The cerebellum plays a role in conscious episodic memory retrieval

The cerebellum has traditionally been considered to be primarily dedicated to motor functions. Its phylogenetic development and connectivity suggest, however, that it also may play a role in cognitive processes in the human brain. In order to examine a potential cognitive role for the cerebellum in human beings, a positron emission tomography (PET) study was conducted during a "pure thought experiment": subjects intentionally recalled a specific past personal experience (consciously retrieved episodic memory). Since there was no motor or sensory input or output, the design eliminated the possibility that cerebellar changes in blood flow were due to motor activity. During silent recall of a consciously retrieved episodic memory, activations were observed in the right lateral cerebellum, left medial dorsal thalamus, medial and left orbital frontal cortex, anterior cingulate, and a left parietal region. These activations confirm a cognitive role for the cerebellum, which may participate in an interactive cortical-cerebellar network that initiates and monitors the conscious retrieval of episodic memory.