The Role of the Cerebellum in Cognition and Emotion: Personal Reflections Since 1982 on the Dysmetria of Thought Hypothesis, and Its Historical Evolution from Theory to Therapy

Abstract

The cognitive neuroscience of the cerebellum is now an established multidisciplinary field of investigation. This essay traces the historical evolution of this line of inquiry from an emerging field to its current status, with personal reflections over almost three decades on this journey of discovery. It pays tribute to early investigators who recognized the wider role of the cerebellum beyond motor control, traces the origins of new terms and concepts including the dysmetria of thought theory, the universal cerebellar transform, and the cerebellar cognitive affective syndrome, and places these developments within the broader context of the scientific efforts of a growing community of cerebellar cognitive neuroscientists. This account considers the converging evidence from theoretical, anatomical, physiological, clinical, and functional neuroimaging approaches that have resulted in the transition from recognizing the cerebellar incorporation into the distributed neural circuits subserving cognition and emotion, to a hopeful new era of treatment of neurocognitive and neuropsychiatric manifestations of cerebellar diseases, and to cerebellar-based interventions for psychiatric disorders.

The 5-HT7 receptor triggers cerebellar long-term synaptic depression via PKC-MAPK

“…Conditions that have an emotional tone, or that produce anxiety or pain, can activate the cerebellar vermis. On the other hand, abnormalities in cerebellar function and structure have been documented in patients with depression and schizophrenia (Konarski et al, 2004 andSchmahmann, 2010). A well-studied form of emotional behavior involving the cerebellum is fear conditioning whereby an organism learns to associate a neutral stimulus to a painful stimulus (Maschke et al, 2002).…”

High‐angular resolution diffusion imaging tractography of cerebellar pathways from newborns to young adults

“…Noted as one of the last structures to mature, the cerebellum plays a major role in motor function, coordination, cognition, and emotion (Desmond & Fiez, 1998; Schmahmann, 1991, 1996, 2010; Schmahmann & Sherman, 1998; Schutter & van Honk, 2005). Lesions in the cerebellum have resulted in disorders of executive function (Courchesne et al., 1994; Tanaka, Harada, Arai, & Hirata, 2003), visuospatial abilities (Fabbro et al., 2004; Schmahmann & Sherman, 1998), expressive language (Fabbro et al., 2004; Molinari, Leggio, & Silveri, 1997), and affective behavior (Courchesne et al., 1994; Schmahmann, 2000), among others.…”

The Cognitive Face of Cerebellum; Implications for Extended Research

“…Some of the anatomical and functional features of the cerebellum include the population of its neurons, its operation speed, its massive neural connections with the cerebral cortex, and the extensive connections of its output fibers (2). Cognitive function of the cerebellum, beyond its motor role, is now the subject of an established multidisciplinary field of investigation known as the cognitive neuroscience of the cerebellum (3). As such, in 2010, an issue of the journal 'Cortex' was dedicated to the cerebellum and cognitive functions.…”

“…The cognitive and psychiatric components of the CCAS, together with the ataxic motor disability of the cerebellar disorders, are conceptualized within the 'dysmetria of thought' hypothesis. This concept holds the idea that cerebellar facilitates automatic modulation of the behavior around a homeostatic baseline, and the behavior being modulated is determined by the specificity of anatomic subcircuits or loops within the cerebrocerebellar system (3,5,6,7).…”