A New Insight on the Role of the Cerebellum for Executive Functions and Emotion Processing in Adults.

Pierre-Aurélien Beuriat,Jordan Grafman,Frank Krueger,Barry Gordon,Shira Cohen-Zimerman,Gretchen N L Smith

doi:10.3389/fneur.2020.593490

Abstract

Objective: We investigated whether the cerebellum plays a critical or supportive role in in executive and emotion processes in adults. Many investigators now espouse the hypothesis that participants with cerebellar lesions experience executive functions and emotions (EE) disorders. But we hypothesized that these disorders would be milder if the damage is relatively limited to the cerebellum compared to damage involving the cerebellum plus additional cortical areas.Methods: We studied veterans with penetrating Traumatic Brain Injury (pTBI) participating in the Vietnam Head Injury Study (VHIS). We selected veterans with a cerebellar lesion (n = 24), a prefrontal cortex lesion (n = 20), along with healthy controls (HC) (n = 55). Tests of executive functions and emotions were analyzed as well as caregiver burden. We performed between-group null hypothesis significance testing, Bayesian hypothesis tests and correlational analyses.Results: Performance of participants with cerebellar lesions which extended to the cerebral cortex was similar to the HC on the Executive Function tests but they were significantly impaired on the Working Memory Index. No differences were found on the emotional processing tasks with one exception—the Facial Expression of Emotion-Test (FEEST). We then examined a sub-group of participants with large cerebellar lesions (>15%) but minimal lesions in the cerebral cortex (<15%). This sub-group of participants performed similarly to the HC on the Working Memory Index and on the FEEST.Conclusions: We suggest that the cerebellar cortex may not be critical for executive functions or processing emotional stimuli in adults as suggested. Instead, we find that the cerebellum has a supportive role characterized by its computing of the motor requirements when EE processing is required.

Highlights

Does the cerebellum play a crucial or supportive role in the functions of the cognitive and emotional networks? While the cerebellum’s membership in brain networks that extend to various regions of the cerebral cortex has been mapped out, its role in executive function and emotion (EE) processes is unclear.Traditionally, the cerebellum has been associated with motor control [1]
The caregivers of cerebellar patients reported no additional burden nor complaints compared to healthy control group (HC) caregivers
In regard to our results, focal cerebellar cortical injury, mostly located in the posterior cerebellum and without damage to the deep cerebellar nuclei does not lead to an impairment in EFs and emotion processing

Summary

Introduction

Does the cerebellum play a crucial or supportive role in the functions of the cognitive and emotional networks? While the cerebellum’s membership in brain networks that extend to various regions of the cerebral cortex has been mapped out, its role in executive function and emotion (EE) processes is unclear.Traditionally, the cerebellum has been associated with motor control [1]. Does the cerebellum play a crucial or supportive role in the functions of the cognitive and emotional networks? While the cerebellum’s membership in brain networks that extend to various regions of the cerebral cortex has been mapped out, its role in executive function and emotion (EE) processes is unclear. Recent research suggests that the cerebellum is crucial in processing higher-order functions such as EE [1]. Its connectivity with the Prefrontal Cortex (PFC), which has a major role in these functions [2], via cortico-cerebellar loops support this role [3]. Other studies suggest a minimal role of the cerebellum in executive functioning [4,5,6,7]. We compared our participants to a healthy control group (HC) of combat veterans without a history of neurological disorders

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Discussion

Conclusion