scholarly journals Activation of Cortical and Cerebellar Motor Areas during Executed and Imagined Hand Movements: An fMRI Study

1999 ◽  
Vol 11 (5) ◽  
pp. 491-501 ◽  
Author(s):  
Martin Lotze ◽  
Pedro Montoya ◽  
Michael Erb ◽  
Ernst Hülsmann ◽  
Herta Flor ◽  
...  
Keyword(s):  
Primary Motor Cortex ◽  
Premotor Cortex ◽  
Neural Substrates ◽  
Anterior Lobe ◽  
Emg Activity ◽  
Cerebral Activation ◽  
Left Hand ◽  
Fmri Study ◽  
The Right ◽  
Flexor Digitorum

Brain activation during executed (EM) and imagined movements (IM) of the right and left hand was studied in 10 healthy right-handed subjects using functional magnetic resonance imagining (fMRI). Low electromyographic (EMG) activity of the musculi flexor digitorum superficialis and high vividness of the imagined movements were trained prior to image acquisition. Regional cerebral activation was measured by fMRI during EM and IM and compared to resting conditions. Anatomically selected regions of interest (ROIs) were marked interactively over the entire brain. In each ROI activated pixels above a t value of 2.45 (p < 0.01) were counted and analyzed. In all subjects the supplementary motor area (SMA), the premotor cortex (PMC), and the primary motor cortex (M1) showed significant activation during both EM and IM; the somatosensory cortex (S1) was significantly activated only during EM. Ipsilateral cerebellar activation was decreased during IM compared to EM. In the cerebellum, IM and EM differed in their foci of maximal activation: Highest ipsilateral activation of the cerebellum was observed in the anterior lobe (Larsell lobule H IV) during EM, whereas a lower maximum was found about 2-cm dorsolateral (Larsell lobule H VII) during IM. The prefrontal and parietal regions revealed no significant changes during both conditions. The results of cortical activity support the hypothesis that motor imagery and motor performance possess similar neural substrates. The differential activation in the cerebellum during EM and IM is in accordance with the assumption that the posterior cerebellum is involved in the inhibition of movement execution during imagination.

Differential Fronto-Parietal Activation Depending on Force Used in a Precision Grip Task: An fMRI Study

2001 ◽  
Vol 85 (6) ◽  
pp. 2613-2623 ◽  
Author(s):  
H. Henrik Ehrsson ◽  
Anders Fagergren ◽  
Hans Forssberg
Keyword(s):  
Primary Motor Cortex ◽  
Premotor Cortex ◽  
Precision Grip ◽  
Parietal Lobes ◽  
Cingulate Motor Area ◽  
Fmri Study ◽  
Small Force ◽  
Tactile Cues ◽  
The Right ◽  
Precision Grips

Recent functional magnetic resonance imaging (fMRI) studies suggest that the control of fingertip forces between the index finger and the thumb (precision grips) is dependent on bilateral frontal and parietal regions in addition to the primary motor cortex contralateral to the grasping hand. Here we use fMRI to examine the hypothesis that some of the areas of the brain associated with precision grips are more strongly engaged when subjects generate small grip forces than when they employ large grip forces. Subjects grasped a stationary object using a precision grip and employed a small force (3.8 N) that was representative of the forces that are typically used when manipulating small objects with precision grips in everyday situations or a large force (16.6 N) that represents a somewhat excessive force compared with normal everyday usage. Both force conditions involved the generation of time-variant static and dynamic grip forces under isometric conditions guided by auditory and tactile cues. The main finding was that we observed stronger activity in the bilateral cortex lining the inferior part of the precentral sulcus (area 44/ventral premotor cortex), the rostral cingulate motor area, and the right intraparietal cortex when subjects applied a small force in comparison to when they generated a larger force. This observation suggests that secondary sensorimotor related areas in the frontal and parietal lobes play an important role in the control of fine precision grip forces in the range typically used for the manipulation of small objects.

scholarly journals Motor Cortical Activity During Drawing Movements: Population Representation During Spiral Tracing

1999 ◽  
Vol 82 (5) ◽  
pp. 2693-2704 ◽  
Author(s):  
Daniel W. Moran ◽  
Andrew B. Schwartz
Keyword(s):  
Motor Cortex ◽  
Primary Motor Cortex ◽  
Prediction Interval ◽  
Premotor Cortex ◽  
Cortical Activity ◽  
Simultaneous Action ◽  
Emg Activity ◽  
Radius Of Curvature ◽  
Time Interval ◽  
Population Vector

Monkeys traced spirals on a planar surface as unitary activity was recorded from either premotor or primary motor cortex. Using the population vector algorithm, the hand's trajectory could be accurately visualized with the cortical activity throughout the task. The time interval between this prediction and the corresponding movement varied linearly with the instantaneous radius of curvature; the prediction interval was longer when the path of the finger was more curved (smaller radius). The intervals in the premotor cortex fell into two groups, whereas those in the primary motor cortex formed a single group. This suggests that the change in prediction interval is a property of a single population in primary motor cortex, with the possibility that this outcome is due to the different properties generated by the simultaneous action of separate subpopulations in premotor cortex. Electromyographic (EMG) activity and joint kinematics were also measured in this task. These parameters varied harmonically throughout the task with many of the same characteristics as those of single cortical cells. Neither the lags between joint-angular velocities and hand velocity nor the lags between EMG and hand velocity could explain the changes in prediction interval between cortical activity and hand velocity. The simple spatial and temporal relationship between cortical activity and finger trajectory suggests that the figural aspects of this task are major components of cortical activity.

Bilateral Opponens Replacement in Post Polio Thenar Paralysis, Using Different Techniques. A Case Report.

HAND ◽  
1983 ◽  
Vol os-15 (2) ◽  
pp. 221-222 ◽  
Author(s):  
J. G. Andersen ◽  
J. W. Brandsma
Keyword(s):  
Case Report ◽  
Ring Finger ◽  
Flexor Digitorum Superficialis ◽  
Left Hand ◽  
Right Hand ◽  
Abductor Digiti Minimi ◽  
The Right ◽  
Flexor Digitorum

A patient is presented with bilateral thenar paralysis, due to poliomyelitis. On the right hand a successful abductor digiti minimi transfer was performed. On the left hand weakness of the hypothenar muscles prevented a good result. Subsequently an opponens replacement, using flexor digitorum superficialis from the ring finger, yielded a good result.

Neural Responses to Human Voice and Hemisphere Dominance for Lexical-semantic Processing

2007 ◽  
Vol 46 (02) ◽  
pp. 247-250 ◽  
Author(s):  
H. Takahashi ◽  
N. Yahata ◽  
M. Matsuura ◽  
K. Asai ◽  
Y. Okubo ◽  
...  
Keyword(s):  
Healthy Subjects ◽  
Semantic Processing ◽  
Hemispheric Dominance ◽  
Cerebral Activation ◽  
Voice Perception ◽  
Lexical Semantic ◽  
Human Voice ◽  
Fmri Study ◽  
The Right ◽  
Parietal Cortices

Summary Objectives : In our previous functional magnetic resonance imaging (fMRI) study, we determined that there was distinct left hemispheric dominance for lexical- semantic processing without the influence of human voice perception in right-handed healthy subjects. However, the degree of right-handedness in the right-handed subjects ranged from 52 to 100 according to the Edinburgh Handedness Inventory (EHI) score. In the present study, we aimed to clarify the correlation between the degree of right-handedness and language dominance in the fronto-temporo-parietal cortices by examining cerebral activation for lexical-semantic processing. Methods : Twenty-seven normal right-handed healthy subjects were scanned by fMRI while listening to sentences (SEN), reverse sentences (rSEN), and identifiable non-vocal sounds (SND). Fronto-temporo-parietal activation was observed in the left hemisphere under the SEN - rSEN contrast, which included lexical- semantic processing without the influence of human voice perception. Laterality Indexwas calculated as LI = (L - R)/(L + R) X 100, L: left, R: right. Results : Laterality Index in the fronto-temporo-parietal cortices did not correlate with the degree of right-handedness in EHI score. Conclusions : The present study indicated that the degree of right-handedness from 52 to 100 in EHI score had no effect on the degree of left hemispheric dominance for lexical-semantic processing in right-handed healthy subjects.

Dominance of the Right Hemisphere and Role of Area 2 in Human Kinesthesia

2005 ◽  
Vol 93 (2) ◽  
pp. 1020-1034 ◽  
Author(s):  
Eiichi Naito ◽  
Per E. Roland ◽  
Christian Grefkes ◽  
H. J. Choi ◽  
Simon Eickhoff ◽  
...  
Keyword(s):  
Right Hemisphere ◽  
Anterior Part ◽  
Premotor Cortex ◽  
Superior Temporal Gyrus ◽  
Lateral Part ◽  
Left Hand ◽  
Hemisphere Dominance ◽  
The Right ◽  
Processus Styloideus ◽  
Motor Areas

We have previously shown that motor areas are engaged when subjects experience illusory limb movements elicited by tendon vibration. However, traditionally cytoarchitectonic area 2 is held responsible for kinesthesia. Here we use functional magnetic resonance imaging and cytoarchitectural mapping to examine whether area 2 is engaged in kinesthesia, whether it is engaged bilaterally because area 2 in non-human primates has strong callosal connections, which other areas are active members of the network for kinesthesia, and if there is a dominance for the right hemisphere in kinesthesia as has been suggested. Ten right-handed blindfolded healthy subjects participated. The tendon of the extensor carpi ulnaris muscles of the right or left hand was vibrated at 80 Hz, which elicited illusory palmar flexion in an immobile hand (illusion). As control we applied identical stimuli to the skin over the processus styloideus ulnae, which did not elicit any illusions (vibration). We found robust activations in cortical motor areas [areas 4a, 4p, 6; dorsal premotor cortex (PMD) and bilateral supplementary motor area (SMA)] and ipsilateral cerebellum during kinesthetic illusions (illusion-vibration). The illusions also activated contralateral area 2 and right area 2 was active in common irrespective of illusions of right or left hand. Right areas 44, 45, anterior part of intraparietal region (IP1) and caudo-lateral part of parietal opercular region (OP1), cortex rostral to PMD, anterior insula and superior temporal gyrus were also activated in common during illusions of right or left hand. These right-sided areas were significantly more activated than the corresponding areas in the left hemisphere. The present data, together with our previous results, suggest that human kinesthesia is associated with a network of active brain areas that consists of motor areas, cerebellum, and the right fronto-parietal areas including high-order somatosensory areas. Furthermore, our results provide evidence for a right hemisphere dominance for perception of limb movement.

scholarly journals Corticospinal mirror neurons

2014 ◽  
Vol 369 (1644) ◽  
pp. 20130174 ◽  
Author(s):  
A. Kraskov ◽  
R. Philipp ◽  
S. Waldert ◽  
G. Vigneswaran ◽  
M. M. Quallo ◽  
...  
Keyword(s):  
Mirror Neurons ◽  
Primary Motor Cortex ◽  
Mirror Neuron System ◽  
Action Observation ◽  
Premotor Cortex ◽  
Mirror Neuron ◽  
Considerable Proportion ◽  
Emg Activity ◽  
Cortex Area ◽  
Similar Range

Here, we report the properties of neurons with mirror-like characteristics that were identified as pyramidal tract neurons (PTNs) and recorded in the ventral premotor cortex (area F5) and primary motor cortex (M1) of three macaque monkeys. We analysed the neurons’ discharge while the monkeys performed active grasp of either food or an object, and also while they observed an experimenter carrying out a similar range of grasps. A considerable proportion of tested PTNs showed clear mirror-like properties (52% F5 and 58% M1). Some PTNs exhibited ‘classical’ mirror neuron properties, increasing activity for both execution and observation, while others decreased their discharge during observation (‘suppression mirror-neurons’). These experiments not only demonstrate the existence of PTNs as mirror neurons in M1, but also reveal some interesting differences between M1 and F5 mirror PTNs. Although observation-related changes in the discharge of PTNs must reach the spinal cord and will include some direct projections to motoneurons supplying grasping muscles, there was no EMG activity in these muscles during action observation. We suggest that the mirror neuron system is involved in the withholding of unwanted movement during action observation. Mirror neurons are differentially recruited in the behaviour that switches rapidly between making your own movements and observing those of others.

scholarly journals Effects of Congruency on Bereitschaftspotential While Performing a Bimanual Motor Task

2018 ◽  
Vol 9 (1) ◽  
pp. 63-79
Author(s):  
Meghan McGowan ◽  
Camille Hémond-Hill ◽  
Justine Nakazawa
Keyword(s):  
Reaction Time ◽  
Primary Motor Cortex ◽  
Brain Activity ◽  
Sensory Modality ◽  
Motor Task ◽  
Left Hand ◽  
Grand Average ◽  
Bimanual Task ◽  
Significant Difference ◽  
The Right

 The bereitschaftspotential (BP)—also known as the readiness potential—is a measure of brain activity that precedes voluntary movement by approximately one second in the supplementary motor area and the contralateral primary motor cortex. Motor task reaction time for bimanual task performance is affected by both the individual and the environment; however, it is unclear whether motor task reaction time (as measured via the BP) is significantly affected by congruency. A congruent motor task is an ipsilateral stimulus (e.g., a stimulus on the right is responded to by the right hand), and an incongruent task is a contralateral stimulus (e.g., a stimulus on the right is responded to by the left hand). Congruency is re-emerging as an important topic in motor learning as it may require different levels of cortical processing. The purpose of this study was to examine the effect of congruency on the BP. Participants were asked to complete the computer task, Keyboard Hero, where they pressed keys with both their left and right hands in response to discrete congruent and incongruent stimuli. A MUSE™  apparatus recorded brain activity 1000 ms prior to, and 1000 ms after each stimulus. Results from every participant for the incongruent and congruent trials were averaged and compared using a grand average waveform. Means of accuracy (how often participants pressed the key correctly) and BP for each condition were averaged and compared using a 95% Confidence Interval (CI). Across congruent and incongruent conditions, a non-significant difference (p > 0.05 ) was found in BP (p > 0.59 ), accuracy (p > 0.64 ), and BP within −200  ms to 200 ms (p > 0.31 ). BP and mean accuracy scores were not significantly different between congruent and incongruent conditions, which may be due to only minute differences in brain activity or due to the study’s design. Further research should analyze individual variations of the present study, such as stimulus location, differences in the responding limb, correctness of responses, and the sensory modality being tested

scholarly journals Microstimulation of dorsal premotor and primary motor cortex delays the volitional commitment to an action choice

2020 ◽  
Vol 123 (3) ◽  
pp. 927-935
Author(s):  
David Thura ◽  
Paul Cisek
Keyword(s):  
Motor Cortex ◽  
Neural Activity ◽  
Primary Motor Cortex ◽  
Premotor Cortex ◽  
Neural Substrates ◽  
Daily Basis ◽  
Decision Task ◽  
Movement Initiation ◽  
Deliberation Process ◽  
The Moment

Humans and other animals are faced with decisions about actions on a daily basis. These typically include a period of deliberation that ends with the commitment to a choice, which then leads to the overt expression of that choice through action. Previous studies with monkeys have demonstrated that neural activity in sensorimotor areas correlates with the deliberation process and reflects the moment of commitment before movement initiation, but the causal roles of these regions are challenging to establish. Here, we tested whether dorsal premotor (PMd) and primary motor cortex (M1) are causally involved in the volitional commitment to a reaching choice. We found that brief subthreshold microstimulation in PMd or M1 delayed commitment to an action but not the initiation of the action itself. Importantly, microstimulation only had a significant effect when it was delivered close to and before commitment time. These results are consistent with the proposal that PMd and M1 participate in the commitment process, which occurs when a critical firing rate difference is reached between cells voting for the selected option and those voting for the competing one. NEW & NOTEWORTHY The neural substrates of decisions between actions are typically investigated by correlating neural activity and subjects’ decision behavior, but this does not establish causality. In a reaching decision task, we demonstrate that subthreshold microstimulation of the monkey dorsal premotor cortex or primary motor cortex delays the deliberation duration if applied shortly before choice commitment. This result suggests a causal role of the sensorimotor cortex in the determination of decisions between actions.

scholarly journals Surface-based Map Plasticity of the Sensorimotor Cortex in Hip Disorder at Local and Extensive Levels: A Resting-state fMRI Study

2020 ◽  
Author(s):  
Jie Ma ◽  
Xu-Yun Hua ◽  
Mou-Xiong Zheng ◽  
Jia-Jia Wu ◽  
Bei-Bei Huo ◽  
...  
Keyword(s):  
Motor Cortex ◽  
Cortical Thickness ◽  
Resting State ◽  
Primary Motor Cortex ◽  
Premotor Cortex ◽  
Frontal Eye Field ◽  
Healthy Controls ◽  
Eye Field ◽  
Somatotopic Map ◽  
The Right

Abstract Background: Pain is one of the manifestations of hip disorder and has been proven to lead to the remodeling of somatotopic map plasticity in the cortex. However, it’s not clear whether hip disorder with pain induces somatotopic map plasticity in the cortex. We aimed to evaluate the surface-based map plasticity of the somatotopic cortex in hip disorder at local and extensive levels by resting-state functional magnetic resonance imaging (rs-fMRI).Methods: 20 patients with osteonecrosis of the femoral head (ONFH) (12 males and 8 females, age= 56.80±13.60 years) with Visual Analogue Scale (VAS) scores ≥ 4 and 20 healthy controls (9 males and 11 females, age= 54.56±10.23 years) were enrolled in this study. rs-fMRI data and T1 imaging data were collected, and surface-based regional homogeneity (ReHo), seed-based functional connectivity (FC), cortical thickness and the volume of subcortical gray nuclei were calculated.Results: Compared with the healthy controls, the ONFH patients showed significantly increased surface-based ReHo in areas distributed mainly in the left dorsolateral prefrontal cortex and frontal eye field, the right frontal eye field and the premotor cortex and decreased surface-based ReHo in the right primary motor cortex and primary sensory cortex. When the area with decreased surface-based ReHo in the frontal eye field and right premotor cortex was used as the regions of interest (ROI), compared with the controls, the ONFH patients displayed increased FC in the right middle frontal cortex and right inferior parietal cortex and decreased FC in the right precentral cortex and right middle occipital cortex. ONFH patients also showed significantly decreased cortical thickness in the para-insular area, supplementary motor cortex area and frontal eye field and decreased volume of subcortical gray matter nuclei in the right nucleus accumbens (479.32±88.26 vs 539.44±68.36, P=0.026). Conclusions: Hip disorder patients showed cortical plasticity changes, mainly in sensorimotor and pain-related regions.

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