The cerebellum tucked away in the back of the brain, a hindbrain part, occupies only 10% of the brain but has more neurons than the entire brain. It has been long associated with regulation of motor movement’s primarily voluntary movements. Damage to this area results in erratic and uncoordinated movements. See the video below to learn more about the cerebellum anatomy and functions.
Cerebellar contributions to higher-order brain functioning are currently being explored. Neuroimaging studies have shown positive activation of cerebellum areas about language, attention, and emotions. However, individual cerebellar functional organization and specificity has not be understood until now. The study published in Neuron by Scott Marek and colleagues from Washington University in St. Louis delineates the spatial and temporal organization of individual human cerebellum using resting state functional connectivity MRI (RSFC).
"We think that the cerebellum is acting as the brain's ultimate quality control unit," says Scott Marek. "It's been woefully understudied," says Dr. Nico Dosenbach, a professor of neurology at Washington University whose lab conducted the study. Their results show that only 20% of the cerebellum regulates the motor-specific function and the rest 80 percent is for other higher-order brain functioning related to abstract thinking, planning, emotion, memory, and language.
Ten patient data from the publically available Midnight Scan Club (MSC) dataset was used. The data included structural, functional and behavioral measures from five females scanned over ten different sessions. Four tasks, motor, semantic, coherence and incident encoding memory tasks were used to acquire data. The data required for cerebellar RSFC was double than those required for reliable cortical RSFC correlations. Cerebellar neuro-imaged activity was delayed to the activity simultaneously measured from cortical structures.
Across the ten datasets, similar network level organization was found, but individual activity showed deviations from the averaged activity regarding the location and relative amount for each task. This individual variability observed in the spatial arrangement is more pronounced in the cerebellum when compared to the cortex. Just like for motor intent fine-tuning, cerebellum acts more on regulating and fact-checking of the signal from the cortex. Given the effects of alcohol on cerebellar activity, the authors believe that it affects more than our physical movements. "We have an explanation for all the bad ideas people have when they're drunk," he says. "They lack cerebellar editing of your thoughts."
The findings show that the frontoparietal network is overrepresented by 2.3 fold, in cerebellum when compared to the cortex and is argued to support adaptive control in humans. The results explain how the expanded cerebellum only seen in humans when compared to non-human primates, allows for more adaptive behavior when faced with new tasks without experience. These results are also in line with the observations and hypothesis made by Dr. Jeremy Schmahmann, a neurology professor at Harvard and director of the ataxia unit at Massachusetts General Hospital. Dr. Schmahmann is another cerebellum research pioneer, who has advocated on looking into a cerebellar function that goes beyond the motor functions and his work primarily is focused on studying the brain functions with cerebellar damage. He says that "There is increasing evidence from a variety of fields now that psychiatric diseases from autism spectrum, schizophrenia, depression, obsessive-compulsive disorder, all have a link to the cerebellum." His 2018 publication in Neuroscience letters shows evidence on a cerebellar role in cognition, emotion, and autonomic functions.
The senior author Dosenbach says that although they believed that cerebellum was much cooler, to begin with, the results from the current study exceeds their imagination. He says that excluding the cerebellar data when understanding brain is like shooting yourself in the foot before even starting. Cerebellar activity plays a role beyond what has been reported so far, and whole brain imaging already provides the data, so he advises to look into it.
Could the cerebellum, our internal efficiency, and quality control center be attributed to some of us being a genius? Please refer to Larry Vandervert’s blog on how he thinks cerebellum contributes to the genius of Albert Einstein.