scholarly journals Distinct Contributions of the Cerebellum and Basal Ganglia to Arithmetic Procedures

2021 ◽  
Author(s):  
William Saban ◽  
Pedro Chagas ◽  
Steven Piantadosi ◽  
Rich Ivry
Keyword(s):  
Basal Ganglia ◽  
Memory Retrieval ◽  
Alternative Hypothesis ◽  
Cerebellar Degeneration ◽  
Subcortical Structures ◽  
Mathematical Skills ◽  
Cognitive Operations ◽  
Patient Groups ◽  
Complex Cognition ◽  
Iterative Procedures

Abstract Humans exhibit complex mathematical skills, often attributed to the exceptionally large neocortex. Using a neuropsychological approach, we report that degeneration within two subcortical structures, the basal ganglia and cerebellum, impairs performance in symbolic arithmetic. Moreover, we identify distinct computational impairments in individuals with Parkinson’s disease (PD) or cerebellar degeneration (CD). The CD group exhibited a disproportionate cost when arithmetic sum increased, suggesting that the cerebellum is critical for iterative procedures required for calculations. The PD group exhibited a disproportionate cost for equations with an increasing number of addends, suggesting that the basal ganglia are critical for the coordination of multiple cognitive operations. In Experiment 2, the two patient groups exhibited intact practice gains for repeated equations at odds with an alternative hypothesis that these impairments were related to memory retrieval. Overall, the results provide a novel demonstration of the contribution of subcortical structures to the computations required for complex cognition.

scholarly journals Double dissociation of single-interval and rhythmic temporal prediction in cerebellar degeneration and Parkinson’s disease

2018 ◽  
Vol 115 (48) ◽  
pp. 12283-12288 ◽  
Author(s):  
Assaf Breska ◽  
Richard B. Ivry
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Basal Ganglia ◽  
Cerebellar Degeneration ◽  
Common Mechanism ◽  
Attentional Orienting ◽  
Subcortical Structures ◽  
Double Dissociation ◽  
Temporal Prediction ◽  
Single Interval

Predicting the timing of upcoming events is critical for successful interaction in a dynamic world, and is recognized as a key computation for attentional orienting. Temporal predictions can be formed when recent events define a rhythmic structure, as well as in aperiodic streams or even in isolation, when a specified interval is known from previous exposure. However, whether predictions in these two contexts are mediated by a common mechanism, or by distinct, context-dependent mechanisms, is highly controversial. Moreover, although the basal ganglia and cerebellum have been linked to temporal processing, the role of these subcortical structures in temporal orienting of attention is unclear. To address these issues, we tested individuals with cerebellar degeneration or Parkinson’s disease, with the latter serving as a model of basal ganglia dysfunction, on temporal prediction tasks in the subsecond range. The participants performed a visual detection task in which the onset of the target was predictable, based on either a rhythmic stream of stimuli, or a single interval, specified by two events that occurred within an aperiodic stream. Patients with cerebellar degeneration showed no benefit from single-interval cuing but preserved benefit from rhythm cuing, whereas patients with Parkinson’s disease showed no benefit from rhythm cuing but preserved benefit from single-interval cuing. This double dissociation provides causal evidence for functionally nonoverlapping mechanisms of rhythm- and interval-based temporal prediction for attentional orienting, and establishes the separable contributions of the cerebellum and basal ganglia to these functions, suggesting a mechanistic specialization across timing domains.

Involvement of Subcortical Structures in the Preparation of Self-Paced Movement

2004 ◽  
Vol 18 (2/3) ◽  
pp. 130-139 ◽  
Author(s):  
Guillermo Paradiso ◽  
Danny Cunic ◽  
Robert Chen
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Basal Ganglia ◽  
Onset Time ◽  
Movement Planning ◽  
Movement Preparation ◽  
Subcortical Structures ◽  
Postoperative Mri ◽  
Deep Brain

Abstract Although it has long been suggested that the basal ganglia and thalamus are involved in movement planning and preparation, there was little direct evidence in humans to support this hypothesis. Deep brain stimulation (DBS) is a well-established treatment for movement disorders such as Parkinson's disease, tremor, and dystonia. In patients undergoing DBS surgery, we recorded simultaneously from scalp contacts and from electrodes surgically implanted in the subthalamic nucleus (STN) of 13 patients with Parkinson's disease and in the “cerebellar” thalamus of 5 patients with tremor. The aim of our studies was to assess the role of the cortico-basal ganglia-thalamocortical loop through the STN and the cerebello-thalamocortical circuit through the “cerebellar” thalamus in movement preparation. The patients were asked to perform self-paced wrist extension movements. All subjects showed a cortical readiness potential (RP) with onset ranging between 1.5 to 2s before the onset of movement. Subcortical RPs were recorded in 11 of 13 with electrodes in the STN and in 4 of 5 patients with electrodes in the thalamus. The onset time of the STN and thalamic RPs were not significantly different from the onset time of the scalp RP. The STN and thalamic RPs were present before both contralateral and ipsilateral hand movements. Postoperative MRI studies showed that contacts with maximum RP amplitude generally were inside the target nucleus. These findings indicate that both the basal ganglia and the cerebellar circuits participate in movement preparation in parallel with the cortex.

scholarly journals A dynamical model for the basal ganglia-thalamo-cortical oscillatory activity and its implications in Parkinson’s disease

2020 ◽  
Author(s):  
Eva M. Navarro-López ◽  
Utku Çelikok ◽  
Neslihan S. Şengör
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Basal Ganglia ◽  
Activity Patterns ◽  
Dynamical Model ◽  
Substantia Nigra Pars Compacta ◽  
Oscillatory Activity ◽  
Subcortical Structures ◽  
Neuron Models ◽  
Neuronal Patterns

AbstractWe propose to investigate brain electrophysiological alterations associated with Parkinson’s disease through a novel adaptive dynamical model of the network of the basal ganglia, the cortex and the thalamus. The model uniquely unifies the influence of dopamine in the regulation of the activity of all basal ganglia nuclei, the self-organised neuronal interdependent activity of basal ganglia-thalamo-cortical circuits and the generation of subcortical background oscillations. Variations in the amount of dopamine produced in the neurons of the substantia nigra pars compacta are key both in the onset of Parkinson’s disease and in the basal ganglia action selection. We model these dopamine-induced relationships, and Parkinsonian states are interpreted as spontaneous emergent behaviours associated with different rhythms of oscillatory activity patterns of the basal ganglia-thalamo-cortical network. These results are significant because: (1) the neural populations are built upon single-neuron models that have been robustly designed to have eletrophysiologically-realistic responses, and (2) our model distinctively links changes in the oscillatory activity in subcortical structures, dopamine levels in the basal ganglia and pathological synchronisation neuronal patterns compatible with Parkinsonian states, this still remains an open problem and is crucial to better understand the progression of the disease.

Disorders of movement

2018 ◽  
Author(s):  
Cris S. Constantinescu ◽  
Fahd Baig
Keyword(s):  
Cerebral Cortex ◽  
Basal Ganglia ◽  
Movement Disorders ◽  
Neural Pathways ◽  
Subcortical Structures ◽  
Clinical Presentations

The neural pathways that control movement involve several structures, from the cerebral cortex through to the muscle. This allows for the maintenance of tone, posture, and volitional movement. Disruption of subcortical structures which modulate these pathways (such as the basal ganglia) can cause a variety of clinical presentations collectively termed movement disorders. They can be simply divided into hypokinetic disorders (e.g. parkinsonism) and hyperkinetic disorders.

scholarly journals Parallel Information Processing in Motor Systems: Intracerebral Recordings of Readiness Potential and CNV in Human Subjects

2000 ◽  
Vol 7 (1-2) ◽  
pp. 65-72 ◽  
Author(s):  
Ivan Rektor
Keyword(s):  
Basal Ganglia ◽  
Motor Cortex ◽  
Primary Motor Cortex ◽  
Human Subjects ◽  
Anterior Cingulate ◽  
Readiness Potential ◽  
Task Context ◽  
Subcortical Structures ◽  
Depth Electrodes ◽  
Simultaneous Activation

We performed intracerebral recordings of Readiness Potential (RP) and Contingent Negative Variation (CNV) with simple repetitive distal limb movement in candidates for epilepsy surgery. In 26 patients (in Paris), depth electrodes were located in various cortical structures; in eight patients (in Brno), in the basal ganglia and the cortex. RPs were displayed in the conteral primary motor cortex, conteral somato-sensory cortex, and bilaterally in the SMA and the caudal part of the anterior cingulate cortices. CNVs were recorded in the same cortical regiom as the RP, as well as in the ipsilateral primary motor cortex, and bilaterally in the premotor fronto-lateral, parietal superior, and middle temporal regions. In the basal ganglia, the RP was recorded in the putamen in six of seven patients, and in the head of the caudate nucleus and the pallidum in the only patient with electrodes in these recording sites. We suggest that our results are consistent with a long-lasting, simultaneous activation of cortical and subcortical structures, before and during self-paced and stimulus-triggered movements. The particular regiom that are simultaneously active may be determined by the task context.

scholarly journals Making Working Memory Work: A Computational Model of Learning in the Prefrontal Cortex and Basal Ganglia

2006 ◽  
Vol 18 (2) ◽  
pp. 283-328 ◽  
Author(s):  
Randall C. O'Reilly ◽  
Michael J. Frank
Keyword(s):  
Working Memory ◽  
Prefrontal Cortex ◽  
Basal Ganglia ◽  
Computational Model ◽  
Computational Models ◽  
Memory Task ◽  
Learning Mechanisms ◽  
Subcortical Structures ◽  
Credit Assignment ◽  
Gating Mechanism

The prefrontal cortex has long been thought to subserve both working memory (the holding of information online for processing) and executive functions (deciding how to manipulate working memory and perform processing). Although many computational models of working memory have been developed, the mechanistic basis of executive function remains elusive, often amounting to a homunculus. This article presents an attempt to deconstruct this homunculus through powerful learning mechanisms that allow a computational model of the prefrontal cortex to control both itself and other brain areas in a strategic, task-appropriate manner. These learning mechanisms are based on subcortical structures in the midbrain, basal ganglia, and amygdala, which together form an actor-critic architecture. The critic system learns which prefrontal representations are task relevant and trains the actor, which in turn provides a dynamic gating mechanism for controlling working memory updating. Computationally, the learning mechanism is designed to simultaneously solve the temporal and structural credit assignment problems. The model's performance compares favorably with standard backpropagation-based temporal learning mechanisms on the challenging 1-2-AX working memory task and other benchmark working memory tasks.

Subcortical Lesions and Aphasia

1990 ◽  
Vol 55 (1) ◽  
pp. 90-100 ◽  
Author(s):  
Donald A. Robin ◽  
Steven Schienberg
Keyword(s):  
Basal Ganglia ◽  
Neural Models ◽  
Subcortical Structures

Recent evidence suggests that subcortical lesions can give rise to aphasic symptoms. Two subcortical structures thought to participate in the pathogenesis of aphasia are the basal ganglia and the thalamus. This paper reports on 3 patients with lesions of the thalamus and 10 patients with lesions of the basal ganglia, most of whom had persistent aphasias. The role of subcortical structures in aphasia and the importance of subcortical structures in neural models of language are discussed.

The Role of Temporo-parietal Cortex in Subcortical Visual Extinction

2010 ◽  
Vol 22 (9) ◽  
pp. 2141-2150 ◽  
Author(s):  
Luca Francesco Ticini ◽  
Bianca de Haan ◽  
Uwe Klose ◽  
Thomas Nägele ◽  
Hans-Otto Karnath
Keyword(s):  
Basal Ganglia ◽  
Decisive Role ◽  
Brain Structures ◽  
Cortical Lesion ◽  
Critical Aspect ◽  
Subcortical Structures ◽  
Visual Extinction ◽  
Subcortical Brain Structures ◽  
The Right

Visual extinction is an intriguing defect of awareness in stroke patients, referring to the unsuccessful perception of contralesional events under conditions of competition. Previous studies have investigated the cortical and subcortical brain structures that, when damaged or inactivated, provoke visual extinction. The present experiment asked how lesions of subcortical structures may contribute to the appearance of visual extinction. We investigated whether lesions centering on right basal ganglia may induce dysfunction in distant, structurally intact cortical structures. Normalized perfusion-weighted MRI was used to identify structurally intact but abnormally perfused brain tissue, that is, zones that are receiving enough blood supply to remain structurally intact but not enough to function normally. We compared patients with right basal ganglia lesions showing versus not showing visual extinction. In the extinction patients, the contrast revealed cortical malperfusion that clustered around the right TPJ. It seems as if malfunction of this area is a critical aspect in visual extinction not only after cortical lesion but also in the case of subcortical basal ganglia damage. Our results support the idea that a normally functioning TPJ area plays a decisive role for the attentional network involved in detecting of visual stimuli under conditions of competition.

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