The language of the cerebellum

ABSTRACT

Background: During the past three decades neuroanatomical, neuroimaging, and clinical studies have substantially altered the view on the role of the cerebellum as a sole coordinator of sensorimotor function. Currently, the cerebellum is believed to be also crucially involved in cognitive, affective, and behavioural functioning.

Aims: This paper aims to summarise a number of critical insights from different research areas (anatomy, functional imaging, clinical practice) that provide evidence for a role of the cerebellum in motor speech and nonmotor language processing.

Main contribution: By means of identifying a dense network of crossed reciprocal connections between the cerebellum and the supratentorial association areas, neuroanatomical studies provided a robust basis for the development of new insights in the modulatory role of the cerebellum in neurocognition, including nonmotor language processing. A topological distinction was established between the “motor” cerebellum, projecting to the cortical motor areas, and the “cognitive/affective” cerebellum, connected with the cortical and limbic association areas. Neuroimaging studies demonstrated cerebellar involvement in several different language tasks, even after controlling for motor aspects. In addition, several clinical studies identified a variety of nonmotor linguistic deficits after cerebellar damage, implying a prominent role for the cerebellum in these linguistic processes. Functional neuroimaging confirmed the functional impact of cerebellar lesions on remote, structurally intact cortical regions via crossed cerebello-cerebral diaschisis.

Conclusion: Evidence from neuroanatomical, neuroimaging, and clinical studies suggests a strongly lateralised involvement of the cerebellum in a broad spectrum of nonmotor language functions through crossed cerebello-cerebral connectivity. It is argued that the cerebellum is involved in language in a similar manner as it is involved in motor functions: through monitoring/coordinating cortical functions.

KEYWORDS:

• Cerebellum
• language
• diaschisis
• Schmahmann’s syndrome
• timing hypothesis
• sequencing hypothesis

Disclosure statement

No potential conflict of interest was reported by the authors.