Magneto-encephalographic correlates of the lateralized readiness potential (original) (raw)
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Origin of Human Motor Readiness Field Linked to Left Middle Frontal Gyrus by MEG and PET
NeuroImage, 1998
Combined magnetoencephalography and positron emission tomography identified a prior source of activity in the left middle frontal gyrus during uncued movements of the right index finger. Voluntary movements gave rise to a change in the cortical electrical potential known as the Bereitschaftspotential or Readiness Potential, recorded as early as 1500 ms before the onset of movement. The Readiness Field is the magnetic field counterpart to the Bereitschaftspotential. In the present study, magnetoencephalography identified four successively active sources of fluctuation in the Readiness Field in the period from 900 ms before, to 100 ms after, the onset of the movement. The first source to be active was registered between 900 and 200 ms prior to the onset of the movement. This source of initial activity was mapped by positron emission tomography to the middle frontal gyrus, Brodmann area 9. The three sources subsequently to be active were mapped to the supplementary motor area, premotor cortex, and motor cortex (M1), all in the left hemisphere. 1998 Academic Press
Movement-related EEG indices of preparation in task switching and motor control
Brain Research, 2006
Lateralized readiness potential (LRP) and time-frequency domain LRP-type measures, called motor-related amplitude asymmetries (MRAA), in the mu band (9-13 Hz; mu-MRAA) and the beta band (18-26 Hz; beta-MRAA) were used to study the time course of preparation in a task-switching task and a response precuing task. Several dissociations between LRP and mu-MRAA and beta-MRAA were found. Mu-MRAA and beta-MRAA, but not LRP, exhibited an early and strong reversal in cortical lateralization when advance preparation for a switch of response hand was required. LRP, but not mu-MRAA or beta-MRAA, was sensitive to manipulation of the probability that advance preparation of response hand would be useful in a response precuing task. These dissociations replicate earlier findings and suggest that movement-related cortical rhythms and cortical potentials are associated with distinct preparatory component processes that differ in terms of level of abstraction and effort, in line with similar functional distinctions between component processes underlying executive control in task switching. This suggests that a fine-grained analysis of subprocesses involved in motor control may provide important guiding principles for the study and understanding of levels and mechanisms of cognitive control.
The Influence of Response Side on the Readiness Potential Prior to Finger and Foot Movements
Annals of the New York Academy of Sciences, 1984
Kornhuber and Deecke (1965) and Gilden et al. (1966) were the first to analyze cerebral activity recorded prior to voluntary movements. The readiness potential (RP) preceding a unilateral movement is present over both hemispheres from frontal to parietal areas. An abundance of R P literature concerns finger or hand movements. In
International Journal of Psychophysiology, 2011
The readiness potential (RP), a slow negative electroencephalographic pre-movement potential, was reported to commence earlier for movements with the non-dominant left hand than with the dominant right hand. Latencies in these reports were always calculated from averaged RPs, whereas onset times of individual trials remained inaccessible. The aim was to use a new statistical approach to examine whether a few left hand trials with very early pre-movement activity disproportionally affect the onset of the average. We recorded RPs in 28 right-handed subjects while they made self-paced repetitive unilateral movements with their dominant and non-dominant hand. Skewness, a measure of distribution asymmetry, was analysed in sets of single-trial RPs to discriminate between a symmetric distribution and an asymmetric distribution containing outlier trials with early onset. Results show that for right hand movements skewness has values around zero across electrodes and pre-movement intervals, whereas for left hand movements skewness has initially negative values which increase to neutral values closer to movement onset. This indicates a symmetric (e.g., Gaussian) distribution of onset times across trials for simple right hand movements, whereas cortical activation preceding movements with the non-dominant hand is characterised by outlier trials with early onset of negativity. These findings may explain differences in the averaged brain activation preceding dominant versus non-dominant hand movements described in previous electrophysiological/neuroimaging studies. The findings also constrain mental chronometry, a technique that makes conclusions upon the time and temporal order of brain processes by measuring and comparing onset times of averaged electroencephalographic potentials evoked by these processes. (G. Dirnberger). 1 The RP onset was often defined as the point in time at which 90% of the area under the averaged RP waveform preceded movement onset, that is, the point after which 90% of pre-movement negativity occur .
Movement-related slow cortical magnetic fields and changes of spontaneous MEG- and EEG-brain rhythms
Electroencephalography and clinical neurophysiology, 1996
Cortical activity was recorded from 5 healthy adults with a 122-channel whole-head magnetometer while the subjects performed during unilateral finger movements at self-paced intervals exceeding 6 s. The readiness field (RF) started over the contralateral somatomotor area 0.3-1 s prior to the movement onset in subjects (Ss) 1, 2, and 4, and culminated in the motor field (MF) 30 ms after it (Ss 1-4). These signals were followed by movement evoked fields MEFI (Ss 1-5) and MEFII (Ss 1-4) at 100-150 ms and 200-250 ms after the movement onset, respectively. One subject showed clear RF over the ipsilateral hemisphere as well. The contralateral dominance of the RF contrasted the more symmetric distribution of the simultaneously recorded electric Bereitschaftspotential (BP). The RF onset never preceded the BP onset. We suggest that BP receives contribution from the early bilateral activation of the crown of the precentral gyrus, whereas RF reflects later activity of the fissural motor cortex...
Movement-related potentials associated with movement preparation and motor imagery
1996
Movement-related potentials (MRPs), reflecting cortical activity associated with voluntary movement, typically show a slowly increasing negative potential beginning between 1 and 2 s prior to movement, which most likely reflects motor preparatory processes. Studies of regional cerebral blood flow implicate the supplementary motor area in such preparatory processes; however, the contribution of the supplementary motor area to premovement activity observed in MRPs is debated. It is possible to examine MRPs relating to movement preparation alone, in the absence of movement execution, by recording MRPs associated with imagined movements. In this study, MRPs were recorded from 11 healthy control subjects while performing a sequential button-pressing task in response to external cues, and while imagining performance of the same task in response to the same cues. The early component of MRPs was found not to differ in amplitude, onset time, or topography when performing compared with imagining movement, indicating that both movement execution and motor imagery involve similar pre-movement preparatory processes generated in the same cortical area -most likely the supplementary motor area. It is therefore concluded that the early component of the MRP reflects activity arising predominantly from the supplementary motor area and is associated with pre-movement motor preparatory processes which occur relatively independently of actual movement execution.
NeuroImage, 2018
Motor 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. certified by peer review) is the author/funder. All rights reserved. No reuse allowed without permission. Highlights • Brain 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.
Internally driven vs. externally cued movement selection: a study on the timing of brain activity
Brain research. Cognitive brain research, 2000
Brain imaging studies in man and single cell recordings in monkey have suggested that medial supplementary motor areas (SMA) and lateral pre-motor areas (PMA) are functionally dissociated concerning their involvement in internally driven and externally cued movements. This dichotomy, however, seems to be relative rather than absolute. Here, we searched for further evidence of relative differences and aimed to determine by what aspect of brain activity (duration, strength, or both) these might be accounted for. Event-related potentials (ERPs) were recorded while healthy, right-handed subjects selected one of three possible right hand digit movements based either on 'internal' choice or 'external' cues. The results obtained from ERP mapping suggest that movement selection evokes the same electrical brain activity patterns in terms of surface potential configurations in the same order and at the same strength independent of the selection mode. These identical configurat...
Movement-related potentials associated with self-paced, cued and imagined arm movements
Experimental Brain Research, 2002
Self-paced movements, movement to a cue and imagined movement have all been reported to be preceded by a prolonged negativity on averaged electroencephalograph (EEG) recordings. Considerable evidence supports an important contribution from the supplementary motor area (SMA) to this potential and all three types of movement have been shown to be associated with SMA activation. This study was designed to compare the premovement component of these movement-related potentials (MRPs) in a group of subjects who performed each of these three types of movement. In addition, in view of the greater SMA activation in association with proximal arm movements, we studied movements at multiple joints in the right arm. All the potentials were largest at Cz. Self-paced movements were preceded by a negativity (mean onset 1.2 s prior to electromyographic activity) with two distinct phases -an early slow increase (early BP, Bereitschaftspotential) and a later, steeper phase (NS', negative slope). Proximal movements were associated with a larger peak amplitude (mean peak amplitude for shoulder 11.6 V, finger movement 9.0 V at Cz, n=14) due to a bigger NS' phase. Movements to a regular cue, but not to a randomly timed cue, were also preceded by a long duration negativity, but the NS' phase began earlier and was less distinct than for self-paced movements (mean peak amplitude for shoulder movement 9.1 V, finger 8.2 V at Cz, n=12). Imagining the movements to a regular cue was associated with a slow negativity, with no clear NS' phase (mean peak amplitude for shoulder movement 6.5 V, finger 6.2 V at Cz). Our results indicate that the MRPs prior to the three types of movement have distinct characteristics, most notably for the NS' phase. The MRP associated with movement to a regular cue may be analogous to the S2-related negativity of the contingent negative variation (CNV). We discuss the findings in the light of current evidence from functional imaging as to the cortical areas activated in similar movements.
A spatio-temporal dipole model of the readiness potential in humans. I. Finger movement
Electroencephalography and Clinical Neurophysiology, 1994
Preceding unilateral finger movements readiness potentials (RPs) were recorded in 9 right-handed subjects. The data are presented as time series, potential maps and spatio-temporal dipole models. The latter are interpreted with respect to the underlying generators of the RP. Explicit hypotheses about the unilateral or bilateral activation of particular sensorimotor areas preceding unilateral movements are addressed. The choice for the best spatio-temporal dipole model was guided by a test on the orthogonality of the individual residuals and by a priori neurophysiological evidence. From the final model it is concluded that the initial bilateral symmetrical part of the RP is generated in the posterior walls of the precentral gyrus bilaterally, whereas the later lateralized components originate from the crown of that same gyrus contralaterally. This confirms and extends data from subdural recording, magnetoencephalography (MEG) and EEG.