Suppression Of Motor Responses Research Articles

Event-related potentials during contralateral switching over motor programs in humans

The study of processes related to the motor response suppression and the evaluation of the next, alternative, response after termination of the already observed initial motor response is of significant interest to modern scientists. The objective of our research is to identify the gender-specific features of the amplitude-time characteristics of induced cortical electrical activity in the process of the excitation of the motor programs of manual movement. Healthy and right-handed men and women aged 18–23 participated in the research. The research tasks investigated the time of simple and complex visual-motor responses, amplitude-temporal features of N2 and P3 components of cognitive evoked potentials in the response to launch and contralateral switching (dominant or subdominant arm) of the motor program of finger flexes (pressing the remote control button) in the Stop-Change paradigm. Event-related potentials (ERPs) were analyzed in the frontal, central, and parietal lobes of the cortex. It was established that male participants had lower time indexes of simple and complex visual-motor responses than women. In addition, during the contralateral switching of motor programs of manual movements the smaller latent periods of the ERPs components in the right central and left frontal sections (component N2), in the left hemisphere lobes (component P3) among men were observed. The amplitudes of the N2 and P3 components revealed higher values in male participants at the parietal lobes. Thus, the process of recognizing and differentiating the stimulus among men was faster, with more powerful focus and attention on the operative memory. In the left hemisphere of men and women the smaller latent periods of P3component (in the central lobe) and amplitudes of N2 and P3 components were determined compared to the right hemisphere. Thus, the motor programs switching in the paradigm of the experiment occurred with the sequential activation of the left and contralateral right hemispheres.

Gender differences in brain processes during inhibition of manual movements programs.

Motor response suppression can be regarded as an important aspect of the executive control, as a way of changing the behavioral pattern depending on the internal state or external factors. The aim of our study was to examine whether there were differences in the ability of cortical inhibition of triggered motor program (in the context of the Stop-Signal task) between females and males. We examined differences in the patterns of event-related EEG synchronization/desynchronization (ERS/ERD) in young volunteers under the conditions of complete inhibition of the triggered motor program of a manual movement. Thirty-six male and thirty-eight female (ages of 19 to 21) took part in the tests. The ERS and ERD indices were estimated within the EEG frequency range 8-35 Hz in frontal, central and parietal leads. In both gender groups, as a global pattern, the prevalence of connected phenomena with the EEG synchronization event in the range of α-activity of the EEG, apparently associated with inhibition of the running motor program was noted. Cortical electrical activity acquired certain specific features of the frequency-spatial organization, which could indicate the course of somewhat different brain processes of men and women.

Supplemental Carbon Dioxide Stabilizes the Upper Airway in Volunteers Anesthetized with Propofol

Propofol impairs upper airway dilator muscle tone and increases upper airway collapsibility. Preclinical studies show that carbon dioxide decreases propofol-mediated respiratory depression. We studied whether elevation of end-tidal carbon dioxide (PETCO2) via carbon dioxide insufflation reverses the airway collapsibility (primary hypothesis) and impaired genioglossus muscle electromyogram that accompany propofol anesthesia. We present a prespecified, secondary analysis of previously published experiments in 12 volunteers breathing via a high-flow respiratory circuit used to control upper airway pressure under propofol anesthesia at two levels, with the deep level titrated to suppression of motor response. Ventilation, mask pressure, negative pharyngeal pressure, upper airway closing pressure, genioglossus electromyogram, bispectral index, and change in end-expiratory lung volume were measured as a function of elevation of PETCO2 above baseline and depth of propofol anesthesia. PETCO2 augmentation dose-dependently lowered upper airway closing pressure with a decrease of 3.1 cm H2O (95% CI, 2.2 to 3.9; P < 0.001) under deep anesthesia, indicating improved upper airway stability. In parallel, the phasic genioglossus electromyogram increased by 28% (23 to 34; P < 0.001). We found that genioglossus electromyogram activity was a significant modifier of the effect of PETCO2 elevation on closing pressure (P = 0.005 for interaction term). Upper airway collapsibility induced by propofol anesthesia can be reversed in a dose-dependent manner by insufflation of supplemental carbon dioxide. This effect is at least partly mediated by increased genioglossus muscle activity.

Less approach, more avoidance: Response inhibition has motivational consequences for sexual stimuli that reflect changes in affective value not a lingering global brake on behavior.

Response inhibition negatively impacts subsequent hedonic evaluations of motivationally relevant stimuli and reduces the behavioral incentive to seek and obtain such items. Here we expand the investigation of the motivational consequences of inhibition by presenting sexually appealing and nonappealing images in a go/no-go task and a subsequent image-viewing task. Each initially obscured image in the viewing task could either be made more visible or less visible by repeatedly pressing different keys. Fewer key presses were made to obtain better views of preferred-sex images when such images had previously been inhibited as no-go items than when previously encountered as noninhibited go items. This finding replicates prior results and is consistent with the possibility that motor-response suppression has lingering effects that include global reductions in all behavioral expression. However, for nonpreferred images, prior inhibition resulted in more key presses to obscure their visibility than when such images had not been inhibited. This novel finding suggests that the motivational consequences of response inhibition are not due to a global brake on action but are instead linked to negative changes in stimulus value that induce corresponding increases in avoidance and decreases in approach.

Effects of Depth of Propofol and Sevoflurane Anesthesia on Upper Airway Collapsibility, Respiratory Genioglossus Activation, and Breathing in Healthy Volunteers.

Volatile anesthetics and propofol impair upper airway stability and possibly respiratory upper airway dilator muscle activity. The magnitudes of these effects have not been compared at equivalent anesthetic doses. We hypothesized that upper airway closing pressure is less negative and genioglossus activity is lower during deep compared with shallow anesthesia. In a randomized controlled crossover study of 12 volunteers, anesthesia with propofol or sevoflurane was titrated using a pain stimulus to identify the threshold for suppression of motor response to electrical stimulation. Measurements included bispectral index, genioglossus electromyography, ventilation, hypopharyngeal pressure, upper airway closing pressure, and change in end-expiratory lung volume during mask pressure drops. A total of 393 attempted breaths during occlusion maneuvers were analyzed. Upper airway closing pressure was significantly less negative at deep versus shallow anesthesia (-10.8 ± 4.5 vs. -11.3 ± 4.4 cm H2O, respectively [mean ± SD]) and correlated with the bispectral index (P < 0.001), indicating a more collapsible airway at deep anesthesia. Respiratory genioglossus activity during airway occlusion was significantly lower at deep compared with light anesthesia (26 ± 21 vs. 35 ± 24% of maximal genioglossus activation, respectively; P < 0.001) and correlated with bispectral index (P < 0.001). Upper airway closing pressure and genioglossus activity during airway occlusion did not differ between sevoflurane and propofol anesthesia. Propofol and sevoflurane anesthesia increased upper airway collapsibility in a dose-dependent fashion with no difference at equivalent anesthetic concentrations. These effects can in part be explained by a dose-dependent inhibiting effect of anesthetics on respiratory genioglossus activity.

Inhibition of Prepotent Motor Responses after Orbitofrontal Lesions is Associated with Hemodynamic Activation in the Parietal Lobe

Event Abstract Back to Event Inhibition of Prepotent Motor Responses after Orbitofrontal Lesions is Associated with Hemodynamic Activation in the Parietal Lobe T. Endestad1, 2, I Funderud1, M. Løvstad3, M. Lindgren4, H. Engen2, P. Due-Tønnessen5, T. Meling6, R. T. Knight7, F. Courivaud8 and A. K. Solbakk1* 1 Oslo University Hospital – Rikshospitalet, Department of Neuropsychiatry and Psychosomatic Medicine, Norway 2 University of Oslo, Department of Psychology, Norway 3 Sunnaas Rehabilitation Hospital, Norway 4 University of Lund, Department of Psychology, Sweden 5 Oslo University Hospital – Rikshospitalet, Department of Radiology, Norway 6 Oslo University Hospital – Rikshospitalet, Department of Neurosurgery, Norway 7 University of California, Department of Psychology and Helen Wills Neuroscience Institute, United States 8 Oslo University Hospital – Rikshospitalet, Intervention Center, Norway Inhibition of prepotent responses is an important aspect of cognitive control. Patients with frontal lobe injury often show impaired inhibitory control at the behavioral level. We examined motor response suppression in patients with orbitofrontal lesions (N = 14) after resection of primary intracranial tumor or contusion due to traumatic brain injury. Behavioral and fMRI hemodynamic responses were recorded during a Stop-signal task where task difficulty was equated across participants. Thus, healthy controls (N = 15) and patients did not differ in the relative number of successful and failed inhibitions. Patients responded more slowly to Go signals, but there was no significant speed difference in failed inhibition trials. Successful versus unsuccessful inhibition engaged pre-supplementary cortex, middle (MFG) and inferior frontal gyri (IFG) in controls, whereas no significant activation foci were seen in the orbitofrontal group. The successful inhibition versus Go signal contrast showed IFG activation in controls only. Both groups had inferior parietal lobe (IPL) activation. Analysis of failed inhibition compared with Go trials revealed dorsomedial and bilateral IPL recruitment in controls, while patients had IPL activation only. The results indicate that a fronto-parietal network subserves response inhibition in healthy controls. Orbitofrontal lesions disrupted frontal lobe involvement in the task. The findings point toward a possible compensatory role for the parietal part of the control network. Conference: The 20th Annual Rotman Research Institute Conference, The frontal lobes, Toronto, Canada, 22 Mar - 26 Mar, 2010. Presentation Type: Poster Presentation Topic: Cognitive Neuroscience Citation: Endestad T, Funderud I, Løvstad M, Lindgren M, Engen H, Due-Tønnessen P, Meling T, Knight RT, Courivaud F and Solbakk AK (2010). Inhibition of Prepotent Motor Responses after Orbitofrontal Lesions is Associated with Hemodynamic Activation in the Parietal Lobe. Conference Abstract: The 20th Annual Rotman Research Institute Conference, The frontal lobes. doi: 10.3389/conf.fnins.2010.14.00104 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 29 Jun 2010; Published Online: 29 Jun 2010. * Correspondence: A. K Solbakk, Oslo University Hospital – Rikshospitalet, Department of Neuropsychiatry and Psychosomatic Medicine, Oslo, Norway, anne-kristin.solbakk@rikshospitalet.no Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers T. Endestad I Funderud M. Løvstad M. Lindgren H. Engen P. Due-Tønnessen T. Meling R. T Knight F. Courivaud A. K Solbakk Google T. Endestad I Funderud M. Løvstad M. Lindgren H. Engen P. Due-Tønnessen T. Meling R. T Knight F. Courivaud A. K Solbakk Google Scholar T. Endestad I Funderud M. Løvstad M. Lindgren H. Engen P. Due-Tønnessen T. Meling R. T Knight F. Courivaud A. K Solbakk PubMed T. Endestad I Funderud M. Løvstad M. Lindgren H. Engen P. Due-Tønnessen T. Meling R. T Knight F. Courivaud A. K Solbakk Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.

FMRI adaptation during performance of learned arbitrary visuomotor conditional associations

In everyday life, people select motor responses according to arbitrary rules. For example, our movements while driving a car can be instructed by color cues that we see on traffic lights. These stimuli do not spatially relate to the actions that they specify. Associations between these stimuli and actions are called arbitrary visuomotor conditional associations. Earlier fMRI studies have tried to dissociate the sensory and motor components of these associations by introducing delays between the presentation of arbitrary cues and go-signals that instructed participants to perform actions. This approach, however, also introduces neural processes that are not necessarily related to the normal real-time production of arbitrary visuomotor responses, such as working memory and the suppression of motor responses. We used fMRI adaptation as an alternative approach to dissociate sensory and motor components. We found that visual areas in the occipital–temporal cortex adapted only to the presentation of arbitrary visual cues whereas a number of sensorimotor areas adapted only to the production of response. Visual areas in the occipital–temporal cortex do not have any known connections with parts of the brain that can control hand musculature. Therefore, it is conceivable that the brain areas that we report as having adapted to both stimulus presentation and response production (namely, the dorsal premotor area, the supplementary motor area, the cingulate, the anterior intra-parietal sulcus area, and the thalamus) are involved in the multiple steps between processing visual stimuli and activating the motor commands that these cues specify.

Inhibition of thoughts and actions in obsessive-compulsive disorder: extending the endophenotype?

BackgroundObsessive-compulsive disorder (OCD) has been associated with impairments in stop-signal inhibition, a measure of motor response suppression. The study used a novel paradigm to examine both thought suppression and response inhibition in OCD, where the modulatory effects of stimuli relevant to OCD could also be assessed. Additionally, the study compared inhibitory impairments in OCD patients with and without co-morbid depression, as depression is the major co-morbidity of OCD.MethodVolitional response suppression and unintentional thought suppression to emotive and neutral stimuli were examined using a novel thought stop-signal task. The thought stop-signal task was administered to non-depressed OCD patients, depressed OCD patients and healthy controls (n=20 per group).ResultsMotor inhibition impairments were evident in OCD patients, while motor response performance did not differ between patients and controls. Switching to a new response but not motor inhibition was affected by stimulus relevance in OCD patients. Additionally, unintentional thought suppression as measured by repetition priming was intact. OCD patients with and without depression did not differ on any task performance measures, though there were significant differences in all self-reported measures.ConclusionsResults support motor inhibition deficits in OCD that remain stable regardless of stimulus meaning or co-morbid depression. Only switching to a new response was influenced by stimulus meaning. When response inhibition was successful in OCD patients, so was the unintentional suppression of the accompanying thought.

Effect of dexmedetomidine on propofol requirements in healthy subjects

Dexmedetomidine–propofol pharmacodynamic interaction was evaluated in nine healthy subjects in a crossover design. Dexmedetomidine/placebo was infused using a computer‐controlled infusion pump (CCIP) to maintain a pseudo‐steady‐state plasma concentration of 0.66 ± 0.080 or 0 ng/mL, respectively. Forty‐five minutes after the dexmedetomidine/placebo infusion was started, propofol was infused using a second CCIP to achieve a stepwise logarithmically ascending propofol concentration (1.00 to 13.8 μg/mL) profile. Each propofol step lasted 10 min. Blood was sampled for plasma concentration determination, and pharmacodynamic endpoint assessments were made during the study. Propofol and dexmedetomidine/placebo infusions were terminated when three endpoints (subjects were too sedated to hold a syringe, followed by loss of eyelash reflex, followed by loss of motor response to electrical stimulation) were achieved sequentially. The concentration of propofol associated with 50% probability of achieving a pharmacodynamic endpoint in the absence of dexmedetomidine (EC50; placebo treatment) was 6.63 μg/mL for motor response to electrical stimulation and ranged from 1.14 to 1.98 μg/mL for the ability to hold a syringe, eyelash reflex, and sedation scores. The apparent EC50 values of propofol (EC50APP; concentration of propofol at which the probability of achieving a pharmacodynamic endpoint is 50% in the presence of dexmedetomidine concentrations observed in the current study; dexmedetomidine treatment) were 0.273, 0.544–0.643, and 3.89 μg/mL for the ability to hold a syringe, sedation scores, and motor response, respectively. Dexmedetomidine reduced propofol concentrations required for sedation and suppression of motor response. Therefore, the propofol dose required for sedation and induction of anesthesia may have to be reduced in the presence of dexmedetomidine. © 2001 Wiley‐Liss, Inc. and the American Pharmaceutical Association J Pharm Sci 90:172–181, 2001

Motor response suppression and the prepotent tendency to respond: a parametric fMRI study

In the present study we utilised functional magnetic resonance imaging (fMRI) to examine cerebral activation during performance of a classic motor task in which response suppression load was parametrically varied. Linear increases in activity were observed in a distributed network of regions across both cerebral hemispheres, although with more extensive involvement of the right prefrontal cortex. Activated regions included prefrontal, parietal and occipitotemporal cortices. Decreasing activation was similarly observed in a distributed network of regions. These response forms are discussed in terms of an increasing requirement for visual cue discrimination and suppression/selection of motor responses, and a decreasing probability of the occurrence of non-target stimuli and attenuation of a prepotent tendency to respond. The results support recent proposals for a dominant role for the right-hemisphere in performance of motor response suppression tasks that emphasise the importance of the right prefrontal cortex.

Non-opiate analgesia induced by carbachol microinjection into the pontine parabrachial region of the cat

These studies investigated the effect of microinjection of the cholinergic agonist carbamylcholine (carbachol) into various sites of the dorsolateral pontine tegmentum of the cat. Carbachol microinjection into an area surrounding the lateral half of the brachium conjunctivium (parabrachial region, PBR) produced profound suppression of nociceptive responses. In the dorsal part of PBR, carbachol microinjection produced no generalized sensory, emotional or motor deficits, indicating that nociceptive transmission was primarily affected. Carbachol microinjection into the ventral part of PBR resulted inslight suppression of motor responses in addition to profound nociceptive suppression. Carbachol-produced analgesia (CPA) observed within PBR blocked supraspinally as well as spinally integrated responses normally elicited by either phasic or tonic noxious stimuli. Atropine sulfate, but not mecamylamine hydrochloride, significantly antagonized CPA, indicating that muscarinic receptors mediate this phenomenon. The opiate antagonist naloxone, systemically administered either prior to or after carbachol microinjection, did not reliably attenuate CPA. Microinjection of morphine into the sites from which CPA had previously been obtained did not produce significant effects on nociceptive responses. Thus, opiate mechanisms appear not to be necessary either for the activation of this system or for the production of the resultant analgesia. These findings indicate that the neural population examined in the present study is anatomically and pharmacologically distinct from previously identified opiate-mediated pain inhibitory systems. Results are discussed in light of other recent evidence indicating the existence of endogenous non-opiate pain inhibitory systems.

Facilitation of the suppressing effect of dopamine upon a motor conditioned response by 6-hydroxydopamine applied into the caudate nucleus in cats

It has been described that the application of DA in the Caudate Nucleus improves the learning of an inhibitory motor conditioned response (SMCR). However, the application of 6-hydroxydopamine (6-OHDA) at low doses of 5, 10 and 20 μg produced a clear increment of the inhibition, while higher doses of 80 or 160 μg diminished markedly the suppression of the MCR. We postulated that although low doses of 6-OHDA produce lesions in the dopaminergic structures they cause hypersensitization by denervation. To prove this hypothesis were observed the effect of DA application into the CN before and after applying one of the lower doses of 6-OHDA. Cats were trained to press a lever (MCR) to obtain 0.5 ml of milk when a conditioned discriminative stimulus (light) was on, and to suppress the response when the light was off (SMCR). The various applications of 10 μg of DA in both CNs, always produced a decrement in the lever pressing rate only in the SMCR situation. The effects of the DA applications after the 6-OHDA application were more significant ( p < 0.01) than when applied before the 6-OHDA. These findings further support the postulation that catecholamines in the CN improve the inhibitory actions required for the suppression of motor responses.