scholarly journals Delay of Movement Caused by Disruption of Cortical Preparatory Activity

2007 ◽  
Vol 97 (1) ◽  
pp. 348-359 ◽  
Author(s):  
Mark M. Churchland ◽  
Krishna V. Shenoy
Keyword(s):  
Reaction Time ◽  
Primary Motor Cortex ◽  
Premotor Cortex ◽  
Reaction Times ◽  
Intracortical Microstimulation ◽  
Movement Preparation ◽  
Preparation Time ◽  
Preparatory Activity ◽  
Specific Increase ◽  
Optimal Subspace

We tested the hypothesis that delay-period activity in premotor cortex is essential to movement preparation. During a delayed-reach task, we used subthreshold intracortical microstimulation to disrupt putative “preparatory” activity. Microstimulation led to a highly specific increase in reach reaction time. Effects were largest when activity was disrupted around the time of the go cue. Earlier disruptions, which presumably allowed movement preparation time to recover, had only a weak impact. Furthermore, saccadic reaction time showed little or no increase. Finally, microstimulation of nearby primary motor cortex, even when slightly suprathreshold, had little effect on reach reaction time. These findings provide the first evidence, of a causal and temporally specific nature, that activity in premotor cortex is fundamental to movement preparation. Furthermore, although reaction times were increased, the movements themselves were essentially unperturbed. This supports the suggestion that movement preparation is an active and actively monitored process and that movement can be delayed until inaccuracies are repaired. These results are readily interpreted in the context of the recently developed optimal-subspace hypothesis.

Contribution of the Premotor Cortex to Consolidation of Motor Sequence Learning in Humans During Sleep

2010 ◽  
Vol 104 (5) ◽  
pp. 2603-2614 ◽  
Author(s):  
Michael A. Nitsche ◽  
Michaela Jakoubkova ◽  
Nivethida Thirugnanasambandam ◽  
Leonie Schmalfuss ◽  
Sandra Hullemann ◽  
...  
Keyword(s):  
Reaction Time ◽  
Task Performance ◽  
Rem Sleep ◽  
Sequence Learning ◽  
Memory Consolidation ◽  
Primary Motor Cortex ◽  
Premotor Cortex ◽  
Reaction Time Task ◽  
Motor Memory ◽  
Motor Sequence

Motor learning and memory consolidation require the contribution of different cortices. For motor sequence learning, the primary motor cortex is involved primarily in its acquisition. Premotor areas might be important for consolidation. In accordance, modulation of cortical excitability via transcranial DC stimulation (tDCS) during learning affects performance when applied to the primary motor cortex, but not premotor cortex. We aimed to explore whether premotor tDCS influences task performance during motor memory consolidation. The impact of excitability-enhancing, -diminishing, or placebo premotor tDCS during rapid eye movement (REM) sleep on recall in the serial reaction time task (SRTT) was explored in healthy humans. The motor task was learned in the evening. Recall was performed immediately after tDCS or the following morning. In two separate control experiments, excitability-enhancing premotor tDCS was performed 4 h after task learning during daytime or immediately before conduction of a simple reaction time task. Excitability-enhancing tDCS performed during REM sleep increased recall of the learned movement sequences, when tested immediately after stimulation. REM density was enhanced by excitability-increasing tDCS and reduced by inhibitory tDCS, but did not correlate with task performance. In the control experiments, tDCS did not improve performance. We conclude that the premotor cortex is involved in motor memory consolidation during REM sleep.

scholarly journals The neural basis for response latency in a sensory-motor behavior

2019 ◽  
Author(s):  
Joonyeol Lee ◽  
Timothy R. Darlington ◽  
Stephen G. Lisberger
Keyword(s):  
Reaction Time ◽  
Eye Movement ◽  
Smooth Pursuit ◽  
Visual Motion ◽  
Threshold Model ◽  
Field Potential ◽  
Reaction Times ◽  
Neural Basis ◽  
Sensory Motor ◽  
Preparatory Activity

AbstractWe seek a neural circuit explanation for sensory-motor reaction times. We have found evidence that two of three possible mechanisms could contribute to reaction times in smooth pursuit eye movements. In the smooth eye movement region of the frontal eye fields (FEFSEM), an area that causally affects the initiation of smooth pursuit eye movement, neural and behavioral latencies have significant trial-by-trial correlations that can account for 40% to 100% of the variation in behavioral latency. The amplitude of preparatory activity, which represents the motor system’s expectations for target motion, shows negative trial-by-trial correlations with behavioral latency and could contribute to the neural computation of reaction time. In contrast, the traditional “ramp-to-threshold” model is contradicted by the responses of many, but not all FEFSEM neurons. As evidence of neural processing that determines reaction time, the local field potential in FEFSEM includes a brief wave in the 5-15 Hz frequency range that precedes pursuit initiation and whose phase is correlated with the latency of pursuit in individual trials. We suggest that the latency of the incoming visual motion signals combines with the state of preparatory activity to determine the latency of the transient response that drives eye movement.

scholarly journals Age-related increases in reaction time result from slower preparation, not delayed initiation

2021 ◽  
Author(s):  
Robert M Hardwick ◽  
Alexander D Forrence ◽  
Maria Gabriela Costello ◽  
Kathy Zachowski ◽  
Adrian M Haith
Keyword(s):  
Reaction Time ◽  
Reaction Times ◽  
Forced Response ◽  
Movement Preparation ◽  
Response Condition ◽  
Time Condition ◽  
Age Related ◽  
Brain Structure And Function ◽  
Time Required ◽  
Reaction Time Condition

Recent work indicates that healthy younger adults can prepare accurate responses faster than their voluntary reaction times indicate, leaving a seemingly unnecessary delay of 80-100ms before responding. Here we examined how the preparation of movements, initiation of movements, and the delay between them are affected by age. Participants made planar reaching movements in two conditions. The "Free Reaction Time" condition assessed the voluntary reaction times at which participants responded to the appearance of a stimulus. The "Forced Reaction Time" condition assessed the minimum time actually needed to prepare accurate movements by controlling the time allowed for movement preparation. The time taken to both initiate movements in the Free Reaction Time and to prepare movements in the Forced Response condition increased with age. Notably, the time required to prepare accurate movements was significantly shorter than participants' self-selected initiation times; however, the delay between movement preparation and initiation remained consistent across the lifespan (~90ms). These results indicate that the slower reaction times of healthy older adults are not due to an increased hesitancy to respond, but can instead be attributed to changes in their ability to process stimuli and prepare movements accordingly, consistent with age-related changes in brain structure and function.

scholarly journals Increased preparation time reduces, but does not abolish, action history bias of saccadic eye movements

2019 ◽  
Vol 121 (4) ◽  
pp. 1478-1490 ◽  
Author(s):  
Eva-Maria Reuter ◽  
Welber Marinovic ◽  
Timothy N. Welsh ◽  
Timothy J. Carroll
Keyword(s):  
Eye Movements ◽  
Reaction Time ◽  
Target Location ◽  
Reaction Times ◽  
Saccadic Eye Movements ◽  
Limb Movements ◽  
Preparation Time ◽  
Movement History ◽  
Target Locations ◽  
Dependent Processes

The characteristics of movements are strongly history-dependent. Marinovic et al. (Marinovic W, Poh E, de Rugy A, Carroll TJ. eLife 6: e26713, 2017) showed that past experience influences the execution of limb movements through a combination of temporally stable processes that are strictly use dependent and dynamically evolving and context-dependent processes that reflect prediction of future actions. Here we tested the basis of history-dependent biases for multiple spatiotemporal features of saccadic eye movements under two preparation time conditions (long and short). Twenty people performed saccades to visual targets. To prompt context-specific expectations of most likely target locations, 1 of 12 potential target locations was specified on ~85% of the trials and each remaining target was presented on ~1% trials. In long preparation trials participants were shown the location of the next target 1 s before its presentation onset, whereas in short preparation trials each target was first specified as the cue to move. Saccade reaction times and direction were biased by recent saccade history but according to distinct spatial tuning profiles. Biases were purely expectation related for saccadic reaction times, which increased linearly as the distance from the repeated target location increased when preparation time was short but were similar to all targets when preparation time was long. By contrast, the directions of saccades were biased toward the repeated target in both preparation time conditions, although to a lesser extent when the target location was precued (long preparation). The results suggest that saccade history affects saccade dynamics via both use- and expectation-dependent mechanisms and that movement history has dissociable effects on reaction time and saccadic direction. NEW & NOTEWORTHY The characteristics of our movements are influenced not only by concurrent sensory inputs but also by how we have moved in the past. For limb movements, history effects involve both use-dependent processes due strictly to movement repetition and processes that reflect prediction of future actions. Here we show that saccade history also affects saccade dynamics via use- and expectation-dependent mechanisms but that movement history has dissociable effects on saccade reaction time and direction.

Repetitive stimulation of premotor cortex affects primary motor cortex excitability and movement preparation

2009 ◽  
Vol 2 (3) ◽  
pp. 152-162 ◽  
Author(s):  
Cathy M. Stinear ◽  
P. Alan Barber ◽  
James P. Coxon ◽  
Toby S. Verryt ◽  
Pratima P. Acharya ◽  
...  
Keyword(s):  
Motor Cortex ◽  
Primary Motor Cortex ◽  
Premotor Cortex ◽  
Repetitive Stimulation ◽  
Movement Preparation ◽  
Motor Cortex Excitability ◽  
Stimulation Of

scholarly journals Neural dynamics of variable grasp movement preparation in the macaque fronto-parietal network

2017 ◽  
Author(s):  
Jonathan A Michaels ◽  
Benjamin Dann ◽  
Rijk W Intveld ◽  
Hansjörg Scherberger
Keyword(s):  
Parietal Cortex ◽  
Premotor Cortex ◽  
Initial Population ◽  
Movement Preparation ◽  
Reach To Grasp ◽  
Movement Initiation ◽  
Preparation Time ◽  
Population Activity ◽  
Grasp Planning ◽  
Macaque Monkeys

AbstractOur voluntary grasping actions lie on a continuum between immediate action and waiting for the right moment, depending on the context. Therefore, studying grasping requires investigating how preparation time affects this process. Two macaque monkeys (Macaca mulatta) performed a grasping task with a short instruction followed by an immediate or delayed go cue (0-1300 ms) while we recorded in parallel from neurons in the hand area (F5) of the ventral premotor cortex and the anterior intraparietal area (AIP). Initial population dynamics followed a fixed trajectory in the neural state space unique to each grip type, reflecting unavoidable preparation, then diverged depending on the delay. Although similar types of single unit responses were present in both areas, population activity in AIP stabilized within a unique memory state while F5 activity continued to evolve, tracking subjective anticipation of the go cue. Intriguingly, activity during movement initiation clustered into two trajectory clusters, corresponding to movements that were either ‘as fast as possible’ or withheld movements, demonstrating a widespread state shift in the fronto-parietal grasping network when movements must be withheld. Our results reveal how dissociation between static and dynamic components of movement preparation as well as differentiation between cortical areas is possible through population level analysis.Significance StatementMany of our movements must occur with no warning, while others we can prepare in advance. Yet, it’s unclear how planning for movements along the spectrum between these two situations differs in the brain. Two macaque monkeys made reach to grasp movements after varying amounts of preparation time while we recorded from premotor and parietal cortex. We found that the initial response to a grasp instruction was specific to the required movement, but not the preparation time, reflecting required processing. However, when more preparation time was given, neural activity achieved unique states that likely related to withholding movements and anticipation of movement, which was more prevalent in premotor cortex, suggesting differing roles of premotor and parietal cortex in grasp planning.

Effects of Small Ischemic Lesions in the Primary Motor Cortex on Neurophysiological Organization in Ventral Premotor Cortex

2006 ◽  
Vol 96 (6) ◽  
pp. 3506-3511 ◽  
Author(s):  
Numa Dancause ◽  
Scott Barbay ◽  
Shawn B. Frost ◽  
Elena V. Zoubina ◽  
Erik J. Plautz ◽  
...  
Keyword(s):  
Motor Cortex ◽  
Primary Motor Cortex ◽  
Premotor Cortex ◽  
Relative Size ◽  
Cortical Lesion ◽  
Intracortical Microstimulation ◽  
Anatomical Changes ◽  
Cortical Areas ◽  
Ventral Premotor Cortex

After a cortical lesion, cortical areas distant from the site of injury are known to undergo physiological and anatomical changes. However, the mechanisms through which reorganization of distant cortical areas is initiated are poorly understood. In a previous publication, we showed that the ventral premotor cortex (PMv) undergoes physiological reorganization after a lesion destroying the majority of the primary motor cortex (M1) distal forelimb representation (DFL). After large lesions destroying >50% of the M1 DFL, the PMv DFL invariably increased in size, and the amount of the increase was positively correlated with the size of lesion. To determine whether lesions destroying <50% of the M1 DFL followed a similar trajectory, we documented PMv reorganization using intracortical microstimulation techniques after small, ischemic lesions targeting subregions within the M1 DFL. In contrast to earlier results, lesions resulted in a reduction of the PMv DFL regardless of their location. Further, because recent anatomical findings suggest a segregation of PMv connectivity with M1, we examined two lesion characteristics that may drive alterations in PMv physiological reorganization: location of the lesion with respect to PMv connectivity and relative size of the lesion. The results suggest that after a lesion in the M1 DFL, the induction of representational plasticity in PMv, as evaluated using intracortical microstimulation, is related more to the size of the lesion than to the disruption of its intracortical connections.

Prior Information in Motor and Premotor Cortex: Activity During the Delay Period and Effect on Pre-Movement Activity

2000 ◽  
Vol 84 (2) ◽  
pp. 986-1005 ◽  
Author(s):  
Donald J. Crammond ◽  
John F. Kalaska
Keyword(s):  
Reaction Time ◽  
Prior Information ◽  
Primary Motor Cortex ◽  
Response Selection ◽  
Premotor Cortex ◽  
Motor Planning ◽  
Large Change ◽  
Delay Period ◽  
Short Latency ◽  
Planning Stage

In instructed-delay (ID) tasks, instructional cues provide prior information about the nature of a movement to execute after a delay. Neuronal responses in dorsal premotor cortex (PMd) during the instructed-delay period (IDP) between the CUE and subsequent GO signals are presumed to reflect early planning stages initiated by the prior information. In contrast, in multiple-choice reaction-time (RT) tasks, all motor planning and execution processes must occur after the GO signal. These assumptions predict that neuronal planning correlates recorded during the IDP of ID trials should share common features with early post-GO activity in RT trials, and that those response components need not be recapitulated after the GO signal of ID trials. These two predictions were tested by comparing activity recorded in RT and ID tasks from 503 neurons in PMd and caudal (MIc) and rostral (MIr) primary motor cortex. The incidence and strength of directionally tuned IDP activity declined progressively from PMd to MIc. The directional tuning of activity during the IDP of ID trials was more similar to that in the reaction-time epoch (RTE) of RT trials than after movement onset, especially in PMd. A modulation of post-GO activity was often observed between RT and ID trials and was confined mainly to the RTE. This effect was also most prominent in PMd. The most common change was a reduction in intensity of short-latency phasic responses to the GO signal between RT and ID trials, especially in PMd cells with a short-latency phasic response to CUE signals. However, the largest group of cells in each area showed no large change in peak RTE activity between RT and ID trials, whether they were active in the IDP or not. Since early phasic CUE-related responses are least likely to be recapitulated after the GO signal in ID trials, they may be a neuronal correlate of an early planning stage such as response selection. Tonic IDP responses, which are not as strongly associated with a post-GO reduction in activity, may be related to other aspects of motor planning and preparation. Finally, a major component of the movement-related activity in both MI and PMd is not susceptible to modification by prior information and is indivisibly coupled temporally to movement execution.

scholarly journals Stimulating the Healthy Brain to Investigate Neural Correlates of Motor Preparation: A Systematic Review

2018 ◽  
Vol 2018 ◽  
pp. 1-14 ◽  
Author(s):  
Cécilia Neige ◽  
Hugo Massé-Alarie ◽  
Catherine Mercier
Keyword(s):  
Systematic Review ◽  
Reaction Time ◽  
Brain Stimulation ◽  
Posterior Parietal Cortex ◽  
Primary Motor Cortex ◽  
Data Extraction ◽  
Premotor Cortex ◽  
Motor Preparation ◽  
Cortical Region ◽  
Noninvasive Brain Stimulation

Objective. Noninvasive brain stimulation techniques can be used to selectively increase or decrease the excitability of a cortical region, providing a unique opportunity to assess the causal contribution of that region to the process being assessed. The objective of this paper is to systematically examine studies investigating changes in reaction time induced by noninvasive brain stimulation in healthy participants during movement preparation. Methods. A systematic review of the literature was performed in the PubMed, MEDLINE, EMBASE, PsycINFO, and Web of science databases. A combination of keywords related to motor preparation, associated behavioral outcomes, and noninvasive brain stimulation methods was used. Results. Twenty-seven studies were included, and systematic data extraction and quality assessment were performed. Reaction time results were transformed in standardised mean difference and graphically pooled in forest plots depending on the targeted cortical area and the type of stimulation. Conclusions. Despite methodological heterogeneity among studies, results support a functional implication of five cortical regions (dorsolateral prefrontal cortex, posterior parietal cortex, supplementary motor area, dorsal premotor cortex, and primary motor cortex), integrated into a frontoparietal network, in various components of motor preparation ranging from attentional to motor aspects.

Modeling Within-Person Variance in Reaction Time Data of Older Adults

GeroPsych ◽  
2011 ◽  
Vol 24 (4) ◽  
pp. 169-176 ◽  
Author(s):  
Philippe Rast ◽  
Daniel Zimprich
Keyword(s):  
Reaction Time ◽  
Cognitive Aging ◽  
Reaction Times ◽  
Reaction Time Task ◽  
Reaction Time Data ◽  
Scale Model ◽  
Time Data ◽  
Time Task ◽  
The Mean ◽  
Second Wave

In order to model within-person (WP) variance in a reaction time task, we applied a mixed location scale model using 335 participants from the second wave of the Zurich Longitudinal Study on Cognitive Aging. The age of the respondents and the performance in another reaction time task were used to explain individual differences in the WP variance. To account for larger variances due to slower reaction times, we also used the average of the predicted individual reaction time (RT) as a predictor for the WP variability. Here, the WP variability was a function of the mean. At the same time, older participants were more variable and those with better performance in another RT task were more consistent in their responses.

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