Search

In the laser-run trial in modern pentathlon, athletes must perform series of five successful shots with a laser pistol. A miss does not lead to a penalty but costs the time needed to lower the arm, charge the weapon and raise the arm. Pentathletes face the following dilemma: is it better to shoot fast or accurately? We investigate experimentally the effect of the shooting cadence on the accuracy. We then predict the consequence of this unavoidable speed-accuracy tradeoff in terms of total time needed to succeed the specific trial of laser-run. We find an optimal shooting cadence for each athlete, which minimizes this time.

The tradeoff between speed and accuracy is a well-known constraint for human movement, but previous work has shown that this tradeoff can be modified by practice, and the quantitative relationship between speed and accuracy may be an indicator of skill in some tasks. We have previously shown that children with dystonia are able to adapt their movement strategy in a ballistic throwing game to compensate for increased variability of movement. Here, we test whether children with dystonia can adapt and improve skills learned on a trajectory task. We use a novel task in which children move a spoon with a marble between two targets. Difficulty is modified by changing the depth of the spoon. Our results show that both healthy children and children with acquired dystonia move more slowly with the more difficult spoons, and both groups improve the relationship between speed and spoon difficulty following 1 wk of practice. By tracking the marble position in the spoon, we show that children with dystonia use a larger fraction of the available variability, whereas healthy children adopt a much safer strategy and remain farther from the margins, as well as learning to adapt and have more control over the marble's utilized area by practice. Together, our results show that both healthy children and children with dystonia choose trajectories that compensate for risk and inherent variability, and that the increased variability in dystonia can be modified with continued practice. NEW & NOTEWORTHY This study provides insights into the adaptability of children with dystonia in learning a point-to-point task. We show that these children adjust their strategies to account for increased difficulty in the task. Our findings underscore the potential of task-specific practice in improving motor skills and show higher level of signal-dependent noise can be controlled through repetition and learned strategies, which provides an avenue for the quantitative evaluation of rehabilitation strategies in this challenging group.

The rationale for Fitts' law is that pointing tasks have the information-theoretic analogy of sending a signal over a noisy channel, thereby matching Shannon's capacity formula. Yet, the currently received analysis is incomplete and unsatisfactory: There is no explicit communication model for pointing; there is a confusion between central concepts of capacity (a mathematical limit), throughput (an average performance measure), and bandwidth (a physical quantity); and there is also a confusion between source and channel coding so that Shannon's Theorem 17 can be misinterpreted. We develop an information-theoretic model for pointing tasks where the index of difficulty (ID) is the expression of both a source entropy and a zero-error channel capacity. Then, we extend the model to include misses at rate ε and prove that ID should be adjusted to (1−ε)ID. Finally, we reflect on Shannon's channel coding theorem and argue that only minimum movement times, not performance averages, should be considered. [ABSTRACT FROM AUTHOR]

A common aspect of individuality is our subjective preferences in evaluation of reward and effort. The neural circuits that evaluate these commodities influence circuits that control our movements, raising the possibility that vigor differences between individuals may also be a trait of individuality, reflecting a willingness to expend effort. In contrast, classic theories in motor control suggest that vigor differences reflect a speed-accuracy trade-off, predicting that those who move fast are sacrificing accuracy for speed. Here we tested these contrasting hypotheses. We measured motion of the eyes, head, and arm in healthy humans during various elementary movements (saccades, head-free gaze shifts, and reaching). For each person we characterized their vigor, i.e., the speed with which they moved a body part (peak velocity) with respect to the population mean. Some moved with low vigor, while others moved with high vigor. Those with high vigor tended to react sooner to a visual stimulus, moving both their eyes and arm with a shorter reaction time. Arm and head vigor were tightly linked: individuals who moved their head with high vigor also moved their arm with high vigor. However, eye vigor did not correspond strongly with arm or head vigor. In all modalities, vigor had no impact on end-point accuracy, demonstrating that differences in vigor were not due to a speed-accuracy trade-off. Our results suggest that movement vigor may be a trait of individuality, not reflecting a willingness to accept inaccuracy but demonstrating a propensity to expend effort. NEW & NOTEWORTHY A common aspect of individuality is how we evaluate economic variables like reward and effort. This valuation affects not only decision making but also motor control, raising the possibility that vigor may be distinct between individuals but conserved across movements within an individual. Here we report conservation of vigor across elementary skeletal movements, but not eye movements, raising the possibility that the individuality of our movements may be driven by a common neural mechanism of effort evaluation across modalities of skeletal motor control. [ABSTRACT FROM AUTHOR]

Language comprehension involves coping with ambiguity and recovering from misanalysis. Syntactic ambiguity resolution is associated with increased reading times, a classic finding that has shaped theories of sentence processing. However, reaction times conflate the time it takes a process to complete with the quality of the behavior-related information available to the system. We therefore used the speed-accuracy tradeoff procedure (SAT) to derive orthogonal estimates of processing time and interpretation accuracy, and tested whether stronger retrieval cues (via semantic relatedness: neighed->horse vs. fell->horse) aid interpretation during recovery. On average, ambiguous sentences took 250ms longer (SAT rate) to interpret than unambiguous controls, demonstrating veridical differences in processing time. Retrieval cues more strongly related to the true subject always increased accuracy, regardless of ambiguity. These findings are consistent with a language processing architecture where cue-driven operations give rise to interpretation, and wherein diagnostic cues aid retrieval, regardless of parsing difficulty or structural uncertainty. [ABSTRACT FROM AUTHOR]

Balancing the speed-accuracy tradeoff (SAT) is necessary for successful behavior. Using a visual search task with interleaved cues emphasizing speed or accuracy, we recently reported diverse contributions of frontal eye field (FEF) neurons instantiating salience evidence and response preparation. Here, we report replication of visual search SAT performance in two macaque monkeys, new information about variation of saccade dynamics with SAT, extension of the neurophysiological investigation to describe processes in the superior colliculus (SC), and a description of the origin of search errors in this task. Saccade vigor varied idiosyncratically across SAT conditions and monkeys but tended to decrease with response time. As observed in the FEF, speed-accuracy tradeoff was accomplished through several distinct adjustments in the superior colliculus. In "Accurate" relative to "Fast" trials, visually responsive neurons in SC as in FEF had lower baseline firing rates and later target selection. The magnitude of these adjustments in SC was indistinguishable from that in FEF. Search errors occurred when visual salience neurons in the FEF and the SC treated distractors as targets, even in the Accurate condition. Unlike FEF, the magnitude of visual responses in the SC did not vary across SAT conditions. Also unlike FEF, the activity of SC movement neurons when saccades were initiated was equivalent in Fast and Accurate trials. Saccade-related neural activity in SC, but not FEF, varied with saccade peak velocity. These results extend our understanding of the cortical and subcortical contributions to SAT. NEW & NOTEWORTHY Neurophysiological mechanisms of speed-accuracy tradeoff (SAT) have only recently been investigated. This article reports the first replication of SAT performance in nonhuman primates, the first report of variation of saccade dynamics with SAT, the first description of superior colliculus contributions to SAT, and the first description of the origin of errors during SAT. These results inform and constrain new models of distributed decision making. [ABSTRACT FROM AUTHOR]

Fitts’ law has been widely used in the human-computer interaction (HCI) field, especially for Graphical User Interface (GUI) design. However, most studies on Fitts’ law were performed with motion control tasks under visual feedback while only a few endeavor to measure human force control behavior. How quickly humans can exert a constant force with a required accuracy and whether this speed-accuracy tradeoff obeys Fitts’ law still needs to be explored. In this paper, human capabilities for controlling absolute magnitudes of fingertip force with discrete visual/audio/haptic feedback cues were observed and compared. Eighteen participants applied constant forces by pressing a force sensor with their index fingers in the three feedback modes respectively. Response time of 24 pairs (4 × 6) of Magnitude-Tolerance conditions were measured. The results showed that the response time obeyed Fitts’ law within a certain range of force accuracy in all the three feedback modes, while the Linear speed-accuracy tradeoff model was almost superior for the force control process than the Meyer formulation and the Shannon formulation. The response time in the audio feedback mode was the shortest among the three feedback conditions. The results may be used as guidelines for applications that rely on accurate and quick force control under different feedback conditions such as fast tapping tasks on a touch screen. [ABSTRACT FROM AUTHOR]

Optimal decision-making requires balancing fast but error-prone and more accurate but slower decisions through adjustments of decision thresholds. Here, we demonstrate two distinct correlates of such speed-accuracy adjustments by recording subthalamic nucleus (STN) activity and electroencephalography in 11 Parkinson’s disease patients during a perceptual decision-making task; STN low-frequency oscillatory (LFO) activity (2–8 Hz), coupled to activity at prefrontal electrode Fz, and STN beta activity (13–30 Hz) coupled to electrodes C3/C4 close to motor cortex. These two correlates differed not only in their cortical topography and spectral characteristics but also in the relative timing of recruitment and in their precise relationship with decision thresholds. Increases of STN LFO power preceding the response predicted increased thresholds only after accuracy instructions, while cue-induced reductions of STN beta power decreased thresholds irrespective of instructions. These findings indicate that distinct neural mechanisms determine whether a decision will be made in haste or with caution.

Place kicking occurs many times during a rugby union game with more than half of all points scored coming from place kicking. Ball velocity is an important biomechanical indicator of kicking success, but it also evident that the ball must be kicked accurately to pass between the posts. This study aimed to identify biomechanical differences in rugby place kicking kinematics when kicking towards a specific target and for maximum velocity. Ten male rugby union kickers performed place kicks in two conditions: (1) for maximum velocity and (2) towards a pre-defined target. Lower extremity kinematics were obtained using an optoelectric motion capture system operating at 500 Hz. Differences in lower extremity kinematics between the two kicking conditions were examined using paired t-tests. Higher ball velocities were obtained when kicking for maximum velocity. Foot linear velocity, knee extension velocity and hip extension velocity were also found to be greater when kicking for maximum velocity. Ankle dorsiflexion and peak external rotation were found to be greater in the accuracy condition. The findings suggest that rugby kickers may have selected distinct kicking mechanics characterised by reduced joint angular velocities and a more externally rotated foot position in a deliberate attempt to improve precision, sacrificing ball velocity and thus the distance that the ball can be kicked. The specific findings from the current work have implications for coaches and applied practitioners which may facilitate improvements in kicking performance. [ABSTRACT FROM AUTHOR]

Organisms making repeated simple decisions are faced with a tradeoff between urgent and cautious strategies. While animals can adopt a statistically optimal policy for this tradeoff, findings about human decision-makers have been mixed. Some studies have shown that people can optimize this 'speed-accuracy tradeoff', while others have identified a systematic bias towards excessive caution. These issues have driven theoretical development and spurred debate about the nature of human decision-making. We investigated a potential resolution to the debate, based on two factors that routinely differ between human and animal studies of decision-making: the effects of practice, and of longer-term feedback. Our study replicated the finding that most people, by default, are overly cautious. When given both practice and detailed feedback, people moved rapidly towards the optimal policy, with many participants reaching optimality with less than 1 h of practice. Our findings have theoretical implications for cognitive and neural models of simple decision-making, as well as methodological implications. [ABSTRACT FROM AUTHOR]

Introduction:Obsessive compulsive disorder (OCD) is occasionally characterized by decision-making deficits. Compared to the isolated analysis of the choice and response times, characterizing decision outputs at the level of latent processes can be a more powerful approach in revealing differences, even in subclinical cases. We hypothesized that participants with higher obsessive compulsive (OC) features would set their decision thresholds higher and thus make more cautious decisions.Method:We used a perceptual two-alternative forced-choice (2AFC) task (dot motion discrimination) to test this hypothesis in a non-clinical sample (N = 74). We fitted the data with the diffusion model and evaluated the optimality of decision outputs. We also conducted exploratory analyses to reveal which subscales best predicted the differences at the level of latent decision processes.Results:Higher OC total scores in Maudsley and Padua scales significantly predicted higher threshold settings (cautiousness). The follow-up exploratory analyses with subscale scores showed that checking and rumination tendencies predicted higher threshold settings whereas washing tendency predicted faster non-decision times.Conclusions:Our primary results showed that participants with higher degrees of OC features exhibit more cautious decision making. Our exploratory analyses also revealed distinctions based on different types of OC features in both controlled (cautiousness in decision making) and automatic (faster non-decision times) elements of the decision process. [ABSTRACT FROM AUTHOR]

To compare effects of verbal, tactile-verbal and visual feedback on muscle activation of the trunk stabilizers relative to trunk-extremity movers during Abdominal Drawing-In Maneuver (ADIM). The study employed a quasi-experimental pre-post intervention design. The study was conducted at School of Health Professions, SUNY Health Sciences University. A convenience sample of 54 healthy participants between18-49 years of age were equally divided among three feedback groups: Verbal, Tactile-Verbal and Visual. All participants were instructed similarly to perform the ADIM prior to receiving intervention 2x/week over a four-week period. The feedback provided during interventions was delivered concurrently but feedback types differed amongst the groups. Verbal group received intermittent feedback based upon observance of substitution patterns. Tactile-verbal group received feedback every trial upon palpation of Transverse Abdominis. Lastly, Visual group received feedback every trial using a pressure biofeedback unit. The percentage of maximum voluntary isometric contraction of rectus abdominis (RA), multifidus (MF), erector spinae (ES), and hamstrings (HS) as outcome measures were acquired using surface electromyography. A two-way factorial ANOVA with bootstrapping allowed comparison of pre-post difference scores across the interaction of feedback and muscle groups. HS activation decreased in the tactile-verbal group, relative to an increase in subjects given visual feedback. Furthermore, in the verbal group, HS activity increased relative to a decline in RA; and in the visual group, HS activity increased relative to a decrease in MF. However, no pre-post changes were seen across muscles with tactile-verbal feedback. Although tactile-verbal feedback did not increase MF recruitment, it recruited less HS activity than verbal and especially visual feedback. Increases in HS recruitment may reflect boredom of simple task or feedback dependency. The authors have no disclosures. [ABSTRACT FROM AUTHOR]

In two experiments, subjects trained in data entry, typing one 4-digit number at a time. At training, subjects either typed the numbers immediately after they appeared (immediate) or typed the previous number from memory while viewing the next number (delayed). In Experiment 2 stimulus presentation time was limited and either nothing or a space (gap) was inserted between the second and third digits. In both experiments after training, all subjects completed a test with no gap and typed numbers immediately. Training with a memory load improved speed across training blocks (Experiment 1) and eliminated the decline in accuracy across training blocks (Experiment 2), thus serving as a cognitive antidote to performance decrements. An analysis of each keystroke revealed different underlying processes and strategies for the two training conditions, including when encoding took place. Chunking (in which the first and last two digits are treated separately) was more evident in the immediate than in the delayed condition and was exaggerated with a gap, even at test when there was no gap. These results suggest that such two-digit chunking is due to stimulus encoding and motor planning processes as well as memory, and those processes transferred from training to testing. [ABSTRACT FROM PUBLISHER]

The flexibility of behavioral control is a testament to the brain's capacity for dynamically resolving uncertainty during goal-directed actions. This ability to select actions and learn from immediate feedback is driven by the dynamics of basal ganglia (BG) pathways. A growing body of empirical evidence conflicts with the traditional view that these pathways act as independent levers for facilitating (i.e., direct pathway) or suppressing (i.e., indirect pathway) motor output, suggesting instead that they engage in a dynamic competition during action decisions that computationally captures action uncertainty. Here we discuss the utility of encoding action uncertainty as a dynamic competition between opposing control pathways and provide evidence that this simple mechanism may have powerful implications for bridging neurocomputational theories of decision making and reinforcement learning. [ABSTRACT FROM AUTHOR]

While all humans are capable of non-verbally representing numerical quantity using so-called the approximate number system (ANS), there exist considerable individual differences in its acuity. For example, in a non-symbolic number comparison task, some people find it easy to discriminate brief presentations of 14 dots from 16 dots while others do not. Quantifying individual ANS acuity from such a task has become an essential practice in the field, as individual differences in such a primitive number sense is thought to provide insights into individual differences in learned symbolic math abilities. However, the dominant method of characterizing ANS acuity--computing the Weber fraction (w)--only utilizes the accuracy data while ignoring response times (RT). Here, we offer a novel approach of quantifying ANS acuity by using the diffusion model, which accounts both accuracy and RT distributions. Specifically, the drift rate in the diffusion model, which indexes the quality of the stimulus information, is used to capture the precision of the internal quantity representation. Analysis of behavioral data shows that w is contaminated by speed-accuracy tradeoff, making it problematic as a measure of ANS acuity, while drift rate provides a measure more independent from speed-accuracy criterion settings. Furthermore, drift rate is a better predictor of symbolic math ability than w, suggesting a practical utility of the measure. These findings demonstrate critical limitations of the use of w and suggest clear advantages of using drift rate as a measure of primitive numerical competence. [ABSTRACT FROM AUTHOR]

Odor discrimination is a complex task that may be improved by increasing sampling time to facilitate evidence accumulation. However, experiments testing this phenomenon in olfaction have produced conflicting results. To resolve this disparity, Frederick et al. (Frederick DE, Brown A, Tacopina S, Mehta N, Vujovic M, Brim E, Amina T, Fixsen B, Kay LM. J Neurosci 37: 4416-4426, 2017) conducted experiments that suggest that sampling time and performance are task dependent. Their findings have implications for understanding olfactory processing and experimental design, specifically the effect of subtle differences in experimental design on study results. [ABSTRACT FROM AUTHOR]

The study investigates the neurocognitive stages involved in the speed-accuracy trade-off (SAT). Contrary to previous approach, we did not manipulate speed and accuracy instructions: participants were required to be fast and accurate in a go/no-go task, and we selected post-hoc the groups based on the subjects’ spontaneous behavioral tendency. Based on the reaction times, we selected the fast and slow groups (Speed-groups), and based on the percentage of false alarms, we selected the accurate and inaccurate groups (Accuracy-groups). The two Speed-groups were accuracy-matched, and the two Accuracy-groups were speed-matched. High density EEG and stimulus-locked analyses allowed us to observe group differences both before and after the stimulus onset. Long before the stimulus appearance, the two Speed-groups showed different amplitude of the Bereitschaftspotential (BP), reflecting the activity of the supplementary motor area (SMA); by contrast, the two Accuracy-groups showed different amplitude of the prefrontal negativity (pN), reflecting the activity of the right prefrontal cortex (rPFC). In addition, the post-stimulus event-related potential (ERP) components showed differences between groups: the P1 component was larger in accurate than inaccurate group; the N1 and N2 components were larger in the fast than slow group; the P3 component started earlier and was larger in the fast than slow group. The go minus no-go subtractive wave enhancing go-related processing revealed a differential prefrontal positivity (dpP) that peaked at about 330 ms; the latency and the amplitude of this peak were associated with the speed of the decision process and the efficiency of the stimulus-response mapping, respectively. Overall, data are consistent with the view that speed and accuracy are processed by two interacting but separate neurocognitive systems, with different features in both the anticipation and the response execution phases.

There are few behavioral effects as ubiquitous as the speed-accuracy tradeoff (SAT). From insects to rodents to primates, the tendency for decision speed to covary with decision accuracy seems an inescapable property of choice behavior. Recently, the SAT has received renewed interest, as neuroscience approaches begin to uncover its neural underpinnings and computational models are compelled to incorporate it as a necessary benchmark. The present work provides a comprehensive overview of SAT. First, I trace its history as a tractable behavioral phenomenon and the role it has played in shaping mathematical descriptions of the decision process. Second, I present a users guide of SAT methodology, including a critical review of common experimental manipulations and analysis techniques and a treatment of the typical behavioral patterns that emerge when SAT is manipulated directly. Finally, I review applications of this methodology in several domains.

Decision making often involves a tradeoff between speed and accuracy. Previous studies indicate that neural activity in the lateral intraparietal area (LIP) represents the gradual accumulation of evidence toward a threshold level, or evidence bound, which terminates the decision process. The level of this bound is hypothesized to mediate the speed-accuracy tradeoff. To test this, we recorded from LIP while monkeys performed a motion discrimination task in two speed-accuracy regimes. Surprisingly, the terminating threshold levels of neural activity were similar in both regimes. However, neurons recorded in the faster regime exhibited stronger evidence-independent activation from the beginning of decision formation, effectively reducing the evidence-dependent neural modulation needed for choice commitment. Our results suggest that control of speed vs accuracy may be exerted through changes in decision-related neural activity itself rather than through changes in the threshold applied to such neural activity to terminate a decision.

Two phenomena are commonly observed in decision-making. First, there is a speed-accuracy tradeoff such that decisions are slower and more accurate when instructions emphasize accuracy over speed, and vice versa. Second, decision performance improves with practice, as a task is learnt. The speed-accuracy tradeoff and learning effects have been explained under a well-established evidence-accumulation framework for decision-making, which suggests that evidence supporting each choice is accumulated over time, and a decision is committed to when the accumulated evidence reaches a decision boundary. This framework suggests that changing the decision boundary creates the tradeoff between decision speed and accuracy, while increasing the rate of accumulation leads to more accurate and faster decisions after learning. However, recent studies challenged the view that speed-accuracy tradeoff and learning are associated with changes in distinct, single decision parameters. Further, the influence of speed-accuracy instructions over the course of learning remains largely unknown. Here, we used a hierarchical drift-diffusion model to examine the speed-accuracy tradeoff during learning of a coherent motion discrimination task across multiple training sessions, and a transfer test session. The influence of speed-accuracy instructions was robust over training and generalized across untrained stimulus features. Emphasizing decision accuracy rather than speed was associated with increased boundary separation, drift rate and non-decision time at the beginning of training. However, after training, an emphasis on decision accuracy was only associated with increased boundary separation. In addition, faster and more accurate decisions after learning were due to a gradual decrease in boundary separation and an increase in drift rate. The results suggest that speed-accuracy instructions and learning differentially shape decision-making processes at different time scales.

The purpose of this paper is to review some of the key literature on response time as it has played a role in cognitive ability measurement, providing a historical perspective as well as covering current research. We discuss the speed-level distinction, dimensions of speed and level in cognitive abilities frameworks, speed–accuracy tradeoff, approaches to addressing speed–accuracy tradeoff, analysis methods, particularly item response theory-based, response time models from cognitive psychology (ex-Gaussian function, and the diffusion model), and other uses of response time in testing besides ability measurement. We discuss several new methods that can be used to provide greater insight into the speed and level aspects of cognitive ability and speed–accuracy tradeoff decisions. These include item-level time limits, the use of feedback (e.g., CUSUMs), explicit scoring rules that combine speed and accuracy information (e.g., count down timing), and cognitive psychology models. We also review some of the key psychometric advances in modeling speed and level, which combine speed and ability measurement, address speed–accuracy tradeoff, allow for distinctions between response times on items responded to correctly and incorrectly, and integrate psychometrics with information-processing modeling. We suggest that the application of these models and tools is likely to advance both the science and measurement of human abilities for theory and applications.

Objective: The authors determine whether transcranial direct current stimulation (tDCS) can reduce resumption time when an ongoing task is interrupted. Background: Interruptions are common and disruptive. Working memory capacity has been shown to predict resumption lag (i.e., time to successfully resume a task after interruption). Given that tDCS applied to brain areas associated with working memory can enhance performance, tDCS has the potential to improve resumption lag when a task is interrupted. Method: Participants were randomly assigned to one of four groups that received anodal (active) stimulation of 2 mA tDCS to one of two target brain regions, left and right dorsolateral prefrontal cortex (DLPFC), or to one of two control areas, active stimulation of the left primary motor cortex or sham stimulation of the right DLPFC, while completing a financial management task that was intermittently interrupted with math problem solving. Results: Anodal stimulation to the right and left DLPFC significantly reduced resumption lags compared to the control conditions (sham and left motor cortex stimulation). Additionally, there was no speed-accuracy tradeoff (i.e., the improvement in resumption time was not accompanied by an increased error rate). Conclusion: Noninvasive brain stimulation can significantly decrease resumption lag (improve performance) after a task is interrupted. Application: Noninvasive brain stimulation offers an easy-to-apply tool that can significantly improve interrupted task performance. [ABSTRACT FROM AUTHOR]

A hallmark of flexible behavior is the brain's ability to dynamically adjust speed and accuracy in decision-making. Recent studies suggested that such adjustments modulate not only the decision threshold, but also the rate of evidence accumulation. However, the underlying neuronallevel mechanism of the rate change remains unclear. In this work, using a spiking neural network model of perceptual decision, we demonstrate that speed and accuracy of a decision process can be effectively adjusted by manipulating a top-down control signal with balanced excitation and inhibition [balanced synaptic input (BSI)]. Our model predicts that emphasizing accuracy over speed leads to reduced rate of ramping activity and reduced baseline activity of decision neurons, which have been observed recently at the level of single neurons recorded from behaving monkeys in speed-accuracy tradeoff tasks. Moreover, we found that an increased inhibitory component of BSI skews the decision time distribution and produces a pronounced exponential tail, which is commonly observed in human studies. Our findings suggest that BSI can serve as a top-down control mechanism to rapidly and parametrically trade between speed and accuracy, and such a cognitive control signal presents both when the subjects emphasize accuracy or speed in perceptual decisions. [ABSTRACT FROM AUTHOR]

An experiment evaluated a transformation of response time (RT) into response rate adjusted for errors (RRAdj) for its ability to accommodate different speed–accuracy tradeoffs (SATs). Participants solved 2-step arithmetic problems under instructional conditions that emphasized speed versus accuracy of responding. RT and error variables were transformed using RRAdj and three additional computations to determine which better equated performance scores under the two tradeoff conditions. Effective adjustment for SAT strategy was evaluated by the equivalence of predictive relationships with other variables, regardless of SAT instructional set. Of the scoring computations compared, RRAdj alone equated performance in the tradeoff conditions, and it was optimized when accuracy was adjusted for guessing. Thus, in certain multistep cognitive tasks, incorporating RT and error data in the RRAdj computation could at least partially adjust for differing SAT strategies and embody additional meaningful variance compared to the commonly used RT for correct responses. [ABSTRACT FROM AUTHOR]

Reaction time (RT) is one of the most commonly used measures of neurological function and dysfunction. Despite the extensive studies on it, no study has ever examined the RT in the ankle. Twenty-two subjects were recruited to perform simple, 2- and 4-choice RT tasks by visually guiding a cursor inside a rectangular target with their ankle. RT did not change with spatial accuracy constraints imposed by different target widths in the direction of the movement. RT increased as a linear function of potential target stimuli, as would be predicted by Hick-Hyman law. Although the slopes of the regressions were similar, the intercept in dorsal-plantar (DP) direction was significantly smaller than the intercept in inversion-eversion (IE) direction. To explain this difference, we used a hierarchical Bayesian estimation of the Ratcliff's (Psychol Rev 85:59, ) diffusion model parameters and divided processing time into cognitive components. The model gave a good account of RTs, their distribution and accuracy values, and hence provided a testimony that the non-decision processing time (overlap of posterior distributions between DP and IE < 0.045), the boundary separation (overlap of the posterior distributions < 0.1) and the evidence accumulation rate (overlap of the posterior distributions < 0.01) components of the RT accounted for the intercept difference between DP and IE. The model also proposed that there was no systematic change in non-decision processing time or drift rate when spatial accuracy constraints were altered. The results were in agreement with the memory drum hypothesis and could be further justified neurophysiologically by the larger innervation of the muscles controlling DP movements. This study might contribute to assessing deficits in sensorimotor control of the ankle and enlighten a possible target for correction in the framework of our on-going effort to develop robotic therapeutic interventions to the ankle of children with cerebral palsy. [ABSTRACT FROM AUTHOR]

In contrast to traditional professional sports, there are few standardized metrics in professional esports (competitive multiplayer video games) for assessing a player's skill and ability. We assessed the performance of professional-level players in Aim Lab TM , a first-person shooter training and assessment game, with two target-shooting tasks. These tasks differed primarily in target size: the task with large targets provided an incentive to be fast but imprecise and the task with large targets provided an incentive to be precise but slow. Each player's motor acuity was measured by characterizing the speed-accuracy trade-off in shot behavior: shot time (elapsed time for a player to shoot at a target) and shot spatial error (distance from center of a target). We also characterized the fine-grained kinematics of players' mouse movements. Our findings demonstrate that: 1) movement kinematics depended on task demands; 2) individual differences in motor acuity were significantly correlated with kinematics; and 3) performance, combined across the two target sizes, was poorly characterized by Fitts Law. Our approach to measuring motor acuity has widespread applications not only in esports assessment and training, but also in basic (motor psychophysics) and clinical (gamified rehabilitation) research., Competing Interests: WM and DH are officers at Statespace Labs. ID, MS, KD, and JL are employees at Statespace Labs., (Copyright © 2022 Donovan, Saul, DeSimone, Listman, Mackey and Heeger.)

We report three experiments investigating the hypothesis that use of internal visual imagery (IVI) would be superior to external visual imagery (EVI) for the performance of different slalom-based motor tasks. In Experiment 1, three groups of participants (IVI, EVI, and a control group) performed a driving-simulation slalom task. The IVI group achieved significantly quicker lap times than EVI and the control group. In Experiment 2, participants performed a downhill running slalom task under both IVI and EVI conditions. Performance was again quickest in the IVI compared to EVI condition, with no differences in accuracy. Experiment 3 used the same group design as Experiment 1, but with participants performing a downhill ski-slalom task. Results revealed the IVI group to be significantly more accurate than the control group, with no significant differences in time taken to complete the task. These results support the beneficial effects of IVI for slalom-based tasks, and significantly advances our knowledge related to the differential effects of visual imagery perspectives on motor performance.

ABSTRACT.The authors’ aim was to investigate the speed-accuracy tradeoff in soccer kicking with the dominant and nondominant foot by using different types of instructions prioritizing speed or accuracy in experienced soccer players. Ten male soccer players were randomly given 1 of the 4 instructions that differed in aspects of the kick they should emphasize and what the secondary aim would be (speed or accuracy). It was found that ball velocity was affected by instruction in the expected way: emphasis on accuracy and ball velocity reduced for both kicking feet. In addition kicking accuracy increased when emphasizing this, but only with the dominant foot indicating that Fitts’ law only was found in kicks with the dominant foot. [ABSTRACT FROM PUBLISHER]

Abstract: The contingent negative variation, a slow cortical potential, occurs when humans are warned by a stimulus about an upcoming task. The cognitive processes that give rise to this EEG potential are not yet well understood. To explain these processes, we adopt a recently developed theoretical framework from the area of perceptual decision-making. This framework assumes that the basal ganglia control the tradeoff between fast and accurate decision-making in the cortex. It suggests that an increase in cortical excitability serves to lower response caution, which results in faster but more error prone responding. We propose that the CNV reflects this increased cortical excitability. To test this hypothesis, we conducted an EEG experiment in which participants performed the random dot motion task either under speed or under accuracy stress. Our results show that trial-by-trial fluctuations in participants' response speed as well as model-based estimates of response caution correlated with single-trial CNV amplitude under conditions of speed but not accuracy stress. We conclude that the CNV might reflect adjustments of response caution, which serves to enhance quick decision-making. [Copyright &y& Elsevier]

The Ising Decision Maker (IDM) is a new formal model for speeded two-choice decision making derived from the stochastic Hopfield network or dynamic Ising model. On a microscopic level, it consists of 2 pools of binary stochastic neurons with pairwise interactions. Inside each pool, neurons excite each other, whereas between pools, neurons inhibit each other. The perceptual input is represented by an external excitatory field. Using methods from statistical mechanics, the high-dimensional network of neurons (microscopic level) is reduced to a two-dimensional stochastic process, describing the evolution of the mean neural activity per pool (macroscopic level). The IDM can be seen as an abstract, analytically tractable multiple attractor network model of information accumulation! In this article, the properties of the IDM are studied, the relations to existing models are discussed, and it is shown that the most important basic aspects of two-choice response time data can be reproduced. In addition, the IDM is shown to predict a variety of observed psychophysical relations such as Piéron's law, the van der Molen-Keuss effect, and Weber's law. Using Bayesian methods, the model is fitted to both simulated and real data, and its performance is compared to the Ratcliff diffusion model. [ABSTRACT FROM AUTHOR]

The study investigates the neurocognitive stages involved in the speed-accuracy trade-off (SAT). Contrary to previous approach, we did not manipulate speed and accuracy instructions: participants were required to be fast and accurate in a go/no-go task, and we selected post-hoc the groups based on the subjects' spontaneous behavioral tendency. Based on the reaction times, we selected the fast and slow groups (Speed-groups), and based on the percentage of false alarms, we selected the accurate and inaccurate groups (Accuracy-groups). The two Speed-groups were accuracy-matched, and the two Accuracy-groups were speed-matched. High density electroencephalographic (EEG) and stimulus-locked analyses allowed us to observe group differences both before and after the stimulus onset. Long before the stimulus appearance, the two Speed-groups showed different amplitude of the Bereitschaftspotential (BP), reflecting the activity of the supplementary motor area (SMA); by contrast, the two Accuracy-groups showed different amplitude of the prefrontal negativity (pN), reflecting the activity of the right prefrontal cortex (rPFC). In addition, the post-stimulus event-related potential (ERP) components showed differences between groups: the P1 component was larger in accurate than inaccurate group; the N1 and N2 components were larger in the fast than slow group; the P3 component started earlier and was larger in the fast than slow group. The go minus no-go subtractive wave enhancing go-related processing revealed a differential prefrontal positivity (dpP) that peaked at about 330 ms; the latency and the amplitude of this peak were associated with the speed of the decision process and the efficiency of the stimulus-response mapping, respectively. Overall, data are consistent with the view that speed and accuracy are processed by two interacting but separate neurocognitive systems, with different features in both the anticipation and the response execution phases. [ABSTRACT FROM AUTHOR]