Cerebellum on emotions

When the neuro-talk falls on emotions, most start thinking about the amygdala. Little do we associate with that hind-brain structure we call the cerebellum. Although it is known that this structure is involved in more than movements, little is really known about it’s cognitive functions, let alone in emotions.

In an article by Turner et al. in Neuropsychologia, the function of the cerebellum in emotions is explored by comparing six patients with cerebellar injury and healthy subjects. By applying both behavioural and PET methods, the results demonstrate that cerebellum plays a role in both positive and negative emotions.

While the role of the cerebellum in motor coordination is widely accepted, the notion that it is involved in emotion has only recently gained popularity. To date, functional neuroimaging has not been used in combination with lesion studies to elucidate the role of the cerebellum in the processing of emotional material. We examined six participants with cerebellar stroke and nine age and education matched healthy volunteers. In addition to a complete neuropsychological, neurologic, and psychiatric examination, participants underwent [(15)O]water positron emission tomography (PET) while responding to emotion-evoking visual stimuli. Cerebellar lesions were associated with reduced pleasant experience in response to happiness-evoking stimuli. Stroke patients reported an unpleasant experience to frightening stimuli similar to healthy controls, yet showed significantly lower activity in the right ventral lateral and left dorsolateral prefrontal cortex, amygdala, thalamus, and retrosplenial cingulate gyrus. Frightening stimuli led to increased activity in the ventral medial prefrontal, anterior cingulate, pulvinar, and insular cortex. This suggests that alternate neural circuitry became responsible for maintaining the evolutionarily critical fear response after cerebellar damage.