Patterns of Modulation in the Activity and Connectivity of Motor Cortex during the Repeated Generation of Movement Sequences

2015 ◽  
Vol 27 (4) ◽  
pp. 736-751 ◽  
Author(s):  
Ella Gabitov ◽  
David Manor ◽  
Avi Karni
Keyword(s):  
Motor Cortex ◽  
Primary Motor Cortex ◽  
Brain Activity ◽  
Rest Interval ◽  
Movement Sequences ◽  
Signal Change ◽  
Average Signal Intensity ◽  
Movement Sequence ◽  
Sequence Representation ◽  
Motor Representations

It is not clear how the engagement of motor mnemonic processes is expressed in online brain activity. We scanned participants, using fMRI, during the paced performance of a finger-to-thumb opposition sequence (FOS), intensively trained a day earlier (T-FOS), and a similarly constructed, but novel, untrained FOS (U-FOS). Both movement sequences were performed in pairs of blocks separated by a brief rest interval (30 sec). We have recently shown that in the primary motor cortex (M1) motor memory was not expressed in the average signal intensity but rather in the across-block signal modulations, that is, when comparing the first to the second performance block across the brief rest interval. Here, using an M1 seed, we show that for the T-FOS, the M1–striatum functional connectivity decreased across blocks; however, for the U-FOS, connectivity within the M1 and between M1 and striatum increased. In addition, in M1, the pattern of within-block signal change, but not signal variability per se, reliably differentiated the two sequences. Only for the U-FOS and only within the first blocks in each pair, the signal significantly decreased. No such modulation was found within the second corresponding blocks following the brief rest interval in either FOS. We propose that a network including M1 and striatum underlies online motor working memory. This network may promote a transient integrated representation of a new movement sequence and readily retrieves a previously established movement sequence representation. Averaging over single events or blocks may not capture the dynamics of motor representations that occur over multiple timescales.

scholarly journals Mapping Human Laryngeal Motor Cortex during Vocalization

2020 ◽  
Vol 30 (12) ◽  
pp. 6254-6269 ◽  
Author(s):  
Nicole Eichert ◽  
Daniel Papp ◽  
Rogier B Mars ◽  
Kate E Watkins
Keyword(s):  
Motor Cortex ◽  
Primary Motor Cortex ◽  
Brain Activity ◽  
Premotor Cortex ◽  
Neural Representation ◽  
Functional Magnetic Resonance ◽  
Human Larynx ◽  
Motor Representations ◽  
Quantitative Neuroimaging ◽  
Hand Area

Abstract The representations of the articulators involved in human speech production are organized somatotopically in primary motor cortex. The neural representation of the larynx, however, remains debated. Both a dorsal and a ventral larynx representation have been previously described. It is unknown, however, whether both representations are located in primary motor cortex. Here, we mapped the motor representations of the human larynx using functional magnetic resonance imaging and characterized the cortical microstructure underlying the activated regions. We isolated brain activity related to laryngeal activity during vocalization while controlling for breathing. We also mapped the articulators (the lips and tongue) and the hand area. We found two separate activations during vocalization—a dorsal and a ventral larynx representation. Structural and quantitative neuroimaging revealed that myelin content and cortical thickness underlying the dorsal, but not the ventral larynx representation, are similar to those of other primary motor representations. This finding confirms that the dorsal larynx representation is located in primary motor cortex and that the ventral one is not. We further speculate that the location of the ventral larynx representation is in premotor cortex, as seen in other primates. It remains unclear, however, whether and how these two representations differentially contribute to laryngeal motor control.

scholarly journals Mapping human laryngeal motor cortex during vocalization

2020 ◽  
Author(s):  
Nicole Eichert ◽  
Daniel Papp ◽  
Rogier B. Mars ◽  
Kate E. Watkins
Keyword(s):  
Motor Control ◽  
Motor Cortex ◽  
Primary Motor Cortex ◽  
Brain Activity ◽  
Premotor Cortex ◽  
Neural Representation ◽  
Human Larynx ◽  
Motor Representations ◽  
Quantitative Neuroimaging ◽  
Hand Area

AbstractThe representations of the articulators involved in human speech production are organized somatotopically in primary motor cortex. The neural representation of the larynx, however, remains debated. Both a dorsal and a ventral larynx representation have been previously described. It is unknown, however, whether both representations are located in primary motor cortex. Here, we mapped the motor representations of the human larynx using fMRI and characterized the cortical microstructure underlying the activated regions. We isolated brain activity related to laryngeal activity during vocalization while controlling for breathing. We also mapped the articulators (the lips and tongue) and the hand area. We found two separate activations during vocalization – a dorsal and a ventral larynx representation. Structural and quantitative neuroimaging revealed that myelin content and cortical thickness underlying the dorsal, but not the ventral larynx representation, are similar to those of other primary motor representations. This finding confirms that the dorsal larynx representation is located in primary motor cortex and that the ventral one is not. We further speculate that the location of the ventral larynx representation is in premotor cortex, as seen in other primates. It remains unclear, however, whether and how these two representations differentially contribute to laryngeal motor control.

Abnormal dynamic brain activity and functional connectivity of primary motor cortex in blepharospasm

2021 ◽  
Author(s):  
Yuhan Luo ◽  
Yaomin Guo ◽  
Linchang Zhong ◽  
Ying Liu ◽  
Chao Dang ◽  
...  
Keyword(s):  
Functional Connectivity ◽  
Motor Cortex ◽  
Primary Motor Cortex ◽  
Brain Activity

scholarly journals Relationship between Finger Movement Rate and Functional Magnetic Resonance Signal Change in Human Primary Motor Cortex

1996 ◽  
Vol 16 (6) ◽  
pp. 1250-1254 ◽  
Author(s):  
S. M. Rao ◽  
P. A. Bandettini ◽  
J. R. Binder ◽  
J. A. Bobholz ◽  
T. A. Hammeke ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Motor Cortex ◽  
Primary Motor Cortex ◽  
Stimulus Presentation ◽  
Functional Magnetic Resonance ◽  
Movement Rate ◽  
Noninvasive Technique ◽  
Movement Rates ◽  
Signal Change ◽  
Flexion Extension

Functional magnetic resonance imaging (FMRI) is a noninvasive technique for mapping regional brain changes in response to sensory, motor, or cognitive activation tasks. Interpretation of these activation experiments may be confounded by more elementary task parameters, such as stimulus presentation or movement rates. We examined the effect of movement rate on the FMRI response recorded from the contralateral primary motor cortex. Four right-handed healthy subjects performed flexion-extension movements of digits 2–5 of the right hand at rates of 1, 2, 3, 4, or 5 Hz. Results of this study indicated a positive linear relationship between movement rate and FMRI signal change. Additionally, the number of voxels demonstrating functional activity increased significantly with faster movement rates. The magnitude of the signal change at each movement rate remained constant over the course of three 8-min scanning series. These findings are similar to those of previous rate studies of the visual and auditory system performed with positron emission tomography (PET) and FMRI.

Functional Connectivity Between Secondary and Primary Motor Areas Underlying Hand–Foot Coordination

2007 ◽  
Vol 98 (1) ◽  
pp. 414-422 ◽  
Author(s):  
Winston D. Byblow ◽  
James P. Coxon ◽  
Cathy M. Stinear ◽  
Melanie K. Fleming ◽  
Garry Williams ◽  
...  
Keyword(s):  
Functional Connectivity ◽  
Motor Cortex ◽  
Muscle Activation ◽  
Primary Motor Cortex ◽  
Premotor Cortex ◽  
Hand Movement ◽  
Physiological Basis ◽  
Activation Conditions ◽  
Motor Representations ◽  
Motor Areas

Coincident hand and foot movements are more reliably performed in the same direction than in opposite directions. Using transcranial magnetic stimulation (TMS) to assess motor cortex function, we examined the physiological basis of these movements across three novel experiments. Experiment 1 demonstrated that upper limb corticomotor excitability changed in a way that facilitated isodirectional movements of the hand and foot, during phasic and isometric muscle activation conditions. Experiment 2 demonstrated that motor cortex inhibition was modified with active, but not passive, foot movement in a manner that facilitated hand movement in the direction of foot movement. Together, these findings demonstrate that the coupling between motor representations within motor cortex is activity dependent. Because there are no known connections between hand and foot areas within primary motor cortex, experiment 3 used a dual-coil paired-pulse TMS protocol to examine functional connectivity between secondary and primary motor areas during active ankle dorsiflexion and plantarflexion. Dorsal premotor cortex (PMd) and supplementary motor area (SMA) conditioning, but not ventral premotor cortex (PMv) conditioning, produced distinct phases of task-dependent modulation of excitability of forearm representations within primary motor cortex (M1). Networks involving PMd–M1 facilitate isodirectional movements of hand and foot, whereas networks involving SMA–M1 facilitate corticomotor pathways nonspecifically, which may help to stabilize posture during interlimb coordination. These results may have implications for targeted neurorehabilitation after stroke.

Facilitation From Ventral Premotor Cortex of Primary Motor Cortex Outputs to Macaque Hand Muscles

2003 ◽  
Vol 90 (2) ◽  
pp. 832-842 ◽  
Author(s):  
G. Cerri ◽  
H. Shimazu ◽  
M. A. Maier ◽  
R. N. Lemon
Keyword(s):  
Motor Cortex ◽  
Primary Motor Cortex ◽  
Premotor Cortex ◽  
Macaque Monkey ◽  
Hand Muscles ◽  
Ventral Premotor Cortex ◽  
Cortex Area ◽  
Light Sedation ◽  
Cortical Inputs ◽  
Motor Representations

We demonstrate that in the macaque monkey there is robust, short-latency facilitation by ventral premotor cortex (area F5) of motor outputs from primary motor cortex (M1) to contralateral intrinsic hand muscles. Experiments were carried out on two adult macaques under light sedation (ketamine plus medetomidine HCl). Facilitation of hand muscle electromyograms (EMG) was tested using arrays of fine intracortical microwires implanted, respectively, in the wrist/digit motor representations of F5 and M1, which were identified by previous mapping with intracortical microstimulation. Single pulses (70–200 μA) delivered to F5 microwires never evoked any EMG responses, but small responses were occasionally seen with double pulses (interval: 3 ms) at high intensity. However, both single- and double-pulse stimulation of F5 could facilitate the EMG responses evoked from M1 by single shocks. The facilitation was large (up to 4-fold with single and 12-fold with double F5 shocks) and occurred with an early onset, with significant effects at intervals of only 1–2 ms between conditioning F5 and test M1 stimuli. A number of possible pathways could be responsible for these effects, although it is argued that the most likely mechanism would be the facilitation, by cortico-cortical inputs from F5, of corticospinal I wave activity evoked from M1. This facilitatory action could be of considerable importance for the coupling of grasp-related neurons in F5 and M1 during visuomotor tasks.

scholarly journals Importance of the Primary Motor Cortex in Development of Human Hand/Finger Dexterity

2020 ◽  
Vol 1 (1) ◽  
Author(s):  
Eiichi Naito ◽  
Tomoyo Morita ◽  
Minoru Asada
Keyword(s):  
Motor Cortex ◽  
Active Control ◽  
Primary Motor Cortex ◽  
Brain Activity ◽  
Individual Performance ◽  
Motor Tasks ◽  
Related Activity ◽  
Finger Dexterity ◽  
Right Hand ◽  
Neuronal Inhibition

Abstract Hand/finger dexterity is well-developed in humans, and the primary motor cortex (M1) is believed to play a particularly important role in it. Here, we show that efficient recruitment of the contralateral M1 and neuronal inhibition of the ipsilateral M1 identified by simple hand motor and proprioceptive tasks are related to hand/finger dexterity and its ontogenetic development. We recruited healthy, right-handed children (n = 21, aged 8–11 years) and adults (n = 23, aged 20–26 years) and measured their brain activity using functional magnetic resonance imaging during active and passive right-hand extension–flexion tasks. We calculated individual active control-related activity (active–passive) to evaluate efficient brain activity recruitment and individual task-related deactivation (neuronal inhibition) during both tasks. Outside the scanner, participants performed 2 right-hand dexterous motor tasks, and we calculated the hand/finger dexterity index (HDI) based on their individual performance. Participants with a higher HDI exhibited less active control-related activity in the contralateral M1 defined by the active and passive tasks, independent of age. Only children with a higher HDI exhibited greater ipsilateral M1 deactivation identified by these tasks. The results imply that hand/finger dexterity can be predicted by recruitment and inhibition styles of the M1 during simple hand sensory–motor tasks.

scholarly journals Cortical activation associated with motor preparation can be used to predict the freely chosen effector of an upcoming movement and reflects response time: An fMRI decoding study

2018 ◽  
Author(s):  
Satoshi Hirose ◽  
Isao Nambu ◽  
Eiichi Naito
Keyword(s):  
Response Time ◽  
Primary Motor Cortex ◽  
Response Times ◽  
Brain Activity ◽  
Premotor Cortex ◽  
Brain Regions ◽  
Cortical Activation ◽  
List Type ◽  
Action Execution ◽  
Motor Representations

AbstractMotor action is prepared in the human brain for rapid initiation at the appropriate time. Recent non-invasive decoding techniques have shown that brain activity for action preparation represents various parameters of an upcoming action. In the present study, we demonstrated that a freely chosen effector can be predicted from brain activity measured using functional magnetic resonance imaging (fMRI) before initiation of the action. Furthermore, the activity was related to response time (RT). We measured brain activity with fMRI while 12 participants performed a finger-tapping task using either the left or right hand, which was freely chosen by them. Using fMRI decoding, we identified brain regions in which activity during the preparatory period could predict the hand used for the upcoming action. We subsequently evaluated the relationship between brain activity and the RT of the upcoming action to determine whether correct decoding was associated with short RT. We observed that activity in the supplementary motor area, dorsal premotor cortex, and primary motor cortex measured before action execution predicted the hand used to perform the action with significantly above-chance accuracy (approximately 70%). Furthermore, in most participants, the RT was shorter in trials for which the used hand was correctly predicted. The present study showed that preparatory activity in cortical motor areas represents information about the effector used for an upcoming action, and that well-formed motor representations in these regions are associated with reduced response times.HighlightsBrain activity measured by fMRI was used to predict freely chosen effectors.M1/PMd and SMA activity predicted the effector hand prior to action initiation.Response time was shorter in trials in which effector hand was correctly predicted.Freely chosen action is represented in the M1/PMd and SMA.Well-formed preparatory motor representations lead to reduced response time.

Motor Function

2017 ◽  
pp. 252-261
Author(s):  
Riitta Hari ◽  
Aina Puce
Keyword(s):  
Motor Cortex ◽  
Motor Function ◽  
Primary Motor Cortex ◽  
Brain Activity ◽  
Surface Emg ◽  
Eeg Signals ◽  
The Voice ◽  
Premotor Areas ◽  
Readiness Field ◽  
Muscle Coherence

Voluntary movements are preceded by slow brain activity, visible in EEG as the Bereitschaftspotential (the readiness potential), and in MEG as the readiness field. These slow shifts can begin a few seconds before movement onset in the primary motor cortex and in the premotor areas. Cortex–muscle coherence refers to coupling between MEG/EEG signals and the surface EMG of a steadily contracted muscle; it typically occurs at around 20 Hz and implies an efferent drive from the cortex to the muscle. Corticokinematic coherence can be measured as the coupling between MEG/EEG signals and the acceleration or velocity of a rhythmically moving limb; it typically occurs are the movement frequency and its first harmonic. Coherence of MEG/EEG signals can be computed also with respect to other peripheral signals, such as the fundamental frequency of the voice measured with an accerometer above the subject’s throat.

scholarly journals Spatially and Temporally Distinct Encoding of Muscle and Kinematic Information in Rostral and Caudal Primary Motor Cortex

2020 ◽  
Vol 1 (1) ◽  
Author(s):  
James Kolasinski ◽  
Diana C Dima ◽  
David M A Mehler ◽  
Alice Stephenson ◽  
Sara Valadan ◽  
...  
Keyword(s):  
Motor Cortex ◽  
Primary Motor Cortex ◽  
Imaging Data ◽  
Top Down ◽  
Human Motor Cortex ◽  
Electrophysiological Recordings ◽  
Human Motor ◽  
Sensory Responses ◽  
Motor Representations ◽  
Kinematic Information

Abstract The organizing principle of human motor cortex does not follow an anatomical body map, but rather a distributed representational structure in which motor primitives are combined to produce motor outputs. Electrophysiological recordings in primates and human imaging data suggest that M1 encodes kinematic features of movements, such as joint position and velocity. However, M1 exhibits well-documented sensory responses to cutaneous and proprioceptive stimuli, raising questions regarding the origins of kinematic motor representations: are they relevant in top-down motor control, or are they an epiphenomenon of bottom-up sensory feedback during movement? Here we provide evidence for spatially and temporally distinct encoding of kinematic and muscle information in human M1 during the production of a wide variety of naturalistic hand movements. Using a powerful combination of high-field functional magnetic resonance imaging and magnetoencephalography, a spatial and temporal multivariate representational similarity analysis revealed encoding of kinematic information in more caudal regions of M1, over 200 ms before movement onset. In contrast, patterns of muscle activity were encoded in more rostral motor regions much later after movements began. We provide compelling evidence that top-down control of dexterous movement engages kinematic representations in caudal regions of M1 prior to movement production.

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