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White CM, Snow EC, Therrien AS. Reinforcement Motor Learning After Cerebellar Damage Is Related to State Estimation. CEREBELLUM (LONDON, ENGLAND) 2024; 23:1061-1073. [PMID: 37828231 DOI: 10.1007/s12311-023-01615-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 10/03/2023] [Indexed: 10/14/2023]
Abstract
Recent work showed that individuals with cerebellar degeneration could leverage intact reinforcement learning (RL) to alter their movement. However, there was marked inter-individual variability in learning, and the factors underlying it were unclear. Cerebellum-dependent sensory prediction may contribute to RL in motor contexts by enhancing body state estimates, which are necessary to solve the credit-assignment problem. The objective of this study was to test the relationship between the predictive component of state estimation and RL in individuals with cerebellar degeneration. Individuals with cerebellar degeneration and neurotypical control participants completed two tasks: an RL task that required them to alter the angle of reaching movements and a state estimation task that tested the somatosensory perception of active and passive movement. The state estimation task permitted the calculation of the active benefit shown by each participant, which is thought to reflect the cerebellum-dependent predictive component of state estimation. We found that the cerebellar and control groups showed similar magnitudes of learning with reinforcement and active benefit on average, but there was substantial variability across individuals. Using multiple regression, we assessed potential predictors of RL. Our analysis included active benefit, somatosensory acuity, clinical ataxia severity, movement variability, movement speed, and age. We found a significant relationship in which greater active benefit predicted better learning with reinforcement in the cerebellar, but not the control group. No other variables showed significant relationships with learning. Overall, our results support the hypothesis that the integrity of sensory prediction is a strong predictor of RL after cerebellar damage.
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Affiliation(s)
- Christopher M White
- Moss Rehabilitation Research Institute, Medical Arts Building, Suite 100, 50 Township Line Rd, Elkins Park, PA, USA
| | - Evan C Snow
- Moss Rehabilitation Research Institute, Medical Arts Building, Suite 100, 50 Township Line Rd, Elkins Park, PA, USA
| | - Amanda S Therrien
- Moss Rehabilitation Research Institute, Medical Arts Building, Suite 100, 50 Township Line Rd, Elkins Park, PA, USA.
- Department of Rehabilitation Medicine, Thomas Jefferson University, Philadelphia, PA, USA.
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Manto M, Adamaszek M, Apps R, Carlson E, Guarque-Chabrera J, Heleven E, Kakei S, Khodakhah K, Kuo SH, Lin CYR, Joshua M, Miquel M, Mitoma H, Larry N, Péron JA, Pickford J, Schutter DJLG, Singh MK, Tan T, Tanaka H, Tsai P, Van Overwalle F, Yamashiro K. Consensus Paper: Cerebellum and Reward. CEREBELLUM (LONDON, ENGLAND) 2024:10.1007/s12311-024-01702-0. [PMID: 38769243 DOI: 10.1007/s12311-024-01702-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 05/06/2024] [Indexed: 05/22/2024]
Abstract
Cerebellum is a key-structure for the modulation of motor, cognitive, social and affective functions, contributing to automatic behaviours through interactions with the cerebral cortex, basal ganglia and spinal cord. The predictive mechanisms used by the cerebellum cover not only sensorimotor functions but also reward-related tasks. Cerebellar circuits appear to encode temporal difference error and reward prediction error. From a chemical standpoint, cerebellar catecholamines modulate the rate of cerebellar-based cognitive learning, and mediate cerebellar contributions during complex behaviours. Reward processing and its associated emotions are tuned by the cerebellum which operates as a controller of adaptive homeostatic processes based on interoceptive and exteroceptive inputs. Lobules VI-VII/areas of the vermis are candidate regions for the cortico-subcortical signaling pathways associated with loss aversion and reward sensitivity, together with other nodes of the limbic circuitry. There is growing evidence that the cerebellum works as a hub of regional dysconnectivity across all mood states and that mental disorders involve the cerebellar circuitry, including mood and addiction disorders, and impaired eating behaviors where the cerebellum might be involved in longer time scales of prediction as compared to motor operations. Cerebellar patients exhibit aberrant social behaviour, showing aberrant impulsivity/compulsivity. The cerebellum is a master-piece of reward mechanisms, together with the striatum, ventral tegmental area (VTA) and prefrontal cortex (PFC). Critically, studies on reward processing reinforce our view that a fundamental role of the cerebellum is to construct internal models, perform predictions on the impact of future behaviour and compare what is predicted and what actually occurs.
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Affiliation(s)
- Mario Manto
- Service de Neurologie, Médiathèque Jean Jacquy, CHU-Charleroi, 6000, Charleroi, Belgium.
- Service Des Neurosciences, Université de Mons, 7000, Mons, Belgium.
- Unité Des Ataxies Cérébelleuses, CHU-Charleroi, Service Des Neurosciences, University of Mons, 7000, Mons, Belgium.
| | - Michael Adamaszek
- Department of Clinical and Cognitive Neurorehabilitation, Klinik Bavaria Kreischa, 01731, Kreischa, Germany
| | - Richard Apps
- School of Physiology, Pharmacology & Neuroscience, Faculty of Life Sciences, University of Bristol, Bristol, BS8 1TD, UK
| | - Erik Carlson
- Department of Psychiatry and Behavioural Sciences, University of Washington, Seattle, WA, 98108, USA
- Geriatric Research, Education and Clinical Center, Veterans Affairs Puget Sound Health Care System, Seattle, WA, 98108, USA
| | - Julian Guarque-Chabrera
- Área de Psicobiología, Facultat de Ciències de La Salut, Universitat Jaume I, 12071, Castellón de La Plana, Spain
- Dominick Purpura Department of Neuroscience, Albert Einstein College of Medicine, New York, 10461, USA
| | - Elien Heleven
- Faculty of Psychology and Center for Neuroscience, Vrije Universiteit Brussel, 1050, Brussels, Belgium
| | - Shinji Kakei
- Department of Anatomy and Physiology, Jissen Women's University, Tokyo, 191-8510, Japan
| | - Kamran Khodakhah
- Dominick Purpura Department of Neuroscience, Albert Einstein College of Medicine, New York, 10461, USA
| | - Sheng-Han Kuo
- Department of Neurology, Columbia University Medical Center, New York, NY, 10032, USA
- Initiative of Columbia Ataxia and Tremor, Columbia University Medical Center, New York, NY, 10032, USA
| | - Chi-Ying R Lin
- Alzheimer's Disease and Memory Disorders Center, Department of Neurology, Baylor College of Medicine, Houston, 77030 TX, USA
- Parkinson's Disease Center and Movement Disorders Clinic, Department of Neurology, Baylor College of Medicine, Houston, 77030 TX, USA
| | - Mati Joshua
- Edmond and Lily Safra Center for Brain Sciences, The Hebrew University, Jerusalem, Israel
| | - Marta Miquel
- Área de Psicobiología, Facultat de Ciències de La Salut, Universitat Jaume I, 12071, Castellón de La Plana, Spain
- Dominick Purpura Department of Neuroscience, Albert Einstein College of Medicine, New York, 10461, USA
| | - Hiroshi Mitoma
- Department of Medical Education, Tokyo Medical University, Tokyo, 160-8402, Japan
| | - Noga Larry
- Edmond and Lily Safra Center for Brain Sciences, The Hebrew University, Jerusalem, Israel
| | - Julie Anne Péron
- Clinical and Experimental Neuropsychology Laboratory, Department of Psychology and Educational Sciences, University of Geneva, 1205, Geneva, Switzerland
| | - Jasmine Pickford
- School of Physiology, Pharmacology & Neuroscience, Faculty of Life Sciences, University of Bristol, Bristol, BS8 1TD, UK
| | - Dennis J L G Schutter
- Department of Experimental Psychology, Helmholtz Institute, Utrecht University, Heidelberglaan 1, 3584 CS, Utrecht, The Netherlands
| | - Manpreet K Singh
- Psychiatry and Behavioral Sciences, University of California Davis, 2230 Stockton Blvd, Sacramento, CA, 95817, USA
| | - Tommy Tan
- Department of Neurology, UT Southwestern Medical Center, Dallas, TX, 75235, USA
| | - Hirokazu Tanaka
- Faculty of Information Technology, Tokyo City University, Tokyo, 158-8557, Japan
| | - Peter Tsai
- Department of Neurology, UT Southwestern Medical Center, Dallas, TX, 75235, USA
- Departments of Neuroscience, Pediatrics, Psychiatry, UT Southwestern Medical Center, Dallas, TX, 75235, USA
| | - Frank Van Overwalle
- Faculty of Psychology and Center for Neuroscience, Vrije Universiteit Brussel, 1050, Brussels, Belgium
| | - Kunihiko Yamashiro
- Department of Neurology, UT Southwestern Medical Center, Dallas, TX, 75235, USA
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Sendhilnathan N, Bostan AC, Strick PL, Goldberg ME. A cerebro-cerebellar network for learning visuomotor associations. Nat Commun 2024; 15:2519. [PMID: 38514616 PMCID: PMC10957870 DOI: 10.1038/s41467-024-46281-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2023] [Accepted: 02/16/2024] [Indexed: 03/23/2024] Open
Abstract
Consensus is rapidly building to support a role for the cerebellum beyond motor function, but its contributions to non-motor learning remain poorly understood. Here, we provide behavioral, anatomical and computational evidence to demonstrate a causal role for the primate posterior lateral cerebellum in learning new visuomotor associations. Reversible inactivation of the posterior lateral cerebellum of male monkeys impeded the learning of new visuomotor associations, but had no effect on movement parameters, or on well-practiced performance of the same task. Using retrograde transneuronal transport of rabies virus, we identified a distinct cerebro-cerebellar network linking Purkinje cells in the posterior lateral cerebellum with a region of the prefrontal cortex that is critical in learning visuomotor associations. Together, these results demonstrate a causal role for the primate posterior lateral cerebellum in non-motor, reinforcement learning.
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Affiliation(s)
- Naveen Sendhilnathan
- Doctoral program in Neurobiology and Behavior, Columbia University, New York, NY, USA.
- Dept. of Neuroscience, Mahoney Center for Brain and Behavior Research, Zuckerman Mind, Brain, and Behavior Institute, Columbia University, New York, NY, USA.
| | - Andreea C Bostan
- Department of Neurobiology, Systems Neuroscience Center, and Brain Institute, University of Pittsburgh, Pittsburgh, PA, USA.
| | - Peter L Strick
- Department of Neurobiology, Systems Neuroscience Center, and Brain Institute, University of Pittsburgh, Pittsburgh, PA, USA
| | - Michael E Goldberg
- Dept. of Neuroscience, Mahoney Center for Brain and Behavior Research, Zuckerman Mind, Brain, and Behavior Institute, Columbia University, New York, NY, USA
- Kavli Institute for Brain Science, Columbia University, New York, NY, USA
- Dept. of Neurology, Psychiatry, and Ophthalmology, Columbia University College of Physicians and Surgeons, New York, NY, USA
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Zhao J, Zhang G, Xu D. The effect of reward on motor learning: different stage, different effect. Front Hum Neurosci 2024; 18:1381935. [PMID: 38532789 PMCID: PMC10963647 DOI: 10.3389/fnhum.2024.1381935] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2024] [Accepted: 02/29/2024] [Indexed: 03/28/2024] Open
Abstract
Motor learning is a prominent and extensively studied subject in rehabilitation following various types of neurological disorders. Motor repair and rehabilitation often extend over months and years post-injury with a slow pace of recovery, particularly affecting the fine movements of the distal extremities. This extended period can diminish the motivation and persistence of patients, a facet that has historically been overlooked in motor learning until recent years. Reward, including monetary compensation, social praise, video gaming, music, and virtual reality, is currently garnering heightened attention for its potential to enhance motor motivation and improve function. Numerous studies have examined the effects and attempted to explore potential mechanisms in various motor paradigms, yet they have yielded inconsistent or even contradictory results and conclusions. A comprehensive review is necessary to summarize studies on the effects of rewards on motor learning and to deduce a central pattern from these existing studies. Therefore, in this review, we initially outline a framework of motor learning considering two major types, two major components, and three stages. Subsequently, we summarize the effects of rewards on different stages of motor learning within the mentioned framework and analyze the underlying mechanisms at the level of behavior or neural circuit. Reward accelerates learning speed and enhances the extent of learning during the acquisition and consolidation stages, possibly by regulating the balance between the direct and indirect pathways (activating more D1-MSN than D2-MSN) of the ventral striatum and by increasing motor dynamics and kinematics. However, the effect varies depending on several experimental conditions. During the retention stage, there is a consensus that reward enhances both short-term and long-term memory retention in both types of motor learning, attributed to the LTP learning mechanism mediated by the VTA-M1 dopaminergic projection. Reward is a promising enhancer to bolster waning confidence and motivation, thereby increasing the efficiency of motor learning and rehabilitation. Further exploration of the circuit and functional connections between reward and the motor loop may provide a novel target for neural modulation to promote motor behavior.
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Affiliation(s)
- Jingwang Zhao
- School of Rehabilitation Science, Shanghai University of Traditional Chinese Medicine, Shanghai, China
- Institute of Rehabilitation Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Guanghu Zhang
- School of Rehabilitation Science, Shanghai University of Traditional Chinese Medicine, Shanghai, China
- Institute of Rehabilitation Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Dongsheng Xu
- School of Rehabilitation Science, Shanghai University of Traditional Chinese Medicine, Shanghai, China
- Institute of Rehabilitation Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai, China
- Engineering Research Center of Traditional Chinese Medicine Intelligent Rehabilitation, Ministry of Education, Shanghai, China
- Department of Rehabilitation Medicine, Shuguang Hospital, Shanghai, China
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Larry N, Zur G, Joshua M. Organization of reward and movement signals in the basal ganglia and cerebellum. Nat Commun 2024; 15:2119. [PMID: 38459003 PMCID: PMC10923830 DOI: 10.1038/s41467-024-45921-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2022] [Accepted: 02/06/2024] [Indexed: 03/10/2024] Open
Abstract
The basal ganglia and the cerebellum are major subcortical structures in the motor system. The basal ganglia have been cast as the reward center of the motor system, whereas the cerebellum is thought to be involved in adjusting sensorimotor parameters. Recent findings of reward signals in the cerebellum have challenged this dichotomous view. To compare the basal ganglia and the cerebellum directly, we recorded from oculomotor regions in both structures from the same monkeys. We partitioned the trial-by-trial variability of the neurons into reward and eye-movement signals to compare the coding across structures. Reward expectation and movement signals were the most pronounced in the output structure of the basal ganglia, intermediate in the cerebellum, and the smallest in the input structure of the basal ganglia. These findings suggest that reward and movement information is sharpened through the basal ganglia, resulting in a higher signal-to-noise ratio than in the cerebellum.
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Affiliation(s)
- Noga Larry
- Edmond and Lily Safra Center for Brain Sciences, the Hebrew University, Jerusalem, Israel.
| | - Gil Zur
- Edmond and Lily Safra Center for Brain Sciences, the Hebrew University, Jerusalem, Israel
| | - Mati Joshua
- Edmond and Lily Safra Center for Brain Sciences, the Hebrew University, Jerusalem, Israel.
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Hu Y, Wang H, Joshua M, Yang Y. Sensorimotor-linked reward modulates smooth pursuit eye movements in monkeys. Front Neurosci 2024; 17:1297914. [PMID: 38264498 PMCID: PMC10803645 DOI: 10.3389/fnins.2023.1297914] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2023] [Accepted: 12/18/2023] [Indexed: 01/25/2024] Open
Abstract
Reward is essential for shaping behavior. Using sensory cues to imply forthcoming rewards, previous studies have demonstrated powerful effects of rewards on behavior. Nevertheless, the impact of reward on the sensorimotor transformation, particularly when reward is linked to behavior remains uncertain. In this study, we investigated how reward modulates smooth pursuit eye movements in monkeys. Three distinct associations between reward and eye movements were conducted in independent blocks. Results indicated that reward increased eye velocity during the steady-state pursuit, rather than during the initiation. The influence depended on the particular association between behavior and reward: a faster eye velocity was linked with reward. Neither rewarding slower eye movements nor randomizing rewards had a significant effect on behavior. The findings support the existence of distinct mechanisms involved in the initiation and steady-state phases of pursuit, and contribute to a deeper understanding of how reward interacts with these two periods of pursuit.
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Affiliation(s)
- Yongxiang Hu
- Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China
- State Key Laboratory of Brain and Cognitive Science, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
| | - Huan Wang
- State Key Laboratory of Brain and Cognitive Science, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
| | - Mati Joshua
- Edmond and Lily Safra Center for Brain Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Yan Yang
- State Key Laboratory of Brain and Cognitive Science, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
- Sino-Danish College, University of Chinese Academy of Sciences, Beijing, China
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Wen Z, Kang Y, Zhang Y, Yang H, Xie B. Alteration of Degree Centrality in Adolescents With Early Blindness. Front Hum Neurosci 2022; 16:935642. [PMID: 35832871 PMCID: PMC9271564 DOI: 10.3389/fnhum.2022.935642] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2022] [Accepted: 06/06/2022] [Indexed: 12/02/2022] Open
Abstract
Congenital nystagmus in infants and young children can lead to early blindness (EB). Previous neuroimaging studies have demonstrated that EB is accompanied by alterations in brain structure and function. However, the effects of visual impairment and critical developmental periods on brain functional connectivity at rest have been unclear. Here, we used the voxel-wise degree centrality (DC) method to explore the underlying functional network brain activity in adolescents with EB. Twenty-one patients with EBs and 21 sighted controls (SCs) underwent magnetic resonance imaging. Differences between the two groups were assessed using the DC method. Moreover, the support vector machine (SVM) method was used to differentiate patients with EB patients from the SCs according to DC values. Compared with the SCs, the patients with EB had increased DC values in the bilateral cerebellum_6, cerebellum vermis_4_5, bilateral supplementary motor areas (SMA), and left fusiform gyrus; the patients with EB had decreased DC values in the bilateral rectal gyrus and left medial orbital frontal gyrus. The SVM classification of the DC values achieved an overall accuracy of 70.45% and an area under the curve of 0.86 in distinguishing between the patients with EB and the SCs. Our study may reveal the neuromechanism of neuroplasticity in EB; the findings provide an imaging basis for future development of restorative visual therapies and sensory substitution devices, and future assessments of visual rehabilitation efficacy.
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Affiliation(s)
- Zhi Wen
- Department of Radiology, Renmin Hospital of Wuhan University, Wuhan, China
| | - Yan Kang
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, National Center for Magnetic Resonance in Wuhan, Wuhan Institute of Physics and Mathematics, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences, Wuhan, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Yu Zhang
- Department of Radiology, Renmin Hospital of Wuhan University, Wuhan, China
| | - Huaguang Yang
- Department of Radiology, Renmin Hospital of Wuhan University, Wuhan, China
| | - Baojun Xie
- Department of Radiology, Renmin Hospital of Wuhan University, Wuhan, China
- *Correspondence: Baojun Xie,
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Chen F, Hu Z, Liu H, Zhen F, Liu C, Li Q. Altered Homotopic Connectivity in the Cerebellum Predicts Stereopsis Dysfunction in Patients With Comitant Exotropia. Front Hum Neurosci 2022; 16:917769. [PMID: 35721355 PMCID: PMC9201504 DOI: 10.3389/fnhum.2022.917769] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Accepted: 05/09/2022] [Indexed: 11/13/2022] Open
Abstract
Purpose Comitant exotropia (CE) is a common eye disorder characterized by impaired stereoscopic vision and eye deviation. Previous neuroimaging studies demonstrated that patients with CE were accompanied by specific functional and structural abnormalities of the brain. However, the effect of impaired stereoscopic vision and eye deviation on interhemispheric homotopic connectivity remains unknown. Methods A total of thirty-six patients with CE (25 males and 11 females) and 36 well-matched healthy controls underwent magnetic resonance imaging scanning. The voxel-mirrored homotopic connectivity (VMHC) method was applied to assess the interhemispheric homotopic connectivity changes in patients with CE. Furthermore, the support vector machine method was applied to assess to differentiate patients with CE from healthy controls (HCs) with the VMHC maps as a feature. Results Compared with HCs, patients with CE showed significantly increased VMHC values in the bilateral cerebelum_ 8 and cerebelum_4_5. Moreover, we found that the VMHC maps showed an accuracy of 81.94% and an area under the curve of 0.87 for distinguishing the patients with CE from HCs. Conclusion Our study demonstrates that patients with CE showed interhemispheric homotopic connectivity changes in the cerebellum, which might reflect the neurological mechanisms of impaired stereoscopic vision and eye deviation in patients with CE.
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Affiliation(s)
- Fei Chen
- Department of Ophthalmology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
- *Correspondence: Fei Chen,
| | - Zhirou Hu
- Department of Ophthalmology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Hui Liu
- Department of Ophthalmology, Jiangxi Provincial People’s Hospital, Nanchang, China
| | - Fangyuan Zhen
- Department of Ophthalmology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Chenlu Liu
- Department of Ophthalmology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Qiuming Li
- Department of Ophthalmology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
- Qiuming Li,
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Kostadinov D, Häusser M. Reward signals in the cerebellum: origins, targets, and functional implications. Neuron 2022; 110:1290-1303. [PMID: 35325616 DOI: 10.1016/j.neuron.2022.02.015] [Citation(s) in RCA: 33] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2021] [Revised: 12/22/2021] [Accepted: 02/16/2022] [Indexed: 12/14/2022]
Abstract
The cerebellum has long been proposed to play a role in cognitive function, although this has remained controversial. This idea has received renewed support with the recent discovery that signals associated with reward can be observed in the cerebellar circuitry, particularly in goal-directed learning tasks involving an interplay between the cerebellar cortex, basal ganglia, and cerebral cortex. Remarkably, a wide range of reward contingencies-including reward expectation, delivery, size, and omission-can be encoded by specific circuit elements in a manner that reflects the microzonal organization of the cerebellar cortex. The facts that reward signals have been observed in both the mossy fiber and climbing fiber input pathways to the cerebellar cortex and that their convergence may trigger plasticity in Purkinje cells suggest that these interactions may be crucial for the role of the cerebellar cortex in learned behavior. These findings strengthen the emerging consensus that the cerebellum plays a pivotal role in shaping cognitive processing and suggest that the cerebellum may combine both supervised learning and reinforcement learning to optimize goal-directed action. We make specific predictions about how cerebellar circuits can work in concert with the basal ganglia to guide different stages of learning.
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Affiliation(s)
- Dimitar Kostadinov
- Wolfson Institute for Biomedical Research and Department of Neuroscience, Physiology and Pharmacology, University College London, London, UK.
| | - Michael Häusser
- Wolfson Institute for Biomedical Research and Department of Neuroscience, Physiology and Pharmacology, University College London, London, UK.
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Passive Motor Learning: Oculomotor Adaptation in the Absence of Behavioral Errors. eNeuro 2021; 8:ENEURO.0232-20.2020. [PMID: 33593731 PMCID: PMC8009667 DOI: 10.1523/eneuro.0232-20.2020] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Revised: 12/20/2020] [Accepted: 12/22/2020] [Indexed: 01/08/2023] Open
Abstract
Motor adaptation is commonly thought to be a trial-and-error process in which the accuracy of movement improves with repetition of behavior. We challenged this view by testing whether erroneous movements are necessary for motor adaptation. In the eye movement system, the association between movements and errors can be disentangled, since errors in the predicted stimulus trajectory can be perceived even without movements. We modified a smooth pursuit eye movement adaptation paradigm in which monkeys learn to make an eye movement that predicts an upcoming change in target direction. We trained the monkeys to fixate on a target while covertly, an additional target initially moved in one direction and then changed direction after 250 ms. The monkeys showed a learned response to infrequent probe trials in which they were instructed to follow the moving target. Additional experiments confirmed that probing learning or residual eye movements during fixation did not drive learning. These results show that motor adaptation can be elicited in the absence of movement and provide an animal model for studying the implementation of passive motor learning. Current models assume that the interaction between movement and error signals underlies adaptive motor learning. Our results point to other mechanisms that may drive learning in the absence of movement.
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Abstract
We discuss a new framework for understanding the structure of motor control. Our approach integrates existing models of motor control with the reality of hierarchical cortical processing and the parallel segregated loops that characterize cortical-subcortical connections. We also incorporate the recent claim that cortex functions via predictive representation and optimal information utilization. Our framework assumes that each cortical area engaged in motor control generates a predictive model of a different aspect of motor behavior. In maintaining these predictive models, each area interacts with a different part of the cerebellum and BG. These subcortical areas are thus engaged in domain-appropriate system identification and optimization. This refocuses the question of division of function among different cortical areas. What are the different aspects of motor behavior that are predictively modeled? We suggest that one fundamental division is between modeling of task and body whereas another is the model of state and action. Thus, we propose that the posterior parietal cortex, somatosensory cortex, premotor cortex, and motor cortex represent task state, body state, task action, and body action, respectively. In the second part of this review, we demonstrate how this division of labor can better account for many recent findings of movement encoding, especially in the premotor and posterior parietal cortices.
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