Top–Down Inhibitory Control Exerted by the Medial Frontal Cortex during Action Selection under Conflict

Top–down control is critical to select goal-directed actions in changeable environments, particularly when several conflicting options compete for selection. In humans, this control system is thought to involve an inhibitory mechanism that suppresses the motor representation of unwanted responses to favor selection of the most appropriate action. Here, we aimed to evaluate the role of a region of the medial frontal cortex, the pre-SMA, in this form of inhibition by using a double coil TMS protocol combining repetitive TMS (rTMS) over the pre-SMA and a single-pulse TMS over the primary motor cortex (M1) during a visuomotor task that required participants to choose between a left or right button press according to an imperative cue. M1 stimulation allowed us to assess changes in motor excitability related to selected and nonselected (unwanted) actions, and rTMS was used to produce transient disruption of pre-SMA functioning. We found that when rTMS was applied over pre-SMA, inhibition of the nonselected movement representation was reduced. Importantly, this effect was only observed when the imperative cue produced a substantial amount of competition between the response alternatives. These results are consistent with previous studies pointing to a role of pre-SMA in competition resolution. In addition, our findings indicate that this function of pre-SMA involves the control of inhibitory influences directed at unwanted action representations.

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Effects of Local Inactivation of Monkey Medial Frontal Cortex in Learning of Sequential Procedures

Journal of Neurophysiology ◽

10.1152/jn.1999.82.2.1063 ◽

1999 ◽

Vol 82 (2) ◽

pp. 1063-1068 ◽

Cited By ~ 61

Author(s):

Kae Nakamura ◽

Katsuyuki Sakai ◽

Okihide Hikosaka

Keyword(s):

Frontal Cortex ◽

Supplementary Motor Area ◽

Medial Frontal Cortex ◽

Button Press ◽

Sequential Movements ◽

Sequential Procedures ◽

Fixed Order ◽

And Control ◽

Differential Contribution

To examine the role of the medial frontal cortex, supplementary motor area (SMA), and pre-SMA in the acquisition and control of sequential movements, we locally injected muscimol into 43 sites in the medial frontal cortex while monkeys (n = 2) performed a sequential button-press task. In this task, the monkey had to press two of 16 (4 × 4 matrix) buttons illuminated simultaneously in a predetermined order. A total of five pairs were presented in a fixed order for completion of a trial. To clarify the differential contribution of the medial frontal cortex for new acquisition and control of sequential movements, we used novel and learned sequences (that had been learned after extensive practice). We found that the number of errors increased for novel sequences, but not for learned sequences, after pre-SMA inactivations. A similar, but insignificant, trend was observed after SMA injections. The reaction time of button presses for both novel and learned sequences was prolonged by inactivations of both SMA and pre-SMA, with a trend for the effect to be larger for SMA inactivations. These findings suggest that the medial frontal cortex, especially pre-SMA, is related to the acquisition, rather than the storage or execution, of the correct order of button presses.

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Corticospinal excitability underlying digit force planning for grasping in humans

Journal of Neurophysiology ◽

10.1152/jn.00815.2013 ◽

2014 ◽

Vol 111 (12) ◽

pp. 2560-2569 ◽

Cited By ~ 13

Author(s):

Pranav Parikh ◽

Marco Davare ◽

Patrick McGurrin ◽

Marco Santello

Keyword(s):

Primary Motor Cortex ◽

Single Pulse ◽

Intracortical Inhibition ◽

Corticospinal Excitability ◽

Reach To Grasp ◽

Grasp Planning ◽

Sensorimotor Memory ◽

Force Planning ◽

Intracortical Inhibition And Facilitation

Control of digit forces for grasping relies on sensorimotor memory gained from prior experience with the same or similar objects and on online sensory feedback. However, little is known about neural mechanisms underlying digit force planning. We addressed this question by quantifying the temporal evolution of corticospinal excitability (CSE) using single-pulse transcranial magnetic stimulation (TMS) during two reach-to-grasp tasks. These tasks differed in terms of the magnitude of force exerted on the same points on the object to isolate digit force planning from reach and grasp planning. We also addressed the role of intracortical circuitry within primary motor cortex (M1) by quantifying the balance between short intracortical inhibition and facilitation using paired-pulse TMS on the same tasks. Eighteen right-handed subjects were visually cued to plan digit placement at predetermined locations on the object and subsequently to exert either negligible force (“low-force” task, LF) or 10% of their maximum pinch force (“high-force” task, HF) on the object. We found that the HF task elicited significantly smaller CSE than the LF task, but only when the TMS pulse coincided with the signal to initiate the reach. This force planning-related CSE modulation was specific to the muscles involved in the performance of both tasks. Interestingly, digit force planning did not result in modulation of M1 intracortical inhibitory and facilitatory circuitry. Our findings suggest that planning of digit forces reflected by CSE modulation starts well before object contact and appears to be driven by inputs from frontoparietal areas other than M1.

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Role of medial frontal cortex in word retrieval

NeuroImage ◽

10.1016/s1053-8119(00)91210-2 ◽

2000 ◽

Vol 11 (5) ◽

pp. S278

Author(s):

Hope Benefield ◽

Bruce Crosson ◽

M. Allison Cato ◽

Joseph R. Sadek ◽

Kaundinya Gopinath ◽

...

Keyword(s):

Frontal Cortex ◽

Word Retrieval ◽

Medial Frontal Cortex

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Short-Latency Influence of Medial Frontal Cortex on Primary Motor Cortex during Action Selection under Conflict

Journal of Neuroscience ◽

10.1523/jneurosci.1396-09.2009 ◽

2009 ◽

Vol 29 (21) ◽

pp. 6926-6931 ◽

Cited By ~ 95

Author(s):

R. B. Mars ◽

M. C. Klein ◽

F.-X. Neubert ◽

E. Olivier ◽

E. R. Buch ◽

...

Keyword(s):

Motor Cortex ◽

Frontal Cortex ◽

Primary Motor Cortex ◽

Action Selection ◽

Short Latency ◽

Medial Frontal Cortex

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PW4-3 Role of the medial frontal cortex in communication

Clinical Neurophysiology ◽

10.1016/s1388-2457(10)60370-7 ◽

2010 ◽

Vol 121 ◽

pp. S88

Author(s):

R. Kawashima

Keyword(s):

Frontal Cortex ◽

Medial Frontal Cortex

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Changes in corticospinal excitability associated with motor learning by observing

10.1101/205385 ◽

2017 ◽

Author(s):

Heather R. McGregor ◽

Michael Vesia ◽

Cricia Rinchon ◽

Robert Chen ◽

Paul L. Gribble

Keyword(s):

Motor Learning ◽

Motor Skills ◽

Primary Motor Cortex ◽

Motor Evoked Potentials ◽

Single Pulse ◽

Abductor Pollicis Brevis ◽

Functional Changes ◽

Hand Muscles ◽

Before And After

AbstractWhile many of our motor skills are acquired through physical practice, we can also learn how to make movements by observing others. For example, individuals can learn how to reach in novel dynamical environments (‘force fields’, FF) by observing the movements of a tutor. Previous neurophysiology and neuroimaging studies in humans suggest a role for the motor system in motor learning by observing. Here we tested the role of primary motor cortex (M1) in motor learning by observing. We used single-pulse transcranial magnetic stimulation (TMS) to elicit motor evoked potentials (MEPs) in right hand muscles at rest. MEPs were elicited before and after participants observed either a video adapting her reaches to a FF or a control video showing a tutor performing reaches in an unlearnable FF. We predicted that observing motor learning would increase M1 excitability to a greater extent than observing movements that did not involve learning. We found that observing FF learning increased MEP amplitudes recorded from right first dorsal interosseous (FDI) and right abductor pollicis brevis (APB) muscles. There were no changes in MEP amplitudes for control participants who observed a tutor performing reaches in an unlearnable, randomly varying FF. The observed MEP changes can thus be specifically linked to observing motor learning. These results are consistent with the idea that observing motor learning produces functional changes in M1, or corticospinal networks or both.

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The primary motor cortex is critical for the retention of implicit sensorimotor adaptation

10.1101/096404 ◽

2016 ◽

Author(s):

Li-Ann Leow ◽

Welber Marinovic ◽

Timothy J Carroll ◽

Stephan Riek

Keyword(s):

Motor Cortex ◽

Implicit Learning ◽

Visual Feedback ◽

Primary Motor Cortex ◽

Single Pulse ◽

Sensorimotor Adaptation ◽

List Type ◽

Movement Preparation ◽

Implicit Processes

AbstractSensorimotor adaptation, or adaptation of movements to external perturbations, is thought to involve the primary motor cortex (M1). In addition to implicit error-driven remapping, explicit re-aiming strategies also contribute to sensorimotor adaptation. However, no studies to date have examined the role of M1 in implicit learning in isolation from explicit strategies. Because the application of explicit strategies requires time, it is possible to emphasise implicit learning by controlling the time available to prepare movement. Here, we examined the role of M1’s role in implicit adaptation to rotated visual feedback whilst suppressing the use of explicit re-aiming strategies by limiting movement preparation times to less than 350ms. Perturbing M1 activity via single-pulse TMS during adaptation to a 30 ° rotation of visual feedback did not alter the rate or extent of error compensation, but elicited poorer retention in post-adaptation trials with no perturbation. This work shows that M1 is critical in the retention of new visuomotor maps as a result of implicit adaptation to a perturbation in sensory feedback when strategic error correction processes are suppressed.HighlightsAdaptation of movements to perturbations occurs through explicit and implicit processes.Here, explicit strategies were suppressed by shortening movement preparation time.Perturbing motor cortex (M1) with TMS selectively impaired retention but not acquisition of sensorimotor adaptation.M1 plays a crucial role in retention of sensorimotor adaptation obtained via implicit learning.

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Posterior Medial Frontal Cortex Regulates Sympathy: A TMS Study

10.31234/osf.io/hduac ◽

2021 ◽

Author(s):

Colin Holbrook ◽

Marco Iacoboni ◽

Chelsea Gordon ◽

Shannon Proksch ◽

Harmony Makhfi ◽

...

Keyword(s):

Frontal Cortex ◽

Control Region ◽

Functional Role ◽

Potential Role ◽

Visual Area ◽

Medial Frontal Cortex ◽

Affective States ◽

Middle Temporal ◽

Harm To Others

Harm to some elicits greater sympathy than harm to others. Here, we examine the role of posterior medial frontal cortex (PMFC) in regulating sympathy, and explore the potential role of PMFC in the related phenomena of mentalizing and representing others as connected with oneself. We down-regulated either PMFC or a control region (middle temporal visual area), then assessed feelings of sympathy for and self-other overlap with two characters described as having suffered physical harm, and who were framed as adversarial or affiliative, respectively. We also measured mentalizing performance with regard to inferring the cognitive and affective states of the adversarial character. As hypothesized, down-regulating PMFC increased sympathy for both characters. Whereas we had predicted that down-regulating PMFC would decrease mentalizing ability given the postulated role of PMFC in the mentalizing network, participants in the PMFC down-regulation condition evinced greater second-order cognitive inference ability relative to controls. We observed no effect of the TMS manipulation on self-other overlap, although sympathy and self-other overlap were positively correlated. These findings are discussed as they may inform understanding of the functional role(s) of PMFC in regulating responses broadly linked with empathy.

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