Consciousness and the Cerebellum

2467 

Abstract Submission 

Yaron Caspi¹, Po-Jang Hsieh¹

¹Department of Psychology, National Taiwan University, Taipei, Taiwan

Yaron Caspi  
Department of Psychology, National Taiwan University
Taipei, Taiwan

Po-Jang Hsieh  
Department of Psychology, National Taiwan University
Taipei, Taiwan

Originally conceived as a purely motor-supporting structure of the brain, the scientific view regarding the cerebellum's function in non-motor-related processes underwent a revolution in the last two decades (1). It is now recognized that the cerebellum contributes to multiple higher-order functions, ranging from language to social cognition (2).

Despite this development in understanding cerebellum functionality, discussions about the cerebellum concerning consciousness are rare. A prevalent view dominating the field of consciousness studies suggests that the cerebellum is dispensable for consciousness (3).

Yet, the discovery that the cerebellum participates in higher-order, non-motor-related functions, coupled with the accumulation of new data regarding its mode of operation, calls for a renewed analysis of the assumption that the cerebellum is dispensable for consciousness. In this abstract, we present such an analysis.

This work constitutes a literature review. We collected data from multiple published studies in brain research, forming a body of evidence regarding the relationships between the cerebellum and consciousness.

The literature review identified several categories suggesting a role of the cerebellum in conscious experience. The well-known example is Cerebellar Cognitive Affective Syndrome, typically caused by insults to the posterior cerebellum (4). Symptoms may include deficiencies in visuospatial cognition and emotion–affect. Some patients exhibit visuospatial disintegration (i.e., deficits in copying and conceptualizing drawn figures) and simultanagnosia (deficits in perceiving two objects simultaneously) (5), suggesting that the cerebellum can influence conscious experience.

Another critical piece of evidence is the cerebellum's role in psychiatric conditions. For instance, the cerebellum was implicated in depression and remission from depression (6), as well as in autism (7), where structural cerebellar changes were found in individuals exhibiting such symptoms. Similarly, cerebellar gray matter volume was associated with symptoms of norm-violating behavior, psychosis, and anxiety among adolescents (8).

Additionally, numerous published pieces of evidence suggest cerebellum function in various conscious experiences, such as emotions, attention, hallucinations, pain, perception, sleep, and the sense of agency. These aspects will be discussed in this presentation.

Currently, no experiments aim to understand the cerebellum's role in conscious experience applied the gold standard paradigm for identifying the neural correlates of consciousness - namely, a comparison between conscious and unconscious experiences of similar stimuli. Therefore, one cannot definitively conclude such a role. However, this fact likely represents Cognitive Sciences cortical myopia (9) and an overemphasis on visual conscious perception (10). In contrast, a plethora of circumstantial evidence suggests such a role. This work is a call for the scientific community to conduct experiments assessing this putative role, since such experiments can contribute intensively to our understanding of conscious experience.

What can be concluded from such a review? We propose that, at least currently, the cerebellum can be conceived as a neural modulator of consciousness (NMC) - a part of a neuronal system that can modulate a conscious experience to produce a variation in some basic conscious experience. In other words, even if the conscious experience is the outcome of the brain activity of other parts of the brain, the conscious experience may be modulated by the coupling between the NMC and the parts of the brain representing the neural correlates of that conscious experience.

Consciousness and Awareness ¹

Perception and Attention Other ²

Cerebellum

Consciousness

Pain

Perception

Psychiatric Disorders

Sleep