scholarly journals Effects of neuromuscular lags on controlling contact transitions

2009 ◽  
Vol 367 (1891) ◽  
pp. 1163-1179 ◽  
Author(s):  
Madhusudhan Venkadesan ◽  
Francisco J Valero-Cuevas
Keyword(s):  
Neural Control ◽  
Deterministic Model ◽  
Optimal Solution ◽  
Trade Off ◽  
Joint Torques ◽  
Human Data ◽  
Force Magnitude ◽  
Trade Offs ◽  
Speed Accuracy ◽  
Force Vectors

We present a numerical exploration of contact transitions with the fingertip. When picking up objects our fingertips must make contact at specific locations, and—upon contact—maintain posture while producing well-directed force vectors. However, the joint torques for moving the fingertip towards a surface ( τ m ) are different from those for producing static force vectors ( τ f ). We previously described the neural control of such abrupt transitions in humans, and found that unavoidable errors arise because sensorimotor time delays and lags prevent an instantaneous switch between different torques. Here, we use numerical optimization on a finger model to reveal physical bounds for controlling such rapid contact transitions. Resembling human data, it is necessary to anticipatorily switch joint torques to τ f at about 30 ms before contact to minimize the initial misdirection of the fingertip force vector. This anticipatory strategy arises in our deterministic model from neuromuscular lags, and not from optimizing for robustness to noise/uncertainties. Importantly, the optimal solution also leads to a trade-off between the speed of force magnitude increase versus the accuracy of initial force direction. This is an alternative to prevailing theories that propose multiplicative noise in muscles as the driver of speed–accuracy trade-offs. We instead find that the speed–accuracy trade-off arises solely from neuromuscular lags. Finally, because our model intentionally uses idealized assumptions, its agreement with human data suggests that the biological system is controlled in a way that approaches the physical boundaries of performance.

Dual Goals for Speed and Accuracy on the Same Performance Task

2012 ◽  
Vol 11 (3) ◽  
pp. 118-126 ◽  
Author(s):  
Olive Emil Wetter ◽  
Jürgen Wegge ◽  
Klaus Jonas ◽  
Klaus-Helmut Schmidt
Keyword(s):  
Memory Scanning ◽  
Performance Task ◽  
Performance Tasks ◽  
Trade Off ◽  
Test Experiment ◽  
Trade Offs ◽  
New Finding ◽  
Sternberg Paradigm ◽  
Speed Accuracy ◽  
Speed And Accuracy

In most work contexts, several performance goals coexist, and conflicts between them and trade-offs can occur. Our paper is the first to contrast a dual goal for speed and accuracy with a single goal for speed on the same task. The Sternberg paradigm (Experiment 1, n = 57) and the d2 test (Experiment 2, n = 19) were used as performance tasks. Speed measures and errors revealed in both experiments that dual as well as single goals increase performance by enhancing memory scanning. However, the single speed goal triggered a speed-accuracy trade-off, favoring speed over accuracy, whereas this was not the case with the dual goal. In difficult trials, dual goals slowed down scanning processes again so that errors could be prevented. This new finding is particularly relevant for security domains, where both aspects have to be managed simultaneously.

scholarly journals Relationship Between Language Dominance and Stimulus-Stimulus or Stimulus-Response Inhibition in Uyghur-Chinese Bilinguals with an Investigation of Speed-Accuracy Trade-Offs

2019 ◽  
Vol 9 (4) ◽  
pp. 41 ◽  
Author(s):  
Wu ◽  
Struys ◽  
Lochtman
Keyword(s):  
Cognitive Control ◽  
Language Processing ◽  
Flanker Task ◽  
Trade Off ◽  
Language Dominance ◽  
Stimulus Response ◽  
Trade Offs ◽  
Monitoring Process ◽  
Response Task ◽  
Speed Accuracy

The effect of bilingualism on inhibition control is increasingly under ongoing exploration. The present study primarily investigated the effect of within bilingual factors (i.e., dominance types of Uyghur-Chinese bilinguals) on a Stimulus-Stimulus task (Flanker) and a Stimulus-Response task (Simon). We also compared the bilinguals' performance on each type of cognitive control task in respect to a possible trade-off between speed and accuracy. The findings showed no explicit differences on performance in response time or accuracy among balanced, L1-dominant and L2-dominant bilinguals but balanced bilinguals demonstrated a significant speed-accuracy trade-off in the overall context switching between non-conflict and conflict trials in both cognitive control tasks where monitoring process is highly demanded. Additionally, all bilinguals across all language dominance types showed a trade-off strategy in inhibition during a Stimulus-Stimulus conflict (flanker task). This evidence indicates that the differences of within bilinguals in cognitive control could lie in the monitoring process, while for all bilinguals, inhibition during a Stimulus-Stimulus conflict could be a major component in the mechanism of bilingual language processing.

Are speed/accuracy trade-offs caused by neuromotor noise, or not?

1997 ◽  
Vol 20 (2) ◽  
pp. 306-307 ◽  
Author(s):  
Willem P. De Jong ◽  
Gerard P. Van Galen
Keyword(s):  
Kinematic Model ◽  
Psychological Processes ◽  
Trade Off ◽  
Kinematic Theory ◽  
Trade Offs ◽  
Biomechanical Constraints ◽  
Speed Accuracy ◽  
Existing Data ◽  
The Way

Notwithstanding its overwhelming descriptive power for existing data, it is not clear whether the kinematic theory of Plamondon & Alimi could generate new insights into biomechanical constraints and psychological processes underlying the way organisms trade off speed for accuracy. The kinematic model should elaborate on the role of neuromotor noise and on biomechanical strategies for reducing endpoint variability related to such noise.

scholarly journals “Satisficing” and trade-offs: evaluating rebuilding strategies for Greenland halibut off the east coast of Canada

2010 ◽  
Vol 67 (9) ◽  
pp. 1896-1902 ◽  
Author(s):  
David C. M. Miller ◽  
Peter A. Shelton
Keyword(s):  
Management Strategy ◽  
East Coast ◽  
A Priori ◽  
Management Strategies ◽  
Optimal Solution ◽  
Greenland Halibut ◽  
Trade Off ◽  
Trade Offs ◽  
Survey Estimates ◽  
Performance Statistics

Abstract Miller, D. C. M., and Shelton, P. A. 2010. “Satisficing” and trade-offs: evaluating rebuilding strategies for Greenland halibut off the east coast of Canada. – ICES Journal of Marine Science, 67: 1896–1902. To be effective, management strategy evaluation (MSE) requires a well-defined procedure for comparing the merits of candidate management strategies. We explore a two-step approach of “satisficing” followed by a trade-off analysis. “Satisficing” (a portmanteau of “satisfy” and “suffice”) is a decision-making procedure that attempts to meet criteria for adequacy, rather than identify an optimal solution. As a case study, we consider the results from a comprehensive MSE for Greenland halibut off the east coast of Canada, carried out under the auspices of the Northwest Atlantic Fisheries Organization. First, we apply satisficing to the results to determine which rebuilding strategies achieve pre-specified thresholds set for imperative performance statistics relating to resource conservation, yield, and stability of the fishery. Next, trade-offs among important, but not necessarily imperative, performance statistics are evaluated for those strategies that pass the satisficing step. For Greenland halibut, a management strategy containing a simple feedback harvest-control rule based on recent trends in survey estimates of abundance satisfices all imperative requirements and provides the best trade-off in other performance statistics. The approach necessitates translating objectives for stock rebuilding and sustainable fisheries into operationally explicit terms and incorporates a priori consideration of stakeholders' concerns.

scholarly journals Tuning the speed-accuracy trade-off to maximize reward rate in multisensory decision-making

eLife ◽  
2015 ◽  
Vol 4 ◽  
Author(s):  
Jan Drugowitsch ◽  
Gregory C DeAngelis ◽  
Dora E Angelaki ◽  
Alexandre Pouget
Keyword(s):  
Decision Making ◽  
Time Pressure ◽  
Human Subjects ◽  
Neural Population ◽  
Trade Off ◽  
Reward Rate ◽  
Trade Offs ◽  
Sensory Modalities ◽  
Effective Decision Making ◽  
Speed Accuracy

For decisions made under time pressure, effective decision making based on uncertain or ambiguous evidence requires efficient accumulation of evidence over time, as well as appropriately balancing speed and accuracy, known as the speed/accuracy trade-off. For simple unimodal stimuli, previous studies have shown that human subjects set their speed/accuracy trade-off to maximize reward rate. We extend this analysis to situations in which information is provided by multiple sensory modalities. Analyzing previously collected data (<xref ref-type="bibr" rid="bib4">Drugowitsch et al., 2014</xref>), we show that human subjects adjust their speed/accuracy trade-off to produce near-optimal reward rates. This trade-off can change rapidly across trials according to the sensory modalities involved, suggesting that it is represented by neural population codes rather than implemented by slow neuronal mechanisms such as gradual changes in synaptic weights. Furthermore, we show that deviations from the optimal speed/accuracy trade-off can be explained by assuming an incomplete gradient-based learning of these trade-offs.

Perception in Volleyball: The Effects of Competitive Stress

1983 ◽  
Vol 5 (2) ◽  
pp. 189-196 ◽  
Author(s):  
Janet L. Starkes ◽  
Fran Allard
Keyword(s):  
Cognitive Flexibility ◽  
Response Speed ◽  
Perceptual Accuracy ◽  
Trade Off ◽  
Trade Offs ◽  
Volleyball Players ◽  
Perceptual Narrowing ◽  
Speed Accuracy ◽  
Speed And Accuracy

Volleyball players and nonplayers were compared for speed and accuracy of performance in a task involving detection of the presence of a volleyball in rapidly presented slides of a volleyball situation. Slides depicted both game and nongame situations, and subjects performed the task in both noncompetitive and competitive conditions. For all subjects, game information was perceived more quickly and accurately than nongame information. In competition all subjects showed decreased perceptual accuracy and no change in criterion, supporting the Easterbrook (1959) notion of perceptual narrowing with stress. Very large accompanying increases in response speed, however, suggested that competition may induce adoption of a particular speed-accuracy trade-off. Cognitive flexibility in the adoption of particular speed-accuracy trade-offs is discussed with reference to volleyball.

scholarly journals A review of grasping as the movements of digits in space

2019 ◽  
Vol 122 (4) ◽  
pp. 1578-1597 ◽  
Author(s):  
Jeroen B. J. Smeets ◽  
Katinka van der Kooij ◽  
Eli Brenner
Keyword(s):  
Neural Control ◽  
The Other ◽  
Reach To Grasp ◽  
Grip Aperture ◽  
Trade Off ◽  
Size Information ◽  
Direct Support ◽  
Speed Accuracy ◽  
Hand Transport ◽  
Fast Responses

It is tempting to describe human reach-to-grasp movements in terms of two, more or less independent visuomotor channels, one relating hand transport to the object’s location and the other relating grip aperture to the object’s size. Our review of experimental work questions this framework for reasons that go beyond noting the dependence between the two channels. Both the lack of effect of size illusions on grip aperture and the finding that the variability in grip aperture does not depend on the object’s size indicate that size information is not used to control grip aperture. An alternative is to describe grip formation as emerging from controlling the movements of the digits in space. Each digit’s trajectory when grasping an object is remarkably similar to its trajectory when moving to tap the same position on its own. The similarity is also evident in the fast responses when the object is displaced. This review develops a new description of the speed-accuracy trade-off for multiple effectors that is applied to grasping. The most direct support for the digit-in-space framework is that prism-induced adaptation of each digit’s tapping movements transfers to that digit’s movements when grasping, leading to changes in grip aperture for adaptation in opposite directions for the two digits. We conclude that although grip aperture and hand transport are convenient variables to describe grasping, treating grasping as movements of the digits in space is a more suitable basis for understanding the neural control of grasping.

scholarly journals Risk sensitivity in a motor task with speed-accuracy trade-off

2011 ◽  
Vol 105 (6) ◽  
pp. 2668-2674 ◽  
Author(s):  
Arne J. Nagengast ◽  
Daniel A. Braun ◽  
Daniel M. Wolpert
Keyword(s):  
High Speed ◽  
Motor Task ◽  
Payoff Function ◽  
Individual Risk ◽  
Risk Sensitivity ◽  
Trade Off ◽  
Trade Offs ◽  
Risk Neutral ◽  
The Mean ◽  
Speed Accuracy

When a racing driver steers a car around a sharp bend, there is a trade-off between speed and accuracy, in that high speed can lead to a skid whereas a low speed increases lap time, both of which can adversely affect the driver's payoff function. While speed-accuracy trade-offs have been studied extensively, their susceptibility to risk sensitivity is much less understood, since most theories of motor control are risk neutral with respect to payoff, i.e., they only consider mean payoffs and ignore payoff variability. Here we investigate how individual risk attitudes impact a motor task that involves such a speed-accuracy trade-off. We designed an experiment where a target had to be hit and the reward (given in points) increased as a function of both subjects' endpoint accuracy and endpoint velocity. As faster movements lead to poorer endpoint accuracy, the variance of the reward increased for higher velocities. We tested subjects on two reward conditions that had the same mean reward but differed in the variance of the reward. A risk-neutral account predicts that subjects should only maximize the mean reward and hence perform identically in the two conditions. In contrast, we found that some (risk-averse) subjects chose to move with lower velocities and other (risk-seeking) subjects with higher velocities in the condition with higher reward variance (risk). This behavior is suboptimal with regard to maximizing the mean number of points but is in accordance with a risk-sensitive account of movement selection. Our study suggests that individual risk sensitivity is an important factor in motor tasks with speed-accuracy trade-offs.

scholarly journals Trial-to-trial adjustments of speed-accuracy trade-offs in premotor and primary motor cortex

2017 ◽  
Vol 117 (2) ◽  
pp. 665-683 ◽  
Author(s):  
David Thura ◽  
Guido Guberman ◽  
Paul Cisek
Keyword(s):  
Motor Cortex ◽  
Primary Motor Cortex ◽  
Premotor Cortex ◽  
Decision Task ◽  
Trade Off ◽  
Task Support ◽  
Trade Offs ◽  
Sensory Evidence ◽  
Speed Accuracy ◽  
After Error

Recent studies have shown that activity in sensorimotor structures varies depending on the speed-accuracy trade-off (SAT) context in which a decision is made. Here we tested the hypothesis that the same areas also reflect a more local adjustment of SAT established between individual trials, based on the outcome of the previous decision. Two monkeys performed a reaching decision task in which sensory evidence continuously evolves during the time course of a trial. In two SAT contexts, we compared neural activity in trials following a correct choice vs. those following an error. In dorsal premotor cortex (PMd), we found that 23% of cells exhibited significantly weaker baseline activity after error trials, and for ∼30% of these this effect persisted into the deliberation epoch. These cells also contributed to the process of combining sensory evidence with the growing urgency to commit to a choice. We also found that the activity of 22% of PMd cells was increased after error trials. These neurons appeared to carry less information about sensory evidence and time-dependent urgency. For most of these modulated cells, the effect was independent of whether the previous error was expected or unexpected. We found similar phenomena in primary motor cortex (M1), with 25% of cells decreasing and 34% increasing activity after error trials, but unlike PMd, these neurons showed less clear differences in their response properties. These findings suggest that PMd and M1 belong to a network of brain areas involved in SAT adjustments established using the recent history of reinforcement. NEW & NOTEWORTHY Setting the speed-accuracy trade-off (SAT) is crucial for efficient decision making. Previous studies have reported that subjects adjust their SAT after individual decisions, usually choosing more conservatively after errors, but the neural correlates of this phenomenon are only partially known. Here, we show that neurons in PMd and M1 of monkeys performing a reach decision task support this mechanism by adequately modulating their firing rate as a function of the outcome of the previous decision.

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