in a semantic executive system and in adequate decision-making. The left thalamus, regulated by the caudate nucleus, might function as a subcortical hub, controlling the access and integration of cortically organized semantic features. Furthermore, a contribution of the cerebellum, thalamus and caudate nucleus in semantic prediction generation and evaluation at sentence level is preliminarily suggested. More research is required to gain insights into the role of the putamen, globus pallidus and subthalamic nucleus.