Movement Sequence-Related Activity Reflecting Numerical Order of Components in Supplementary and Presupplementary Motor Areas

1998 ◽  
Vol 80 (3) ◽  
pp. 1562-1566 ◽  
Author(s):  
William T. Clower ◽  
Garrett E. Alexander

Clower, William T. and Garrett E. Alexander. Movement sequence-related activity reflecting numerical order of components in supplementary and presupplementary motor areas. J. Neurophysiol. 80: 1562–1566, 1998. The supplementary motor area (SMA) and presupplementary motor areas (pre-SMA) have been implicated in movement sequencing, and neurons in SMA have been shown to encode what might be termed the relational order among sequence components (e.g., movement X followed by movement Y). To determine whether other aspects of movement sequencing might also be encoded by SMA or pre-SMA neurons, we analyzed task-related activity recorded from both areas in conjunction with a sequencing task that dissociated the numerical order of components (e.g., movement X as the 2nd component, irrespective of which movements precede or follow X). Sequences were constructed from eight component movements, each characterized by three spatial variables (origin, direction, and endpoint). Task-related activity recorded from 56 SMA and 63 pre-SMA neurons was categorized according to both the epoch (delay, reaction time, and movement time) and the spatial variable or component movement with which it was associated. All but one instance of task-related activity was selective for one of the spatial variables (SV-selective) rather than for any of the component movements themselves. Of 110 instances of SV-selective activity in SMA, 43 (39%) showed significant effects of numerical order. The corresponding incidence in pre-SMA, 82 (71%) of 116, was substantially higher ( P < 0.00001). No effects of numerical order were evident among the hand paths, movement times, or electromyographic activity associated with task performance. We concluded that neurons in SMA and pre-SMA may encode the numerical order of components, at least for sequences that are distinguished mainly by that aspect of component ordering.

2005 ◽  
Vol 94 (1) ◽  
pp. 550-566 ◽  
Author(s):  
Kiyoshi Kurata

The activity of neurons in the motor nuclei of the thalamus that project to the cortical motor areas (the primary motor cortex, the ventral and dorsal premotor cortex, and the supplementary motor area) was investigated in monkeys that were performing a task in which wrist extension and flexion movements were instructed by visuospatial cues before the onset of movement. Movement was triggered by a visual, auditory, or somatosensory stimulus. Thalamocortical neurons were identified by a spike collision, and exhibited 2 distinct types of task-related activity: 1) a sustained change in activity during the instructed preparation period in response to the instruction cues (set-related activity); and 2) phasic changes in activity during the reaction and movement time periods (movement-related activity). A number of set- and moment-related neurons exhibited direction selectivity. Most movement-related neurons were similarly active, irrespective of the different sensory modalities of the cue for movement. These properties of neuronal activity were similar, regardless of their target cortical motor areas. There were no significant differences in the antidromic latencies of neurons that projected to the primary and nonprimary motor areas. These results suggest that the thalamocortical neurons play an important role in the preparation for, and initiation and execution of, the movements, but are less important than neurons of the nonprimary cortical motor areas in modality-selective sensorimotor transformation. It is likely that such transformations take place within the nonprimary cortical motor areas, but not through thalamocortical information channels.


1997 ◽  
Vol 78 (3) ◽  
pp. 1516-1530 ◽  
Author(s):  
Ruth E. Martin ◽  
Gregory M. Murray ◽  
Pentti Kemppainen ◽  
Yuji Masuda ◽  
Barry J. Sessle

Martin, Ruth E., Gregory M. Murray, Pentti Kemppainen, Yuji Masuda, and Barry J. Sessle. Functional properties of neurons in the primate tongue primary motor cortex during swallowing. J. Neurophysiol. 78: 1516–1530, 1997. Recent studies conducted in our laboratory have suggested that the tongue primary motor cortex (i.e., tongue-MI) plays a critical role in the control of voluntary tongue movements in the primate. However, the possible involvement of tongue-MI in semiautomatic tongue movements, such as those in swallowing, remains unkown. Therefore the present study was undertakein in attempts to address whether tongue-MI plays a role in the semiautomatic tongue movements produced during swallowing. Extracellular single neuron recordings were obtained from tongue-MI, defined by intracortical microstimulation (ICMS), in two awake monkeys as they performed three types of swallowing (swallowing of a juice reward after successful tongue task performance, nontask-related swallowing of a liquid bolus, and nontask-related swallowing of a solid bolus) as well as a trained tongue-protrusion task. Electromyographic activity was recorded simultaneously from various orofacial and laryngeal muscles. In addition, the afferent input to each tongue-MI neuron and ICMS-evoked motor output characteristics at each neuronal recording site were determined. Neurons were considered to show swallow and/or tongue-protrusion task-related activity if a statistically significant difference in firing rate was seen in association with these behaviors compared with that observed during a control pretrial period. Of a total of 80 neurons recorded along 40 microelectrode penetrations in the ICMS-defined tongue-MI, 69% showed significant alterations of activity in relation to the swallowing of a juice reward, whereas 66% exhibited significant modulations of firing in association with performance of the trained tongue-protrusion task. Moreover, 48% showed significant alterations of firing in relation to both swallowing and the tongue-protrusion task. These findings suggest that the region of cortex involved in swallowing includes MI and that tongue-MI may play a role in the regulation of semiautomatic tongue movement, in addition to trained motor behavior. Swallow-related tongue-MI neurons exhibited a variety of swallow-related activity patterns and were distributed throughout the ICMS-defined tongue-MI at sites where ICMS evoked a variety of types of tongue movements. These findings are consistent with the view that multiple efferent zones for the production of tongue movements are activated in swallowing. Many swallow-related tongue-MI neurons had an orofacial mechanoreceptive field, particularly on the tongue dorsum, supporting the view that afferent inputs may be involved in the regulation of the swallowing synergy.


2010 ◽  
Vol 68 ◽  
pp. e372
Author(s):  
Sayuki Takara ◽  
Nobuhiko Hatanaka ◽  
Masahiko Takada ◽  
Atsushi Nambu

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
J. M. Castellote ◽  
M. E. L. Van den Berg ◽  
J. Valls-Solé

Preparation of the motor system for movement execution involves an increase in excitability of motor pathways. In a reaction time task paradigm, a startling auditory stimulus (SAS) delivered together with the imperative signal (IS) shortens reaction time significantly. In self-generated tasks we considered that an appropriately timed SAS would have similar effects. Eight subjects performed a ballistic wrist extension in two blocks: reaction, in which they responded to a visual IS, and action, in which they moved when they wished within a predetermined time window. In 20–25% of the trials, a SAS was applied. We recorded electromyographic activity of wrist extension and wrist movement kinematic variables. No effects of SAS were observed in action trials when movement was performed before or long after SAS application. However, a cluster of action trials was observed within 200 ms after SAS. These trials showed larger EMG bursts, shorter movement time, shorter time to peak velocity, and higher peak velocity than other action trials (P<0.001for all), with no difference from Reaction trials containing SAS. The results show that SAS influences the execution of self-generated human actions as it does with preprogrammed reaction time tasks during the assumed building up of preparatory activity before execution of the willed motor action.


1997 ◽  
Vol 77 (4) ◽  
pp. 2164-2174 ◽  
Author(s):  
Gereon R. Fink ◽  
Richard S. J. Frackowiak ◽  
Uwe Pietrzyk ◽  
Richard E. Passingham

Fink, Gereon R., Richard S. J. Frackowiak, Uwe Pietrzyk, and Richard E. Passingham. Multiple nonprimary motor areas in the human cortex. J. Neurophysiol. 77: 2164–2174, 1997. We measured the distribution of regional cerebral blood flow with positron emission tomography while three subjects moved their hand, shoulder, or leg. The images were coregistered with each individual's anatomic magnetic resonance scans. The data were analyzed for each individual to avoid intersubject averaging and so to preserve individual gyral anatomy. Instead of inspecting all pixels, we prospectively restricted the data analysis to particular areas of interest. These were defined on basis of the anatomic and physiological literature on nonhuman primates. By examining only a subset of areas, we strengthened the power of the statistical analysis and thereby increased the confidence in reporting single subject data. On the lateral convexity, motor related activity was found for all three subjects in the primary motor cortex, lateral premotor cortex, and an opercular area within the premotor cortex. In addition, there was activation of somatosensory cortex (SI), the supplementary somatosensory area (SII) in the Sylvian fissure, and parietal association areas (Brodmann areas 5 and 40). There was also activation in the insula. We suggest that the activation in the dorsal premotor cortex may correspond with dorsal premotor area (PMd) as described in the macaque brain. We propose three hypotheses as to the probable location of vental premotor area (PMv) in the human brain. On the medial surface, motor-related activity was found for all three subjects in the leg areas of the primary motor cortex and somatosensory cortex and also activity for the hand, shoulder, and leg in the supplementary motor area (SMA) on the dorsal medial convexity and in three areas in the cingulate sulcus. We suggest that the three cingulate areas may correspond with rostral cingulate premotor area, dorsal cingulate motor area (CMAd), and ventral cingulate motor area (CMAv) as identified in the macaque brain. Somatotopic mapping was demonstrated in the primary motor and primary somatosensory cortex. In all three subjects, the arm region lay anterior to the leg region in parietal area 5. Also in all three subjects, the arm region lay anterior to the leg region in the supplementary motor cortex.


1984 ◽  
Vol 52 (5) ◽  
pp. 787-796 ◽  
Author(s):  
M. C. Carter ◽  
D. C. Shapiro

The neuromotor processes underlying the control of rapid sequential limb movements were investigated. Subjects learned to pronate and supinate their forearms rapidly to four target locations in a specific spatio-temporal pattern under two movement-time conditions. The response sequence was first performed in a total movement time of 600 ms. Subjects were then told to produce the movement as quickly as possible while ignoring any timing pattern that they had previously learned. Electromyographic (EMG) signals were recorded from the biceps brachii and pronator teres muscles. Kinematic and EMG analyses were performed to investigate the temporal characteristics underlying the two movement-time conditions. When subjects produced the response as quickly as possible, average movement time to perform each reversal movement decreased while average peak velocity increased. Average total movement time was reduced by approximately 100 ms. Although movement time decreased, the proportion of total time to perform each movement of the sequence remained essentially invariant between movement-time conditions. Similar results were obtained for velocity. The time at which peak velocity was achieved occurred earlier in absolute time, although when normalized to the proportion of total movement time, the time to reach peak velocity was also invariant. Thus subjects proportionally compressed the entire movement sequence in time. The EMG analysis demonstrated that total EMG time decreased 89 ms on the average when subjects sped up the movement sequence. Thus average burst durations for both the biceps and pronator teres muscles decreased when movement speed increased. When burst durations were normalized to a proportion of total EMG time, the average proportion of time each muscle was active remained invariant. Therefore, the temporal pattern of activity for the biceps and pronator teres muscles were also proportionally compressed. The present experiment provided additional evidence for the structure of generalized motor programs consisting of invariant and variant features. Movement speed was considered a variant feature, which is specified each time the program is executed. Relative timing, the proportion of total time to produce each segment of the response, was considered to be an invariant feature and inherent in the structure of the motor program. Support for the invariance of relative timing was observed at both the kinematic and neuromuscular levels of analyses. Alternative models (9-11, 24) were found inadequate to account for the invariance of relative timing with the variation in movement time observed in the present experiment.


2005 ◽  
Vol 22 (3) ◽  
pp. 509-530 ◽  
Author(s):  
Jacques LaRue

We investigate differences in timing errors in a task that imitated the movement sequence of a cello player. We trained a group of 17 young adults to perform a sequence of linear reversal movements of different lengths but with a constant movement time. Thus, each segment required the movement speed to be changed. The sequence had to be performed with fluidity, except for a �no-movement� segment that was embedded in the movement series. Feedback on timing was given for each segment. Results from this experiment show that the no-movement segment is more variable than any of the movement segments. There was no significant correlation between the timing errors of the successive movements and the timing error of the pause. These results provide further evidence in favor of two distinct timing processes: one used for continuous movements and one used for no-movement and discontinuous movements.


2019 ◽  
Vol 40 (1) ◽  
pp. 1-25 ◽  
Author(s):  
Amin Ghamari ◽  
Mehdi Sohrabi ◽  
Alireza Saberi Kakhki

AbstractDepending on the difficulty of the task in terms of movement duration and the number of elements forming the sequence, recent research has shown that movement sequences are coded in visual-spatial coordinates or motor coordinates. An interesting question that arises is how a specific manner of performance without a change in such functional difficulties affects the representation of movement sequences. Accordingly, the present study investigated how the way in which a movement sequence is performed affects the transfer of timing properties (absolute and relative timing) from the practised to unpractised hand under mirror (same motor commands as those used in practice) and non-mirror (the same visual-spatial coordinates as those present during practice) conditions in two experiments each with segment movement time goals that were arranged differently. The study showed that after a limited amount of practice, the pattern of results obtained for relative timing differed between the two experiments. In the first experiment, there was no difference between retention and non-mirror transfer, but performance on these tasks was significantly better than that for mirror transfer, whereas in the second experiment, there was no difference between the mirror and non-mirror transfer. For total errors, no significant difference was found between the retention and transfer tests in both experiments. It was concluded that the way in which a sequence is performed could affect the representation of the task and the transfer of relative timing, while absolute timing could purposefully be maintained if necessary.


1990 ◽  
Vol 64 (1) ◽  
pp. 151-163 ◽  
Author(s):  
M. D. Crutcher ◽  
G. E. Alexander

1. Movement-related neuronal activity in the supplementary motor area (SMA), primary motor cortex (MC), and putamen was studied in monkeys performing a visuomotor tracking task designed to determine 1) the extent to which neuronal activity in each of these areas represented the direction of visually guided arm movements versus the pattern of muscle activity required to achieve those movements and 2) the relative timing of different types of movement-related activity in these three motor areas. 2. A total of 455 movement-related neurons in the three motor areas were tested with a behavioral paradigm, which dissociated the direction of visually guided elbow movements from the accompanying pattern of muscular activity by the application of opposing and assisting torque loads. The movement-related activity described in this report was collected in the same animals performing the same behavioral paradigm used to study preparatory activity described in the preceding paper. Of the total sample, 87 neurons were located within the arm region of the SMA, 150 within the arm region of the MC, and 218 within the arm region of the putamen. 3. Movement-related cells were classified as “directional” if they showed an increase in discharge rate predominantly or exclusively during movements in one direction and did not have significant static or dynamic load effects. A cell was classified as “muscle-like” if its directional movement-related activity was associated with static and/or dynamic load effects whose pattern was similar to that of flexors or extensors of the forearm. Both directional and muscle-like cells were found in all three motor areas. The largest proportion of directional cells was located in the putamen (52%), with significantly smaller proportions in the SMA (38%) and MC (41%). Conversely, a smaller proportion of muscle-like cells was seen in the putamen (24%) than in the SMA (41%) or MC (36%). 4. The time of onset of movement-related discharge relative to the onset of movement ("lead time") was computed for each cell. On average, SMA neurons discharged significantly earlier (SMA lead times 47 +/- 8 ms, mean +/- SE) than those in MC (23 +/- 6 ms), which in turn were earlier than those in putamen (-33 +/- 6 ms). However, the degree of overlap of the distributions of lead times for the three areas was extensive.(ABSTRACT TRUNCATED AT 400 WORDS)


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