scholarly journals Modulation of error-sensitivity during a prism adaptation task in people with cerebellar degeneration

2015 ◽  
Vol 114 (4) ◽  
pp. 2460-2471 ◽  
Author(s):  
Ritsuko Hanajima ◽  
Reza Shadmehr ◽  
Shinya Ohminami ◽  
Ryosuke Tsutsumi ◽  
Yuichiro Shirota ◽  
...  
Keyword(s):  
Visual Feedback ◽  
Cortical Atrophy ◽  
Motor Memory ◽  
Error Sensitivity ◽  
Cerebellar Damage ◽  
Trial Analysis ◽  
Block Trial ◽  
Pure Cerebellar Ataxia ◽  
Human Motor ◽  
Cerebellar Cortical Atrophy

Cerebellar damage can profoundly impair human motor adaptation. For example, if reaching movements are perturbed abruptly, cerebellar damage impairs the ability to learn from the perturbation-induced errors. Interestingly, if the perturbation is imposed gradually over many trials, people with cerebellar damage may exhibit improved adaptation. However, this result is controversial, since the differential effects of gradual vs. abrupt protocols have not been observed in all studies. To examine this question, we recruited patients with pure cerebellar ataxia due to cerebellar cortical atrophy ( n = 13) and asked them to reach to a target while viewing the scene through wedge prisms. The prisms were computer controlled, making it possible to impose the full perturbation abruptly in one trial, or build up the perturbation gradually over many trials. To control visual feedback, we employed shutter glasses that removed visual feedback during the reach, allowing us to measure trial-by-trial learning from error (termed error-sensitivity), and trial-by-trial decay of motor memory (termed forgetting). We found that the patients benefited significantly from the gradual protocol, improving their performance with respect to the abrupt protocol by exhibiting smaller errors during the exposure block, and producing larger aftereffects during the postexposure block. Trial-by-trial analysis suggested that this improvement was due to increased error-sensitivity in the gradual protocol. Therefore, cerebellar patients exhibited an improved ability to learn from error if they experienced those errors gradually. This improvement coincided with increased error-sensitivity and was present in both groups of subjects, suggesting that control of error-sensitivity may be spared despite cerebellar damage.

scholarly journals Tagging motor memories with transcranial direct current stimulation allows later artificially-controlled retrieval

eLife ◽  
2016 ◽  
Vol 5 ◽  
Author(s):  
Daichi Nozaki ◽  
Atsushi Yokoi ◽  
Takahiro Kimura ◽  
Masaya Hirashima ◽  
Jean-Jacques Orban de Xivry
Keyword(s):  
Direct Current ◽  
Sensorimotor Cortex ◽  
Transcranial Direct Current Stimulation ◽  
Background Activity ◽  
Training Session ◽  
Motor Memory ◽  
Activity Levels ◽  
Direct Current Stimulation ◽  
Cathodal Tdcs ◽  
Human Motor

We demonstrate that human motor memories can be artificially tagged and later retrieved by noninvasive transcranial direct current stimulation (tDCS). Participants learned to adapt reaching movements to two conflicting dynamical environments that were each associated with a different tDCS polarity (anodal or cathodal tDCS) on the sensorimotor cortex. That is, we sought to determine whether divergent background activity levels within the sensorimotor cortex (anodal: higher activity; cathodal: lower activity) give rise to distinct motor memories. After a training session, application of each tDCS polarity automatically resulted in the retrieval of the motor memory corresponding to that polarity. These results reveal that artificial modulation of neural activity in the sensorimotor cortex through tDCS can act as a context for the formation and recollection of motor memories.

scholarly journals Role of the somatosensory cortex in motor memory consolidation

2020 ◽  
Vol 124 (3) ◽  
pp. 648-651
Author(s):  
Manasi Wali
Keyword(s):  
Motor Learning ◽  
Somatosensory Cortex ◽  
Memory Consolidation ◽  
Motor Memory ◽  
Implicit Motor Learning ◽  
Implicit Motor ◽  
Human Motor ◽  
Plos Biol

Motor memories become resistant to interference by the process of consolidation, which leads to long-term retention. Studies have shown involvement of the somatosensory cortex in motor learning-related plasticity, but not directly in motor memory consolidation. This Neuro Forum article reviews evidence from a continuous theta-burst transcranial magnetic stimulation (cTBS) study by Kumar and colleagues (Kumar N, Manning TF, Ostry DJ. PLoS Biol 17: e3000469, 2019) that demonstrates the role of somatosensory, rather than motor, cortex in human motor memory consolidation during implicit motor learning.

scholarly journals Human Motor Plasticity Induced by Mirror Visual Feedback

2012 ◽  
Vol 32 (4) ◽  
pp. 1293-1300 ◽  
Author(s):  
I. Nojima ◽  
T. Mima ◽  
S. Koganemaru ◽  
M. N. Thabit ◽  
H. Fukuyama ◽  
...  
Keyword(s):  
Visual Feedback ◽  
Mirror Visual Feedback ◽  
Human Motor

Consolidation in human motor memory

Nature ◽  
1996 ◽  
Vol 382 (6588) ◽  
pp. 252-255 ◽  
Author(s):  
Thomas Brashers-Krug ◽  
Reza Shadmehr ◽  
Emilio Bizzi
Keyword(s):  
Motor Memory ◽  
Human Motor

Chediak-Higashi syndrome with cerebellar cortical atrophy detected by MRI

2008 ◽  
Vol 46 (6) ◽  
pp. 439-440 ◽  
Author(s):  
Naomi Kondo ◽  
Nobuyuki Shimozawa ◽  
Junichi Asano ◽  
Atsushi Imamura ◽  
Tadao Orii
Keyword(s):  
Cortical Atrophy ◽  
Chediak Higashi Syndrome ◽  
Cerebellar Cortical Atrophy

scholarly journals The Cerebellar Serotoninergic System and its Possible Involvement in Cerebellar Ataxia

1993 ◽  
Vol 20 (S3) ◽  
pp. S78-S82 ◽  
Author(s):  
P. Trouillas
Keyword(s):  
Cerebellar Ataxia ◽  
Purkinje Cells ◽  
Molecular Layer ◽  
Cortical Atrophy ◽  
Target Cells ◽  
Serotoninergic System ◽  
Synaptic Connections ◽  
Cerebellar Syndrome ◽  
Cerebellar Cortical Atrophy ◽  
The Brain

ABSTRACT:A review concerning the characteristics of the cerebellar serotoninergic system is presented. In rat, cat and oppossum, the perikarya of origin are located in the brain stem raphe nuclei and in other brainstem structures. The projections to the cerebellar layers and deep nuclei include synaptic connections, but also non synaptic terminals, espedaily in a diffuse cortical plexus. Serotoninergic receptors have been described: 5-HT1B in the molecular layer and 5-HT2 in the inferior olive. Serotonin exerts neurophysiological effects on several target cells, directly or indirectly, presynaptically or postsynaptically. A modulatory effect on Purkinje cells is well documented. In thiamine deprived animals, a specific serotoninergic cerebellar syndrome includes a selective degeneration of the serotoninergic cerebellar system, an increase of the 5-HIAA cerebellar values and an exaggerated serotoninergic turnover. In human here-doataxias (Friedreich’s ataxia and cerebellar cortical atrophy), serotoninergic disturbances have been observed in the CSF, including low 5-HIAA values and an increased serotoninergic turnover. Therapeutic results have been obtained with L-5-HTP, a precursor of serotonin, in several conditions presenting cerebellar ataxia. L-5-HTP resistance of olivo-pontocerebellar atrophies may be explained by the destruction of serotonin-sensitive target cells, especially Purkinje cells.

scholarly journals Neural Basis for the Processes That Underlie Visually Guided and Internally Guided Force Control in Humans

2003 ◽  
Vol 90 (5) ◽  
pp. 3330-3340 ◽  
Author(s):  
David E. Vaillancourt ◽  
Keith R. Thulborn ◽  
Daniel M. Corcos
Keyword(s):  
Prefrontal Cortex ◽  
Visual Feedback ◽  
Visual Information ◽  
Grip Force ◽  
Transformation Process ◽  
Anterior Cingulate ◽  
Motor Memory ◽  
Visually Guided ◽  
Visuomotor Transformation ◽  
Neural Basis

Despite an intricate understanding of the neural mechanisms underlying visual and motor systems, it is not completely understood in which brain regions humans transfer visual information into motor commands. Furthermore, in the absence of visual information, the retrieval process for motor memory information remains unclear. We report an investigation where visuomotor and motor memory processes were separated from only visual and only motor activation. Subjects produced precision grip force during a functional MRI (fMRI) study that included four conditions: rest, grip force with visual feedback, grip force without visual feedback, and visual feedback only. Statistical and subtractive logic analyses segregated the functional process maps. There were three important observations. First, along with the well-established parietal and premotor cortical network, the anterior prefrontal cortex, putamen, ventral thalamus, lateral cerebellum, intermediate cerebellum, and the dentate nucleus were directly involved in the visuomotor transformation process. This activation occurred despite controlling for the visual input and motor output. Second, a detailed topographic orientation of visuomotor to motor/sensory activity was mapped for the premotor cortex, parietal cortex, and the cerebellum. Third, the retrieval of motor memory information was isolated in the dorsolateral prefrontal cortex, ventral prefrontal cortex, and anterior cingulate. The motor memory process did not extend to the supplementary motor area (SMA) and the basal ganglia. These findings provide evidence in humans for a model where a distributed network extends over cortical and subcortical regions to control the visuomotor transformation process used during visually guided tasks. In contrast, a localized network in the prefrontal cortex retrieves force output from memory during internally guided actions.

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