scholarly journals Uncertainty in contextual and kinematic cues jointly modulate motor resonance in primary motor cortex

2018 ◽  
Author(s):  
Andreea Loredana Cretu ◽  
Kathy Ruddy ◽  
Maria Germann ◽  
Nicole Wenderoth
Keyword(s):  
Motor Cortex ◽  
Neural Activity ◽  
Primary Motor Cortex ◽  
Contextual Information ◽  
Single Pulse ◽  
Contextual Cues ◽  
Motor Resonance ◽  
Corticomotor Excitability ◽  
Movement Observation ◽  
Motor Representations

ABSTRACTContextual information accompanying others’ actions modulates “motor resonance”, i.e. neural activity within motor areas that is elicited by movement observation. One possibility is that we weight and combine such information in a Bayesian manner according to their relative uncertainty. Therefore, contextual information becomes particularly useful when others’ actions are ambiguous. It is unclear, however, whether this uncertainty modulates the neural activity in primary motor cortex (M1) during movement observation. Here we applied single-pulse transcranial magnetic stimulation (TMS) while subjects watched different grasping actions. We operationalized motor resonance as grip specific modulation of corticomotor excitability measured in the index (FDI) versus the little finger abductor (ADM). We experimentally modulated either the availability of kinematic information (Exp. 1) or the reliability of contextual cues (Exp. 2). Our results indicate that even in the absence of movement kinematics, reliable contextual information is enough to trigger significant muscle-specific corticomotor excitability changes in M1 (p<.0001) which are strongest when both kinematics and contextual information are available (p<.005). These findings suggest that bottom-up mechanisms that activate motor representations as a function of the observed kinematics, and top-down mechanisms which activate motor representations associated with arbitrary cues converge in M1 in a statistically optimal manner.

scholarly journals Uncertainty in contextual and kinematic cues jointly modulates motor resonance in primary motor cortex

2019 ◽  
Vol 121 (4) ◽  
pp. 1451-1464 ◽  
Author(s):  
Andreea Loredana Cretu ◽  
Kathy Ruddy ◽  
Maria Germann ◽  
Nicole Wenderoth
Keyword(s):  
Motor Cortex ◽  
Neural Activity ◽  
Primary Motor Cortex ◽  
Contextual Information ◽  
Action Observation ◽  
Motor Resonance ◽  
Movement Kinematics ◽  
Corticomotor Excitability ◽  
Movement Observation ◽  
Motor Representations

Contextual information accompanying others’ actions modulates “motor resonance”, i.e., neural activity within motor areas that is elicited by movement observation. One possibility is that we weigh and combine such information in a Bayesian manner according to their relative uncertainty. Therefore, contextual information becomes particularly useful when others’ actions are difficult to discriminate. It is unclear, however, whether this uncertainty modulates the neural activity in primary motor cortex (M1) during movement observation. Here, we applied single-pulse transcranial magnetic stimulation (TMS) while subjects watched different grasping actions. We operationalized motor resonance as grip-specific modulation of corticomotor excitability measured in the index (FDI) versus the little finger abductor (ADM). We experimentally modulated either the availability of kinematic information ( experiment 1) or the reliability of contextual cues ( experiment 2). Our results indicate that even in the absence of movement kinematics, reliable contextual information is enough to trigger significant muscle-specific corticomotor excitability changes in M1, which are strongest when both kinematics and contextual information are available. These findings suggest that bottom-up mechanisms that activate motor representations as a function of the observed kinematics and top-down mechanisms that activate motor representations associated with arbitrary cues converge in M1. NEW & NOTEWORTHY Our study reveals new neurophysiological insights in support of the Bayesian account of action observation by showing that “motor resonance”, i.e., neural activity evoked by observing others’ actions, incorporates the uncertainty related to both contextual (prior beliefs) and kinematic (sensory evidence) cues. Notably, we show that muscle-specific modulation of M1 is strongest when context and movement kinematics are available, and it can be elicited even in the absence of movement kinematics.

scholarly journals Reward modulates behaviour and neural responses in motor cortex during action observation

2019 ◽  
Author(s):  
Andreea Loredana Cretu ◽  
Rea Lehner ◽  
Rafael Polania ◽  
Nicole Wenderoth
Keyword(s):  
Motor Cortex ◽  
Primary Motor Cortex ◽  
Response Times ◽  
Contextual Information ◽  
Action Observation ◽  
Neural Responses ◽  
Motor Resonance ◽  
Neural Representations ◽  
Attentional Engagement ◽  
Physiological Outcomes

AbstractTranscranial magnetic stimulation (TMS) studies demonstrated that observing the actions of other individuals leads to action-specific facilitation of primary motor cortex (M1) (i.e., “motor resonance”). Motor resonance is modulated by contextual information accompanying others’ actions, however, it is currently unknown whether action value influences behavioural and physiological outcomes during action observation in humans. Here we tested whether response times (RT) and muscle-specific changes of M1 excitability are modulated by the value an observer assigns to the action executed by another agent and whether this effect can be distinguished from attentional engagement. We show that observing highly-valued actions leads to a significant decrease in RT variability and a significant strengthening of action-specific neural representations in M1. This “sharpening” of behavioural and neural responses was observed over and beyond a control task requiring similar attentional engagement but did not include any rewards. Our finding that reward influences action specific representations in human M1 even if no motor response is required is new, suggesting that reward influences the transformation of action stimuli from the perceptual to the motor domain. We suggest that premotor areas are important for mediating the observed effect, most likely by optimizing grasp-specific PMv-M1 interactions which cause muscular facilitation patterns in M1 to be more distinct for rewarded actions.

scholarly journals Online and offline effects of transcranial alternating current stimulation of the primary motor cortex

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ivan Pozdniakov ◽  
Alicia Nunez Vorobiova ◽  
Giulia Galli ◽  
Simone Rossi ◽  
Matteo Feurra
Keyword(s):  
Motor Cortex ◽  
Primary Motor Cortex ◽  
Cortical Excitability ◽  
Motor Evoked Potentials ◽  
Random Noise ◽  
Single Pulse ◽  
Alternating Current ◽  
Online Application ◽  
Transcranial Random Noise Stimulation ◽  
Transcranial Alternating Current Stimulation

AbstractTranscranial alternating current stimulation (tACS) is a non-invasive brain stimulation technique that allows interaction with endogenous cortical oscillatory rhythms by means of external sinusoidal potentials. The physiological mechanisms underlying tACS effects are still under debate. Whereas online (e.g., ongoing) tACS over the motor cortex induces robust state-, phase- and frequency-dependent effects on cortical excitability, the offline effects (i.e. after-effects) of tACS are less clear. Here, we explored online and offline effects of tACS in two single-blind, sham-controlled experiments. In both experiments we used neuronavigated transcranial magnetic stimulation (TMS) of the primary motor cortex (M1) as a probe to index changes of cortical excitability and delivered M1 tACS at 10 Hz (alpha), 20 Hz (beta) and sham (30 s of low-frequency transcranial random noise stimulation; tRNS). Corticospinal excitability was measured by single pulse TMS-induced motor evoked potentials (MEPs). tACS was delivered online in Experiment 1 and offline in Experiment 2. In Experiment 1, the increase of MEPs size was maximal with the 20 Hz stimulation, however in Experiment 2 neither the 10 Hz nor the 20 Hz stimulation induced tACS offline effects. These findings support the idea that tACS affects cortical excitability only during online application, at least when delivered on the scalp overlying M1, thereby contributing to the development of effective protocols that can be applied to clinical populations.

Role of Voluntary Drive in Encoding an Elementary Motor Memory

2005 ◽  
Vol 93 (2) ◽  
pp. 1099-1103 ◽  
Author(s):  
Alain Kaelin-Lang ◽  
Lumy Sawaki ◽  
Leonardo G. Cohen
Keyword(s):  
Motor Cortex ◽  
Primary Motor Cortex ◽  
Motor Memory ◽  
Motor Drive ◽  
Motor Training ◽  
Corticomotor Excitability ◽  
Proprioceptive Input ◽  
Active Training ◽  
Passive Movements

Motor training consisting of repetitive thumb movements results in encoding of motor memories in the primary motor cortex. It is not known if proprioceptive input originating in the training movements is sufficient to produce this effect. In this study, we compared the ability of training consisting of voluntary (active) and passively-elicited (passive) movements to induce this form of plasticity. Active training led to successful encoding accompanied by characteristic changes in corticomotor excitability, while passive training did not. These results support a pivotal role for voluntary motor drive in coding motor memories in the primary motor cortex.

scholarly journals Chronic low-frequency rTMS of primary motor cortex diminishes exercise training-induced gains in maximal voluntary force in humans

2009 ◽  
Vol 106 (2) ◽  
pp. 403-411 ◽  
Author(s):  
Tibor Hortobágyi ◽  
Sarah Pirio Richardson ◽  
Mikhael Lomarev ◽  
Ejaz Shamim ◽  
Sabine Meunier ◽  
...  
Keyword(s):  
Motor Cortex ◽  
Primary Motor Cortex ◽  
Repetitive Transcranial Magnetic Stimulation ◽  
Low Frequency ◽  
Motor Evoked Potential ◽  
Single Pulse ◽  
Compound Action Potential ◽  
Voluntary Contraction ◽  
Maximal Voluntary Force ◽  
Resting Motor Threshold

Although there is consensus that the central nervous system mediates the increases in maximal voluntary force (maximal voluntary contraction, MVC) produced by resistance exercise, the involvement of the primary motor cortex (M1) in these processes remains controversial. We hypothesized that 1-Hz repetitive transcranial magnetic stimulation (rTMS) of M1 during resistance training would diminish strength gains. Forty subjects were divided equally into five groups. Subjects voluntarily (Vol) abducted the first dorsal interosseus (FDI) (5 bouts × 10 repetitions, 10 sessions, 4 wk) at 70–80% MVC. Another group also exercised but in the 1-min-long interbout rest intervals they received rTMS [Vol+rTMS, 1 Hz, FDI motor area, 300 pulses/session, 120% of the resting motor threshold (rMT)]. The third group also exercised and received sham rTMS (Vol+Sham). The fourth group received only rTMS (rTMS_only). The 37.5% and 33.3% gains in MVC in Vol and Vol+Sham groups, respectively, were greater ( P = 0.001) than the 18.9% gain in Vol+rTMS, 1.9% in rTMS_only, and 2.6% in unexercised control subjects who received no stimulation. Acutely, within sessions 5 and 10, single-pulse TMS revealed that motor-evoked potential size and recruitment curve slopes were reduced in Vol+rTMS and rTMS_only groups and accumulated to chronic reductions by session 10. There were no changes in rMT, maximum compound action potential amplitude (Mmax), and peripherally evoked twitch forces in the trained FDI and the untrained abductor digiti minimi. Although contributions from spinal sources cannot be excluded, the data suggest that M1 may play a role in mediating neural adaptations to strength training.

Comparison of Neural Activity in the Supplementary Motor Area and in the Primary Motor Cortex in Monkeys

1991 ◽  
Vol 8 (1) ◽  
pp. 27-44 ◽  
Author(s):  
Chen Dao-fen ◽  
B. Hyland ◽  
V. Maier ◽  
A. Palmeri ◽  
M. Wiesendanger
Keyword(s):  
Motor Cortex ◽  
Neural Activity ◽  
Primary Motor Cortex ◽  
Supplementary Motor Area ◽  
Motor Area

Cerebral Blood-Flow Changes Induced by Paired-Pulse Transcranial Magnetic Stimulation of the Primary Motor Cortex

2001 ◽  
Vol 85 (6) ◽  
pp. 2624-2629 ◽  
Author(s):  
A. P. Strafella ◽  
T. Paus
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Transcranial Magnetic Stimulation ◽  
Motor Cortex ◽  
Magnetic Stimulation ◽  
Primary Motor Cortex ◽  
Premotor Cortex ◽  
Single Pulse ◽  
Paired Pulse ◽  
Positive Correlation

Positron emission tomography (PET) was used to assess changes in regional cerebral blood flow (CBF) induced by paired-pulse transcranial magnetic stimulation (TMS) of primary motor cortex (M1). The study was performed in eight normal volunteers using two Magstim-200 stimulators linked with a Bistim module. A circular TMS coil was held in the scanner by a mechanical arm and located over the left M1. Surface electrodes were used to record motor evoked potentials (MEPs) from the contralateral first dorsal interosseous muscle (FDI). Cortical excitability was evaluated in the relaxed FDI using a paired conditioning-test stimulus paradigm with two interstimulus intervals (ISIs): 3 and 12 ms. The subjects were scanned three times during each of the following four conditions: 1) baseline with no TMS (BASE); 2) single-pulse TMS (TMSsing); 3) 3-ms paired-pulse TMS (TMS3); and 4) 12-ms paired-pulse TMS (TMS12). CBF and peak-to-peak MEP amplitudes were measured over each 60-s scanning period. To assess TMS-induced changes in CBF, a t-statistic map was generated by first subtracting the single-pulse TMS condition from the 3- and 12-ms paired-pulse TMS conditions and then correlating the CBF differences, respectively, with the amount of suppression and facilitation of the EMG responses. A significant positive correlation was observed between the CBF difference (TMS3-TMSsing) and the amount of suppression of EMG response, as well as between the CBF difference (TMS12-TMSsing) and the amount of facilitation of EMG response. This positive correlation was observed in the left M1, left lateral premotor cortex, and right M1 in the case of 3-ms paired-pulse TMS, but only in the left M1 in the case of 12-ms paired-pulse TMS. The above pattern of CBF response to paired-pulse TMS supports the possibility that suppression and facilitation of the EMG response are mediated by different populations of cortical interneurons.

Hand perceptions induced by single pulse transcranial magnetic stimulation over the primary motor cortex

2019 ◽  
Vol 12 (3) ◽  
pp. 693-701 ◽  
Author(s):  
Matteo Franza ◽  
Giuliana Sorrentino ◽  
Matteo Vissani ◽  
Andrea Serino ◽  
Olaf Blanke ◽  
...  
Keyword(s):  
Transcranial Magnetic Stimulation ◽  
Motor Cortex ◽  
Magnetic Stimulation ◽  
Primary Motor Cortex ◽  
Single Pulse

scholarly journals Primary Motor Cortex Excitability Is Modulated During the Mental Simulation of Hand Movement

2017 ◽  
Vol 23 (2) ◽  
pp. 185-193 ◽  
Author(s):  
Christian Hyde ◽  
Ian Fuelscher ◽  
Jarrad A.G. Lum ◽  
Jacqueline Williams ◽  
Jason He ◽  
...  
Keyword(s):  
Motor Cortex ◽  
Primary Motor Cortex ◽  
Motor Evoked Potentials ◽  
Hand Movement ◽  
Single Pulse ◽  
Stimulus Presentation ◽  
Mental Simulation ◽  
Right Hand ◽  
Hand Laterality ◽  
Motor Cortex Excitability

AbstractObjectives:It is unclear whether the primary motor cortex (PMC) is involved in the mental simulation of movement [i.e., motor imagery (MI)]. The present study aimed to clarify PMC involvement using a highly novel adaptation of the hand laterality task (HLT).Methods:Participants were administered single-pulse transcranial magnetic stimulation (TMS) to the hand area of the left PMC (hPMC) at either 50 ms, 400 ms, or 650 ms post stimulus presentation. Motor-evoked potentials (MEPs) were recorded from the right first dorsal interosseous via electromyography. To avoid the confound of gross motor response, participant response (indicating left or right hand) was recorded via eye tracking. Participants were 22 healthy adults (18 to 36 years), 16 whose behavioral profile on the HLT was consistent with the use of a MI strategy (MI users).Results:hPMC excitability increased significantly during HLT performance for MI users, evidenced by significantly larger right hand MEPs following single-pulse TMS 50 ms, 400 ms, and 650 ms post stimulus presentation relative to baseline. Subsequent analysis showed that hPMC excitability was greater for more complex simulated hand movements, where hand MEPs at 50 ms were larger for biomechanically awkward movements (i.e., hands requiring lateral rotation) compared to simpler movements (i.e., hands requiring medial rotation).Conclusions:These findings provide support for the modulation of PMC excitability during the HLT attributable to MI, and may indicate a role for the PMC during MI. (JINS, 2017,23, 185–193)

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