Cerebellar theta and beta noninvasive stimulation rhythms differentially influence episodic memory versus language

Abstract

The cerebellum is thought to interact with distributed brain networks to support cognitive abilities such as episodic memory and language. Episodic memory and language networks have been associated with distinct endogenous oscillatory activity frequency bands: theta ([~]3-8 Hz) versus beta ([~]13-30 Hz), respectively. We sought to test whether it is possible to toggle cerebellar participation in episodic memory versus language by noninvasively stimulating with theta versus beta rhythmic transcranial magnetic stimulation. Cerebellar theta stimulation improved episodic memory encoding but did not influence neural signals of language processing, whereas beta stimulation of the same cerebellar location increased neural signals of language processing but did not influence episodic memory encoding. This constitutes evidence for double-dissociation of cerebellar contributions to language versus episodic memory based on stimulation frequency pattern, supporting the hypothesis that the cerebellum can be biased to support these distinct cognitive abilities at the command of network-specific rhythmic activity.